Developmental Disorders of the Lymphatics

An information blog for disorders of the lymphatics. For all articles, please click on "Archives" - Due to spammers, I will no longer allow comments, sorry.

Saturday, April 29, 2006

Role of VEGF3 signaling in differentiation of mouse embryonic stem cell-derived vascular progenitor cells into endothelial cells.

Roles of vascular endothelial growth factor receptor 3 signaling in differentiation of mouse embryonic stem cell-derived vascular progenitor cells into endothelial cells.

Suzuki H, Watabe T, Kato M, Miyazawa K, Miyazono K.

Department of Molecular Pathology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan. miyazono-ind@umin.ac.jp

Vascular endothelial growth factor receptor 2 (VEGFR2/Flk-1)-positive cells derived from embryonic stem (ES) cells serve as vascular progenitors, which differentiate into endothelial cells (ECs) in the presence of VEGF-A. VEGFR3/Flt-4 (fms-like tyrosine kinase 4) signaling is known to be important for the development of lymphatic endothelial cells (LECs).

To elucidate the roles of VEGFR3 signaling in the differentiation of vascular progenitor cells into ECs, we introduced various types of VEGFR3 cDNAs into mouse ES cells. VEGF-C, a ligand for VEGFR2 and VEGFR3, stimulated the endothelial differentiation of the VEGFR2(+) cells transfected with the VEGFR3 cDNA but not those transfected with kinasenegative mutants of VEGFR3. The VEGFR3-transfected ECs exhibited high expression levels of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), one of the markers of LECs, and showed efficient binding of hyaluronan. VEGF-C(C152S), which is able to activate VEGFR3 but not VEGFR2, failed to induce the endothelial differentiation of mock- and VEGFR3-transfected VEGFR2(+) cells, suggesting the essential role of VEGFR2 signaling for endothelial differentiation.

Furthermore, kinase-negative mutants of VEGFR3 prevented the VEGF-C-mediated endothelial differentiation of the vascular progenitor cells.

Thus, VEGFR2 signaling is required for the endothelial differentiation of mouse ES cells induced by VEGF-C, and VEGFR3 signaling may confer lymphatic endothelial-like phenotypes to ECs.

PMID: 15561887

[PubMed - in process]

Full Text Article - HEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY

Saturday, April 22, 2006

Lymphoid Nodular Hyperplasia

Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children

J Wakefield, S H Murch, A Anthony, J Linnell, D M Casson, M Malik, M Berelowitz, A P Dhillon, M A Thomson, P Harvey, A Valentine, S E Davies, J A Walker-Smith

Volume 351, Number 9103 28 February 1998

Inflammatory Bowel Disease Study Group, University Departments of Medicine and Histopathology (A J Wakefield FRCS, A Anthony MB, J Linnell PhD, A P Dhillon MRCPath, S E Davies MRCPath) and the University Departments of Paediatric Gastroenterology (S H Murch MB, D M Casson MRCP, M Malik MRCP, M A Thomson FRCP, J A Walker-Smith FRCP,), Child and Adolescent Psychiatry (M Berelowitz FRCPsych), Neurology (P Harvey FRCP), and Radiology (A Valentine FRCR), Royal Free Hospital and School of Medicine, London NW3 2QG, UK

Correspondence to: Dr A J Wakefield Summary

Background

We investigated a consecutive series of children with chronic enterocolitis and regressive developmental disorder.

Methods 12 children (mean age 6 years [range 3-10], 11 boys) were referred to a paediatric gastroenterology unit with a history of normal development followed by loss of acquired skills, including language, together with diarrhoea and abdominal pain. Children underwent gastroenterological, neurological, and developmental assessment and review of developmental records. Ileocolonoscopy and biopsy sampling, magnetic-resonance imaging (MRI), electroencephalography (EEG), and lumbar puncture were done under sedation. Barium follow-through radiography was done where possible. Biochemical, haematological, and immunological profiles were examined.

Findings

Onset of behavioural symptoms was associated, by the parents, with measles, mumps, and rubella vaccination in eight of the 12 children, with measles infection in one child, and otitis media in another. All 12 children had intestinal abnormalities, ranging from lymphoid nodular hyperplasia to aphthoid ulceration. Histology showed patchy chronic inflammation in the colon in 11 children and reactive ileal lymphoid hyperplasia in seven, but no granulomas. Behavioural disorders included autism (nine), disintegrative psychosis (one), and possible postviral or vaccinal encephalitis (two). There were no focal neurological abnormalities and MRI and EEG tests were normal. Abnormal laboratory results were significantly raised urinary methylmalonic acid compared with age-matched controls (p=0•003), low haemoglobin in four children, and a low serum IgA in four children.

Interpretation

We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers. Lancet 1998; 351: 637-41

Introduction

We saw several children who, after a period of apparent normality, lost acquired skills, including communication. They all had gastrointestinal symptoms, including abdominal pain, diarrhoea, and bloating and, in some cases, food intolerance. We describe the clinical findings, and gastrointestinal features of these children.

Patients and methods

12 children, consecutively referred to the department of paediatric gastroenterology with a history of a pervasive developmental disorder with loss of acquired skills and intestinal symptoms (diarrhoea, abdominal pain, bloating and food intolerance), were investigated. All children were admitted to the ward for 1 week, accompanied by their parents.

Clinical investigations

We took histories, including details of immunisations and exposure to infectious diseases, and assessed the children. In 11 cases the history was obtained by the senior clinician (JW-S). Neurological and psychiatric assessments were done by consultant staff (PH, MB) with HMS-4 criteria.1 Developmental histories included a review of prospective developmental records from parents, health visitors, and general practitioners. Four children did not undergo psychiatric assessment in hospital; all had been assessed professionally elsewhere, so these assessments were used as the basis for their behavioural diagnosis.

After bowel preparation, ileocolonoscopy was performed by SHM or MAT under sedation with midazolam and pethidine. Paired frozen and formalin-fixed mucosal biopsy samples were taken from the terminal ileum; ascending, transverse, descending, and sigmoid colons, and from the rectum. The procedure was recorded by video or still images, and were compared with images of the previous seven consecutive paediatric colonoscopies (four normal colonoscopies and three on children with ulcerative colitis), in which the physician reported normal appearances in the terminal ileum. Barium follow-through radiography was possible in some cases.

Also under sedation, cerebral magnetic-resonance imaging (MRI), electroencephalography (EEG) including visual, brain stem auditory, and sensory evoked potentials (where compliance made these possible), and lumbar puncture were done.

Laboratory investigations

Thyroid function, serum long-chain fatty acids, and cerebrospinal-fluid lactate were measured to exclude known causes of childhood neurodegenerative disease. Urinary methylmalonic acid was measured in random urine samples from eight of the 12 children and 14 age-matched and sex-matched normal controls, by a modification of a technique described previously.2 Chromatograms were scanned digitally on computer, to analyse the methylmalonic-acid zones from cases and controls. Urinary methylmalonic-acid concentrations in patients and controls were compared by a two-sample t test. Urinary creatinine was estimated by routine spectrophotometric assay.

Children were screened for antiendomyseal antibodies and boys were screened for fragile-X if this had not been done before. Stool samples were cultured for Campylobacter spp, Salmonella spp, and Shigella spp and assessed by microscopy for ova and parasites. Sera were screened for antibodies to Yersinia enterocolitica.

Histology

Formalin-fixed biopsy samples of ileum and colon were assessed and reported by a pathologist (SED). Five ileocolonic biopsy series from age-matched and site-matched controls whose reports showed histologically normal mucosa were obtained for comparison. All tissues were assessed by three other clinical and experimental pathologists (APD, AA, AJW).

Ethical approval and consent

Investigations were approved by the Ethical Practices Committee of the Royal Free Hospital NHS Trust, and parents gave informed consent.

Results

Clinical details of the children are shown in tables 1 and 2. None had neurological abnormalities on clinical examination; MRI scans, EEGs, and cerebrospinal-fluid profiles were normal; and fragile X was negative. Prospective developmental records showed satisfactory achievement of early milestones in all children. The only girl (child number eight) was noted to be a slow developer compared with her older sister. She was subsequently found to have coarctation of the aorta. After surgical repair of the aorta at the age of 14 months, she progressed rapidly, and learnt to talk. Speech was lost later. Child four was kept under review for the first year of life because of wide bridging of the nose. He was discharged from follow-up as developmentally normal at age 1 year.

LNH=lymphoid nodular hyperplasia; T ileum=terminal ileum. Normal ranges and units: Hb=haemoglobin 11•5-14•5 g/dL; PCV=packed cell volume 0•37-0•45; MCV=mean cell volume 76-100 pg/dL; platelets 140-400 109/L; WBC=white cell count 5•0-15•5 109/L; lymphocytes 2•2-8•6 109/L; eosinophils 0-0•4 109/L; ESR=erythrocyte sedimentation rate 0-15 mm/h; IgG 8-18 g/L; IgG1 3•53-7•25 g/L; IgG4 0•1-0•99 g/L; IgA 0•9-4•5 g/L; IgM 0•6-2•8 g/L; IgE 0-62 g/L; ALP=alkaline phosphatase 35-130 U/L; AST=aspartate transaminase 5-40 U/L. Table 1: Clinical details and laboratory, endoscopic, and histological findings

In eight children, the onset of behavioural problems had been linked, either by the parents or by the child's physician, with measles, mumps, and rubella vaccination. Five had had an early adverse reaction to immunisation (rash, fever, delirium; and, in three cases, convulsions). In these eight children the average interval from exposure to first behavioural symptoms was 6•3 days (range 1-14). Parents were less clear about the timing of onset of abdominal symptoms because children were not toilet trained at the time or because behavioural features made children unable to communicate symptoms.

One child (child four) had received monovalent measles vaccine at 15 months, after which his development slowed (confirmed by professional assessors). No association was made with the vaccine at this time. He received a dose of measles, mumps, and rubella vaccine at age 4•5 years, the day after which his mother described a striking deterioration in his behaviour that she did link with the immunisation. Child nine received measles, mumps, and rubella vaccine at 16 months. At 18 months he developed recurrent antibiotic-resistant otitis media and the first behavioural symptoms, including disinterest in his sibling and lack of play.

Table 2 summarises the neuropsychiatric diagnoses; the apparent precipitating events; onset of behavioural features; and age of onset of both behaviour and bowel symptoms.

Laboratory tests

All children were antiendomyseal-antibody negative and common enteric pathogens were not identified by culture, microscopy, or serology. Urinary methylmalonic-acid excretion was significantly raised in all eight children who were tested, compared with age-matched controls (p=0•003; figure 1). Abnormal laboratory tests are shown in table 1.

Endoscopic findings

The caecum was seen in all cases, and the ileum in all but two cases. Endoscopic findings are shown in table 1. Macroscopic colonic appearances were reported as normal in four children. The remaining eight had colonic and rectal mucosal abnormalities including granularity, loss of vascular pattern, patchy erythema, lymphoid nodular hyperplasia, and in two cases, aphthoid ulceration. Four cases showed the "red halo" sign around swollen caecal lymphoid follicles, an early endoscopic feature of Crohn's disease.3 The most striking and consistent feature was lymphoid nodular hyperplasia of the terminal ileum which was seen in nine children (figure 2), and identified by barium follow-through in one other child in whom the ileum was not reached at endoscopy. The normal endoscopic appearance of the terminal ileum (figure 2) was seen in the seven children whose images were available for comparison.

Figure 2: Endoscopic view of terminal ilium in child three and in a child with endoscopically and histologically normal ileum and colon Greatly enlarged lymphoid nodule in right-hand field of view. A and B=child three; C=normal ileum. Remainder of mucosal surface of` terminal ileum is a carpet of enlarged lymphoid nodules.

Histological findings

Histological findings are summarised in table 1. Terminal ileum A reactive lymphoid follicular hyperplasia was present in the ileal biopsies of seven children. In each case, more than three expanded and confluent lymphoid follicles with reactive germinal centres were identified within the tissue section (figure 3). There was no neutrophil infiltrate and granulomas were not present.

Figure 3: Biopsy sample from terminal ileum (top) and from colon (bottom) A=child three; lymphoid hyperplasia with extensive, confluent lymphoid nodules. B=child three; dense infiltration of the lamina propria crypt epithelium by neutrophils and mononuclear cells. Stained with haematoxylin and eosin.

Colon The lamina propria was infiltrated by mononuclear cells (mainly lymphocytes and macrophages) in the colonic-biopsy samples. The extent ranged in severity from scattered focal collections of cells beneath the surface epithelium (five cases) to diffuse infiltration of the mucosa (six cases). There was no increase in intraepithelial lymphocytes, except in one case, in which numerous lymphocytes had infiltrated the surface epithelium in the proximal colonic biopsies. Lymphoid follicles in the vicinity of mononuclear-cell infiltrates showed enlarged germinal centres with reactive changes that included an excess of tingible body macrophages.

There was no clear correlation between the endoscopic appearances and the histological findings; chronic inflammatory changes were apparent histologically in endoscopically normal areas of the colon. In five cases there was focal acute inflammation with infiltration of the lamina propria by neutrophils; in three of these, neutrophils infiltrated the caecal (figure 3) and rectal-crypt epithelium. There were no crypt abscesses. Occasional bifid crypts were noted but overall crypt architecture was normal. There was no goblet-cell depletion but occasional collections of eosinophils were seen in the mucosa. There were no granulomata. Parasites and organisms were not seen. None of the changes described above were seen in any of the normal biopsy specimens.

Discussion

We describe a pattern of colitis and ileal-lymphoid-nodular hyperplasia in children with developmental disorders. Intestinal and behavioural pathologies may have occurred together by chance, reflecting a selection bias in a self-referred group; however, the uniformity of the intestinal pathological changes and the fact that previous studies have found intestinal dysfunction in children with autistic-spectrum disorders, suggests that the connection is real and reflects a unique disease process.

Asperger first recorded the link between coeliac disease and behavioural psychoses.4 Walker-Smith and colleagues5 detected low concentrations of alpha-1 antitrypsin in children with typical autism, and D'Eufemia and colleagues6 identified abnormal intestinal permeability, a feature of small intestinal enteropathy, in 43% of a group of autistic children with no gastrointestinal symptoms, but not in matched controls. These studies, together with our own, including evidence of anaemia and IgA deficiency in some children, would support the hypothesis that the consequences of an inflamed or dysfunctional intestine may play a part in behavioural changes in some children.

The "opioid excess" theory of autism, put forward first by Panksepp and colleagues7 and later by Reichelt and colleagues8 and Shattock and colleagues9 proposes that autistic disorders result from the incomplete breakdown and excessive absorption of gut-derived peptides from foods, including barley, rye, oats, and caesin from milk and dairy produce. These peptides may exert central-opioid effects, directly or through the formation of ligands with peptidase enzymes required for breakdown of endogenous central-nervous-system opioids,9 leading to disruption of normal neuroregulation and brain development by endogenous encephalins and endorphins.

One aspect of impaired intestinal function that could permit increased permeability to exogenous peptides is deficiency of the phenyl-sulphur-transferase systems, as described by Waring.10 The normally sulphated glycoprotein matrix of the gut wall acts to regulate cell and molecular trafficking.11 Disruption of this matrix and increased intestinal permeability, both features of inflammatory bowel disease,17 may cause both intestinal and neuropsychiatric dysfunction. Impaired enterohepatic sulphation and consequent detoxification of compounds such as the phenolic amines (dopamine, tyramine, and serotonin)12 may also contribute. Both the presence of intestinal inflammation and absence of detectable neurological abnormality in our children are consistent with an exogenous influence upon cerebral function. Lucarelli's observation that after removal of a provocative enteric antigen children achieved symptomatic behavioural improvement, suggests a reversible element in this condition.13

Despite consistent gastrointestinal findings, behavioural changes in these children were more heterogeneous. In some cases the onset and course of behavioural regression was precipitous, with children losing all communication skills over a few weeks to months. This regression is consistent with a disintegrative psychosis (Heller's disease), which typically occurs when normally developing children show striking behaviour changes and developmental regression, commonly in association with some loss of coordination and bowel or bladder function.14 Disintegrative psychosis is typically described as occurring in children after at least 2-3 years of apparently normal development. Disintegrative psychosis is recognised as a sequel to measles encephalitis, although in most cases no cause is ever identified.14 Viral encephalitis can give rise to autistic disorders, particularly when it occurs early in life.15 Rubella virus is associated with autism and the combined measles, mumps, and rubella vaccine (rather than monovalent measles vaccine) has also been implicated. Fudenberg16 noted that for 15 of 20 autistic children, the first symptoms developed within a week of vaccination. Gupta17 commented on the striking association between measles, mumps, and rubella vaccination and the onset of behavioural symptoms in all the children that he had investigated for regressive autism. Measles virus18,19 and measles vaccination20 have both been implicated as risk factors for Crohn's disease and persistent measles vaccine-strain virus infection has been found in children with autoimmune hepatitis.21

We did not prove an association between measles, mumps, and rubella vaccine and the syndrome described. Virological studies are underway that may help to resolve this issue.

If there is a causal link between measles, mumps, and rubella vaccine and this syndrome, a rising incidence might be anticipated after the introduction of this vaccine in the UK in 1988. Published evidence is inadequate to show whether there is a change in incidence22 or a link with measles, mumps, and rubella vaccine.23 A genetic predisposition to autistic-spectrum disorders is suggested by over-representation in boys and a greater concordance rate in monozygotic than in dizygotic twins.15 In the context of susceptibility to infection, a genetic association with autism, linked to a null allele of the complement (C) 4B gene located in the class III region of the major-histocompatibility complex, has been recorded by Warren and colleagues.24 C4B-gene products are crucial for the activation of the complement pathway and protection against infection: individuals inheriting one or two C4B null alleles may not handle certain viruses appropriately, possibly including attenuated strains.

Urinary methylmalonic-acid concentrations were raised in most of the children, a finding indicative of a functional vitamin B12 deficiency. Although vitamin B12 concentrations were normal, serum B12 is not a good measure of functional B12 status.25 Urinary methylmalonic-acid excretion is increased in disorders such as Crohn's disease, in which cobalamin excreted in bile is not reabsorbed. A similar problem may have occurred in the children in our study. Vitamin B12 is essential for myelinogenesis in the developing central nervous system, a process that is not complete until around the age of 10 years. B12 deficiency may, therefore, be a contributory factor in the developmental regression.26

We have identified a chronic enterocolitis in children that may be related to neuropsychiatric dysfunction. In most cases, onset of symptoms was after measles, mumps, and rubella immunisation. Further investigations are needed to examine this syndrome and its possible relation to this vaccine.

Addendum:

Up to Jan 28, a further 40 patients have been assessed; 39 with the syndrome.

Contributors

A J Wakefield was the senior scientific investigator. S H Murch and M A Thomson did the colonoscopies. A Anthony, A P Dhillon, and S E Davies carried out the histopathology. J Linnell did the B12 studies. D M Casson and M Malik did the clinical assessment. M Berelowitz did the psychiatric assessment. P Harvey did the neurological assessment. A Valentine did the radiological assessment. JW-S was the senior clinical investigator.

Acknowledgments

This study was supported by the Special Trustees of Royal Free Hampstead NHS Trust and the Children's Medical Charity. We thank Francis Moll and the nursing staff of Malcolm Ward for their patience and expertise; the parents for providing the impetus for these studies; and Paula Domizo, Royal London NHS Trust, for providing control tissue samples.

References :

1 Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). 4th edn. Washington DC, USA: American Psychiatric Association, 1994. 2 Bhatt HR, Green A, Linnell JC. A sensitive micromethod for the routine estimations of methylmalonic acid in body fluids and tissues using thin-layer chromatography. Clin Chem Acta 1982; 118: 311-21. 3 Fujimura Y, Kamoni R, Iida M. Pathogenesis of aphthoid ulcers in Crohn's disease: correlative findings by magnifying colonoscopy, electromicroscopy, and immunohistochemistry. Gut 1996; 38: 724-32. 4 Asperger H. Die Psychopathologie des coeliakakranken kindes. Ann Paediatr 1961; 197: 146-51. 5 Walker-Smith JA, Andrews J. Alpha-1 antitrypsin, autism and coeliac disease. Lancet 1972; ii: 883-84. 6 D'Eufemia P, Celli M, Finocchiaro R, et al. Abnormal intestinal permeability in children with autism. Acta Paediatrica 1996; 85: 1076-79. 7 Panksepp J. A neurochemical theory of autism. Trends Neurosci 1979; 2: 174-77. 8 Reichelt KL, Hole K, Hamberger A, et al. Biologically active peptide-containing fractions in schizophrenia and childhood autism. Adv Biochem Psychopharmacol 1993; 28: 627-43. 9 Shattock P, Kennedy A, Rowell F, Berney TP. Role of neuropeptides in autism and their relationships with classical neurotransmitters. Brain Dysfunction 1991; 3: 328-45. 10 Waring RH, Ngong JM. Sulphate metabolism in allergy induced autism: relevance to disease aetiology, conference proceedings, biological perspectives in autism, University of Durham, NAS 35-44. 11 Murch SH, MacDonald TT, Walker-Smith JA, Levin M, Lionetti P, Klein NJ. Disruption of sulphated glycosaminoglycans in intestinal inflammation. Lancet 1993; 341: 711-41. 12 Warren RP, Singh VK. Elevated serotonin levels in autism: association with the major histocompatibility complex. Neuropsychobiology 1996; 34: 72-75. 13 Lucarelli S, Frediani T, Zingoni AM, et al. Food allergy and infantile autism. Panminerva Med 1995; 37: 137-41. 14 Rutter M, Taylor E, Hersor L. In: Child and adolescent psychiatry. 3rd edn. London: Blackwells Scientific Publications: 581-82. 15 Wing L. The Autistic Spectrum. London: Constable, 1996: 68-71. 16 Fudenberg HH. Dialysable lymphocyte extract (DLyE) in infantile onset autism: a pilot study. Biotherapy 1996; 9: 13-17. 17 Gupta S. Immunology and immunologic treatment of autism. Proc Natl Autism Assn Chicago 1996; 455-60. 18 Miyamoto H, Tanaka T, Kitamoto N, Fukada Y, Takashi S. Detection of immunoreactive antigen with monoclonal antibody to measles virus in tissue from patients with Crohn's disease. J Gastroenterol 1995; 30: 28-33. 19 Ekbom A, Wakefield AJ, Zack M, Adami H-O. Crohn's disease following early measles exposure. Lancet 1994; 344: 508-10. 20 Thompson N, Montgomery S, Pounder RE, Wakefield AJ. Is measles vaccination a risk factor for inflammatory bowel diseases? Lancet 1995; 345: 1071-74. 21 Kawashima H, Mori T, Takekuma K, Hoshika A, Hata A, Nakayama T. Polymerase chain reaction detection of the haemagglutinin gene from an attenuated measles vaccines strain in the peripheral mononuclear cells of children with autoimmune hepatitis. Arch Virol 1996; 141: 877-84. 22 Wing L. Autism spectrum disorders: no evidence for or against an increase in prevalence. BMJ 1996; 312: 327-28. 23 Miller D, Wadsworth J, Diamond J, Ross E. Measles vaccination and neurological events. Lancet 1997; 349: 730-31. 24 Warren RP, Singh VK, Cole P, et al. Increased frequency of the null allele at the complement C4B locus in autism. Clin Exp Immunol 1991; 83: 438-40. 25 England JM, Linnell JC. Problems with the serum vitamin B12 assay. Lancet 1980; ii: 1072-74. 26 Dillon MJ, England JM, Gompertz D, et al. Mental retardation, megaloblastic anaemic, homocysteine metabolism due to an error in B12 metabolism. Clin Sci Mol Med 1974; 47: 43-61.

Article

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Colonic CD8 and gamma delta T-cell infiltration with epithelial damage in children with autism.

Furlano RI, Anthony A, Day R, Brown A, McGarvey L, Thomson MA, Davies SE, Berelowitz M, Forbes A, Wakefield AJ, Walker-Smith JA, Murch SH.

University Department of Paediatric Gastroenterology, the Inflammatory Bowel Diseases Study Group, Royal Free and University College School of Medicine, London, United Kingdom.

OBJECTIVES: We have reported colitis with ileal lymphoid nodular hyperplasia (LNH) in children with regressive autism. The aims of this study were to characterize this lesion and determine whether LNH is specific for autism.

METHODS: Ileo-colonoscopy was performed in 21 consecutively evaluated children with autistic spectrum disorders and bowel symptoms. Blinded comparison was made with 8 children with histologically normal ileum and colon, 10 developmentally normal children with ileal LNH, 15 with Crohn's disease, and 14 with ulcerative colitis. Immunohistochemistry was performed for cell lineage and functional markers, and histochemistry was performed for glycosaminoglycans and basement membrane thickness.

RESULTS: Histology demonstrated lymphocytic colitis in the autistic children, less severe than classical inflammatory bowel disease. However, basement membrane thickness and mucosal gamma delta cell density were significantly increased above those of all other groups including patients with inflammatory bowel disease. CD8(+) density and intraepithelial lymphocyte numbers were higher than those in the Crohn's disease, LNH, and normal control groups; and CD3 and plasma cell density and crypt proliferation were higher than those in normal and LNH control groups. Epithelial, but not lamina propria, glycosaminoglycans were disrupted. However, the epithelium was HLA-DR(-), suggesting a predominantly T(H)2 response.

INTERPRETATION: Immunohistochemistry confirms a distinct lymphocytic colitis in autistic spectrum disorders in which the epithelium appears particularly affected. This is consistent with increasing evidence for gut epithelial dysfunction in autism.

PMID: 11241044 [PubMed - indexed for MEDLINE]

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Lymphoid Nodular Hyperplasia and Cow's Milk Hypersensitivity in Children With Chronic Constipation

Turunen S, Karttunen TJ, Kokkonen JThe Journal of Pediatrics. 2004;145(6):606-611

The investigators begin by reviewing recent findings that suggest that lymphoid nodular hyperplasia (LNH) in the intestinal mucosa is associated with cow's milk allergy and other food allergies. They hypothesized that some children with chronic constipation would suffer from cow's mild protein allergy, and that this allergy could be diagnosed endoscopically by evaluating for LNH.

The study evaluated 35 children who had symptoms of chronic constipation that had not resolved with over 1 year of treatment (the average duration of symptoms was 4.7 years). The researchers compared endoscopic findings in these 35 children to those of 15 children who underwent endoscopy for other gastrointestinal problems. The participants eliminated milk products for 4 weeks prior to a test diet that included gradually increasing milk amounts (up to goal of consumption of approximately one half liter of milk per day). A desirable stool frequency was at least 3 stools per week. A participant was considered intolerant to milk if the stools decreased to 2 per week, or if they experienced the onset of abdominal pain. Parents completed symptom logs and stool frequency logs during the study. The endoscopy was performed when the participant was on the milk-containing diet.

Twenty-five percent of the cases compared with 13% of controls were diagnosed with food allergies during infancy. During the elimination period, 83% of the constipated children had increase in stool frequency to at least 2 or 3 per week. In 41% of the "responders," the symptoms returned during the 4-week milk escalation diet phase. These children were considered to be allergic to milk.

Lymphonodular hyperplasia was noted in 46% of the subjects, but in only 7% (1 individual) of controls. Other endoscopic findings, such as degree of eosinophils in the mucosa, did not correlate as well as anticipated. The authors concluded that a long trial of milk protein elimination is indicated in children with long-standing, refractory constipation.

Reviewer comment: The investigators admitted that theirs was a highly selected study group that had been referred to a tertiary center and had very long-standing constipation. However, this strikes me as one of those dilemmas where the risk (eliminating milk proteins) compared with the benefit so heavily favors "treatment" (elimination of milk), that a trial of milk elimination should be considered for any child with long-standing constipation.

There are at least 2 challenges to this – selecting which patients might benefit from the elimination trial, and then providing dietary counseling for those who remit and would therefore, presumably, continue to avoid milk products. The investigators offer 1 year of unresolved symptoms as a cutoff. This seems a reasonable and very conservative cutoff, meaning that you would be placing relatively few subjects on milk-elimination diets. Then, if symptoms resolve, I would bet that most parents and even patients would be much more receptive to suggestions on how to ensure adequate calcium intake if milk is "out of the picture."

Medscape

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Sunday, April 16, 2006

Developmental lymphatic disorders of the thorax

Department of Radiology, State University of New York Health Science Center, Syracuse 13210.

Developmental disorders that involve the lymphatic channels of the thorax, although rare, are important and must be distinguished from the more common causes of chest masses or diffuse lung disease.

There are four major types of developmental lymphatic disorders that affect the thorax: lymphangiectasis, characterized by congenital anomalous dilatation of pulmonary lymph vessels; localized lymphangioma, a rare and benign, usually cystic, lesion characterized by masslike proliferation of lymph vessels; diffuse lymphangioma, a proliferation of vascular, mainly lymphatic, spaces in which visceral and skeletal involvement are common; and lymphangioleiomyoma, which involves a haphazard proliferation of smooth muscle in the lungs and dilatation of lymphatic spaces.

These characteristic findings can be seen with radiographic studies as well as with histologic evaluation. The discovery of one of these lymphatic disorders may prompt an investigation for associated congenital anomalies, including Noonan syndrome, asplenia, Gorham syndrome, and tuberous sclerosis.

PMID: 1749850 [PubMed - indexed for MEDLINE]

Related Abstract

Thoracic lymphatic disorders.

Davis KK, Berry GJ, Raffin TA, Faul JL.

Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, California 94305-5236, USA.

Thoracic complications of lymphatic disorders can culminate in respiratory failure and death and should be considered in any patient with a lymphatic disease and clinical or radiographic evidence of chest disease. Congenital lymphatic disorders are being increasingly recognized in the adult population. The spectrum of thoracic manifestations of lymphatic disorders ranges from incidental radiographic findings to diffuse lymphatic disease with respiratory failure. This article serves to review some recent advances that allow improved diagnosis and management of thoracic lymphatic disorders. Herein, we describe their anatomical and physiologic effects, the time course of their progression, and the therapies that are currently available. The management of malignant (cancerous) lymphatic disorders of the thorax is beyond the scope of this paper.

Publication Types:
Review

PMID: 15609812 [PubMed - indexed for MEDLINE]

Wednesday, April 12, 2006

Lymphatic malformations of the head and neck: Introduction of a disease score for children, Cologne Disease Score (CDS)

Wittekindt C, Michel O, Streppel M, Roth B, Quante G, Beutner D, Guntinas-Lichius O.

Clinic of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Cologne, Germany.

OBJECTIVE:

A clinical staging system for children with lymphatic malformations that would allow for a standardized comparison of disease and treatment outcomes.

METHODS:

We developed an examination sheet for the determination of a disease score ranging from 0 (worst) points to 10 (best) points, Cologne Disease Score (CDS). Disfigurement, dysphagia, dysphonia, dyspnea and an observer statement towards progression were contributing to CDS. Each parameter yielded two, one or zero points. Two points were given when no limitation was seen in the patient concerning the respective item. One point was given at mild limitation and zero points were given when considerable limitation in the respective item could be observed. We evaluated 26 patients with lymphatic malformations of the head and neck retrospectively by completing one examination sheet for each patient-visit.

RESULTS:

Four patients had an initial CDS value of three or less points (severe disease-group). After therapy the mean value of their score increased only slightly to 3.9+/-2.6 points. Six patients had an initial CDS value of four, five or six points (advanced disease-group). After treatment their mean score value increased dramatically to 9.0+/-1.5 points (P<0.001).>

CONCLUSIONS:

The evaluation of the CDS was easy and expeditious. The score itself was a good predictor in view of the outcome. This new disease score for paediatric patients might be appropriate to evaluate therapeutic trials in paediatric patients.

PMID: 16460815

[PubMed - as supplied by publisher]

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Management of lymphatic malformations in oral and maxillofacial regions: the rationale according to the new classification

Zheng JW, Qin ZP, Zhang ZY.

According to the classification of ISSVA, Waner and Suen, the traditionally called lymphangiomas are now referred to as lymphatic malformations, including both macrocystic and microcystic lesions. They are commonly seen vascular anomalies, and most frequently diagnosed at birth and most often occur in the head and neck area. The etiology of lymphatic malformations is still unknown, resulting in a variety of treatment modalities.

This paper reviewed the recent literatures with respect to the indications, contraindications, advantages and disadvantages of surgical excision, sclerotherapy and laser ablation of lymphatic malformations of the head and neck, with detailed discussion of the advances in molecular biology and clinical treatment prospects. It is concluded that although lymphatic malformations are benign lesions, they seldom involute spontaneously. Of all vascular malformations, lymphatic malformations are the most difficult to be eradicated. Their infiltrating nature coupled with the difficulty in distinguishing involved important structures of the head and neck from adjacent normal tissues makes complete surgical extirpation even more difficult. The likelihood of postsurgical recurrence and complications is thus higher than other vascular lesions.

Although many treatment protocols are available in clinic, indications, contraindications, advantages and disadvantages exist in each modality. The selection of treatment modalities should depend on the patients' status and techniques available. The treatment protocol should be individualized and comprehensive as well as sequential, in order to obtain the best treatment outcomes. In general, treatment will vary according to the depth and the extent of the lesions. Superficial mucosal microcystic lesions and cervicofacial macrocystic lesions are amenable to ablation with sclerotherapy using Bleomycin and OK-432 with the advantages of the absence of a surgical scar.

The sclerosing agent OK-432 is effective for macrocystic lymphatic malformations but showed less promise for microcystic lesions, mixed lesions, and lesions outside the head and neck region. In addition, superficial mucosal microcystic lesions are also amenable to CO2 laser therapy. Deeper microcystic lesions are still challenging head and neck surgeons, which are usually extensive and sometimes need to be resected in stages, and even may be impossible to be completely removed.

Somnoplasty shows promise for reduction of tongue lymphatic malformations. Surgical excision, staged when necessary, continues to be integral to management in many cases, but should not be overused without consideration of the histologic types and extent. Localized mucosal microcystic lesions and major cervicofacial macrocystic lesions are amenable to primary excision.

Care should be exercised in identifying and preserving important cervical and facial structures because anatomical planes are often distorted. Combined sequential approach is recommended for mixed lesions as well as extensive lesions involving both the mucosa and soft tissues.

Publication Types:
Editorial

PMID: 16400476 [PubMed - in process]

Friday, April 07, 2006

Primary pulmonary lymphangiectasia in infancy and childhood

P.M. Barker1, C.R. Esther, Jr1, L.A. Fordham2, S.J. Maygarden3 and W.K. Funkhouser3

Depts of 1 Paediatrics (Division of Paediatric Pulmonology), 2 Radiology, and 3 Pathology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA

CORRESPONDENCE: P.M. Barker, Division of Paediatric Pulmonology, Dept of Paediatrics, 200 Mason Farm Road, CB 7220, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA. Fax: 1 9199666179.

E-mail: Pierre_Barker@med.unc.edu

Keywords: Growth, pathology, radiology, spirometry

Received: February 4, 2004Accepted May 20, 2004
C.R. Esther Jr is supported by a Parker B. Francis Pulmonary Fellowship.

Abstract:

Primary pulmonary lymphangiectasia (PPL) is a rare disorder of unknown aetiology characterised by dilatation of the pulmonary lymphatics. PPL is widely reported to have a poor prognosis in the neonatal period and little is known about the clinical features of patients who survive the newborn period.

The current authors report the outcome in nine patients diagnosed in infancy with PPL over a 15-yr period at a single university-based hospital clinic and followed for a median of 6 yrs.

Although all of the patients initially experienced respiratory distress, respiratory symptoms improved in most patients after infancy and were notably better by the age of 6 yrs. Many patients had poor weight gain in the first years of life, which eventually improved. Radiological scans showed progressive resolution of neonatal infiltrates, but were characterised by hyperinflation and increased interstitial markings in older children. Most patients had evidence of bronchitis and grew pathogenic organisms from quantitative bronchoalveolar lavage culture. Pulmonary function tests showed predominantly obstructive disease that did not deteriorate over time.

In conclusion, these results suggest that primary pulmonary lymphangiectasia does not have as dismal a prognosis as previously described and symptoms and clinical findings improve after the first year of life.

Pulmonary lymphangiectasia is an abnormal dilatation ofthe lymphatics draining the interstitial and subpleural (SP) space of the lungs. It is a rare condition, first described by Virchow 1 in 1856, which can be a primary abnormality or acquired as a result of obstruction of the pulmonary lymphatics or veins. In primary pulmonary lymphangiectasia (PPL), the lymphatic abnormality can belocalised to the lung or be part of a more widespread abnormality of lymphatic drainage 2. Although PPL is assumed to result from an arrest in the development of thepulmonary lymphatics 3, the cause of PPL is not known. Most cases are sporadic and, although familial occurrences ofthis condition have been described 46, no genetic aetiology has been identified. PPL has been described in association with a number of chromosomal anomalies 7 andin patients with Noonan's syndrome 811. In addition, PPL is often described in association with cardiac anomalies 12 that are not associated with pulmonary venous hypertension.

Early descriptions of pulmonary lymphangiectasia from the pathology literature reported an incidence of 1% in consecutive necropsies on stillbirths and neonates 12, 13. The true incidence of PPL after the newborn period is not known and reports of PPL in infants and children are restricted to isolated case reports. Despite a number of case reports in which infants with PPL have survived and improved over time 2, 5, 11, 1417, congenital pulmonary lymphangiectasia continues to be considered as a condition with a poor prognosis 15, 18.

The current study describes the presentation, clinical findings, diagnosis, clinical course and outcome of infants diagnosed with PPL.

Methods

Study subjects and design - Retrospective chart review was used to identify nine patients who were diagnosed with pulmonary lymphangiectasia in a university hospital-based paediatric pulmonology practice (North Carolina Children's Hospital, University ofNorth Carolina, Chapel Hill, NC, USA) over a 15-yr period (1987–2002). Evaluation of patients with PPL (n=9) included: radiological studies with chest radiograph (n=9) andchest computed tomography (CT) scan (n=5); flexible fibreoptic bronchoscopy (n=8); sweat chloride test (n=8); cardiac evaluation with echocardiography or catheterisation (n=8); pH probe for gastroesophageal reflux (n=7); andan immunological evaluation, including complete bloodcount with differential and immunoglobulin levels(n=8).

To determine the frequency of a diagnosis of PPL in infants and children who underwent open lung biopsy, the current authors reviewed the pathology reports of all open lung biopsies in infants and children over a 3-yr period (1999–2002).

Results

Patients - Nine patients were identified with a diagnosis of PPL from 17,000 new patients seen in the current authors' clinic (North Carolina Children's Hospital) during the period under review (table 1). Eight of the nine patients were males. The patients were followed for a median of 6 yrs (range 3 months to 14 yrs) and ranged between 22 months and 17 yrs of age at the time of the current study. Two patients were lost to follow-up when they relocated to another area; another patient died of respiratory disease at 3 months of age.

Presentation - The median age at presentation was 3 months (range: newborn–12 months; table 1). Three of these patients presented in the neonatal period; the remaining six patients presented in the post-neonatal period. The diagnosis of PPL was made on the basis of lung biopsy in eight patients and classic clinical presentation, including respiratory distress and chylothorax, in one patient (patient 1).

Three patients had some degree of generalised oedema at presentation, which resolved, but none of these patients had intestinal lymphangiectasia, which characterises the general form of lymphangiectasia as described by Noonan et al. 2.

Three of the patients required mechanical ventilation, all of whom presented in the neonatal period. One infant with generalised oedema had severe respiratory failure and was considered for extracorporeal membrane oxygenation. None of the patients who presented in the postneonatal period required mechanical ventilation, but three required home supplemental oxygen for some period of time. All but one of these patients had fine crackles on lung auscultation with clinical evidence of decreased lung compliance (intercostal retractions, increased work of breathing) at presentation. Wheezing was present in some cases and was variably responsive to albuterol. Respiratory symptoms improved in all patients who survived the neonatal period. The patient who died had Costello's syndrome and support was withdrawn at the age of 3 months.

Other diagnoses were common in these patients. One patient was diagnosed with Noonan's syndrome and had echocardiographic evidence of mild pulmonary valvular stenosis. The patient with Costello's syndrome also had mild pulmonary valvular stenosis. None of the other patients had clinically apparent chromosomal abnormalities. All but one of the patients had echocardiogram or cardiac catheterisation and no other major cardiac anomalies were detected. One patient did have pulmonary hypertension and tricuspid regurgitation noted on the first day of life, but this was resolved later. Gastroesophageal reflux disease was present in four patients and decreased immunoglobulins were detected in two patients.

Growth - Growth data up to the age of 3 yrs was available for six of the patients in this study and weight percentiles were derived from the Center for Disease Control 2000 population growth data for males aged 0–36 months 19. All of these patients were born at term with normal birth weights, but showed poor weight gain and some degree of growth failure between the ages of 3 months and 1 yr (fig. 1). By 3 yrs old, four of the six had regained normal growth. Two other patients did not have evidence of growth failure and another died at three months old.

Lung biopsy - PPL was confirmed in eight of the nine patients with open lung biopsy. No complications occurred in any patients during surgery. In one case, the diagnosis of pulmonary lymphangiectasia was not made until the pathology was re-reviewed 3 yrs after the original biopsy. In two other cases, the pulmonary lymphangiectasia was not evident on the first lung biopsy. In these two cases, initial lung biopsy showed diffuse alveolar damage or nonspecific changes with no evidence of lymphatic dilation. The patient who did not have a lung biopsy had generalised lymphoedema and chylothorax at birth. Lung biopsy was deferred because the patient's clinical condition improved. For the purposes of the current study, all available lung biopsies (n=6) from these patients were reviewed independently by two anatomic pathologists for lymphatic dilation in SP, peri-arterial (PA) and interlobular (IL) regions. In these patients, lymphangiectasia involved all of the regions that were examined (fig. 2). The lymphatic dilation was described as "severe" in five of six re-reviewed cases and "moderate" in one of six.

To exclude the possibility of lymphatic dilation that may be an artefact and associated with the cross-clamp wedge biopsy technique, control groups of all paediatric open lung biopsies over a 3 yr period (1999–2002) and all adult wedge biopsies from 2002 were reviewed. A total of 42 wedge biopsies in 31paediatric patients were evaluated. Focal lymphatic dilation was detected in six of 42 biopsies (14%) from four of 31 patients (13%). Two patients had pulmonary lymphangiectasia in a single region: one with osteosarcoma and extensive lung metastases (SP dilation in two of four biopsies) and another patient evaluated at 14 months for persistent tachypnoea (SP dilation in two of two biopsies). One patient with bronchopulmonary dysplasia and persistent tachypnoea had lymphatic dilation in two regions (SP and IL) of a single-wedge biopsy at 3 months old. One patient with known pulmonary veno-occlusive disease had lymphatic dilation in all three regions in a single-wedge biopsy obtained for the evaluation of a persistent radiological density. In the adult control group, 48 biopsies from 38 patients were reviewed. Single-site lymphatic dilation (SP: n=4; IL: n=2; PA: n=2) was observed in seven of 48 biopsies (14%) from seven of 38 patients (18%). These seven biopsies demonstrated carcinoma (n=4) and interstitial lung disease (n=3).

In summary, PPL biopsies showed lymphatic dilation involving three contiguous sites (SP, IL and PA) in all wedge biopsies, whereas control paediatric and adult wedge biopsies performed for non-lymphangiectasia lung diseases typically showed, at most, single-site lymphatic dilation and, then, in only 15% of biopsies.

Radiology - Radiological findings for four of these patients have been described previously 20. Two of the patients in the current authors' study had pleural effusions (figs 3a and b). Initially, the three patients with a neonatal presentation had diffuse interstitial infiltrates. With the resolution of clinical symptoms, chest radiographs became progressively clearer, but with the emergence of increased interstitial markings and hyperinflation (figs 3c and d). Patients who presented outside the neonatal period had hyperinflation and increased interstitial markings at presentation, which improved over time (figs 4a and b). CT scans showed considerable parenchymal inhomogeneity with patchy areas of ground-glass infiltrates in the perihilar and SP regions. In two patients, lung disease was monitored by repeated CT scans (over an 18 month and 5 yr period, respectively). Although there was interval improvement in both patients, the pattern of parenchymal inhomogeneity was observed to persist in patient-specific regions of the lung.

Pulmonary function tests - Spirometry was performed on six of the nine patients (patients 1, 3, 4, 5, 7 and 8). Of the three missing patients, one patient died in infancy and the remaining two survivors were not old enough for reliable pulmonary function testing (PFT) at the time of the current study. Spirometry values obtained at the age of 6 yrs were compared. Four of the six patients had decreased forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) with a relatively normal FEV1/FVC ratio. Two patients had small airways obstruction which improved after bronchodilator treatment, including one of thepatients with decreased FVC. One patient had normal spirometry. Lung volume measurements were obtained from three patients aged 7–14 yrs, all of whom had decreased FVC and FEV1 at the time of the measurement. These studies revealed relatively normal total lung capacity (range: 81–117% predicted) with increased residual volume (range: 139–234% pred) suggesting obstructive lung disease. Diffusion capacity obtained from two patients was normal. Longitudinal PFT data was available for four of the remaining seven patients. In four patients, in whom lung function was tracked by spirometry, FEV1 did not change significantly over time

Bronchoscopy - Eight of the nine patients underwent elective flexible fibreoptic bronchoscopy as part of a diagnostic evaluation for chronic lung disease. Three patients with recurrent lung infections underwent multiple procedures to assist with the identification of pathogenic organisms. Airway anatomy was normal in six of the eight patients; mild subglottic stenosis was noted in two. Bronchitis (increased secretions and neutrophil percentage on bronchoalveolar lavage fluid) was apparent on at least one occasion in six of the eight patients studied. In seven of the eight patients, bronchoalveolar lavage cultures grew pathogenic organisms including Moraxella catharralis and Staphylococcus aureus. In three of these patients, significant quantities (>100,000 organisms·mL–1 bronchoalveolar lavage fluid) of organisms were isolated.

Discussion

The cases described in the current study suggest that PPL has a variable presentation and the widespread characterisation of this condition as having a near-uniform poor prognosis needs to be revised. Although most patients had tachypnoea (increased respiratory effort with inspiratory crackles and failure to thrive), these symptoms improved over time.

Since this is a retrospective review of cases from one tertiary institution, the current authors were unable to accurately determine the incidence of PPL over this period. Although no neonatal death was ascribed to PPL during this period, it is possible that the diagnosis was not recognised in some cases of severe neonatal respiratory failure that resulted in early death. In addition, it is possible that a number of patients with mild disease were not diagnosed in infancy because of spontaneous regression of their disease.

The studied patients fell into two broad categories: those with neonatal or postneonatal onset. In the three patients with neonatal onset, all required prolonged mechanical ventilation, one required chest tube placement for removal oflarge amounts of chylous effusion and another had persistent unilateral nonchylous effusion. In the current study, respiratory symptoms improved over time in most patients, even in those who presented in the neonatal period. This contrasts with a study of 11 patients with PPL reported recently by Bouchard et al. 15 in which none of the six patients diagnosed in the neonatal period survived. However, two of these infants were <30>

Many of the previous reports that built the consensus about the poor outcome for PPL come from an era of limited neonatal intensive care capabilities and/or included infants with significant additional congenital or chromosomal abnormalities 3, 6, 12, 21. Whilst there are undoubtedly infants with extensive lymphangial derangements that may not be compatible with life, it is possible that many of the infants reported previously with uncomplicated PPL would have survived with current practices of neonatal intensive care. This assertion is supported by a recent study of an infant with respiratory failure and severe chylous drainage who survived following aggressive neonatal respiratory support 22. The current study suggests that survival of neonatal onset PPL is not uncommon and that, in survivors, the condition will improve.

Of the six patients with a postneonatal onset, all presented between 2 and 12 months of age with increased work of breathing and crackles on auscultation of the chest, after an apparently symptom-free period earlier in life. The reason these infants do not present at birth is difficult to explain. At birth, additional stress is placed on interstitial clearance mechanisms as the large volume of foetal lung liquid that occupies the alveolar compartment during gestation is absorbed from the lung lumen to make way for air-breathing 23. Whilst some alveolar fluid is cleared via the lung lymphatics, resulting in an increase in lung lymph flow at birth, most of lung liquid reabsorbed from the alveolar space is thought to pass directly into the foetal circulation 24. This lack of reliance of the pulmonary lymph channels at birth may explain why the majority of patients with PPL did not develop respiratory failure in the neonatal period. There is a paucity of information regarding lymphatic development in infancy that can assist in explaining why a number of infants present with symptoms for the first time at a few months of age, some of whom worsen during the first few months after presentation 15, 25. There are few chronic clinical entities that mimic these findings; the differential diagnosis includes: pulmonary aspiration syndromes, interstitial lung disease and indolent/recurrent pulmonary infection.

In addition to significant respiratory symptoms and recurrent lower respiratory infections, the infants in the current study had significant growth failure during the first year of life, which corrected fully by 3 yrs of age. There was no clinical evidence of malabsorption in these infants, and the failure to gain weight was ascribed to decreased intake and increased energy expenditure associated with respiratory effort and infections. The repeated lower respiratory infections in the studied patients were assumed to be secondary to mechanical factors (e.g. poor lung compliance) related to retention of interstitial fluid. The mild immune deficiencies detected in two patients may have contributed to the recurrent infections, but other patients did not have evidence of immune dysfunction. Since gastroesophageal reflux has been associated with other chronic respiratory diseases 26, two patients underwent Nissen fundoplication for documented reflux that was unresponsive to medical therapy. There was no improvement in respiratory condition after surgery.

A clinical diagnosis of PPL can be made in full-term neonates presenting with respiratory distress, pleural effusions (particularly if chylous) with or without generalised oedema. In older infants, the diagnosis may be harder to determine because symptoms are likely to be more subtle and may be similar to other causes of persistent tachypnoea in infancy 27. The diagnosis can be assisted by radiological findings and confirmed by lung biopsy. The radiological findings in the studied patients are similar to those described previously by others 2, 11, 15, 20, 25. The progression of generalised hazy infiltrates in the neonatal period to a more perihilar interstitial pattern with hyperinflation was seen consistently. A recent report suggests that magnetic resonance imaging may be useful for the imaging of pulmonary lymphangiectasia 18. The decision to submit patients to lung biopsy was determined by the uncertainty of the diagnosis. In the patient who did not have a lung biopsy, the diagnosis of PPL was made from a presentation of generalised oedema and chylothorax. In the patients who had repeat lung biopsy, the pathological findings changed over time. The first biopsies indicated nonspecific changes that were probably secondary to an acute viral infection. The absence of lymphagiectatic changes on the first biopsies raises the possibility that viral infection may have been a trigger for subsequent lymphatic obstruction. The ability of viruses to induce structural changes in the lung is well documented 28; however, the current authors are not aware of any reports of damage to pulmonary lymphatics following viral infection.

From the current authors' experience, the pathological diagnosis of PPL from a lung biopsy can be made with confidence, since minimal evidence of lymphangiectasia artefacts that could be ascribed to biopsy technique were seen. The biopsy samples from infants with clinical and radiological evidence of PPL showed severe lymphatic dilation in all three lymphatic compartments and were readily differentiated from the occasional isolated lymphangiectasia seen in the control samples from children's lungs.

The widely held view that this condition has a fatal outcome was moulded by earlier reports of primary pulmonary lymphangiectasia in the pre-ventilation era of neonatal intensive care. The current authors conclude that the recent descriptions of this condition as having a "dismal" 15, "usually lethal" 29 or "very poor" 30 prognosis do not take account of the contribution of coexisting disease to outcome in many of these patients or the recent advances in neonatal care that allow survival in neonates with primary pulmonary lymphangiectasia. The current authors' experience, as well asthat described in numerous case reports, suggests that survival can be anticipated in neonatal onset primary pulmonary lymphangiectasia without additional anomalies, and that the prognosis is excellent for the postneonatal onset form of primary pulmonary lymphangiectasia. The limited observation of a number of these studied patients over time suggests that, although not normal, lung function does not worsen with advancing age. However, the long-term prognosis and lung function in adult survivors with primary pulmonary lymphangiectasia has not been determined.

European Respiratory Journal

Thursday, April 06, 2006

Congenital Intestinal Lymphatic Hypoplasia Presenting as Non-Immune Hydrops In Utero, and Subsequent Neonatal Protein-Losing Enteropathy

Journal of Pediatric Gastroenterology and Nutrition: Volume 35(5) November 2002 pp 691-694

Stormon, M.O.*; Mitchell, J.D.*‡; Smoleniec, J.S.§; Tobias, V.†; Day, A.S.*‡

Departments of Gastroenterology and †SEALS, Sydney Children's Hospital; ‡School of Women's and Children's Health, University of New South Wales, and §Feto Maternal Medicine, Liverpool Hospital, Sydney, Australia
Correspondence to Dr. Andrew S. Day, Department of Gastroenterology, Sydney Children's Hospital, High Street, Randwick, NSW, 2031, Australia (e-mail:
andrew.day@unsw.edu.au).

Intestinal lymphangiectasia and other abnormalities of lymphatic drainage from the gastrointestinal tract result in protein-losing enteropathy. Recently, hypoplasia of intestinal lymphatics has been described as an additional cause of protein-losing enteropathy presenting in infancy. We report the case of a child, with features consistent with intestinal lymphatic hypoplasia, in whom non-immune hydrops, requiring repeated intervention, was detected at 18 weeks' gestation and who developed protein-losing enteropathy post-natally.

Case Report

Antenatal History

This was the 26-year-old mother's second pregnancy, having 2 years earlier delivered a healthy female infant at term. The parents were unrelated. A routine antenatal ultrasound scan at 18 weeks' gestation suggested the presence of ascites. Repeat ultrasound performed by the Fetal Medicine Unit (FMU) at Liverpool Hospital, NSW, Australia, confirmed moderate fetal ascites, and also demonstrated bilateral pleural effusions and peripheral edema, thereby defining a diagnosis of fetal hydrops. Subsequent investigations included detailed fetal anatomy, fetal echocardiography, and cordocentesis. An in utero karyotype analysis showed normal male (46 XY). Since no cause had been identified, a diagnosis of idiopathic non-immune hydrops was made.

The consensus at this stage was that the prognosis was likely poor. Consequently, the parents were counseled extensively. The mother, who felt the fetal activity was more than in her previous pregnancy, declined termination and the parents requested that everything possible be done for the fetus.

Because of the risk of pulmonary hypoplasia secondary to bilateral pleural effusions, repeated pleural aspirations were commenced at 22 weeks. Although pleurocentesis was initially required every few days to maintain lung expansion, the frequency steadily decreased over subsequent weeks with the final aspiration performed at 36 weeks gestation. In total, the right pleural effusion was drained 12 times and the left on four occasions. In addition, paracentesis was undertaken twice, at 23 and 24 weeks gestation. Despite these repeated interventions, all measured parameters of fetal well being and growth, especially of the thorax, remained normal throughout the pregnancy.

Postnatal History

At 38 weeks' gestation emergency caesarian section was performed because of the development of fetal distress. After delivery, bag and mask resuscitation was required briefly. APGAR scores were six and nine at one and five minutes respectively.

On initial examination the infant weighed 3410 g and had mild generalized edema. Serum albumin on the first day of life was measured at 28 g/L (normal range 32-48 g/L). Although a right pleural effusion was demonstrated on chest radiograph, there was no respiratory distress. He remained well over the first week of life, established feeding with no further concerns, and was discharged home on day seven.


At seven weeks of age the child was admitted to Sydney Children's Hospital, Sydney, Australia, for repair of bilateral inguinal hernias which had been first noted during week two. On examination at admission he weighed 3.85 kg and had gross generalized edema. Inspiratory stridor was noted.


Initial laboratory investigations demonstrated hypoalbuminaemia (21 g/L), and hypo-gammaglobulinaemia (IgA 0.1 g/l; IgM 0.3 g/l; IgG 0.6 g/l). There was a trace of protein on urinalysis and a markedly increased stool α-1-antitrypsin level of 31.1 g/kg (normal <1.5>


Gross ascites was demonstrated on abdominal ultrasound. Portal venous flow was normal. Echocardiography revealed a small secundum atrial septal defect. There was no evidence of malrotation on a barium contrast study; however, nodular thickening of the small bowel mucosa was evident.


To determine the cause of the protein-losing enteropathy, multiple small intestinal biopsies were undertaken. Initially Crosby capsule biopsies were undertaken at 8 and 10 weeks of age. Subsequently, duodenal biopsies were obtained endoscopically at 10 weeks, 15 weeks, and 8 months of age. The duodenal mucosa was uniformly milky white on each occasion that it was visualized. Duodenal fluid trypsin and enterokinase levels were adequate.


Laparotomy was performed in conjunction with endoscopy at 15 weeks of age to define the extent of bowel involved. The serosal surface of the small intestine was milky white and fatty in appearance from the proximal duodenum up to 20 cm from the ileo-cecal valve. There were no dilated lacteals or fat-laden lymph nodes visible in the small bowel mesentery. A partial malrotation was noted with a high fixed right-sided caecum in close proximity to the duodenal-jejunal flexure, but there was no evidence of intermittent volvulus. Full-thickness biopsies were taken from the duodenal-jejunal flexure and terminal ileum. Following these biopsies milky-white fluid exuded from the luminal surface. In addition, cecopexy and appendicectomy were performed.


Dietary changes were initiated within days of the initial admission. However, despite the administration of medium-chain triglyceride (MCT)-based formulae, semi-elemental formulae, or periods of bowel rest with total parenteral nutrition, marked albumin and immunoglobulin losses continued. The hypoalbuminemia was managed with intravenous infusions of 20% albumin initially given daily. Albumin requirements decreased progressively over the following months. By six months of age the frequency of infusions was reduced to an interval of ten to fourteen days. Regular gammaglobulin infusions were administered to maintain IgG levels in an attempt to reduce the occurrence of intercurrent respiratory infections.


The distribution of edema seen after the serum albumin had initially normalized was often somewhat asymmetric. The occiput was particularly affected, even when sitting and later when ambulant. Moderate to marked edema, fluctuating with the albumin level, persisted through the first few years of life. Recently, however, edema has been present only at lower serum albumin levels and is now predominantly pedal. In addition to peripheral edema, pleural effusions and ascites were present in the first months of life. Pleural effusions were managed conservatively. However, paracentesis was required on one occasion to manage ascites, following the development of respiratory compromise. The ascitic fluid was an exudate that was grossly lipemic (cholesterol 3.1 mmol/l and triglyceride 13.5 mmol/l) with total protein of 36g/l (albumin 28g/l). Stridor, secondary to laryngeal edema, has been present intermittently since initial presentation. At times of increased respiratory distress both nebulized adrenalin and oral steroids proved efficacious. Anterior cricoid split was required on one occasion to manage moderately severe stridor associated with respiratory distress.


Over time a number of further diagnostic possibilities were considered. Carbohydrate deficient glycoprotein syndrome was excluded by normal transferrin electrophoresis pattern. Clinical assessment by a geneticist at 13 months of age delineated mild dysmorphic features not present in either of his parents. These included short upturned nose, long philtrum with full lips, broad nasal bridge with mild epicanthic folds, sparse hair, a very broad forehead and horizontal eyebrows with some flaring. The pattern of these features was not felt to be diagnostic.


Various therapeutic modalities have been tried over time. These modalities include systemic corticosteroids, a six-month trial of subcutaneous octreotide (somatostatin), treatment with pancreatic enzyme supplements (pancrease), and spironolactone. While receiving octreotide and steroids, fecal α-1-anti trypsin levels decreased slightly and albumin requirements decreased transiently.


Now aged five and a half years, he has remained very well for over two years. Albumin and immunoglobulin requirements have continued to decrease and infusions have been administered every six to eight weeks recently. He has made normal developmental progress and is growing at the 10th centile for weight and height.

Pathology

Examination of all mucosal biopsies by light microscopy showed essentially normal small bowel mucosa with villi of normal height in most areas. Occasional areas of mild partial villous atrophy were present in jejunal biopsies along with mild accompanying inflammatory infiltrate within the lamina propria. There was, in addition, focal vacuolation of the surface epithelium. Modified oil red O staining of frozen tissue sections of mucosal biopsies showed prominent fat in the epithelium and lamina propria. This was especially marked in biopsies obtained after returning the infant to a cow's milk-based formula for a 24-hour period. No lymphatic vessels were visible in the many sections examined.

Light microscopy of the full-thickness specimens showed preservation of villous architecture with markedly edematous villi. No lymphatic vessels could be identified with certainty in any of the sections. In contrast, lymphatics were easily identifiable in full-thickness biopsy sections obtained from normal controls. This difference was especially noticeable when comparing the appendix of the case with that of controls (Fig. 1). Electron microscopy of the intestinal full-thickness was reviewed by Dr. C.W. Chow (Royal Children's Hospital, Melbourne, Victoria, Australia) who confirmed the absence of lymphatic channels utilizing previously described criteria (1).

Discussion

This child was initially thought to have intestinal lymphangiectasia as the cause of his severe protein-losing enteropathy. However, several features suggested an alternative diagnosis, including in utero hydrops, absence of lymphopenia, lack of response to the high MCT diet, and failure to identify dilated or ectatic lymphatics on multiple small bowel biopsies. Indeed, lymphatic spaces were noted to be inconspicuous and difficult to identify suggesting lymphatic hypoplasia as a possible etiology. This might explain the absence of lymphopenia, which is typically seen in lymphangiectasia, and is thought to be due to gut losses of lymph from ruptured lymphatics. Given that lymphatics could not be identified in our case, absence of lymphopenia is perhaps not surprising.

Hardikar et al. (1) report two siblings presenting with neonatal protein-losing enteropathy most likely due to intestinal lymphatic hypoplasia. The authors noted difficulties in making this diagnosis. In particular, the authors highlighted the problems associated with diagnosing the absence of a normal structure as opposed to defining the presence of an abnormal feature. Similar obstacles in identifying lymphatic spaces were encountered in the current case, despite reference to the features suggested by Hardikar and others (1,2).
Lymphangiography or lymphoscintigraphy may have been potentially useful methods to confirm hypoplasia of lymphatic spaces. These tests were not attempted in this child because of the technical difficulties associated with performing such a procedure in a small child and the risks of exposure to a relatively large dose of radiation occurring at a localized site if lymphatic hypoplasia caused failure of removal of the radiolabel. There was also concern that the outcome of such a study would be unlikely to alter the management.


The endoscopic features of a milky white duodenal mucosa, in conjunction with the macroscopic appearance of the serosal surface seen at laparotomy, and the absence of either dilated lacteals or fat-laden lymph nodes in the small bowel mesentery, are consistent with the findings in previously reported cases of histologically proven lymphangiectasia (3-5). Other causes of fat-filled enterocytes include Anderson disease (chylomicron retention disease) (6) and abetalipoproteinemia (7). These have been excluded, the former by the presence of fat within the lamina propria and a normal serum cholesterol and the latter by normal apolipoprotein levels. Other lymphoedema syndromes such as Nanne-Milroy syndrome (8) and Noonan syndrome (9) were considered but clinical findings were inconsistent. The similarity to the autosomal recessive Hennekam syndrome (10), which has features of lymphoedema, intestinal lymphangiectasia, characteristic facial anomalies and mental retardation, also was raised. The absence of limb abnormalities, mental retardation, lymphocytopenia, and evidence of lymphangiectasia made this diagnosis unlikely. A further syndrome considered was carbohydrate deficient glycoprotein syndrome (CDGS). Niehues et al. (11) include protein-losing enteropathy in their initial description of CDGS Type 1b, which also may feature thrombosis and life-threatening bleeding but does not involve neurologic manifestations. In addition, de Koning et al. (12) have shown that CDGS may present with non-immune hydrops fetalis. Transferrin electrophoresis testing has, however, excluded this as a diagnosis in the current case.


The histologic findings in mucosal biopsies, of prominent fat in the epithelium and lamina propria on modified oil red staining, is suggestive of the histologic picture seen in lymphangiectasia. However, lymphatics were not seen during histologic analysis. The absence of these structures was confirmed by histologic assessment of full-thickness biopsies, and electron microscopy of the mucosa. The characteristics of small bowel biopsies mean that lesions may be missed if disease is focal rather than generalized. However, in the current case, representative samples were taken from duodenal-jejunal flexure and the terminal ileum, which were both abnormal macroscopically. In fact, almost the entire small bowel was milky white at laparotomy, suggesting generalized changes. Despite the prominence of fat in the epithelium and lamina propria, serum lipid (cholesterol and triglyceride) levels were normal. The mucosal biopsy findings of partial villous atrophy, lamina propria inflammatory infiltrate, and focal vacuolation of the surface epithelium were mild, and the significance of these findings is uncertain.


A number of therapies were utilized over time in attempts to decrease enteric protein loss in the current case. Octreotide, for instance, has been demonstrated to reduce enteral losses of protein in both Menetrier disease (13) and lymphangiectasia (14), via mechanisms that include reduction of lymph fluid excretion through the action of octreotide on vascular somatostatin receptors (14). Dietary changes are also generally efficacious in lymphangiectasia (15). The relatively poor response in our patient to a diet low in long-chain triglycerides suggests a more severe hypoplasia, or even absence, of lymphatics. This is in contrast to the report from Hardikar et al. (1) in which both patients responded to this diet. The intrauterine involvement (with predominance of pleural fluid accumulation), more severe postnatal protein losses and the unusual distribution of edema over the first year may result from a more widespread lymphatic abnormality than purely intestinal in the current case. It would seem likely that the current case more clearly illustrates the features of congenital lymphatic hypoplasia.


In conclusion, this case illustrates clinical findings consistent with congenital lymphatic hypoplasia. Thus far a satisfactory treatment has not been found for this child and he remains albumin dependent, although this requirement has decreased over time. Given the in utero presentation and the initial requirements for aggressive management, the outcome of this child has been much better than expected and includes age-appropriate developmental progress. Early and severe symptomatic hydrops may lead to demise of the infant. Consequently, it is conceivable that the incidence of this condition may be more than previously reported and warrants consideration in cases with similar features.

Acknowledgements:

Our thanks to Dr CW Chow, Royal Children's Hospital, Melbourne, Australia, for his electron microscopy assessment of mucosal biopsies.

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Keywords:

Intestinal lymphatic hypoplasia; Protein-losing enteropathy; Infant