Frances V. White

Obese children with steatohepatitis can develop cirrhosis in childhood.

Nonalcoholic steatohepatitis, in which fatty change and inflammation of the liver occur in the absence of excess alcohol intake, is increasingly recognized in obese children. Although fibrosis is common in pediatric nonalcoholic steatohepatitis, cirrhosis has been reported rarely. The two boys reported here developed cirrhosis from nonalcoholic steatohepatitis at ages 10 and 14 yr. One child progressed to cirrhosis with symptomatic portal hypertension within a 2-yr period.

Granulocyte macrophage colony-stimulating factor ameliorates DSS-induced experimental colitis

Background: Sargramostim, granulocyte macrophage colony‐stimulating factor (GM‐CSF), a hematopoietic growth factor, stimulates cells of the intestinal innate immune system. Clinical trials show that sargramostim induces clinical response and remission in patients with active Crohns disease. To study the mechanism, we examined the effects of GM‐CSF in the dextran sulfate sodium (DSS)‐induced acute colitis model. We hypothesized that GM‐CSF may work through effects on dendritic cells (DCs). Methods: Acute colitis was induced in Balb/c mice by administration of DSS in drinking water. Mice were treated with daily GM‐CSF or phosphate‐buffered saline (PBS). To probe the role of plasmacytoid DCs (pDCs) in the response to GM‐CSF, we further examined the effects of monoclonal antibody 440c, which is specific for a sialic acid‐binding immunoglobulin (Ig)‐like lectin expressed on pDCs. Results: GM‐CSF ameliorates acute DSS‐induced colitis, resulting in significantly improved clinical parameters and histology. Microarray analysis showed reduced expression of proinflammatory genes including TNF‐&agr; and IL1‐&bgr;; the results were further confirmed by real‐time reverse‐transcriptase polymerase chain reaction and serum Bio‐plex analysis. GM‐CSF treatment significantly expands pDCs and type 1 IFN production. Administration of mAb 440c completely blocked the therapeutic effect of GM‐CSF. GM‐CSF is also effective in RAG1−/− mice, demonstrating activity‐independent effects on T and B cells. IFN‐&bgr; administration mimics the therapeutic effect of GM‐CSF in DSS‐treated mice. GM‐CSF increases systemic and mucosal type 1 IFN expression and exhibits synergy with pDC activators, such as microbial cytosine‐phosphate‐guanosine (CpG) DNA. Conclusions: GM‐CSF is effective in the treatment of DSS colitis in a mechanism involving the 440c+ pDC population.

Congenital disseminated malignant rhabdoid tumor: a distinct clinicopathologic entity demonstrating abnormalities of chromosome 22q11.

The clinical, pathologic, and immunohistochemical features of a widely disseminated tumor with rhabdoid phenotype are described in nine infants < or = 3 months of age. Five neonates had tumor evident at birth, two of which had placental metastases. The average survival following diagnosis was < 6 weeks. None of the infants had an apparent primary tumor in either the kidney or brain. In four cases, the dominant mass involved the head and neck region, and in two cases, the primary mass was paraspinal. The histologic features were those of a high-grade, round cell neoplasm with abundant cytoplasm and containing cells with cytoplasmic filamentous inclusions. Immunohistochemical studies revealed polyphenotypic antigen expression. Genetic information was available from eight of nine cases. Karyotype analysis revealed abnormalities of chromosome band 22q11-12 in three of six tumors. Fluorescence in situ hybridization studies or molecular studies demonstrated 22q11.2 deletions in all five cases with available frozen tissue, two of which had translocations involving 22q by karyotype analysis. The similar clinical and pathologic findings in these rapidly fatal tumors in infants and the demonstration of abnormalities of chromosome 22q11 in a majority of the cases supports their histogenetic and nosologic relationship to the family of malignant rhabdoid tumors that typically occur in young children in several anatomic sites, including kidney, soft tissues, liver, and brain. Like neuroblastoma and rhabdomyosarcoma, malignant rhabdoid tumor can appear as disseminated disease at birth or shortly thereafter.

Surfactant Composition and Function in Patients with ABCA3 Mutations

Mutations in the gene encoding the ATP binding cassette transporter member A3 (ABCA3) are associated with fatal surfactant deficiency. ABCA3 lines the limiting membrane of lamellar bodies within alveolar type-II cells, suggesting a role in surfactant metabolism. The objective of this study was to determine the surfactant phospholipid composition and function in patients with mutations in the ABCA3 gene. Bronchoalveolar lavage (BAL) fluid was analyzed from three groups of infants: 1) Infants with ABCA3 mutations, 2) infants with inherited surfactant protein-B deficiency (SP-B), and 3) patients without parenchymal lung disease (CON). Surfactant phospholipid profile was determined using two-dimensional thin-layer chromatography, and surface tension was measured with a pulsating bubble surfactometer. Phosphatidylcholine comprised 41 ± 19% of the total phospholipid in the BAL fluid of the ABCA3 group compared with 78 ± 3% and 68 ± 18%, p = 0.008 and 0.05, of the CON and SP-B groups, respectively. Surface tension was 31.5 ± 9.3 mN/m and was significantly greater than CON but no different from SP-B. We conclude that mutations in ABCA3 are associated with surfactant that is deficient in phosphatidylcholine and has decreased function, suggesting that ABCA3 plays an important role in pulmonary surfactant phospholipid homeostasis.

Prolonged Survival in Hereditary Surfactant Protein B (SP-B) Deficiency Associated with a Novel Splicing Mutation

Hereditary surfactant protein B (SP-B) deficiency has been lethal in the first year of life without lung transplantation. We tested the hypothesis that SP-B gene mutations may result in milder phenotypes by investigating the mechanisms for lung disease in two children with less severe symptoms than have been previously observed in SP-B deficiency. Immunostaining patterns for pulmonary surfactant proteins were consistent with SP-B deficiency in both children. DNA sequence analysis indicated that both children were homozygous for a mutation in exon 5 that created an alternative splice site. Reverse transcriptase PCR and sequence analysis confirmed use of this splice site, which resulted in a frameshift and a premature termination codon in exon 7. The predominant reverse transcriptase PCR product, however, lacked exon 7, which restored the reading frame but would not allow translation of the exons that encode mature SP-B. Western blot analysis detected reduced amounts of mature SP-B as well as an aberrant SP-B proprotein that corresponded to the size expected from translation of the abnormal transcript. We conclude that a novel splicing mutation was the cause of lung disease in these children and that hereditary SP-B deficiency can be the cause of lung disease in older children.

A protocol for the handling of tissue obtained by operative lung biopsy: recommendations of the chILD pathology co-operative group.

This is the first of a series on pediatric pulmonary disease that will appear as Perspectives in Pediatric Pathology over the coming months. The series will include practical issues, such as this protocol for handling lung biopsies and another on bronchoalveolar lavage in childhood, as well as reviews of advances in various areas in pediatric pulmonary pathology. It has been 11 years since the last Perspectives on pulmonary disease. Much has happened since then in this area, and this collection will highlight some emerging and rapidly advancing areas in pediatric lung disease. These will include a review of molecular mechanisms of lung development, and another of mechanisms of pulmonary vascular development. The surfactant system and its disorders, as well as recent advances in the biology of the pulmonary neuroendocrine system and mechanisms of respiratory viral disease, will be addressed. Articles on pulmonary hypertension, pulmonary neoplasia, and pediatric lung transplantation, with their implications for the pediatric pathologist, are also planned. The contributors to this series are a diverse group with special interests and expertise in these areas. As Dr. William Thurlbeck noted in his foreword to the previous volume, Pulmonary Disease, volume 18 of Perspectives in Pediatric Pathology, pediatric pathology had been largely concerned with phenomenology, rather than with mechanisms, model systems, and experimental investigation. I think he would have been pleased to see the changes that have occurred over the past 10 years in pediatric lung biology and pathology in particular, because these were particularly favored interests of his later years.

Heterogeneous Pulmonary Phenotypes Associated With Mutations in the Thyroid Transcription Factor Gene NKX2-1

BACKGROUND Mutations in the gene encoding thyroid transcription factor, NKX2-1, result in neurologic abnormalities, hypothyroidism, and neonatal respiratory distress syndrome (RDS) that together are known as the brain-thyroid-lung syndrome. To characterize the spectrum of associated pulmonary phenotypes, we identified individuals with mutations in NKX2-1 whose primary manifestation was respiratory disease. METHODS Retrospective and prospective approaches identified infants and children with unexplained diffuse lung disease for NKX2-1 sequencing. Histopathologic results and electron micrographs were assessed, and immunohistochemical analysis for surfactant-associated proteins was performed in a subset of 10 children for whom lung tissue was available. RESULTS We identified 16 individuals with heterozygous missense, nonsense, and frameshift mutations and five individuals with heterozygous, whole-gene deletions of NKX2-1. Neonatal RDS was the presenting pulmonary phenotype in 16 individuals (76%), interstitial lung disease in four (19%), and pulmonary fibrosis in one adult family member. Altogether, 12 individuals (57%) had the full triad of neurologic, thyroid, and respiratory manifestations, but five (24%) had only pulmonary symptoms at the time of presentation. Recurrent respiratory infections were a prominent feature in nine subjects. Lung histopathology demonstrated evidence of disrupted surfactant homeostasis in the majority of cases, and at least five cases had evidence of disrupted lung growth. CONCLUSIONS Patients with mutations in NKX2-1 may present with pulmonary manifestations in the newborn period or during childhood when thyroid or neurologic abnormalities are not apparent. Surfactant dysfunction and, in more severe cases, disrupted lung development are likely mechanisms for the respiratory disease.

Circumferential Distribution of Ganglion Cells in the Transition Zone of Children with Hirschsprung Disease

We prospectively studied the circumferential distribution of ganglion cells in the transition zone from a study population of 21 patients with Hirschsprung disease (HD) undergoing a pull-through procedure over a 26-month period. Twelve cases were satisfactory for examination, in that the transition zone was contained within a single surgical specimen and specimen distortion was minimal. Ganglion cells in the submucosa were counted in all 12 cases. In seven of the cases, the transition zone was proximal to the rectal sleeve and myenteric plexus ganglion cells were also counted.We found an uneven circumferential distribution of ganglion cells in both myenteric plexus and submucosa of the transition zone, resulting in a “leading edge” of ganglion cells extending into aganglionic distal bowel. The maximum length of this leading edge was 2.4 cm and 2.1 cm in the myenteric plexus and submucosa, respectively. Ganglion cells at the tip of the leading edge were present in clusters of up to six ganglion cells, in marked contrast to an absence of ganglion cells for most of the remainder of the circumference. Closely spaced myenteric plexus ganglia were seen at the tip of the leading edge in some cases. The leading edge was more frequently observed along the antimesenteric side, but this was not statistically significant.Our findings have relevance in the interpretation of intraoperative biopsies at the time of pull-through surgery and subsequent biopsies of neorectum in patients with surgically corrected HD.

Outcome after portoenterostomy in biliary atresia: pivotal role of degree of liver fibrosis and intensity of stellate cell activation.

Objectives: Biliary atresia (BA), a congenital idiopathic obliterative cholangiopathy, rapidly leads to liver cirrhosis and liver failure if untreated. A timely Kasai portoenterostomy (KP) variably alters this natural history. We evaluated liver fibrogenesis by the intensity of α-smooth-muscle actin (SMA) expression, which is a marker for hepatic stellate cell activation. We hypothesized that liver fibrogenesis as determined by intensity of α-SMA is already progressing at the time of KP, is related to age and degree of fibrosis at KP, and predicts outcome after KP. Methods: BA patients at KP (n = 22, age 22-84 days, median 59) had wedge liver biopsies assessed by quantitative morphometry of immunohistochemistry for α-SMA expression. Fibrosis was scored by blinded pathologists. Outcome, reflected by conjugated bilirubin concentration 3 months after KP (CBili3m), survival of the native liver, need for liver transplant, or death, were assessed for 2 to 10 years after KP. Results: At KP, age, fibrosis score, and α-SMA expression were significantly correlated. Moderate-severe fibrosis and intense α-SMA expression was observed in 15 of 22 (68%) patients. Severe fibrosis and high α-SMA expression were significantly associated with CBili3m greater than 2 g/dL and unfavorable liver survival (>90% of these ultimately underwent liver transplantation or died). Conversely, those with mild fibrosis and low α-SMA expression had normal CBili3m and favorable liver survival. Conclusion: Intense liver fibrogenesis is already established in many cases of BA at the time of KP. Fibrosis scores and intensity of α-SMA expression may be predictors of outcome after KP and may indicate those patients who might benefit from trials of potential antifibrotic agents early in the course of BA.

Lung transplantation for pulmonary fibrosis in dyskeratosis congenita: Case Report and systematic literature review

BackgroundDyskeratosis congenita (DC) is a progressive, multi-system, inherited disorder of telomere biology with high risks of morbidity and mortality from bone marrow failure, hematologic malignancy, solid tumors and pulmonary fibrosis. Hematopoietic stem cell transplantation (HSCT) can cure the bone marrow failure, but it does not eliminate the risks of other complications, for which life-long surveillance is required. Pulmonary fibrosis is a progressive and lethal complication of DC.Case presentationIn this report, we describe a patient with DC who developed pulmonary fibrosis seven years after HSCT for severe aplastic anemia, and was successfully treated with bilateral lung transplantation. We also performed a systematic literature review to understand the burden of pulmonary disease in patients with DC who did or did not receive an HSCT. Including our patient, we identified 49 DC patients with pulmonary disease (12 after HSCT and 37 without HSCT), and 509 with no reported pulmonary complications.ConclusionOur current case and literature review indicate that pulmonary morbidity is one of the major contributors to poor quality of life and reduced long-term survival in DC. We suggest that lung transplantation be considered for patients with DC who develop pulmonary fibrosis with no concurrent evidence of multi-organ failure.