Severe Features of Systemic Juvenile Idiopathic Arthritis in Patients With Congenital Heart Disease.

OBJECTIVE: To describe the clinical features of patients with congenital heart disease (CHD) who subsequently developed systemic juvenile idiopathic arthritis (sJIA). METHODS: We conducted a retrospective review of patients diagnosed with CHD and sJIA at our institution. Detailed clinical, laboratory, and radiographic data were collected from the medical record and reviewed with each patient's primary medical team. RESULTS: Five patients with sJIA and CHD were identified. Each child had a unique cardiac anatomy, but all the patients required surgical repair during the first year of life. Four children had thymectomies at the time of cardiac surgery. Classic signs of sJIA such as fever (n = 5), rash (n = 5), and arthritis (n = 4) developed after surgical intervention in all the patients. The individuals in this cohort displayed risk factors associated with severe sJIA, including disease onset before 2 years of age (n = 5), elevated interleukin 18 levels (n = 5), baseline eosinophilia prior to initiation of biologic disease-modifying antirheumatic drugs (n = 4), and positivity for HLA-DRB1*15:01 alleles (n = 4). Macrophage activation syndrome (MAS) occurred in 3 patients and sJIA-associated lung disease (sJIA-LD) was identified in 4 patients. Two children died from complications of their cardiac and/or pulmonary disease. CONCLUSION: We identified an association between CHD and severe forms of sJIA. Although these findings will need to be confirmed in larger, multicenter cohorts, the results highlight the importance of considering a diagnosis of sJIA in children with CHD and remaining vigilant for complications such as MAS and sJIA-LD.

A homozygous stop-gain variant in ARHGAP42 is associated with childhood interstitial lung disease, systemic hypertension, and immunological findings.

ARHGAP42 encodes Rho GTPase activating protein 42 that belongs to a member of the GTPase Regulator Associated with Focal Adhesion Kinase (GRAF) family. ARHGAP42 is involved in blood pressure control by regulating vascular tone. Despite these findings, disorders of human variants in the coding part of ARHGAP42 have not been reported. Here, we describe an 8-year-old girl with childhood interstitial lung disease (chILD), systemic hypertension, and immunological findings who carries a homozygous stop-gain variant (c.469G>T, p.(Glu157Ter)) in the ARHGAP42 gene. The family history is notable for both parents with hypertension. Histopathological examination of the proband lung biopsy showed increased mural smooth muscle in small airways and alveolar septa, and concentric medial hypertrophy in pulmonary arteries. ARHGAP42 stop-gain variant in the proband leads to exon 5 skipping, and reduced ARHGAP42 levels, which was associated with enhanced RhoA and Cdc42 expression. This is the first report linking a homozygous stop-gain variant in ARHGAP42 with a chILD disorder, systemic hypertension, and immunological findings in human patient. Evidence of smooth muscle hypertrophy on lung biopsy and an increase in RhoA/ROCK signaling in patient cells suggests the potential mechanistic link between ARHGAP42 deficiency and the development of chILD disorder.

Emergent high fatality lung disease in systemic juvenile arthritis.

OBJECTIVE: To investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA). METHODS: In a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data. RESULTS: LD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features. CONCLUSIONS: A rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.

Pediatric Hemoptysis without Bronchiectasis or Cardiac Disease: Etiology, Recurrence, and Mortality.

OBJECTIVES: To describe the etiologies of hemoptysis in patients without pre-existing bronchiectasis or cardiac disease; to assess odds of recurrent hemoptysis by diagnostic category; and to assess odds of mortality by diagnostic category. STUDY DESIGN: This retrospective case series included all patients with hemoptysis documented during an admission to Boston Children's Hospital from January 1, 2007 to June 1, 2017. Patients with bronchiectasis, congenital heart disease, primary pulmonary hypertension, bleeding above the glottis, hemoptysis before 38 weeks of corrected gestational age, hematemesis, foreign body, and trauma were excluded. Patients were also characterized by coagulation status. Primary outcomes were recurrent hemoptysis and death. Univariate analysis was performed to determine ORs for recurrence and death per diagnostic category with infection as the reference category. RESULTS: In total, 257 patients met study criteria and were analyzed. The most common causes of hemoptysis were infection (n = 122), neoplasm (n = 58), and other diagnoses (n = 49). Of the patients with infection, recurrence was 28% and all-cause mortality was 12%. Neoplasm had lower odds of recurrence (OR 0.3, P = .012) but higher odds of mortality (OR 15.8, P < .001). Thrombocytopenia had lower odds of recurrence (OR 0.2, P = .005) but higher odds of mortality (OR 5.9, P < .001). Patients with a tracheostomy had higher odds of recurrence (OR 6.3, P < .001), but lower odds of death (OR 0.4, P = .042). CONCLUSIONS: This study confirms that infection is the most common cause of hemoptysis in patients without severe underlying pulmonary or cardiac disease. Hemoptysis associated with neoplasm and/or thrombocytopenia confers mortality risk. Tracheostomy confers risk of recurrence. Future prospective research on diagnoses associated with hemoptysis is warranted.

Genotype-phenotype correlations for infants and children with ABCA3 deficiency.

RATIONALE: Recessive mutations in the ATP-binding cassette transporter A3 (ABCA3) cause lethal neonatal respiratory failure and childhood interstitial lung disease. Most ABCA3 mutations are private. OBJECTIVES: To determine genotype-phenotype correlations for recessive ABCA3 mutations. METHODS: We reviewed all published and unpublished ABCA3 sequence and phenotype data from our prospective genetic studies of symptomatic infants and children at Washington and Johns Hopkins Universities. Mutations were classified based on their predicted disruption of protein function: frameshift and nonsense mutations were classified as "null," whereas missense, predicted splice site mutations, and insertion/deletions were classified as "other." We compared age of presentation and outcomes for the three genotypes: null/null, null/other, and other/other. MEASUREMENTS AND MAIN RESULTS: We identified 185 infants and children with homozygous or compound heterozygous ABCA3 mutations and lung disease. All of the null/null infants presented with respiratory failure at birth compared with 75% of infants with null/other or other/other genotypes (P = 0.00011). By 1 year of age, all of the null/null infants had died or undergone lung transplantation compared with 62% of the null/other and other/other children (P < 0.0001). CONCLUSIONS: Genotype-phenotype correlations exist for homozygous or compound heterozygous mutations in ABCA3. Frameshift or nonsense ABCA3 mutations are predictive of neonatal presentation and poor outcome, whereas missense, splice site, and insertion/deletions are less reliably associated with age of presentation and prognosis. Counseling and clinical decision making should acknowledge these correlations.

Approach to the patient with Childhood Interstitial and Diffuse Lung Disease.

Childhood Interstitial and Diffuse Lung Disease (chILD) encompasses a group of rare, chronic lung disorders in infants and children with overlapping clinical features but diverse etiologies. The clinical presentation of chILD is of chronic or recurring respiratory signs and symptoms, often including increased work of breathing and hypoxia, with diffuse radiographic abnormalities on chest imaging. Recognition can be challenging since some clinical features overlap with those of more common pediatric respiratory diseases including asthma and recurrent viral infections, among others. chILD should be considered as an underlying diagnosis when a patient's respiratory symptoms seem disproportionate to the clinical scenario and/or persist. The diagnostic process involves multiple steps and is tailored to the individual patient. Nearly all children will undergo imaging and pulmonary function testing, many will undergo bronchoscopy with bronchoalveolar lavage, many will receive genetic testing, and some will require lung biopsy. Treatment includes preventive care, evaluation for comorbidities, pharmacotherapy according to diagnosis, and ongoing disease surveillance, including revisiting genetic and histopathologic results as new clinical information becomes available and as our understanding of these rare disorders improves. The purpose of this review is to provide a broad approach to the diagnosis and management of patients with chILD.

An intronic variant in TBX4 in a single family with variable and severe pulmonary manifestations.

A male infant presented at term with neonatal respiratory failure and pulmonary hypertension. His respiratory symptoms improved initially, but he exhibited a biphasic clinical course, re-presenting at 15 months of age with tachypnea, interstitial lung disease, and progressive pulmonary hypertension. We identified an intronic TBX4 gene variant in close proximity to the canonical donor splice site of exon 3 (hg 19; chr17:59543302; c.401 + 3 A > T), also carried by his father who had a typical TBX4-associated skeletal phenotype and mild pulmonary hypertension, and by his deceased sister who died shortly after birth of acinar dysplasia. Analysis of patient-derived cells demonstrated a significant reduction in TBX4 expression resulting from this intronic variant. Our study illustrates the variable expressivity in cardiopulmonary phenotype conferred by TBX4 mutation and the utility of genetic diagnostics in enabling accurate identification and classification of more subtly affected family members.

Development of a Screening Algorithm for Lung Disease in Systemic Juvenile Idiopathic Arthritis.

OBJECTIVE: Lung disease (LD) is an increasingly recognized complication of systemic juvenile idiopathic arthritis (sJIA). As there are no currently available guidelines for pulmonary screening in sJIA, we sought to develop such an algorithm at our institution. METHODS: A multidisciplinary workgroup was convened, including members representing rheumatology, pulmonary, stem cell transplantation, and patient families. The workgroup leaders drafted an initial algorithm based on published literature and experience at our center. A modified Delphi approach was used to achieve agreement through three rounds of anonymous, asynchronous voting and a consensus meeting. Statements approved by the workgroup were rated as appropriate with moderate or high levels of consensus. These statements were organized into the final approved screening algorithm for LD in sJIA. RESULTS: The workgroup ultimately rated 20 statements as appropriate with a moderate or high level of consensus. The approved algorithm recommends pulmonary screening for newly diagnosed patients with sJIA with clinical features that the workgroup agreed may confer increased risk for LD. These "red flag features" include baseline characteristics (young age of sJIA onset, human leukocyte antigen type, trisomy 21), high disease activity (macrophage activation syndrome [MAS], sJIA-related ICU admission, elevated MAS biomarkers), respiratory symptoms or abnormal pulmonary examination findings, and features of drug hypersensitivity-like reactions (eosinophilia, atypical rash, anaphylaxis). The workgroup achieved consensus on the recommended pulmonary work-up and monitoring guidelines. CONCLUSION: We developed a pulmonary screening algorithm for sJIA-LD through a multidisciplinary consensus-building process, which will be revised as our understanding of sJIA-LD continues to evolve.

The US national registry for childhood interstitial and diffuse lung disease: Report of study design and initial enrollment cohort.

INTRODUCTION: Childhood interstitial and diffuse lung disease (chILD) encompasses a broad spectrum of rare disorders. The Children's Interstitial and Diffuse Lung Disease Research Network (chILDRN) established a prospective registry to advance knowledge regarding etiology, phenotype, natural history, and management of these disorders. METHODS: This longitudinal, observational, multicenter registry utilizes single-IRB reliance agreements, with participation from 25 chILDRN centers across the U.S. Clinical data are collected and managed using the Research Electronic Data Capture (REDCap) electronic data platform. RESULTS: We report the study design and selected elements of the initial Registry enrollment cohort, which includes 683 subjects with a broad range of chILD diagnoses. The most common diagnosis reported was neuroendocrine cell hyperplasia of infancy, with 155 (23%) subjects. Components of underlying disease biology were identified by enrolling sites, with cohorts of interstitial fibrosis, immune dysregulation, and airway disease being most commonly reported. Prominent morbidities affecting enrolled children included home supplemental oxygen use (63%) and failure to thrive (46%). CONCLUSION: This Registry is the largest longitudinal chILD cohort in the United States to date, providing a powerful framework for collaborating centers committed to improving the understanding and treatment of these rare disorders.

Incidence and Risk Factors for Eosinophilia and Lung Disease in Biologic-Exposed Children With Systemic Juvenile Idiopathic Arthritis.

OBJECTIVE: Although interleukin-1 (IL-1)/IL-6 inhibitors are effective therapies for systemic juvenile idiopathic arthritis (JIA), some patients develop eosinophilia and lung disease during treatment. This study was undertaken to retrospectively evaluate incidence and risk factors for eosinophilia and describe lung disease outcomes in IL-1/IL-6 inhibitor-exposed patients with systemic JIA. METHODS: Among JIA patients at our institution exposed to interleukin-1 (IL-1)/IL-6 inhibitors (1995-2022), we compared incidence rate of eosinophilia in systemic JIA compared to other JIA, stratified by medication class (IL-1/IL-6 inhibitors, other cytokine inhibitors, methotrexate). We used Cox models to identify predictors of eosinophilia during IL-1/IL-6 inhibitor use and summarized treatment changes and outcomes after eosinophilia, including lung disease. HLA typing was performed on a clinical or research basis. RESULTS: There were 264 new medication exposures in 75 patients with systemic JIA and 41 patients with other JIA. A total of 49% of patients with systemic JIA with HLA typing (n = 45) were positive for HLA-DRB1*15 alleles. Eosinophilia was common during IL-1/IL-6 inhibitor use and did not differ by systemic JIA compared to other JIA (0.08 and 0.07 per person-year, respectively; P = 0.30). Among systemic JIA patients, pretreatment macrophage activation syndrome (MAS) was associated with a higher rate of subsequent eosinophilia on biologic therapy (unadjusted hazard ratio 3.2 [95% confidence interval 1.2-8.3]). A total of 4 of 5 patients who switched therapy within 10 weeks of eosinophilia experienced disease flare compared to none of the patients who continued the original therapy. A total of 8 of 25 patients with pulmonary evaluations had lung disease, and all had severe manifestations of systemic JIA (MAS, intensive care unit stay). One death was attributed to systemic JIA-lung disease. CONCLUSION: Eosinophilia is common in JIA patients using IL-1/IL-6 inhibitors. Severe disease may be associated with eosinophilia and lung disease in systemic JIA.

Nonsurgical management of dynamic pneumatocele via endobronchial administration of fibrin sealant.

A 12-year-old male was admitted to the Medical Intensive Care Unit for respiratory failure requiring temporary tracheostomy secondary to an extensive necrotizing methicillin-resistant Staphylococcus aureus pneumonia. Imaging revealed destructive bronchiectasis and multifocal lung abscesses, more advanced in the right lung. He was discharged home after 42-day hospital admission. 3.5 months after his discharge, he re-presented to the Emergency Department with a large right pneumothorax and a pneumatocele measuring 10.2 × 6.2 cm2 . He was admitted to the hospital and while his pneumothorax resolved in 2 days, the size of the pneumatocele was noted to fluctuate with different phases of respiration. A computed tomography scan of the chest demonstrated a fistula between the pneumatocele and right upper lobe bronchus. Following discussion between Pulmonary medicine and Interventional radiology, transbronchial closure of the air leak was planned. Intubation was done with a dual-lumen endotracheal tube. Bronchography was performed using a diagnostic catheter. A large air leak was noted from the anterior segment of the right upper lobe bronchus. Embolization of the fistula was performed using n-butyl cyanoacrylate (nBCA, glue) injected through a second catheter under fluoroscopic guidance. The residual pneumatocele slowly resolved over 2 months. Endobronchial embolization has been described in the literature as a treatment strategy for air leaks, largely in adult patients. Endobronchial embolization of large pneumatoceles and bronchopleural fistulas may offer an alternative treatment option with less morbidity than the classic surgical approach.

Pulmonary manifestations of immune dysregulation in CTLA-4 haploinsufficiency and LRBA deficiency.

OBJECTIVE: The primary immunodeficiency syndromes of cytotoxic T lymphocyte-associated protein 4 (CTLA-4) haploinsufficiency and lipopolysaccharide-responsive and beige-like anchor protein (LRBA) deficiency present with multisystem immune dysregulation. The aim of this study was to characterize and compare the pulmonary manifestations of these two diseases. METHODS: We retrospectively analyzed the pulmonary clinical, radiologic, and histopathologic characteristics of six patients with CTLA-4 haploinsufficiency and four patients with LRBA deficiency with pulmonary involvement followed at a large tertiary care center. RESULTS: Chronic respiratory symptoms were more frequent in patients with LRBA deficiency versus CTLA-4 haploinsufficiency (3/4 vs. 1/6). Cough was the most common respiratory symptom. Abnormalities in pulmonary exam and pulmonary function testing were more frequent in LRBA deficiency (4/4, 2/4) compared to CTLA-4 haploinsufficiency (1/6, 2/6). Chest computed tomography (CT) findings included mediastinal lymphadenopathy (4/4 in LRBA deficiency vs. 1/4 in CTLA-4 haploinsufficiency), pulmonary nodules (4/4, 3/4), ground-glass opacification (4/4, 3/4), and bronchiectasis (3/4, 1/4). Lymphocytic inflammation, concentrated bronchovasculocentrically and paraseptally, was the predominant pathologic finding and was observed in all patients who had lung biopsies (N = 3 with LRBA deficiency; N = 3 with CTLA-4 haploinsufficiency). CONCLUSION: Despite phenotypic overlap amongst these diseases, LRBA deficiency demonstrated greater severity of pulmonary disease, indicated by respiratory symptoms, pulmonary exam, and intrathoracic radiologic findings. Chest CT was the most sensitive indicator of pulmonary involvement in both disorders. Lymphocytic inflammation is the key histologic feature of both disorders. Pediatric pulmonologists should consider these disorders of immune dysregulation in the relevant clinical context to provide earlier diagnosis, comprehensive pulmonary evaluation and treatment.

Swine-origin influenza a (H1N1) viral infection in children: initial chest radiographic findings.

PURPOSE: To evaluate initial chest radiographic findings of swine-origin influenza A (S-OIV) (also known as H1N1) viral infection in children. MATERIALS AND METHODS: This was an institutional review board-approved, HIPAA-compliant retrospective study of 108 patients who had microbiologically confirmed S-OIV infection and available initial chest radiographs obtained between April 2009 and October 2009. The final study group was divided on the basis of clinical course (group 1, outpatients without hospitalization [n = 72]; group 2, inpatients with brief hospitalization [n = 22]; group 3, inpatients with intensive care unit admission [n = 14]). Two pediatric radiologists blinded to patient group and lung parenchymal, airway, pleural, hilar, and mediastinal abnormalities systematically reviewed initial chest radiographs. Lung parenchyma and airways were evaluated for pattern (peribronchial markings, consolidation, and ground-glass, nodular, and reticular opacity), distribution, and extent of abnormalities. Radiographs were assessed for presence of pleural effusions or lymphadenopathy. Medical records were reviewed for underlying medical conditions and patient outcomes. Association between frequency of underlying medical conditions and clinical course of S-OIV infection among study groups was evaluated with the Pearson chi(2) test. RESULTS: The frequency of normal chest radiographs was significantly higher in group 1 (n = 48) than in groups 2 (n = 1) and 3 (n = 0) (P < .001, Pearson chi(2) test). Among patients with abnormal radiographs, the most common finding in group 1 was prominent peribronchial markings with hyperinflation (n = 17), whereas the most common findings in groups 2 (n = 12) and 3 (n = 12) were bilateral, symmetric, and multifocal areas of consolidation, often associated with ground-glass opacities. Nodular opacities, reticular opacities, pleural effusion, or lymphadenopathy were not observed in any patient. An increased frequency of underlying medical conditions was observed in patients with greater severity of illness due to S-OIV infection (group 3, 71%; group 2, 59%; group 1, 31%) (P = .003, Pearson chi(2) test). All 84 patients with available follow-up information have fully recuperated from S-OIV infection. CONCLUSION: Initial chest radiographs in children with a mild and self-limited clinical course of S-OIV infection are often normal, but they may demonstrate prominent peribronchial markings with hyperinflation. Bilateral, symmetric, and multifocal areas of consolidation, often associated with ground-glass opacities, are the predominant radiographic findings in pediatric patients with a more severe clinical course of S-OIV infection. (c) RSNA, 2009.

Overview of the ChILD Research Network: A roadmap for progress and success in defining rare diseases.

Children's interstitial and diffuse lung diseases are a diverse group of rare lung disorders that present in childhood with diffuse pulmonary infiltrates and respiratory signs and symptoms. Children with these disorders face high morbidity and mortality and their families must cope with overwhelming uncertainty. Physicians caring for these patients are challenged by a paucity of directed therapies, or even understanding of natural history. Through the establishment of the Children's Interstitial Lung Disease Foundation Research Network and the Children's Interstitial Lung Disease Foundation significant progress has been made through collaboration and research. This review outlines the past and current successes in the new and rapidly growing field of Children's Interstitial and Diffuse Lung Disease.

Neuroendocrine Cell Hyperplasia of Infancy. Clinical Score and Comorbidities.

Rationale: Neuroendocrine cell hyperplasia of infancy (NEHI) is an important form of children's interstitial and diffuse lung disease for which the diagnostic strategy has evolved. The prevalence of comorbidities in NEHI that may influence treatment has not been previously assessed.Objectives: To evaluate a previously unpublished NEHI clinical score for assistance in diagnosis of NEHI and to assess comorbidities in NEHI.Methods: We performed a retrospective chart review of 199 deidentified patients with NEHI from 11 centers. Data were collected in a centralized Research Electronic Data Capture registry and we performed descriptive statistics.Results: The majority of patients with NEHI were male (66%). The sensitivity of the NEHI Clinical Score was 87% (95% confidence interval [CI], 0.82-0.91) for all patients from included centers and 93% (95% CI, 0.86-0.97) for those with complete scores (e.g., no missing data). Findings were similar when we limited the population to the 75 patients diagnosed by lung biopsy (87%; 95% CI, 0.77-0.93). Of those patients evaluated for comorbidities, 51% had gastroesophageal reflux, 35% had aspiration or were at risk for aspiration, and 17% had evidence of immune system abnormalities.Conclusions: The NEHI Clinical Score is a sensitive tool for clinically evaluating NEHI; however, its specificity has not yet been addressed. Clinicians should consider evaluating patients with NEHI for comorbidities, including gastroesophageal reflux, aspiration, and immune system abnormalities, because these can contribute to the child's clinical picture and may influence clinical course and treatment.

Pulmonary hemorrhage in infancy: A 10-year single-center experience.

AIM: Pulmonary hemorrhage in infancy is rare, with challenges in determining its incidence, causes, and outcomes across diverse groups. Our aim was to better understand the incidence and identified causes. We further analyzed the subgroup of patients meeting criteria for acute idiopathic pulmonary hemorrhage of infancy (AIPHI) to determine recurrence, mortality, and treatment. METHODS: We performed a 10-year retrospective cohort study of infants with pulmonary hemorrhage in a large tertiary care center. One-hundred fifty-seven patients overall were identified. RESULTS: The most common diagnoses in infants with pulmonary hemorrhage were congenital heart disease (36.6%), prematurity/premature lung disease (34.6%), congenital or acquired lung disorders (15.0%), and congenital or acquired coagulopathies (13.7%). Nonaccidental trauma (NAT; n = 3) was also an important cause of pulmonary hemorrhage. All patients diagnosed with NAT had normal retinal examinations and skeletal surveys. Only four patients were identified with AIPHI. There was no mortality in this group of infants. One of four patients with AIPHI had a recurrence. Steroids were the consistent treatment for AIPHI, with a large range of treatment duration. CONCLUSION: Diagnostic studies should focus on identifying non-pulmonary sources of bleeding, infection, underlying lung disease, congenital heart defects, coagulopathies, infection, and NAT, as these were the most frequently identified causes of bleeding. NAT is not adequately identified with ophthalmology exam and skeletal survey. Overall, we found AIPHI to be a rare diagnosis. All of the patients with idiopathic hemorrhage received systemic steroids with varying doses and lengths of treatment.

Current Update on Interstitial Lung Disease of Infancy: New Classification System, Diagnostic Evaluation, Imaging Algorithms, Imaging Findings, and Prognosis.

Childhood interstitial lung disease represents a rare and heterogeneous group of diseases that can result in significant morbidity and mortality, some leading to death during infancy. CT is the imaging test of choice. Although many CT findings are nonspecific and a definitive diagnosis usually cannot be reached by CT alone, the interpreting radiologist is instrumental in defining disease extent and refining the diagnosis. Chest CTs are of key importance in guiding site selection for lung biopsy and for following disease progression and response to treatment. Thus, from the radiologist's perspective, ensuring maximal quality of CT imaging and interpretation is paramount.

Pancreatic lineage analysis using a retroviral vector in embryonic mice demonstrates a common progenitor for endocrine and exocrine cells.

The origin of pancreatic endocrine cells is unknown. Some studies have suggested that there is a common pancreatic progenitor which gives rise to both endocrine and exocrine cells, while others have suggested separate endocrine and exocrine lineages. Previous conclusions have been based on indirect data, such as the co-expression of molecular markers. We directly assessed the relationship between endocrine and exocrine cells during development using a lineage tracer. A replication-incompetent retrovirus was used to introduce the reporter gene alkaline phosphatase into single cells in explants of mouse embryonic pancreas. After a week in culture, the subsequent fate of the infected cells could then be determined. The results show that a common pancreatic progenitor cell exists, which gives rise to both endocrine and exocrine cells.