Complex Compound Inheritance of Lethal Lung Developmental Disorders Due to Disruption of the TBX-FGF Pathway.

Primary defects in lung branching morphogenesis, resulting in neonatal lethal pulmonary hypoplasias, are incompletely understood. To elucidate the pathogenetics of human lung development, we studied a unique collection of samples obtained from deceased individuals with clinically and histopathologically diagnosed interstitial neonatal lung disorders: acinar dysplasia (n = 14), congenital alveolar dysplasia (n = 2), and other lethal lung hypoplasias (n = 10). We identified rare heterozygous copy-number variant deletions or single-nucleotide variants (SNVs) involving TBX4 (n = 8 and n = 2, respectively) or FGF10 (n = 2 and n = 2, respectively) in 16/26 (61%) individuals. In addition to TBX4, the overlapping ∼2 Mb recurrent and nonrecurrent deletions at 17q23.1q23.2 identified in seven individuals with lung hypoplasia also remove a lung-specific enhancer region. Individuals with coding variants involving either TBX4 or FGF10 also harbored at least one non-coding SNV in the predicted lung-specific enhancer region, which was absent in 13 control individuals with the overlapping deletions but without any structural lung anomalies. The occurrence of rare coding variants involving TBX4 or FGF10 with the putative hypomorphic non-coding SNVs implies a complex compound inheritance of these pulmonary hypoplasias. Moreover, they support the importance of TBX4-FGF10-FGFR2 epithelial-mesenchymal signaling in human lung organogenesis and help to explain the histopathological continuum observed in these rare lethal developmental disorders of the lung.

Rapidly fatal "congenital lung dysplasia": a case report and review of the literature.

Acinar dysplasia congenital alveolar dysplasia and alveolar capillary dysplasia with misalignment of pulmonary veins belong to the diffuse developmental disorders (congenital lung dysplasia), very rare fatal disorders of infancy that occur early in lung development. A case of quickly fatal congenital lung dysplasia in a full-term infant is presented and underlines the necessity to suspect this disease in a newborn suffering from severe and refractory respiratory distress.

Community-acquired pneumonia in children: what's old? What's new?

Community-acquired pneumonia (CAP) still remains a significant cause for childhood morbidity worldwide. Streptococcus pneumoniae is the most important causative agent at all ages. Respiratory syncytial virus is common in young children, and Mycoplasma pneumoniae in schoolchildren. Paediatric CAP is universally treated with antibiotics; amoxicillin is the drug of choice for presumably pneumococcal and a macrolide for presumably atypical bacterial cases. Because of globally increased resistances, macrolides are not safety for pneumococcal CAP. At present, available prospective research data on the epidemiology of paediatric CAP in western countries are from 1970s to 1980s; correspondingly, data on bacterial aetiology are mainly from 1980s to 1990s. Current concepts on pneumococcal aetiology are mostly based on poorly validated antibody assays. Most data on clinical characteristics in children's CAP, as well as on antibiotic treatment come from developing countries, thus not being directly applicable in western communities. Recent viral studies have revealed the role of rhinoviruses, metapneumovirus and bocavirus in the aetiology of paediatric CAP. This review critically summarizes the available data on epidemiology, aetiology, clinical presentation, treatment and outcome of CAP in children, with special focus on the newest microbial findings, the age and applicability of the data and the need of new studies.

Differentiation of bacterial and viral community-acquired pneumonia in children.

BACKGROUND: Microbe-specific diagnosis of pediatric community-acquired pneumonia (CAP) and the distinction between typical-bacterial, atypical-bacterial and viral cases are difficult. The aim of the present study was to evaluate the role of four serum non-specific inflammatory markers and their combinations, supplemented by chest radiological findings, in the screening of bacterial etiology of pediatric CAP. METHODS: Serum procalcitonin (PCT), serum C-reactive protein (CRP), blood erythrocyte sedimentation rate (ESR) and white blood cell (WBC) counts were determined in 101 children with CAP, all confirmed on chest radiograph. Evidence of etiology was achieved in 68 patients (67%) mainly using a serologic test panel including 15 pathogens. RESULTS: For the combination of CRP > 100 mg/L, WBC count > 15 x 10(9)/L, PCT > 1.0 ng/mL and ESR > 65 mm/h, the likelihood ratio for a positive test result (LR+) was 2.7 in the distinction between pneumococcal and viral CAP and 3.9 between atypical and viral CAP. If there was a higher value in one of these four parameters (CRP > 200 mg/L, WBC count > 22 x 10(9)/L, PCT > 18 ng/mL or ESR > 90 mm/h) LR+ changed to >or=3.4, which means a significant increase from pre-test to post-test disease probability. An alveolar radiological infiltration was associated with higher values in non-specific inflammatory markers when compared with interstitial infiltrates, but there were no significant associations between radiological and etiological findings. CONCLUSIONS: CRP, WBC count, PCT and ESR or their combinations have a limited role in screening between bacterial and viral pediatric CAP. If all or most of these markers are elevated, bacterial etiology is highly probable, but low values do not rule out bacterial etiology.

Transient hemi-diaphragmatic palsy following pleural empyema: a pediatric case report.

Phrenic nerve palsy generally is a jatrogenic damage of invasive neck and/or chest procedures in the pediatric age, but it does not represent a common complication of pleural empyema. One case of transient monolateral diaphragmatic paralysis following a decorticated pleural empyema is here reported. Common causes of the present disorder and its possible physiopathologic mechanisms are discussed, too.

Hyper- and hypoglycemia in children with community-acquired pneumonia.

Clinical conditions characterized by sufficient biological stress may be associated with hyperglycemia. The aim of the present study was to evaluate whether stress induced by community-acquired pneumonia (CAP) is associated with disturbances in glucose metabolism in children. Plasma glucose was measured in 108 children with CAP. The relationships between plasma glucose and clinical/laboratory characteristics of CAP were studied by multiple linear regression. The etiology of CAP was determined by serological methods. Plasma glucose level was 100.3 +/- 21.2 mg/dl (mean +/- SD). Only one patient developed hyperglycemia (167 mg/dl), and hypoglycemia (< 60 mg/dl) was present in four patients (3.7%). Plasma glucose had a significant association only with body temperature. Hyperglycemia was rare, about 1%, and the severity or etiology of CAP was not predictive for plasma glucose levels. However, about 4% of the patients had hypoglycemia, which could be explained by reduced calorie intake during acute infection or by the effect of stress-induced cytokines.

Prediction of delayed recovery from pediatric community-acquired pneumonia.

BACKGROUND: If children with community-acquired pneumonia (CAP) do not recover within 48 hours after starting antibiotic therapy, complications are possible and a checkup must be ensured.Aim of the present study was to evaluate the improvement of pediatric CAP, within 48 hours after starting therapy, in relation to age, etiology, clinical/laboratory characteristics and selected antibiotics. METHODS: Ninety-four children were treated for radiologically confirmed CAP, 64 by oral amoxicillin, 23 by intravenous ampicillin and 7 by other antibiotics. The etiology of CAP was studied by serology, data on more than 20 clinical characteristics were collected retrospectively, and antibiotics were selected on clinical grounds. RESULTS: After starting of antibiotics, the mean duration of fever was higher in children >or=5 than <2 or 2-4 years of age (p = 0.003). Fever continued >48 hours in 4 (4.3%) children and 2 additional children had empyema. Clinical, radiological and laboratory characteristics and serological findings were not significantly associated with the duration of fever. Fever continued >24 hours in 1 (4.8%) child treated with ampicillin and in 2 (8%) inpatients compared with 19 (28.8%) children treated with amoxicillin (p = 0.007) and 23 (33%) outpatients (p = 0.0012), respectively. CONCLUSIONS: Respiratory rate and erythrocyte sedimentation rates were associated with rapid decrease of fever. Anyway, none of the reported characteristics was able to predict treatment failures or delayed fever decrease in children suffering from CAP.

Serologically verified human bocavirus pneumonia in children.

WORKING HYPOTHESIS: Human bocavirus (HBoV) is a newly identified parvovirus frequently found in children suffering from acute respiratory and intestinal infections. The aim of the present study was to evaluate, by using a newly developed antibody assay, the role of HBoV in pediatric community-acquired pneumonia (CAP) and the seropositivity rate to HBoV in a prospective study in North-Italian children. MATERIALS/PATIENTS AND METHODS: During a 15-month study period, 124 children were admitted due to presumptive pneumonia, and in 101 of them, pneumonia was radiologically confirmed. The etiology of CAP was studied by antibody assays to 16 microbes, including the newly developed enzyme immunoassay for HBoV. RESULTS: Serological evidence of acute HBoV infection was found in 12 (12%) children, being single in 7 and mixed in 5 cases (4 with other viruses and 3 with bacteria). IgM was positive in 11 cases. A diagnostic rise in IgG antibodies between paired sera was observed in six cases. HBoV was the second most common virus next to respiratory syncytial virus (17%). The seropositivity rate to HBoV increased with age, reaching nearly 100% before school age. CONCLUSIONS: The present results show that HBoV is able to induce significant antibody responses and suggest that HBoV may be a fairly common cause of pneumonia in children. Seroconversion to HBoV in most children takes place in early childhood.