CD4+/CD8+ T lymphocytes imbalance in children with severe 2009 pandemic influenza A (H1N1) pneumonia.

PURPOSE: This study was conducted to investigate the immune responses of children with moderate and severe novel influenza A virus (H1N1) pneumonia, and to compare their clinical and immunological findings with those of control subjects. METHODS: Thirty-two admitted patients with H1N1 pneumonia were enrolled in the study. The clinical profiles, humoral and cell-mediated immune responses of the 16 H1N1 pneumonia patients who were admitted to the pediatric intensive care unit (severe pneumonia group), 16 H1N1 pneumonia patients admitted to the pediatric general ward (moderate pneumonia group) and 13 control subjects (control group) were measured. RESULTS: Total lymphocyte counts were significantly lower in patients with H1N1 pneumonia than in the control group (P=0.02). The number of CD4+ T lymphocytes was significantly lower in the severe pneumonia group (411.5±253.5/µL) than in the moderate pneumonia (644.9±291.1/µL, P=0.04) and control (902.5±461.2/µL, P=0.01) groups. However, the number of CD8+ T lymphocytes was significantly higher in the severe pneumonia group (684.2±420.8/µL) than in the moderate pneumonia (319.7±176.6/µL, P=0.02) and control (407.2±309.3/µL, P=0.03) groups. The CD4+/CD8+ T lymphocytes ratio was significantly lower in the severe pneumonia group (0.86±0.24) than in the moderate pneumonia (1.57±0.41, P=0.01) and control (1.61±0.49, P=0.01) groups. The serum levels of IgG, IgM and IgE were significantly higher in the severe pneumonia group than in the 2 other groups. CONCLUSION: The results of this study suggest that increased humoral immune responses and the differences in the CD4+ and CD8+ T lymphocyte profiles, and imbalance of their ratios may be related to the severity of H1N1 pneumonia in children.

Relationships of methacholine and adenosine monophosphate responsiveness with serum vascular endothelial growth factor in children with asthma.

BACKGROUND: Airway hyperresponsiveness, which is a characteristic feature of asthma, is usually measured by means of bronchial challenge with direct or indirect stimuli. Vascular endothelial growth factor (VEGF) increases vascular permeability and angiogenesis, leads to mucosal edema, narrows the airway diameter, and reduces airway flow. OBJECTIVE: To examine the relationships between serum VEGF level and airway responsiveness to methacholine and adenosine monophosphate (AMP) in children with asthma. METHODS: Peripheral blood eosinophil counts, serum eosinophil cationic protein (ECP) concentrations, and serum VEGF concentrations were measured in 31 asthmatic children and 26 control subjects. Methacholine and AMP bronchial challenges were performed on children with asthma. RESULTS: Children with asthma had a significantly higher mean (SD) level of VEGF than controls (361.2 [212.0] vs 102.7 [50.0] pg/mL; P < .001). Blood eosinophil counts and serum ECP levels significantly correlated inversely with AMP provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20% (PC20) (r = -0.474, P =.01; r = -0.442, P =.03, respectively), but not with methacholine PC20 (r = -0.228, P = .26; r = -0.338, P =.10, respectively). Serum VEGF levels significantly correlated with airway responsiveness to AMP (r = -0.462; P = .009) but not to methacholine (r = -0.243; P = .19). CONCLUSIONS: Serum VEGF levels were increased in children with asthma and were related to airway responsiveness to AMP but not to methacholine. Increased VEGF levels in asthmatic children may result in increased airway responsiveness by mechanisms related to airway inflammation or increased permeability of airway vasculature.

Isolated pulmonary cryptococcosis in an immunocompetent boy.

Pulmonary cryptococcosis is rare in immunocompetent subjects. Here, we present the case of a 16-year-old boy who was referred to our pediatric department for the management of multiple consolidations detected on chest radiography, which was routinely performed when the patient was being evaluated for an ankle fracture. Fine needle aspiration biopsy was performed, and the definitive diagnosis was established as cryptococcal pneumonia. After 8 weeks of antifungal treatment, the pulmonary nodules on the chest radiographs disappeared.