The cellular immunophenotype expression of influenza A virus and influenza B virus infection in children.

BACKGROUND: The innate immune response is the primary defense against influenza virus infection. METHODS: This is a prospective study carried out in children <18 years of age who were diagnosed with influenza A or influenza B infection. Demographic and clinical data, laboratory findings and cell immunophenotypes on first presentation were compared. RESULTS: With respect to immunophenotype, influenza A infection resulted in a higher fraction of CD14+ and CD4+IL-17A+cells compared to children infected with influenza B. By contrast, influenza B infection resulted in a comparatively higher percentage of double-negative CD4-CD8- lymphocyte subsets. Influenza A infection was associated with comparatively higher percentages of CD4+CD25highFoxp3+ and CD4+CD25lowFoxp3+ cells. By contrast, the percentage of CD8+CD25high and CD8+CD25low cells was similar among patients with influenza A infection and influenza B infection. CONCLUSIONS: An improved understanding of the fraction of regulatory T cells with influenza virus infections may provide further understandings on immune responses.

Comparative study of clinical and epidemiological characteristics of major pediatric adenovirus epidemics in southern Taiwan.

BACKGROUND: Human adenoviruses (HAdV) are important pathogens of pediatric respiratory tract infections in Taiwan. There were two major HAdV epidemics in southern Taiwan in 2011 and 2014, respectively. METHODS: The demographic, clinical characteristics, and risk factors for hospitalization of pediatric patients with HAdV infection in the two outbreaks were retrospectively compared. The epidemic was defined as > 7% HAdV detection rate for six consecutive weeks. HAdV infection was defined as positive HAdV isolates from respiratory tract specimens. HAdV genotype was determined by PCR-based hexon gene sequencing. RESULTS: A total of 1145 pediatric patients were identified (635 cases in 2011; 510 cases in 2014). HAdV genotype 3 and 7 contributed to both epidemics, although the proportion of HAdV3 decreased significantly (64.7% in 2011 to 25.5% in 2014, p < 0.001) and was replaced by other genotypes (type 1, 4, and 6) in the 2014 epidemic. Among the hospitalized patients, there were more patients hospitalized with bronchopneumonia/or pneumonia in the 2011 epidemic (10.6% vs 5.1%, p < 0.001), while more patients hospitalized with acute pharyngitis/pharyngoconjunctival fever (63.9% vs. 38.6%, p < 0.001) in the 2014 epidemic. In both epidemics, hospitalized patients had higher WBC and C-reactive protein (CRP) levels than non-hospitalized patients. Using multivariate regression analysis, underlying disease and elevated CRP levels were independent risk factors for hospitalization in both epidemics. CONCLUSION: There were significant differences in clinical, viral characteristics and risk factors of hospitalization between the 2011 and 2014 epidemics. Understanding changes in the epidemiological and clinical characteristics of HAdV epidemics is important from a public health perspective.

Immunophenotype expressions and cytokine profiles of influenza A H1N1 virus infection in pediatric patients in 2009.

BACKGROUND: A novel swine-origin influenza A H1N1 virus (S-OIV) caused human infection and acute respiratory illness in 2009, resulting in an influenza pandemic. OBJECTIVES: This study characterized the immune responses of S-OIV infection in pediatric patients at risk of pulmonary complications. METHODS: All enrolled pediatric patients were confirmed virologically for S-OIV infection in 2009-2010, prospectively. Changes in cellular immunophenotypes were analyzed using flow cytometry. Plasma cytokine levels associated with S-OIV infection by pulmonary and without pulmonary complications were measured using cytokine cytometric bead assay kits. RESULTS: A total of 85 patients with a mean age of 10.3 years were recruited. The level of C-reactive protein (CRP) was high in patients exhibiting pulmonary complications. The percentage of cellular immunophenotypes did not change between patients with and without pulmonary complications. The absolute numbers of peripheral blood mononuclear cells (PBMC), CD3, CD8, and CD16CD56 decreased with acute S-OIV pulmonary complications. Acute influenza infection with pulmonary complications was associated with high plasma concentrations of IL-1ß, IL-6, IL-12, and IFN-γ. CONCLUSION: Immunophenotype studies have reported variability in immune response to the severity of S-OIV infections. Acute phase cytokine profiles of the 2009 S-OIV infection might have contributed to the pathogenesis of the pulmonary complications.