Cytokine profiles of suction pulmonary secretions from children infected with pandemic influenza A(H1N1) 2009

Excerpt

Uncomplicated influenza in humans is characterized by massive virus replication in respiratory epithelial cells, inflammation and an abrupt onset. The novel influenza A (H1N1) 2009 caused an epidemic of critical illness and some patients rapidly developed severe acute respiratory distress syndrome [1, 2]. Van Reeth [3] reviewed growing evidence that the so-called early cytokines produced at the site of infection mediate many of the clinical and pathological manifestations of influenza infection. Of those cytokines, Bermejo-Martin and colleagues [4] reported in Critical Care that T-helper 1 (Th1) and Th17 hypercytokinemia plays an important role as an early host response in severe pandemic influenza. Evaluating the differences in early immune responses between hospitalized patients with severe pandemic influenza and those with mild disease, high systemic levels of IFN-γ and a group of mediators involved in the development of the Th17 (IL-8, IL-9, IL-17, IL-6) and Th1 (TNF-α, IL-15, IL-12p70) responses were found exclusively in hospitalized patients. A significant inverse association was found between IL-6 and IL-8 and PaO₂ in critical patients. They concluded that severe disease with respiratory involvement is characterized by early secretion of Th17 and Th1 cytokines. …