Differences in serum cytokine levels between influenza virus A and B infections in children.

OBJECTIVE

To investigate differences in cytokine production between influenza A and B.

MATERIALS AND METHODS

thirty one patients with influenza A and 16 with influenza B were enrolled in this study. We measured soluble tumor necrosis factor receptor (sTNFR) 1, interleukin (IL)-6, interferon (IFN)-gamma and IL-4 concentrations in serum obtained from all patients during the acute and convalescence phases of their illnesses.

RESULTS

the sTNFR1 and IL-6 serum concentrations of patients with influenza A and B were equivalently elevated in the acute phase of their illness. However, the acute phase concentrations of IFN-gamma and IL-4 were significantly higher in patients with influenza A than in patients with influenza B. The concentration of all cytokines in influenza A and sTNFR1 in influenza B significantly decreased from the acute to convalescent phase. Plotted from the onset of symptoms it appeared that all of the cytokines peaked within 24h after onset.

DISCUSSION

the production pattern of the inflammatory cytokines - TNF and IL-6 - were the same between influenza A and B. However, a Th2 predominant cytokine pattern was induced after natural influenza virus A infection, notably IL-4 that differed from that to influenza B.