Correlation between serum interleukin 6 and C-reactive protein concentrations in patients with adenoviral respiratory infection

Objective. To characterize adenoviral respiratory infection, we evaluated clinical features, laboratory findings and serum cytokine concentrations in patients with adenoviral infection and compared them with those in patients with influenza virus and respiratory syncytial virus (RSV) infections. Methods. We enrolled 106 patients who had been diagnosed with acute viral respiratory infection caused by adeno-, influenza and respiratory syncytial viruses from January, 1995, through December, 1998. Forty-nine patients had adenovirus infection, 19 patients had influenza virus infection and 38 patients had RSV infection. Etiologic diagnosis was made based on the antigen detection by enzyme immunoassay (influenza virus, RSV), and viral isolation was done by tissue culture (adenovirus, influenza virus) from nasopharyngeal specimens. We evaluated clinical manifestations, laboratory findings (white blood cell count, C-reactive protein, erythrocyte sedimentation rate) and serum cytokine [interleukin (IL)-1-beta, IL-6, IL-8, interferon gamma and tumor necrosis factor alpha] concentrations. Results. We observed prolonged fever, strong inflammatory response such as leukocytosis with neutrophilia and high C-reactive protein values in patients with adenoviral respiratory infection compared with those in patients with influenza virus and RSV infections. Serum IL-6 concentrations in patients with adenoviral respiratory infection were higher than those in patients with influenza virus and RSV infections. Other cytokine (IL-1-beta, IL-2, interferon gamma and tumor necrosis factor alpha) values did not differ among adenovirus, influenza virus and RSV infections. Conclusions. Patients with adenoviral respiratory infection have high grade and prolonged fever, strong inflammatory response and higher serum IL-6 than in influenza and RSV infection.