Investigation of IRF7 gene mutation in people with severe influenza virüs infection

This study aimed to investigate the distribution of lymphocyte subgroups and the potential presence of underlying IRF7 gene mutation in adults with severe influenza infection. We included 32 patients who had influenza infection with respiratory failure hospitalized in the Internal Medicine Departments during the influenza season in this study. The median age of the patients was 67 (26-96) years, and 21 were women; 13 were followed up in the intensive care unit; five patients underwent invasive and 13 patients underwent non-invasive mechanical ventilation. Median hospitalization time was 11.5 (4-56) days and 3 patients died. The median leukocyte count was 7000 / ml (3200-26000) and the median lymphocyte count was 948 / ml (92-3078). Both T and B lymphocyte subsets of 16 patients were analyzed by flow cytometry. Two different polymorphisms were detected in 3 patients by IRF7 gene analysis by Sanger method; K179E (rs1061502) and H195L (rs139709725). The changes in T and B lymphocyte subgroups can be explained by influenza infection, but may also be due to underlying diseases. Advanced age and presence of comorbidities may predispose to severe influenza infection. No mutation was identified in the IRF7 gene known to be proning to susceptible to influenza virus infection in these patients.