OBJECTIVETo investigate the characters and changes of peripheral white blood cells and lymphocyte subsets of patients with influenza B virus infection and to provide evidences for diagnosis, treatment and prognosis of influenza B virus infection.

METHODSPeripheral white blood cell parameters and the percentages of lymphocyte subsets in acute and recovery phases of 47 cases of influenza B virus infection patients(32 mild cases and 15 severe cases)were investigated and analyzed,and compared respectively with those of 38 cases of healthy people using whole blood cell analysis and flow cytometry.

RESULTSPeripheral white blood cell counts of mild cases decreased greatly but peripheral white blood cell counts and the neutrophils of severe cases increased significantly in acute phase; the peripheral lymphocytes, CD3, CD4, CD8 and CD19 of all patients with influenza B virus infection decreased greatly in acute phase and quickly recovered in recovery phase;there were similar characteristics of change in NK cells between patients with influenza B virus and healthy people. NK cells absolute counts of severe cases decreased significantly in acute phase.

CONCLUSIONPeripheral white blood cell counts and the neutrophils of increased significantly in acute phase and the great decrease of NK cells absolute counts of patients with influenza B virus infection may suggest the severe tendency of diseases.