In COPD patients, 26% had peripheral blood eosinophilia > 300/ul and the serology for HCMV was positive in 87.9%, similar to the control group (81.8%) and to previous reports in the general population of comparable age [30], We did not find significant relationship between HCMV+ serology and NK and NKG2C+ cells (p = 0.1 and 0.5 respectively). This evidence concerns the gene KLRC2 and chronic obstructive pulmonary disease.