High Correlations of Anti-CMV Titers with Lymphocyte Activation Status and CD57 Antibody-Binding Capacity as Estimated with Three-Color, Quantitative Flow Cytometry in Blood Donors

Abstract

Blood samples of 58 blood donors (ages 19-64 years, 31 males and 27 females) were investigated with three-color, quantitative flow cytometry. IgG anticytomegalovirus (CMV) was estimated with ELISA. Nineteen men and 21 women were found CMV-seropositive. The seropositive individuals (CMV-pos) compared to the seronegative ones (CMV-neg) presented no significant changes in the absolute number of lymphocytes or in the main lymphocyte subpopulations identified by CD20, CD3, CD4, and CD8. Nevertheless, CMV-pos showed significantly higher numbers of lymphocytes with the following phenotypes: CD4 +HLA-DR +, CD8 +HLA-DR +, CDS +CD45RA +CD45RO +, and CD20 +CD5 +. The CD3 +CD57 + subset of T lymphocytes was also significantly higher in CMV-pos ( P < 0.0001), whereas the CD57 +CD16& CD56 +CD3 - NKC subset presented similar values in both groups. Higher values for the antibody-binding capacity of lymphocytes CD38 ( P < 0.05) and CD45 ( P = 0.02) antigens and of CD57 antigen on CD3 + lymphocytes ( P < 0.0005) were found in the CMV-pos group. These results show that CMV upregulates the number of CD57 molecules on CD3 + and not on CD3 - lymphocytes and suggest that the CD3 molecule or other molecules specifically present in T cells can play a role in CMV latency. The study also showed that CMV plays a major role in the maintenance of a fraction of lymphocyte in the activated state.