Increase in percentage of CD45RO⁺/CD8⁺ cells is associated with previous severe primary HIV infection

The purpose of the study was to examine how memory (CD45RO) and naive (CD45RA) phenotypes of CD4⁺ and CD8⁺ T-cell subpopulations changed with respect to progression and duration of human immunodeficiency virus (HIV) infection. Forty-three HIV-seropositive (HIV+) subjects with known time for seroconversion were included in this cross-sectional study. They were divided into the following groups for comparison: persons with and without AIDS, persons who had seroconverted >72 and <72 months before entering the study, persons with or without previous severe primary infection, persons who had developed AIDS >72 and <72 months before entering the study. Furthermore, the HIV+ group was compared with an HIV-seronegative (HIV-) age- and sex-matched group. There was no difference in the proportion of total naive relative to total memory cells between HIV+ and HIV- subjects, showing an equal loss of naive and memory CD4+ cells in this study. Moreover, there was no difference in the proportion of total naive relative to memory CD8⁺ cells, showing an equal increase in both subgroups of CD8⁺ cells in HIV⁺ subjects. However, HIV⁺ subjects who had experienced severe primary symptoms resembled the AIDS group regarding shift in the CD8 phenotype from naive to memory and by down- regulation of amounts of CD45RA protein. Furthermore, the results showed that during infection with HIV the amounts of both CD45RA and CD45RO markers on CD4⁺ cells and CD45RA on CD8⁺ cells were down-regulated, although with different kinetics. Duration of HIV infection and time from seroconversion to AIDS were not reflected in the amount of or proportional expression of CD45RA and CD45RO markers.