The significance of activation markers on CD8 lymphocytes in human immunodeficiency syndrome: staging and prognostic value.

The objective of this prospective cohort study was to evaluate the expression of activation markers on CD8 lymphocytes at various clinical stages of HIV infection and to determine the value of these markers in identifying patients likely to have rapidly progressive disease. One hundred and three HIV+ patients, divided into four disease stages, and 34 seronegative controls were evaluated at study entry using flow cytometric immunophenotyping. The HIV patients were followed clinically for disease progression during the following 2 years. CD8 cell numbers and percentage of lymphocytes are increased after HIV infection. Expression of the CD38, HLA-DR and CD57 markers on CD8 cells was significantly increased in asymptomatic HIV-infected patients when compared with controls, as was the CD8 cell population which did not coexpress Leu-8. These activation markers were observed to be further increased in patient groups with more clinically advanced infection. The percentage of CD38 on CD8 cells emerged not only as a discriminator of disease severity, but was a strong predictor of progression in asymptomatic, lymphadenopathy and ARC patients. Given the utility of activation markers on CD8 lymphocytes in staging disease and predicting clinical outcome, the measurement of these parameters should be considered in the monitoring and management of HIV patients.