CD8+, CD38+ Lymphocyte Percent

Abstract

We investigated the relationship between three prognostic markers, CD4 lymphocyte count, serum β₂-microglobulin (β₂M) levels, and CD8⁺, CD38⁺ lymphocyte percent, and the association with the rate of development of AIDS. The markers were measured regularly throughout follow-up in 224 patients. The risk of developing AIDS during follow-up was investigated using Cox proportional hazards models. Time-updated values of the prognostic markers were used, which modelled the risk of AIDS according to the latest measurement of the marker rather than using a single value of the marker at baseline. During a median follow-up period of 13.6 months(range 0.5-31.9 months), 34 cases of AIDS occurred. In a univariate analysis, all three markers predicted the development of AIDS; a 10% increase in the percentage of CD8⁺ T cells expressing CD38⁺ resulted in an 88% increase in the risk of AIDS (95% confidence interval: 53-130%; p < 0.0001). After adjustment for the current CD4 count and β₂M, a 10% increase in the CD8⁺, CD38⁺ population was associated with a 37% increase in the risk of AIDS (95% confidence interval: 4-81%; p = 0.02). Thus, the percentage CD8⁺, CD38⁺ level predicts the development of AIDS independently of the latest CD4 count and β₂M. This assay is therefore potentially useful in conjunction with blood CD4 counts and serum β₂M levels in patient management and clinical trial design.