The Predictive Value of Several Markers in the Progression to Acquired Immunodeficiency Syndrome

Abstract

Serum β₂-microglobulin, neopterin, immunoglobulins A, G and M, adenosine deaminase and CD4+ lymphocyte count were evaluated as predictors of progression of HIV-1 infection to AIDS. A population of HIV-1 seropositive, initially asymptomatic men (n=213) and women (n=101) was followed up quarterly.

We estimated the AIDS-free time using the actuarial method (median survival time 47.2 months). Cox proportional hazard analysis revealed that all markers studied were significant (p<0.05) in relation to progression to AIDS. The best markers for predicting progression to AIDS were, in descending order, CD4+ lymphocyte count, β₂-microglobulin, IgA, neopterin, IgG, IgM and adenosine deaminase. On stratifying population into four groups (devided at percentiles 25, 50 and 75—from group 1, with values nearest to reference ranges, to group 4, with most abnormal values) we observed statistically significant differences (p<0.05) for all markers except for adenosine deaminase. The relative risk from the Cox proportional hazards model were used to quantify the effects of the best markers and compared to the risk obtained in group 1.

CD4+ lymphocyte count was the best predictor of progression to AIDS. When considering β₂-microglobulin and CD4+ together, the relative risk in the group with lowest CD4+ cell count (group 4) ranged from 25.6% (with lower β₂-microglobulin values) to 41.1% (with higher β₂-microglobulin values). Similar results were obtained when considering neopterin and CD4+ together. The addition of β₂-microglobulin or neopterin values to CD4+ lymphocyte count improved the predictive value of CD4+ lymphocyte count.