PREDICTING PROGRESSION OF HIV DISEASE - USEFULNESS OF ACID-DISSOCIATED P24 ANTIGEN

To ascertain whether immune complex dissociation (ICD) improves the va lue of p24 antigen as a prognostic marker for progression of HIV infec tion, 53 patients were followed over a 3-year period, including at lea st one visit per year. All had CD4(+) counts at entry >400/mm(3); prog ressors (n = 18) were defined as having CD4(+) counts <200/mm(3) and n onprogressors (n = 35) as having CD4(+) counts still >400/mm(3) at the end of follow-up. Serum specimens were collected at each annual visit and assayed for p24 antigen with and without ICD treatment. At entry, the percentage of progressors positive for ICD p24 antigen was signif icantly higher than the percentage of positive nonprogressors (39% ver sus 3%, p < 0.01). The sensitivity of p24 antigen over all visits in t erms of predicting the progression increased from 61% before ICD to 83 % after. The specificity of p24 antigen in terms of predicting progres sion decreased from 97% before ICD to 89% after. The relative risk of progression in individuals positive for p24 antigen was 6.7 before ICD and increased after ICD to 12.7. When evaluating the respective progn ostic value of the p24 antigen and of the ICD p24 antigen, only ICD p2 4 was significant (RR 10.2, 95% CI 2.2-46.9). ICD p24 antigen appears to be a marker of progression that may be detected earlier than p24 an tigen without ICD.