Monitoring of antibodies against human immunodeficiency virus type 1 p25 core protein as prognostic marker.

Anti-p25 antibodies were evaluated by cross-sectional analysis of sera from 130 human immunodeficiency virus type 1-infected patients and in a longitudinal study of 56 patients by retrospective analysis of sequentially collected sera. High and stable antibody levels were found in Centers for Disease Control stage II or III patients, 78% of whom had levels greater than 10 arbitrary units/mL. Patients with AIDS-related complex displayed heterogeneous levels. Patients with AIDS had the lowest values: less than or equal to 10 units/mL in 96% of cases. In patients whose CD4+ cell counts eventually fell below 200/mm3 or who developed AIDS (or both), antibodies were initially less than 40 units/mL and/or they declined with a rate greater than 1 log unit/5 years, beginning at least 4 years before the index symptom. Because the only point at which CD4+ cell counts significantly differed between progressors and nonprogressors was 1 year before the disease, both initial anti-p25 values and antibody decline seemed to be better long-term prognostic markers than CD4+ cell counts.