PREDICTIVE VALUE OF ANTI-P25 ANTIBODY-LEVELS IN HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 (HIV-1)-INFECTED PATIENTS

To assess whether monitoring of antibodies (Ab) directed against the HIV-1 p25 core protein may be used as a predictive marker in the biological monitoring of HIV-infected patients, a study was performed on a transversal cohort of 68 CDC stage II-II, and 36 ARC and 26 AIDS stage IV patients, 37 of whom were being treated with anti-retroviral therapy. A second cohort included 56 patients followed for 3-7 years : 15 stage II-III, 11 ARC and 30 AIDS patients (opportunistic infections : 14 ; Kaposi's sarcoma : 11 ; non-Hodgkin's lymphoma : 5). p25 antigenemia and CD4+ blood lymphocyte counts were determined in parallel. Stage II-III patients usually had high and stable anti-p25 Ab levels, ARC patients exhibited more heterogeneous Ab values, while those with AIDS had very low values. No significant difference was observed in the serum anti-p25 levels of patients treated or not with anti-retroviral therapy. In patients whose CD4+-cell counts were going to fall below 200/mm3 and/or who were going to progress towards AIDS, the Ab levels started to decrease at a rate of > 1 log U/ml (expressed in arbitrary units/ml) per 5 years at least 2 to 4 years, respectively, before the appearance of the index symptom, despite the fact that the CD4+-cell count only differed significantly between progressors and non-progressors one year before the appearance of the disease. In contrast, anti-p25 Ab levels remained stable or high in patients whose CD4+-cell counts remained greater-than-or-equal-to 200/mm3 or who did not progress at mid-term towards AIDS (93 % of patients with no detectable antigenemia had anti-p25 Ab levels > 1 U, while 89 % of the patients with detectable antigenemia had Ab levels less-than-or-equal-to 1 U). Therefore, the anti-p25 Ab level and the rapidity of its decrease seem to be good mid-to-long-term prognostic markers of disease progression in HIV-1 infection. These parameters complement the CD4+-cell count, a short-term indicator of disease evolution.