LACK OF PREDICTIVE VALUE FOR PROGRESSION OF DISSOCIATED CIRCULATING P24 ANTIGEN IN HUMAN-IMMUNODEFICIENCY-VIRUS TYPE 1-INFECTED BLACK PATIENTS

In human immunodeficiency virus type 1 (HIV)-1-infected Black people, the circulating p24 antigen is hidden frequently in immune complexes, because of high titers of serum anti-p24 antibodies. In order to evalu ate the prognostic values for progression of free and dissociated seru m p24 antigen in Black people, sera from 45 HIV-1-infected Black patie nts, all at non-AIDS stages, were evaluated prospectively for p24 anti gen by several assays: circulating free p24 antigen was measured by im munocapture ELISA only (method 1) and with BLAST(TM) amplification (me thod 2), and dissociated p24 antigen determined after glycine-HCl pret reatment of serum, by immunocapture ELISA only (method 3) and with BLA ST(TM) amplification (method 4). Serum CD4 and CD8 cell counts, beta 2 -microglobulin, and total IgA were determined also at least twice a ye ar. Clinical events for AIDS were those included in the 1986 CDC class ification for HIV infection. At entry, p24 antigen was found in 3 (6.7 %) patients by method 1, in 7 (15.6%) by method 2, in 14(31.1%) by met hod 3, and in 22 (48.9%) by method 4. Methods 3 and 4 were more sensit ive than method 1 (P < 0.001) and method 2 (P<0.001). The mean follow- up was 30 months. The free symptom survival times (mean +/- SD months) were significantly lower in patients being p24 antigen positive by me thod 1 [(+) 33 +/- 27 vs. (-) 61 +/- 15, P = 0.03], but they were simi lar in patients positive and in those negative for p24 antigen determi ned by method 2 [(+/-) 71 +/- 17 vs. (-) 74 +/- 9, P = 0.54], method 3 [(+) 76 +/- 12 vs. (-) 69 +/- 13.2, P = 0.80], and method 4 [(+) 79 /- 9 vs. (-) 63 +/- 7, P = 0.71]. At 24 months, p24 antigen positivity did not correlate either with CD4 or CD4/CD8 slops, nor with beta(2)- microglobulin or IgA variations. By contrast, a CD4 cell count below 2 00/mm(3) at entry was significantly associated with disease progressio n. In conclusion, dissociated p24 antigenemia does not appear as a use ful surrogate marker for progression in HIV-1-infected Black people. ( C) 1996 Wiley-Liss, Inc.