Predictor of the rate of CD4 lymphocyte loss in HIV-1-seropositive asymptomatic hemophiliacs by in vitro immunoglobulin synthesis.

The objective of the present study was to evaluate the prognostic utility in determining the risk of AIDS progression in HIV-1-infected asymptomatic hemophiliacs by in vitro immunoglobulin (Ig) synthesis. With this aim, a cohort of 28 HIV-1-seropositive hemophiliacs were studied. All showed the number of CD4 lymphocytes higher than 400 positive cells/mm3. In all cases the spontaneous and pokeweed mitogen-induced in vitro production of Ig by peripheral blood lymphocytes was evaluated at the beginning of the study and the ratio stimulated/spontaneous (Stim/Spon) synthesis was calculated. At the same time, the absolute CD8+ cell count, IgA serum immunoglobulin, p24 HIV-1 antigenemia, and beta2 microglobulin were calculated. These data were monitored during the 4-year follow-up of patients and compared with the stimulated/spontaneous Ig synthesis ratio to evaluate the predictive significance on the progression of HIV infection. According to the stimulated/spontaneous Ig synthesis ratio, hemophilic patients were separated into two categories. Group I included 12 subjects with a Stim/Spon ratio higher than 2 (the lowest value of normal controls) and group II included 16 cases with a ratio lower than 2. As control, in 36 HIV-1-negative hemophiliac individuals the stimulated/spontaneous Ig ratio ranged between 2 and 42; mean +/- SEM, 12.9 +/- 1.8. At the end of the 4-year follow-up, group I patients showed a CD4 count and clinical staging consistent with those of the first evaluation; in contrast group II demonstrated a significant decrease in CD4 lymphocytes and deterioration of clinical conditions. Our results show that a low Stim/Spon Ig ratio when the CD4 lymphocyte count was still normal appears to predict the depletion of this lymphoid subset and progression to AIDS before T CD8, IgA immunoglobulin, p24 HIV-1 antigenemia, and beta2 microglobulin abnormalities. In this setting, the stimulated/spontaneous Ig ratio may represent a useful tool for clinical decisions in HIV-1-infected hemophiliacs.