CD4(+) AND CD8(+) LYMPHOCYTES OF PATIENTS WITH AIDS SYNTHESIZE INCREASED AMOUNTS OF INTERFERON-GAMMA

Individual cells capable of interferon-gamma (IFN-gamma) synthesis are easily detected by immunofluorescence and flow cytometric analysis using an anti-IFN-gamma monoclonal antibody as specific reagent. By IFN-gamma flow cytometry assay, we demonstrated that HIV-seropositive patients, starting at the early stage of viral infection, generally have an increased percentage of lymphocytes potentially able to produce IFN-gamma, compared with healthy blood donors. IFN-gamma expression in patient lymphocytes was observed to increase with the progressive stages of HIV infection, with the highest figures occurring in stage C patients. Such increased IFN-gamma expression involved both CD4(+) and CD8(+) T cell subsets. Most interestingly, we found patients at the same stage of HIV infection who had similar numbers of total and CD4(+) lymphocytes but highly different percentages of lymphocytes potentially capable of producing IFN-gamma.