The significance of antilymphocyte antibodies in patients with acquired immune deficiency syndrome (AIDS) and their sexual partners.

Antilymphocyte antibodies have been demonstrated in autoimmune diseases, acute viral infections, and acquired immune deficiency syndrome (AIDS) by using either the conventional microlymphocytotoxicity or the double fluorescence technique. In the present study, we used both methods to detect the antilymphocyte antibodies and to characterize further their immunologic significance in patients with AIDS and their sexual partners. The results using the conventional microlymphocytotoxicity method demonstrated that 8 of 10 patients with AIDS and 6 of 10 partners had significant levels of antilymphocyte antibodies which were reactive with B and T cells at cold and warm temperatures. A significant loss in antibody activity following absorption with B, T, and Daudi cells and Staphylococcus aureus, but not platelets or red cells, indicated that these antibodies are not directed to HLA class I antigens but, rather, to antigens that are common to both groups of lymphocytes. There is a close association between antilymphocyte antibodies and lymphopenia in patients but not in partners. Antibodies against lymphocyte subclasses [helper (T4) and suppressor (T8)] were detected by the double fluorescence staining technique, which employs C6-deficient serum as a nonlytic source of complement, and demonstrated the binding of antibodies to target cells, in contrast to lysing of the target cells as in the microlymphocytotoxicity method. The results of this assay showed that antibodies were directed to both populations, and there was no correlation or association between the absolute numbers of peripheral T4 and T8 cells and the percentage of antibody binding. Taken together, there appear to be at least two kinds of antilymphocyte antibodies: lymphocytotoxic antibodies detected by the conventional microlymphocytotoxicity assay and noncytotoxic antibodies detected by the double fluorescence staining technique. The former may be responsible in part for the lymphopenia. The latter may alter lymphocyte function. The patients and partners who had antilymphocyte antibodies also had anti-HTLV-III antibodies, although there was not any close correlation between titers. These findings support the possibility that both types of antibodies occur as part of a generalized immune response, possibly stimulated by the same viral agent.