Immunological studies in homosexual men with and without antibodies to human T-cell lymphotropic virus type III.

T-cell subsets were studied in 559 homosexual or bisexual men attending outpatient clinics for AIDS-screening in Copenhagen during the period July 1984 to April 1985. Of the 559 individuals studied, HTLV III antibodies were found in 161 (29%). Persistent generalised lymphadenopathy (PGL) defined as the presence of lymph nodes greater than 1 cm in diameter at two or more extrainguinal sites for at least three months were found in 91 patients, 72 (79%) of whom had HTLV III antibodies. The seropositive group had lower counts of T-helper/inducer cells (p less than 0.001), higher counts of T-suppressor/cytotoxic cells (p less than 0.001), lower T-helper/T-suppressor ratios (p less than 0.001) and higher levels of IgG (p less than 0.001), compared to the seronegative group. Compared to seropositive men without PGL, seropositive men with PGL had higher levels of IgA and IgG (p less than 0.05) and lower T-helper/T-suppressor ratios (p less than 0.05), the latter primarily caused by an elevated number of T-suppressor/cytotoxic cells. It is concluded that HTLV III infection is accompanied by a number of immunological abnormalities, including depletion of T-helper/inducer cells and B-lymphocyte activation. A subgroup of patients is characterised by having PGL and increased serum concentrations of IgA and IgG. The clinical and prognostic importance of PGL and B-cell activation is unknown. To study this more closely, prospective studies are needed.