Immunological alterations in anti-HTLV-III negative haemophiliacs and homosexual men in Hungary.

Hungary can be considered as a low risk area for AIDS since no patient with full-blown AIDS or AIDS-related complex has been found in the country. A complex clinical and immunological (T cell subsets, DNCB sensitization test, circulating immune complexes, acid-labile alpha interferon) investigation was performed between November, 1983 and June, 1984 in order to study whether alterations found in symptom-free homosexuals and haemophiliacs in the risk areas for AIDS can be observed in Hungary as well. 38 patients with mild haemophilia, 35 patients with severe haemophilia and 40 homosexual men were investigated in parallel to 37 heterosexual blood donors as controls. Anti-HTLV-III antibodies were measured later in the stored serum aliquots from the same subjects by the indirect membrane immunofluorescence assay. Although specific anti-HTLV-III antibodies were not detected in the haemophiliacs or homosexuals, immunological alterations characteristic for the members of AIDS risk groups in the high risk areas (decrease in the percentage of OKT4 cells and/or decrease of the OKT4/8 ratio) were found in one-third of the homosexuals and haemophiliacs tested. In addition, a significant part of these subjects did not develop delayed type hypersensitivity skin reaction on DNCB rechallenge. These findings indicate that an immunodeficiency independent of HTLV-III infection can be present in two major AIDS risk groups, in homosexual men and haemophiliacs.