Lymphadenopathy in drug addicts. A study of the distribution of T lymphocyte subsets in the lymph nodes.

Lymph node biopsies from 24 male heroin addicts and 9 control patients were studied using immunohistochemical, and in 1/3 of cases, quantitative methods. 5 out of these 24 patients were also homosexual. All presented diffuse lymphadenopathy but none had any signs or symptoms of opportunistic infections nor Kaposi's sarcoma. Histologically the lymph nodes showed a very peculiar follicular hyperplasia with atrophy of the paracortex. The germinal centers appeared irregular, ill defined and contained clusters of small lymphocytes. The mantle zone was atrophic. Immunolabelling of T lymphocytes by monoclonal antibodies showed that germinal centers were invaded by small nests of Leu 2a (and OKT8) positive lymphocytes, i.e. chiefly cytotoxic-suppressor phenotype; the number of these cells increased by about 100 times in the follicles. OKT4 (and Leu 3a) positive cells, i.e. chiefly helper-inducer phenotype, appeared to decrease. These histological and immunohistochemical changes are considered to be suggestive of drug addicts' lymphadenopathy, and also possibly of other conditions increasing the risk of AIDS.