The immunohistology of non-T cells in the acquired immunodeficiency syndrome.

The authors employed a panel of monoclonal antibodies to characterize B cells, histiocytes, and natural killer cells in lymph node biopsies obtained from 7 homosexual men with the acquired immune deficiency syndrome (AIDS) and 5 heterosexual controls. Six of the AIDS patients, each with cutaneous and/or nodal Kaposi's sarcoma, exhibited reactive follicular hyperplasia, as did the 5 controls. The seventh AIDS patient had opportunistic infections and exhibited a lymphocyte depletion pattern in lymph nodes. In AIDS patients, reactive B-cell follicles often exhibited attenuation of their mantle zones. Many were regressively transformed and composed predominantly of dendritic reticulum cells. Occasional germinal center dendritic reticulum cell networks exhibited fragmentation reminiscent of the "follicle lysis" described previously in the persistent generalized lymphadenopathy syndrome. In the 1 AIDS patient with the lymphocyte depletion pattern of lymph node histology, germinal center elements, including dendritic reticulum cells, were totally absent. In all cases, the mononuclear-cell subsets exhibited normal patterns of antigen expression. Quantitative studies, however, revealed a significant increase (P less than or equal to 0.01) in natural killer cells and histiocytes within the paracortical T-cell domain of lymph nodes obtained from patients with AIDS. There was no significant difference in the number of natural killer cells within the mantle or germinal center B-cell domains. While there was no significant difference in the absolute number of paracortical B cells, they were relatively increased due to an absolute decrease in T cells. It is concluded that quantitative alterations in mononuclear-cell subsets in patients with AIDS are not restricted to T cells and that these alterations are microenvironmentally specific.