Immunohistopathology of lymph nodes in HTLV-III infected homosexuals with persistent adenopathy or AIDS.

Lymph node biopsies from 43 male homosexuals with persistent generalized lymphadenopathy and from ten acquired immunodeficiency syndrome patients, all with serum antibodies to human T-cell leukemia virus III, were studied with regard to histopathology, immunohistology, and T-cell subsets in cell suspensions. All acquired immunodeficiency syndrome biopsies except one with Kaposi's sarcoma had the same histopathological pattern of follicular depletion, whereas the persistent generalized lymphadenopathy nodes showed a spectrum of changes characterized as follicular hyperplasia, involution with follicular fragmentation, or involution with follicular atrophy. Immunohistology showed a temporal and structural relation between follicular involution, disappearance of follicular dendritic reticulum cells, and follicular invasion by T-cells. These observations suggest elimination of dendritic reticulum cells as part of a pathogenic mechanism in follicular involution. Angiogenesis measured by staining of endothelial cells with antibodies to Factor VIII was increased in many biopsies in stages of involution and depletion. Our observations indicate the occurrence of marked changes not only in T-cells but also in the B-cell compartment of patients with persistent generalized lymphadenopathy or acquired immunodeficiency syndrome. The possibility of staging lymph nodes of these patients by combined histopathology and immunohistology is indicated. This might improve the evaluation of prognosis in these patients. A possible importance of angiogenesis for the tumorigenesis of Kaposi's sarcoma is suggested.