Nucleic acid cytometry of homosexual-associated lymphoproliferative disease

Abstract

Twenty-six reactive lymph nodes and 5 malignant lymphomas from homosexual males were studied by acridine orange flow cytometry (AO-FCM) for determination of ploidy, proliferation, and RNA characteristics. Two reactive lymph nodes showed ploidy abnormalities as compared with none of 27 reactive lymph nodes from nonhomosexual patients. The homosexual-associated (HA) lymphadenopathy had a higher mean proliferative activity (11.2% versus 5.6%) and higher ribonucleic acid (RNA) content (1.11 versus 0.96) than non-HA counterparts. The proliferative activity of HA lymphadenopathy was also higher than follicular small cleaved cell lymphoma, and not dissimilar to that of follicular large cell lymphoma. These findings indicate that HA-reactive lymphadenopathy is a hyperproliferative state associated with high cellular RNA content and rare DNA-abnormal stemlines. One HA lymphoma had an abnormal stemline by AO-FCM, compared with 9 of 15 (63%) non-HA high grade lymphomas. This lymphoma also demonstrated an abnormal karyotype (47,XY, +12, t[8;22]) by classic cytogenetic studies. The mean proliferative activity and RNA content of HA lymphomas was higher than non-HA counterparts (37% versus 22.5% and 2.48 versus 1.73, respectively). The proliferation and RNA features of HA lymphoma were on higher planes than non-HA lesions histologically comparable. Thus, in addition to differences in clinical presentation, histologic subtype, stage distribution, and therapeutic response, HA lymphomas have DNA/RNA characteristics different from those of counterparts in the general population.