Epstein-Barr virus infection in Richter's transformation

Chronic lymphocytic leukemia (CLL) may convert to a diffuse large cell lymp homa (Richter's syndrome) over time. In occasional cases of Richter's trans formation, Epstein-Barr virus (EBV) has been identified in the lymphoma cel ls. To evaluate the association of EBV infection with Richter's syndrome, t he biopsy specimens and clinical records of 25 patients who were seen at th e Mayo Clinic between 1984-1996 were retrospectively evaluated for the pres ence of EBV by immunoperoxidase staining for expression of EBV latent membr ane protein (LMP), as well as the expression of EBV RNA and DNA in the cell s by in situ hybridization, Four of the 25 patients showed evidence of EBV in the diffuse large cell lymphoma cells-three patients with a B-cell pheno type were positive for LMP, EBV RNA, and RNA; and one patient with a T-cell phenotype had positive EBV RNA in the large cell lymphoma cells. The Richt er's syndrome was treated with combination chemotherapy in 15 patients, thr ee received radiotherapy, three were followed without further therapy after a splenectomy, two died before treatment could be started, and one patient had insufficient follow-up. One patient with evidence of EBV in large cell lymphoma cells was treated with acyclovir as initial therapy. The median s urvival of EBV-positive patients was three months compared with nine months for EBV-negative patients, but this difference was not statistically signi ficant (P = 0.385). Evidence for EBV infection related to Richter's transfo rmation was present in 16% of the patients in this study and may be associa ted with a poorer outcome. Primary therapy with acyclovir in one patient di d not seem to be beneficial and other therapeutic modalities in patients wi th EBV-positive Richter's transformation need to be explored. (C) 1999 Wile y-Liss, Inc.