DETERMINATION OF EPSTEIN-BARR-VIRUS ASSOCIATION WITH B-CELL LYMPHOMASIN JAPAN - STUDY OF 72 CASES - IN-SITU HYBRIDIZATION, POLYMERASE-CHAIN-REACTION, IMMUNOHISTOCHEMICAL STUDIES

The association of Epstein-Barr virus (EBV) with B-cell lymphoma was e xamined in 72 human immunodeficiency virus-negative Japanese patients using the polymerase chain reaction (PCR) on DNA obtained from formali n-fixed paraffin-embedded tissues and an in situ hybridization (ISH) t echnique. EBV-encoded RNA 1 (EBER-1) was detected in 12 of 72 cases (1 7%); five of 33 cases (15%) of nodal B-cell lymphomas and seven of 39 cases (18%) of extranodal B-cell lymphomas. Three cases of post-bone m arrow transplantation and one case of autoimmune disease (Evans syndro me) were included among seven EBER-1 positive extranodal lymphomas. A combined study of immunohistochemistry and EBER-1 revealed that some L 26 positive cells were EBER-1 positive. A DNA band was also observed i n 13 of 70 examined cases (19%) (four of 33 cases of nodal B-cell lymp homas (12%) and nine of 37 cases of extranodal B-lymphomas (24%)) in t he PCR study using primers to detect the Ram HI-W fragment of EBV. In the immunohistochemical study using a monoclonal antibody to the laten t membrane protein 1 (LMP-1) of the EBV, one of the EBV-encoded latent gene products, LMP-I, was expressed in six of 34 cases (18%) of extra nodal B-lymphomas, but none of the cases with nodal B-cell lymphomas w ere shown to be LMP-I positive. Oncoprotein bcl-2 was examined by immu nohistochemistry and found to be expressed in seven cases of nodal lym phomas and three cases of extranodal lymphomas, and two of these nodal cases were EBER ISH positive. In EBV serology, only two cases of noda l and one case of extranodal EBER positive B-cell lymphomas revealed a reactivation pattern. In the PCR study using primers to detect the ly mphocyte-determined membrane antigen (LYDMA), the same sized monoclona l bands were observed in case 36 in the PCR products from the nose and skin, suggesting the monoclonal proliferation of the tumor. These fin dings suggested a low incidence of EBV association with B-cell lymphom as unless patients were in an immunologically impaired condition such as post-organ transplantation or autoimmune diseases. (C) 1998 Elsevie r Science Ireland Ltd. All rights reserved.