Lymphoproliferative disorders in autoimmune diseases in Japan: analysis of clinicopathological features and Epstein-Barr virus infection.

Lymphoproliferative disorders (LPD) occasionally develop in individuals with immune deficiencies such as immunosuppressive conditions and autoimmune diseases (AID). In our study, the clinicopathologic features and virus status were analyzed in 53 cases with LPD developing in rheumatoid arthritis (RA) and other AID. AID in only 4 of 53 patients had been treated with some sort of immunosuppressive therapy, including methotrexate. Median age at the diagnosis of LPD in AID was 60 years old with marked female predominance (M/F = 0.4). The median interval between the onset of AID and LPD development was 45 months, and longer in RA patients than in other AID (p < 0.01). The primary site of lymphoma was nodal in 21 cases and extra-nodal in 24, with clinical Stage I in 17, II in 5, III in 13, and IV in 13. Immunohistochemistry showed that 39 cases were B cell type, 10 were T cell type and 4 were Hodgkin lymphoma (HL). Then majority of B cell cases were diffuse large B cell lymphomas, and 2 were diffuse polymorphic type. EBER-1 in situ hybridization for Epstein-Barr virus (EBV) showed positive signals in tumor cells in 16 of 53 (30.2%) cases. The EBV-positive rate in T cell LPD (70%) was much higher than that in B cell LPD (12.8%) (p < 0.01). All 4 cases of HL were EBV-positive. Immunohistochemistry showed a latency II pattern of EBV infection (LMP-1(+) and EBNA-2(-)). Five-year overall survival rate was 33%. Multivariate analysis showed that only type of AID was an independent factor for survival of patients, i.e., LPD in RA showed the most favorable prognosis. In conclusion, LPD in AID generally shared common features with sporadic LPD except for a much higher EBV-positive rate in T cell LPD.