A population based, case control study of non-Hodgkin's lymphoma in patients with rheumatoid arthritis

Objective. Epstein-Barr virus (EBV) associated lymphoproliferative disorder s (LPD) similar to those that occur in immunosuppressed solid organ recipie nts have been reported in patients with rheumatoid arthritis (RA). These LP D cause significant morbidity and/or mortality in a state of sustained immu nosuppression, but may spontaneously regress if immunocompetence is restore d. We determined the population based frequency of EBV associated LPD relat ive to all non-Hodgkin's lymphomas (NHL) that occur in the general populati on of patients with RA. Methods, Forty-two case patients with NHL and RA and 49 control patients wi th NHL and no RA were identified in a population based, case control study of NHL that occurred in a 6 county Northern California area during the year s 1988-94. The lymphoma tissue specimens were reviewed and the diagnosis of NHL was confirmed. In addition, the specimens were analyzed for NHL grade, histologic subtype, histopathologic features associated with immunosuppres sion, immunophenotype, and the presence of EBV genome in the tumor cells. Results. No significant differences were identified between NHL in the RA c ase group ana the control group (no RA) with respect to any variables inves tigated. One patient (2%) in the case group and one (2%) in the control gro up developed LPD containing EBV. Conclusion. Our findings reveal that EBV associated lymphomas represent onl y a small fraction of all NHL in the general RA patient population. EBV ass ociated LPD should be recognized when they occur because they require a spe cial approach to patient management. However, these data indicate that the majority of NHL that occurs in patients with RA is probably coincidental wi th RA and not the result of significant immunosuppression.