Rheumatoid Arthritis and Lymphoma: Cause and Effect?

Rheumatoid arthritis has been found to be associated with lymphoma. This Eurekalert newsrelease reports on a new study presented in the March issue of Arthritis and Rheumatism.

Drawing their sample from a national register of nearly 75,000 RA patients, the research team analyzed the medical records and case histories of 378 RA patients afflicted with malignant lymphoma between 1964 and 1995 and 378 individually matched, lymphoma-free controls. Using statistical analysis, the relative risks or odds ratios for lymphoma were assessed for three different levels of overall disease activity--low, medium, or high--based on disease duration and swollen and tender joint counts. Odds ratios for lymphoma were also compared to treatment in broad categories: any DMARD, any NSAID, aspirin, oral steroids, injected steroids, and cytotoxic drugs. No patient in the sample had received anti-TNF therapy. In addition, lymphoma specimens were reclassified and tested for Epstein-Barr virus (EBV).

Compared with low RA activity, medium RA activity was associated with an 8-fold increase in the risk for lymphoma. The odds ratio rose dramatically for high RA activity--to a 70-fold increase in lymphoma risk. The researchers also observed increased risks of lymphoma associated with pronounced, irreversible joint damage in the hands, feet, and knees documented in the last year before lymphoma diagnosis.

....Given the many uncertainties surrounding the link between lymphoma and chronic inflammatory diseases, this study has substantial clinical implications. As its lead author, Dr. Lars Klareskog of Karolinska University Hospital in Stockholm, observes, since lymphoma risk is strongly associated with exceptionally severe and longstanding RA activity, aggressive treatment may reduce the risk by reducing cumulative inflammation. "From a drug safety perspective," he notes, "our results provide background data that should be considered essential for the evaluation of lymphoma risk following therapy with TNF blockers, for example, as well as other new drugs."

Rheumatoid arthritis (RA) is related to reduced lifespan and increased mortality.
RA affects many critical systems of the body with a wide variety of manifestations and complications. Understanding HIV has led to remarkable new understandings of the immune system and cellular biology. Now it is time that medical science devoted the same type of research funding to the understanding of RA and related autoimmune disorders, that it devotes to HIV. The return in understanding from such a program would benefit everyone.