Study: Immunosuppressive Drugs Up TB Risk for Rheumatoid Arthritis Patients

People suffering from rheumatoid arthritis taking immunosuppressive drugs are four times more likely than those without the disease to contract tuberculosis, according to a study reported in the July issue of the Journal of Rheumatology.

A team of Spanish researchers studied 788 patients with rheumatoid arthritis selected randomly from the registries of 34 participating centers in Spain who were receiving therapy involving different immunosuppressive drugs.

Seven cases of tuberculosis were found among the participants, resulting in an average annual incidence of 134 in 100,000 patients.

"These results might help to interpret the magnitude of the problem attributable to the introduction of new therapies in rheumatoid arthritis," concluded the researchers.

In an accompanying editorial in the journal, Michael Gardam and Karen Iverson, of University Health Network in Toronto, said rheumatoid arthritis patents who receive medications that appear to raise their risk of tuberculosis should be screened for that disease.

Although the study was conducted too early to include new TNF-alpha drugs such as etanercept and infliximab, Gardam and Iverson observed that previous studies have found that these drugs increased the risk of tuberculosis by a four-fold amount as well.

Other sources: Journal of Rheumatology 2003;30:1436-9