Observational Studies of Infections in Rheumatoid Arthritis: A Metaanalysis of Tumor Necrosis Factor Antagonists

Objective. Published metaanalyses of tumor necrosis factor (TNF) antagonists and infection have focused on randomized controlled trials, which tend to have short duration, relatively small size, and stringent inclusion/exclusion criteria that may limit enrollment to patients at low risk of infection. We performed a systematic review and synthesis of observational studies of TNF antagonists and infection risk. Methods. We conducted a systematic literature search of studies estimating overall risk of serious infection after anti-TNF exposure in rheumatoid arthritis (RA). We estimated a pooled relative risk (RR) for the relevant observational studies, using a random-effects model. Results. Five cohort studies and 2 nested case-control studies were included in the metaanalysis. Anti-TNF therapy appeared to significantly increase risk of serious infection (pooled adjusted RR 1.37, 95% CI 1.18, 1.60). Conclusion. Our metaanalysis of observational data demonstrated an increased risk of serious infection in subjects with RA receiving anti-TNF therapy, versus those not receiving these agents. (First Release April 1 2010; J Rheumatol 2010;37:928-31; doi:10.3899/jrheum.091107)