Objective. - To evaluate the prevalence and risk factors of severe pyogenic infections in rheumatology patients taking infliximab in everyday practice.

Methods. - Regional prospective cohort study of patients taking infliximab for rheumatoid arthritis or ankylosing spondylitis with data collection on standardized forms. The medical records of patients with severe pyogenic infections were subjected to a detailed retrospective review. Patients with and without severe pyogenic infections were compared.

Results. - The cohort included 83 patients (55 women and 28 men). Severe pyogenic infections occurred in five (6%) patients (three women and two men), all of whom had acute or underlying risk factors. Higher values were found in these five patients for mean age (65.8 ± 12 vs. 53.9 ± 13 years, P = 0.04) and mean daily glucocorticoid dosage (15.5 ± 9 vs. 6.9 ± 7 mg/day prednisone-equivalent, P = 0.036), as compared to the other patients.

Conclusion. - Older age and high-dose glucocorticoid therapy are associated with an increased risk of severe pyogenic infection during infliximab therapy. Caution is in order when starting and monitoring infliximab therapy in patients with risk factors. Our data also emphasize the need for a careful search for risk factors before each infliximab infusion.