TNF inhibitors linked to septic arthritis

Among 145,129 incident cases of ankylosing spondylitis (AS) and seropositive rheumatoid arthritis (RA) between 2010 and 2020 identified in a South Korean national health insurance database, 1,170 (0.8%) of these patients developed septic arthritis during the follow-up period. In the overall study population, the incidence of septic arthritis was associated with the use of the TNF inhibitors infliximab or etanercept, as well as with age, male sex, diagnosis of seropositive RA, and comorbidities including hypertension, diabetes mellitus and chronic pulmonary disease. Among the patients with AS, only age and renal disease were predictors of septic arthritis. By contrast, in patients with seropositive RA, the incidence of septic arthritis was greater in those treated with TNF inhibitors (infliximab, etanercept, adalimumab or golimumab), particularly within the first year of starting anti-TNF antibody treatment; other factors associated with septic arthritis in this group included age, hypertension, diabetes mellitus and chronic pulmonary disease.