BackgroundA high rate of infection has been reported in patients receiving treatment with anti-tumor necrosis factor (anti-TNF). This study describes the rate of and risk factors for serious infections in patients receiving anti-TNF agents in Jordan.MethodsThis retrospective observational study was conducted at a large tertiary referral center in the north of Jordan. Between January 2006 and January 2012, 199 patients who received an anti-TNF agent (infliximab, adalimumab, or etanercept) were included. Patients received the anti-TNF treatment for rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, or other conditions. A serious infection was defined as any bacterial, viral, or fungal infection that required hospitalization, administration of appropriate intravenous antimicrobial therapy, and temporary withholding of anti-TNF treatment.ResultsThe mean duration of anti-TNF treatment was 26.2 months. Steroids were used in 29.1% of patients, while 54.8% were given additional immunosuppressant therapy (methotrexate or azathioprine). Only one anti-TNF agent was given in 70.4% of patients, while 29.6% received different anti-TNF agents for the duration of treatment. Serious infections were documented in 39 patients (19.6%), including respiratory tract infections (41%), urinary tract infections (30.8%), and skin infections (20.5%), and extrapulmonary tuberculosis in three patients (7.7%). Exposure to more than one anti-TNF agent was the only factor associated with a significant increase in the rate of infection (relative risk 1.9, 95% confidence interval 1.06–4.0, P=0.03).ConclusionSerious infections, including tuberculosis, were a common problem in patients receiving anti-TNF agents, and exposure to more than one anti-TNF agent increased the risk of serious infection.