Since the introduction of biologics, many concerns about the increased risk of infections have been reported and, to date, the real impact of infections on the daily practice in the rheumatologic centers is still largely unknown. In this work, we evaluated the infection rates associated with the use of biologics in a large cohort of patients. A prospective study, between January 2010 and December 2013, enrolling 731 rheumatic patients, was performed. Demographic and disease characteristics, therapies, comorbidities, and infectious events were recorded and statistically analyzed by multivariate analysis. Two-hundred thirty-five infectious episodes were observed in 28.4 % of patients. About total infections, bacteria were identified in 70.6 % of total cases and viruses in 18.3 %. The most common site of not-serious infection was the urinary tract. Duration of disease, longer follow-up, concomitant steroid therapy, and comorbidities were significantly associated with not-serious infection. In our cohort, 17 episodes fulfilled the criteria of serious infection and occurred in 17 different patients (2.3 %), the majority involving the lower respiratory tract. Serious infections were associated with the beginning of biologics in older age. Our prospective, observational study showed that, in daily practice, a lesser rate of serious as well as not-serious infections may be observed in rheumatic patients treated with biologics than those reported in previous papers. The most common sites of not-serious infections are both the urinary and the respiratory tracts, and for serious infections, the respiratory tract. When pathogens were isolated, we did not find any multidrug-resistant organism.
Keywords: Biological therapies; Infection and arthritis; Rheumatoid arthritis; Serious infection; Spondyloarthropathies; TNF inhibitor.