Rheumatoid arthritis and infections: not only a coincidence

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease affecting the synovial membrane damaging the cartilage and bone and leading to destructive arthritis, if left untreated [1]. In fact, RA is not a joint confined disease, as extra-articular manifestations and multi-systemic involvement are among the specific features of the disease. Of importance are the cardiovascular and respiratory system RA-associated diseases [2, 3]. Therefore, morbidity, life expectancy, and mortality were demonstrated to be increased in patients with RA in comparison with the general population [4, 5]. Interestingly, infections contribute to a critical portion of the cases [6].