Advances in immunology and rheumatoid arthritis pathogenesis

The pathogenesis of Rheumatoid Arthritis (RA) is still largely unknown. From the seminal experimental studies, suggesting a multifactorial mechanism leaded by an antigen specific activation, the direct role of innate immunity in the disease progression has been recently emphasized. In the natural history of RA, characterized by the three phases of the induction, maintenance and tissue destruction, innate immunity seems to be the central player. On the other hands the recent advances about the molecules involved in the T lymphocyte activation, the T cell role in the mechanism of erosion, and the studies about chemochines in the homing and angiogenesis processes support the theory of an antigen specific activation of the adaptive immune system. Therefore, during RA, the pathogenesis of sinovitis and erosions comes from independent pathways involving either innate and adaptive immunity resulting in the final induction of the articular damage.