One year in review 2019: pathogenesis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease influenced by both genetic and environmental factors. Over the last few years, particular attention has been given to novel genes and to the close interaction between genetic factors and epigenetic mechanisms. Research has also focused on the influence of environmental factors on disease development, and on new mechanisms of the innate and adaptive immune system that can influence the different stages of RA. However, there are still several aspects of the disease that need further investigation. Shedding some light on the different aspects of RA pathogenesis will help to improve the current diagnostic tools and to identify new targets for the development of disease-modifying therapies. Thus, in this review we summarise the new insights in RA pathogenesis, resulting from literature research data published in the last year.