Systemic lupus erythematosus: year in review 2019

Systemic lupus erythematosus (SLE) is an autoimmune disease with extreme heterogeneity and potentially involvement of any organ or system. Numerous unanswered questions and challenges in SLE always prompt further exploration. In 2019, great progress in various aspects of SLE emerged. Both the classification criteria and management recommendation for SLE were updated. New promising medications have been widely developed and tested, although subsequent clinical studies are warranted. As an emerging number of most notable studies in SLE were published in both clinical area and basic research in 2019, we aim to summarize the highest quality data on SLE regarding novel insights of pathogenesis, updated recommendations, hot-spot issues on clinical manifestations, new understanding of disease prognosis, and most importantly, the therapeutic advances in SLE in this review.