B cell targeted therapies in autoimmune disease

Purpose of review FDA-approved B cell-targeted therapy has expanded to a multitude of autoimmune diseases ranging from organ specific diseases, like pemphigus and multiple sclerosis, to systemic diseases such as ANCA-associated vasculitis, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). In this review, we discuss the variability in response to B cell-targeted therapies with a focus on the diversity of human B cells and plasma cells, and will discuss several of the promising new B cell-targeted therapies. Recent finding The pathogenic roles for B cells include autoantibody-dependent and autoantibody-independent functions whose importance may vary across diseases or even in subsets of patients with the same disease. Recent data have further demonstrated the diversity of human B cell subsets that contribute to disease as well as novel pathways of B cell activation in autoimmune disease. The importance of eliminating autoreactive B cells and plasma cells will be discussed, as well as new approaches to do so. Summary The past several years has witnessed significant advances in our knowledge of human B cell subsets and function. This has created a nuanced picture of the diverse ways B cells contribute to autoimmunity and an ever-expanding armamentarium of B cell-targeted therapies.