[Autoantibodies and antibody-secreting cells]

Autoantibodies are a hallmark of systemic and organ-specific autoimmune diseases. They contribute both directly and indirectly to the pathogenesis of these diseases. There is now a rising interest in cells that secrete (auto)antibodies. Antibody-secreting cells are plasma blasts and plasma cells that differentiate from B cells following antigen encounter. The view held by the immunology community for decades was that (auto)antibodies are produced by short-lived cells arising from chronic (auto)antigen-mediated B cell stimulation. However, it was recently shown that plasma cells can survive in niches in the bone marrow and inflamed tissues for months to years. These long-lived plasma cells continuously secrete (auto)antibodies without the need for any additional antigen stimulation. They are resistant to immuno-suppressants and are not eliminated by B-cell depleting therapies. Depending on which antibodies are secreted, this plasma cell memory may play an important role in maintaining protective humoral immunity or in the pathogenesis of autoimmune diseases. Consequently, strategies targeting long-lived autoreactive plasma cells may provide new therapeutic options in the treatment of autoimmune diseases.