The specificity of monoclonal anti citrulline protein antibodies - reply to Dr Holmdahl's letter.

Rikard Holmdahl has commented on our recently published paper on specificity and function of human monoclonal antibodies (mAbs) from synovial plasma cells that react with citrullinated proteins and peptides (1). He also comments on our previous study from 2013 (2) that was based on mAbs generated from synovial B cells. Dr Holmdahl's letter provides us with an opportunity to discuss and clarify some methodological issues concerning RA monoclonal autoantibody expression, specificity, and functionality. In our eyes, cloning and characterization of human monoclonal autoantibodies from patients represents an important approach to the understanding of origins and functions of autoantibodies in the pathogenesis of immune-mediated diseases. In fact, the RA field has been especially active on making use of mAbs derived from the immunoglobulin sequences from patient-derived B cells and plasma cells. This article is protected by copyright. All rights reserved.