Smith MJ, et al. - This study, including patients with recent onset and long-standing autoimmune thyroid disease (AITD), entails an analysis of the phenotype of thyroid antigen-reactive B cells in the peripheral blood of those patients. Findings revealed that thyroid antigen-reactive B cells in blood samples from recent-onset patients expressed CD86, a marker of activation, and no longer appeared anergic. This finding indicated production of autoantibodies by these cells most likely consequent to their activation. Hence, this study reports the early loss of anergy in thyroid antigen-reactive B cells, an event that contributes to development of AITD.