SERPINA1 and autoimmune disease: A1AT also has an effect on B lymphocytes, reducing their proliferation and function, as demonstrated in murine models of autoimmune diseases mediated by autoantibodies, such as rheumatoid arthritis, indicating a possible exploitation of A1AT as a therapeutic agent in autoimmune diseases (59) As for the effect on T cells, also the effect of A1AT on B lymphocytes seems to be indirect, mediated by the alterations in the extracellular milieu (Figure 2).