IFNA1 and systemic sclerosis: Since it was previously shown that SSc plasma/sera have interferogenic effects on pDCs in vitro due to the presence of autoantibodies (anti-scleroderma 70—Scl-70 or anti-centromere—ACA), we used a blocking anti-CD32 antibody to inhibit antibody-mediated pDC activation/IFN-α release8,9,23.