Autoantigen TRIM21/Ro52 is expressed on the surface of antigen-presenting cells and its enhanced expression in Sjögren’s syndrome is associated with B cell hyperactivity and type I interferon activity

Key messagesWhat is already known on this subject ► TRIM21/Ro52 is a major autoantibody target in pSS and regulates downstream signalling of type I IFNs. ► Apoptosis-associated surface expression of TRIM21on non-immune cells is associated with enhanced binding of anti-Ro52 autoantibodies. What this study adds► Enhanced expression of TRIM21 in type I IFNproducing immune cells from patients with pSS is associated with an IFN signature and B cell hyperactivity.► TRIM21 is expressed on the cell surface of nonapoptotic antigen-presenting cells and its expression is enhanced by IFN-β exposure. How might this impact on clinical practice► Elucidating the relationship between type I IFNs and anti-SSA autoantibodies in pSS may aid identification of promising therapeutic avenues.