TRIM21 and autoimmune disease: A relevant observation deriving from the analysis of similar previously published studies is that the pSS classification criteria adopted are not homogeneous and, more importantly, the proportion of patients with circulating anti-Ro/SSA antibodies, which represent markers of autoimmune disease and key elements for the diagnosis and prognosis definition of pSS, is rather low compared to that characterizing our cohort and other published studies (18).