All 21 patients in our cohort met the two criteria for the diagnosis of SS described by Baer [17]: (1) having objective markers of dry eye and/or salivary gland parenchyma abnormalities characteristic of SS detected using imaging techniques, and (2) serologic evidence of SS such as anti-Ro/SSA antibodies (with or without anti-La/SSB antibodies) or, alternatively, a combination of an ANA ≥1:320 with a positive RF. This evidence concerns the gene TRIM21 and Keratoconjunctivitis sicca.