Briefly, Italian young pSS patients had significantly higher frequency of dry mouth, dry eyes, lymphadenopathy, chronic fatigue, anti-Ro/SSA positivity, and leukopenia and lower frequency of cryoglobulinemia, C4 hypocomplementemia, skin vasculitic ulcer, lymphoma, and MSG FS ≥ 1 compared to the Greek young. Here, TRIM21 is linked to Decreased total leukocyte count.