Objective: To study evolution of pSS immunological profile, impact on pSS activity and the long-term evolution of patients with atypical auto-antibodies in a bicentric cohort of patients with pSS (n=445, mean age 53.6+/-14years, mean follow-up 76.1+/-51months).
Results: 212 patients were SSA positive and 131 were both SSA and SSB positive. During follow-up, SSA antibodies disappear in 8 patients; 2 of them exhibit new systemic complications of pSS. 68 patients had cryoglobulinemia. 52 patients had other anti-nuclear antibodies (ANA) specificities: anti-RNP (n=12), anti-centromere (n=14), anti-DNA native (n=19), anti-Scl70 (n=3), anti-JO1 (n=3), anti-Sm (n=3) and anti-histone (n=1). Fourteen patients developed ANA-associated auto-immune disease during the follow-up: 5 polymyositis (mean apparition delay 78months), 6 systemic lupus erythematosus (mean occurrence delay 77months) and 2 systemic sclerosis (mean occurrence delay 133+/-64months). Among these 14 patients, only three presented atypical-ANA at pSS diagnosis. Cryoglobulinemia and anti-SSA and SSB antibodies at diagnosis were associated with new systemic involvements.
In conclusion: Cryoglobulinemia and SSA/SSB positivity are associated with systemic activity after diagnosis in pSS. Although atypical ANA are found in 12% of the cases, long-term evolution to ANA associated auto-immune diseases concerned patients with active immunological profile and extra-glandular manifestations.