C3 and peeling skin syndrome: Lung involvement (OR = 2.50, 95% CI 1.11–5.59, p = 0.026), the presence of anti-SSA autoantibodies (OR = 3.63, 95% CI 1.12–11.8, p = 0.032), and low level of C3 (OR = 2.3, 95% CI 1.03–5.14, p = 0.043) were found to be significantly different between pSS patients with and without CNS involvement.