CS and Sjogren syndrome: pSS: Primary Sjögren’s syndrome; ANA, antinuclear antibodies; Anti-SSA, anti-SSA antinuclear antibodies; Anti-SSB, anti-SSB antinuclear antibodies; RF, rheumatoid factor; Igs: immunoglobulins; Cs: complement factors; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; OSDI: ocular surface disease index, ST: the Schirmer’s test; CFS: corneal fluorescein staining score; TBUT: tear break-up time