CD40LG and peeling skin syndrome: There were significant differences in RF, IgA, IgG, C3, C4, and ESR levels between pSS patients and HCs (P value<0.001; P value<0.001; P value<0.001; P value<0.001; P value=0.025; P value<0.001; respectively), but no significant difference was found in IgM and CRP levels between them (P value=0.919; P value=0.187; respectively).