Autoantibodies other than antineutrophil cytoplasmic antibodies are not positive in patients with psoriasis vulgaris.

There is a great deal of evidences that a link may exist between psoriasis and autoimmunity. In this study, thirty-six patients with psoriasis vulgaris and twenty healthy controls were screened for antinuclear antibody (ANA), anti-ds-DNA antibodies, anti-SSA (anti-Ro), anti-SSB (anti-La), anti-Scl-70, anti-Jo-1, rheumatoid factor (RF), C3 and C4 levels, IgG and IgM anti-cardiolipin antibodies (aCL) and anti-neutrophil cytoplasmic antibodies (pANCA and cANCA) in order to determine the role of autoimmunity in the pathogenesis. In addition, the MPO-ANCA test was performed on pANCA-positive patients. In ANA screening, one patient showed 1/80 granular positivity. No positive results were obtained from either the study or control groups for anti-dsDNA, anti-SSA, anti-SSB, anti-Scl-70, or anti-Jo-1 determinations. For RF, 5.8% of the patients had positive values. Both C3 and C4 levels were found to be significantly elevated in psoriasis patients compared to healthy controls (p<0.001). IgG-aCL and IgM-aCL positivity was not significantly different between the two group. pANCA was positive in 33.3% of the patients and a significant difference was observed between study and control groups (p<0.05). MPO-ANCA was negative in all the pANCA-positive patients. In conclusion, only serum C3 and C4 levels and pANCA determinations showed significant differences when compared to healthy controls. Our findings may be evidence of associations between autoimmunity and psoriasis vulgaris. However, more detailed studies in this field need to be done to determine the relationship between them.