Positivity rates of antithyroid antibody, antinuclear antibody and thyroid peroxidase antibody in different types of vitiligo.

BACKGROUND: Vitiligo is associated with various autoimmune disorders, and organ-specific autoantibodies are frequently found in patients with this disorder. Vitiligo is classically divided into segmental vitiligo (SV) and nonsegmental vitiligo (NSV), and it is believed that the pathogenesis differs between these two types. As the NSV type is related to an autoimmune mechanism, autoantibody detection rates are likely to be higher in the NSV type than in the segmental type; however, no comparative studies have been performed. AIM: To analyse the rates of autoantibody positivity according to the clinical features in patients with vitiligo. METHODS: Rates of antithyroid antibody (Tg Ab), antinuclear antibody (ANA) and thyroid peroxidase antibody (TPO Ab) positivity were analysed and compared according to the sex, clinical type and age of onset of 807 patients with vitiligo. RESULTS: There were 106 patients with SV (13.1%) and 701 patients with NSV (86.9%). Tg Ab and ANA positivity did not differ between the SV and NSV types. A positive TPO Ab result was obtained in 16 patients with SV (15.1%) and 173 patients with NSV (24.7%). The TPO Ab positivity rate was significantly higher in NSV (χ² = 4.14, P < 0.05). The positivity rates of the three autoantibodies differed significantly according to age of onset (P = 0.001, P = 0.02 and P < 0.001 for Tg Ab, ANA and TPO Ab positivity, respectively). The TPO Ab positivity rate also showed a sex difference (P < 0.001). CONCLUSIONS: The positivity rates for the three autoantibodies showed differences according to age of onset and sex. The rates of Tg Ab and ANA positivity showed no significant differences according to clinical type, but the TPO Ab positivity rate was significantly different between SV and NSV. It appears likely that an autoimmune mechanism contributes to the pathogenesis of SV.