Abstract
Background: The precise pathogenesis remains not fully understood. However, it is thought to involve an autoimmune process directed against melanocytes. Thyroid disorders and autoimmune thyroid diseases have been shown in some reports to be associated with vitiligo. Additionally, there is limited and conflicting data examining the association of antinuclear antibodies (ANA) with vitiligo.

Methods: We conducted a cross-sectional study among 50 vitiligo patients diagnosed according to established clinical criteria at King Khalid University Hospital, Riyadh from January 2008 through December 2010. Blood samples were obtained from the study participants and were tested for antinuclear antibodies (ANA), thyroid stimulating hormone (TSH) and free thyroxin hormone (T4).

Results: Males represented 62% and the mean age was 28.2±11.0 years. A total of 20 (41.7%) had positive ANA values (titer ≥1:40). The mean TSH level was 2.69±2.17 µIU/mL. The mean free T4 level was 16.40±2.74 pmol/L and all patients were in the normal range (10.3-25.8 pmol/L). There were no statistically significant associations between ANA and age, gender, extent of skin lesion, face inclusion, and free thyroxin levels. On the other hand, positive ANA level had significant association with TSH level (p=0.041). With exception of ANA, TSH level had no statistically significant associations with the above variables.

Conclusions: The results of the current study showed higher prevalence of ANA in vitiligo patients, probably suggesting autoimmune process. The current finding may need to be confirmed in a larger prospective multicentric study before recommending periodic screening of patients with vitiligo for thyroid function and antithyroid antibodies.

Key words: Vitiligo, autoimmune, thyroid disease, antinuclear antibodies