One Year Cross-Sectional Study Of Evaluation Of Association Between Vitiligo And Thyroid Autoimmunity

Abstract

Background: Vitiligo is a common acquired dermatological disorder characterized by depigmented macules and patches. Over the years, researchers have hypothesized many theories for its cause but autoimmune etiology appears most plausible. This is supported by the association of vitiligo with other autoimmune conditions, most commonly thyroid disorders. Vitiligo has been noted to precede thyroid dysfunction in many patients. The assessment of anti-thyroperoxidase (TPO) antibodies in vitiligo patients can be used as a sensitive tool for early detection of subclinical autoimmune thyroid disease. Aim: 1. To study the relation of vitiligo with demographic data of the participants (like age, sex, duration of lesions, etc.). 2. To evaluate the prevalence of thyroid autoimmunity in vitiligo patients. Materials and methods: This was a cross-sectional study conducted at Dr. Prabhakar Kore KLE Hospital and Medical Research Centre, Belgaum from January to December 2012. A total of 100 patients clinically diagnosed (old and new) as having vitiligo were enrolled in the study. Patients with known thyroid disease on supplementation therapy or anti-thyroid medication, those who had undergone thyroid surgery, patients with other causes of leucoderma or those who did not provide informed consent were excluded from the study. Serum anti-TPO antibodies were measured in all the patients. The serum was considered positive for anti-TPO antibodies if the concentration was greater than 35 IU/ml (Normal range: 0.00 – 35 IU/ml was labelled ‘negative’). Detailed profiling (descriptive and comparative) of the study particpants vis-à-vis their anti-TPO antibody status was done using SPSS version 16.0. Non-parametric tests (Mann Whitney U test, Chi-squared test and Fisher’s Exact Probability Test) were applied to test statistical significance at a p < 0.05. Results: The attendance of females was higher than males. Females manifested vitiligo around 10 years earlier than males and this difference was significant (p=0.017). The prevalence of anti-TPO antibody positivity was found to be 28%. We found a significant relationship of anti-TPO Ab with higher mean age (p=0.037) and with presence of coincident precipitating ‘trigger’ factor (p=0.037) in the participants. Other parameters did not have significant association with anti-TPO positivity. Conclusion: According to our study, none of our vitiligo patients had symptoms or signs of thyroid disease at the time of presentation but on biochemical evaluation, anti-TPO antibodies were found in 28% of patients. Hence, we recommend screening of these patients for anti-TPO antibodies