Modulation of Serum Anti-thyroglobulin and Anti-thyroid Microsomal Autoantibody Levels by Levamisole in Patients With Oral Lichen Planus

Background/Purpose: Several types of serum autoantibodies including anti-thyroglobulin (TGA) and anti-thyroid microsomal autoantibody (TMA) were detected in patients with oral lichen planus (OLP). This study evaluated whether Chinese OLP patients had significantly higher frequencies of serum TGA and TMA than healthy control subjects, and whether levamisole treatment could modulate serum TGA and TMA levels in Chinese OLP patients. Methods: This study used a semi-quantitative microtiter particle agglutination test to measure the baseline serum levels of TGA and TMA in a group of 278 Chinese OLP patients and 53 healthy control subjects. Forty-one TGA-positive and 48 TMA-positive OLP patients were treated with levamisole for a complete period of 1 year, and their serum TGA and TMA levels were measured after treatment. Results: We found that the frequencies of serum TGA and TMA in patients with OLP (21.6% and 24.5%, respectively), erosive OLP (21.8% and 24.5%, respectively), or non-erosive OLP (19.0% and 23.8%, respectively) were significantly higher than those (1.9% and 1.9%, respectively) in healthy control subjects. After 1 year of levamisole treatment, the serum TGA and TMA titers decreased partially or became undetectable in 36 (88%) TGA-positive and 46 (9604)) TMA-positive OLP patients. At least 9 months or 3 months of levamisole treatment were needed to reduce the mean serum TGA or TMA titer to a significantly lower level in OLP patients, respectively. Conclusion: Significantly higher frequencies of serum TGA and TMA were found in Chinese OLP patients than in healthy control subjects. After 1 year of levamisole treatment, serum TGA and TMA levels were reduced partially or became undetectable in approximately 88% of TGA-positive and 96% of TMA-positive OLP patients.