Study on thyroid autoimmunity of oral lichen planus and oral lichenoid mucositis

Oral lichen planus (OLP) and oral lichenoid mucositis (OLM) are immune-mediated mucosal conditions with multifactorial etiology, with similar clinical and histological characteristics. Diagnosis should be confirmed considering both clinical and histological aspects. Some subsets are associated with immune-mediated thyroid dysfunction due to anti-thyroid peroxidase antibody (TPO) and anti-thyroglobulin antibody (TGA).

To ascertain the presence of thyroid autoantibodies in a cohort of patients with OLP and OLM from a South Indian population.

This observational study comprised 21 patients with 7 cases of OLP (Group I) and 14 cases of OLM (Group II) who reported from 2021-2023 for 2 years. Serum anti-thyroid antibodies including TPO and TGA was estimated using chemiluminescence immunoassay technique along with clinical and histological aspects. Altered levels of serological parameters were compared with respect to these auto-immune conditions.

Increased level of thyroid autoantibodies was observed in three (42%) of the seven cases of OLP. Two cases had elevated TPO (3-4 folds) and TGA (6-38 folds) and the subjects were above 50 years. Seven (50%) of the 14 OLM cases exhibited increased thyroid autoantibody levels and were above 50 years, predominantly females. TPO levels were increased in the range of 12 to 178 and TGA from 2 to 136 folds. Duration of these lesions were more than a year.

Increased thyroid autoantibodies observed in both OLP and OLM represent an underlying autoimmune response. Long-term monitoring will enable the clinicians to correlate the antibody levels with the management of these lesions.