Low serum levels of vitamin C in patients with oral lichen planus: a case-control study

Objective: To clarify the relationship between oral lichen planus (OLP) and systemic oxidative stress, we examined serum antioxidant and urinary oxidative stress marker levels in patients with OLP. Methods: Fifteen female patients with clinical and histopathological diagnoses of OLP were enrolled in this study. The mean patient age was 67.6 years (range, 56-81 years). Ten age- and sex-matched volunteers without oral mucosal lesions were selected as a control group. Serum levels of the antioxidants vitamin A, vitamin C, vitamin E, folate, zinc, uric acid, and superoxide dismutase activity were evaluated. Urinary levels of the oxidative stress marker 8-hydroxy2'-deoxyguanosine (8-OHdG) were measured by enzyme immunoassays. All values were compared between the two groups. Results: The mean value of serum vitamin C was lower in the OLP group (5.73 +/- 2.34 mu g/mL) than in the control group (9.22 +/- 3.65 mu g/mL; P = 0.0125). Serum levels of vitamin A, vitamin E, folate, zinc, uric acid, and superoxide dismutase activity did not significantly differ between the two groups. The mean values of creatinine adjusted urinary 8-OHdG were 10.1 +/- 7.34 ng/mg creatinine in the OLP group and 13.7 +/- 12.7 ng/mg creatinine in the control group; these values did not significantly differ between the two groups (P = 0.5189). Conclusion: Our results suggested that serum levels of vitamin C are low in patients with OLP. However, oxidative stress (determined by measurement of urinary 8-OHdG level) was not significantly higher in patients with OLP. Thus, the relationship between OLP and systemic oxidative stress was not fully elucidated in this study. (c) 2021 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.*