Anti-M3 Muscarinic Acetylcholine Receptor Autoantibody in the Serum and Saliva of Oral Lichen Planus Patients: A Case-Control Study Publisher

Summary: Can low saliva flow indicate more than just autoantibodies in oral lichen planus? A study finds reduced saliva but no increase in anti-M3R autoantibodies in OLP patients. #OralHealth #Autoimmunity

Aghahosseini F ; Koochaki M ; Moosavi MS ; Mirzaeidizgah I ; Khayamzadeh M
Source: Health Science Reports Published:2026

Abstract

Background and Aims: Oral lichen planus OLP) is a chronic, T-cell–mediated disease frequently accompanied by xerostomia. Prior work suggests reduced salivary M3 muscarinic acetylcholine receptor (M3R) may contribute to hyposalivation. We investigated whether anti-M3R autoantibodies are elevated in serum and saliva of OLP patients compared with healthy controls. Methods: In this case–control study, we enrolled 30 patients with OLP and 30 matched healthy controls. Exclusion criteria eliminated confounders of salivary dysfunction. Unstimulated and stimulated salivary flow rates were collected under standardized conditions; venous blood was drawn. Anti-M3R autoantibody levels were measured in serum and in both saliva fractions using enzyme‑linked immunosorbent assay. Group comparisons used independent t-tests for approximately normal variables (flow rates) and nonparametric tests for nonnormal variables (autoantibodies). Results: Stimulated salivary flow was lower in OLP versus controls (0.67 ± 0.12 vs. 1.20 ± 0.22 mL/min; n = 30 per group). Unstimulated flow was likewise lower (0.51 ± 0.09 vs. 0.90 ± 0.11 mL/min). Xerostomia severity was higher in OLP (mean XI 43.64 ± 31.7) than controls (17.23 ± 2.06). Between-group differences in anti-M3R autoantibody levels were not significant in serum or in unstimulated or stimulated saliva. Conclusion: OLP patients showed significantly reduced stimulated and unstimulated salivary flow and higher xerostomia scores, but no elevation of anti-M3R autoantibodies in serum or saliva versus controls. These findings suggest that mechanisms other than circulating anti-M3R autoantibodies—such as receptor functional alterations, salivary composition changes, or other immune pathways—may underlie xerostomia in OLP. Future studies should consider more sensitive detection methods, concurrent immunoglobulin isotype assessment, and tissue-level analyses to clarify M3R-related dysfunction. © 2026 The Author(s). Health Science Reports published by Wiley Periodicals LLC.