Anti-ganglionic nicotinic acetylcholine receptor 3 subunit antibody as a potential biomarker associated with lupus enteritis

Objectives We aimed to identify the clinical significance of anti-ganglionic nicotinic acetylcholine receptor alpha 3 subunit (gAChR alpha 3) antibodies (Abs) in patients with systemic lupus erythematosus (SLE). Methods This retrospective study comprised adult patients with SLE who visited our hospital from 2006 through 2019. Anti-gAChR alpha 3 Abs were measured in the sera of patients with SLE using a luciferase immunoprecipitation system assay. The clinical features of the patients with or without anti-gAChR alpha 3 Abs were compared. We evaluated whether the Abs predict a specific manifestation and affect its development or relapse rate. Results Among 144 patients, anti-gAChR alpha 3 Abs were detected in 29 patients. Lupus enteritis (LE) was more frequently seen in anti-gAChR alpha 3 Ab-positive patients than negative patients. The levels of anti-gAChR alpha 3 Abs were significantly higher in patients with LE than those with other lupus manifestations. Logistic regression analysis revealed the anti-gAChR alpha 3 Abs were independent predictors for LE (odds ratio 6.2, 95% confidence interval 1.9-20.3, p = .002). Kaplan-Meier analysis showed the rate of LE development or relapse from the time of sera collection was higher in anti-gAChR alpha 3 Ab-positive patients than in negative patients (p < .001). Conclusion Anti-gAChR alpha 3 Abs could be a predictive biomarker for the development or relapse of LE.