RESUMO
BACKGROUND: A role for nondesmoglein antigens in the pathogenesis of pemphigus vulgaris (PV) has been suggested in several studies. Acetylcholine receptors (AchR), are one of the most important groups of these antigens. However, the exact role of both antimuscarinic (m) and nicotinic (n) AchR antibodies (Abs) is still controversial. AIM: To evaluate anti-desmoglein (Dsg)1, Dsg 3 and anti-γ/ε nAchR Abs values in patients with PV before and 3 months after rituximab (RTX) treatment, and to assess their correlation with disease severity. METHODS: In total, 75 patients with PV (26 men, 49 women) who were planned to receive RTX were enrolled. Disease activity was assessed by using the Pemphigus Disease Area Index (PDAI). Using ELISA, anti-Dsg1,3 and anti-γ/ε nAchR Abs were determined at baseline and 3 months after RTX treatment. RESULTS: At baseline, 53.33% patients had positive values for anti-Dsg1, 89.33% for anti-Dsg3 and 13.33% for anti-γ/ε nAchR Abs. All patients with positive anti-γ/ε nAchR Abs had the mucocutaneous phenotype. PDAI, anti-Dsg1,3 and anti-γ/ε nAchR values were dramatically decreased 3 months after RTX infusion (P < 0.001). There was a significant positive correlation between disease activity and anti-γ/ε nAchR values at baseline (P = 0.04), whereas no significant correlation was observed between anti-Dsg1,3 and anti-γ/ε nAchR values at baseline and 3 months after RTX infusion. CONCLUSION: The reduction in anti-γ/ε nAchR Abs with clinical improvement in this study may suggest a synergic role for anti-γ/ε nAchR Abs with anti-Dsg1,3 Abs, or it could be an epiphenomenon.