The role of non-desmoglein (Dsg) antigens in pemphigus vulgaris (PV) pathogenesis have been suggested in several studies. Acetylcholine receptors (AchR), are one of the most important groups of these antigens. However, the exact role of both anti-muscarinic(M) and nicotinic(N) AchR antibodies(Abs) is still controversial.We designed this prospective study to evaluate the anti-Dsg1,3 and anti-γ/ε N AchR Abs values in PV patients before and 3 months after rituximab(RTX) as well as their correlation with disease severity.Seventy-five PV patients (26 males and 49 females) who planned to receive RTX were enrolled. Disease activity was assessed by using the pemphigus disease area index (PDAI) score. Anti-Dsg 1,3 and anti-γ/ε N AchR Abs were determined at baseline and 3 months after RTX by using enzyme-linked immunosorbent assay (ELISA).At baseline, 53.33% patients had positive anti-Dsg1, 89.33% had positive anti-Dsg3 and 13.33% had positive anti-γ/ε N AchR Ab values. All patients with positive anti-γ/ε N AchR Ab suffered from mucocutaneous phenotype. PDAI score, anti-Dsg1,3 and anti-γ/ε N AchR values dramatically decreased 3 months after RTX infusion (P<0.001). There was a significant positive correlation between disease activity and anti-γ/ε N AchR values at baseline (P:0.044). No significant correlation was observed between anti-Dsg1,3 and anti-γ/ε N AchR values at baseline and 3 months after RTX infusion.The reduction in anti-γ/ε N AchR Ab with clinical improvement in this study may suggest a synergic role for anti-γ/ε N AchR Ab with anti-Dsg1,3 Abs or could be an epiphenomenon.
Authors: R Toosi, A Teymourzadeh, H Mahmoudi, K Balighi, M Daneshpazhooh