Fig. 1.

Study flow diagram. The initial cohort consisted of 160 patients with clinically suspected AChR Ab-negative (RIPA) generalized MG. Of these, 104 patients were confirmed clinically, and 89 were finally identified as AChR Ab-negative generalized MG, excluding those seropositive for clustered AChR Ab in CBA. Following MuSK-ELISA, confirmatory antibody testing was performed using CBA and RIPA. Ab antibody, AChR acetylcholine receptor, CBA cell-based assay, dSN-MG double seronegative generalized myasthenia gravis, ELISA enzyme-linked immunosorbent assay, MuSK muscle-specific tyrosine kinase, NA not available, RIPA radioimmunoprecipitation assay