Comparison of the Specificity, Sensitivity and Clinical Correlation of CBA, RIPA and ELISA Assay in Detecting AChR and MuSK IgG of Myasthenia Gravis: a National Multicenter Study

Myasthenia gravis (MG) is a neuromuscular junction (NMJ) disorder mediated by autoantibodies against AChR, MuSK or other autoantigens located at the post synaptic membrane of the neuromuscular junction. Presence of autoantibodies specific for AChR or MuSK can establish diagnosis in conjunction with clinical presentations. In most established guidelines for the diagnosis and treatment of myasthenia gravis, determination of AChR and MuSK antibodies has been recommended. Radioimmunoprecipitation assay (RIPA), enzyme-linked immunosorbent assay (ELISA), and cell-based assay (CBA) are all commercially available and have been adopted for autoantibody detection by most referring neurologists. At present, specificity and sensitivity of these methods have not been compared in large cohorts within a context of stringent quality control. As a consequence, there are no national or international consensus regarding selection of methods and interpretation of results, resulting in challenges to neurologists managing these patients. To this end, the investigators proposed to conduct a multicenter, double-blind, prospective study to compare the sensitivity and specificity of CBA, RIPA and ELISA assays to detect AChR and MuSK antibodies.