No difference in plasma concentration of C2, C3, C5, and MBL was observed between corticosteroid-naïve and -treated AChR-MG patients, and no correlation was found between the protein concentrations and the duration of IS treatment (data not shown), with the exception of MBL levels, that showed a trend to be higher in corticosteroid-naïve than corticosteroid-treated patients. Here, MBL2 is linked to myasthenia gravis.