MuSK antibody positive myasthenia gravis plasma modifies MURF-1 expression in C2C12 cultures and mouse muscle in vivo

These results provide the first evidence that MuSK-MG plasma can influence expression of an atrophy-related protein, and preliminary evidence that a facial muscle, the masseter, is more susceptible to this effect. They indicate the need for further studies on muscle atrophy, MuSK-MG antibodies, the effects of steroids, and the intracellular pathways involved.