When do you test for myasthenia antibodies beyond AChR and MuSK?  

I always check an LRP4 antibody. This is helpful to prognosticate and to determine specific treatments. For example, MuSK Ab (+) MG, as an IgG4 mediated disorder, responds particularly well to B cell therapies and FcRn treatments, but since IgG4 poorly activates complement, a complement inhibitor wo...