MUSK and systemic lupus erythematosus: In the SLE cohort, two SLE patients were positive for MOG autoantibodies; one SLE patient and two SLE-neuro patients were positive for AQP4 autoantibodies; one SLE patient, one HD, and three SLE-neuro patients were positive for AChR autoantibodies; and four SLE patients, one HD, and one SLE-Neuro patient were positive for MuSK autoantibodies.