Autoantibody testing
Twelve participants (67%; IVIG n=7/10 (70%), placebo n=5/8 (63%)) had autoantibody testing. One participant (placebo n=1) was positive for LGI1 antibodies, and one participant (placebo n=1) was positive for MOG antibodies. Two additional participants (IVIG n=2) were positive for IgG binding to the surface of live neurons, indicating the presence of IgG antibodies binding to neurons, but negative for antibodies to the specific antigens tested, indicating the presence of undefined IgG antibodies that could be pathogenic.