Figure 1. Examination of MuSK antibody levels and B-cell subsets.

Flow cytometric analysis (n = 13) using standardized Human Immunology Project Consortium panels to identify (A) naive, memory, IgD−, and IgD+ B cells, along with (B) transitional B cells and (C) plasmablasts. Plasmablasts, IgD−, and IgD+ B cells were gated from CD19⁺ CD27⁺ memory B cells. Transitional cells were gated from CD19⁺ cells. MuSK = muscle-specific tyrosine kinase.