IGHG4 and myeloid sarcoma: Across patients and controls, T cells (CD4+ > CD8+) and myeloid-lineage cells dominated in CSF, as described previously.32 However, when comparing LGI1- and CASPR2-AIE patients with the IIH and MS controls, we found a pronounced increase of CSF antibody-secreting B lymphocytes (ASCs expressing CD19, CD38 and IGHG4) both in LGI1-AIE and in CASPR2-AIE patients compared with the control groups (Fig. 1C–F).