LGI1 and viral encephalitis: Single-cell approaches from the CSF of patients with long-lasting progressive LGI1 encephalitis identified IgG1, IgG2, and IgG4, LGI1-specific CD3- CD14- CD16- CD20+ CD27+ memory B cells and CD3- CD14- CD16- CD138+ ASCs (could be both SLPBs or LLPCs); V gene sequences of the LGI1-specific B cells were mutated (248).