Expanded B cell clone in the cerebrospinal fluid of a patient with GABAA-R encephalitis

Encephalitis associated with antibodies against the neuronal gamma-aminobutyric-acid-A receptor (GABAA-R) is a rare form of autoimmune encephalitis. The pathogenesis is still unknown but autoimmune mechanisms were surmised. Here we identified a strongly expanded B cell clone in the cerebrospinal fluid of a patient with GABAA-R encephalitis. We expressed the antibody produced by it, and showed by ELISA and immunohistochemistry that it recognizes the GABAA-R.