Transcobalamin receptor antibodies in autoimmune vitamin B12 central deficiency

Vitamin B12 is essential for myelination, and its deficiency leads to neurological deficits such as loss of coordination, memory loss, and psychosis. In this cutting-edge work, Pluvinage et Al. described for the first time that autoantibodies (Abs) against the transcobalamin receptor (CD320), discovered by PhIP-seq, were associated in eight patients with neurological disorders (i.e progressive tremor, ataxia, encephalopathy and psychosis). Anti-CD320 Abs were associated with normal serum B12 levels, but almost undetectable in cerebrospinal fluid (CSF). Immunomodulatory treatment and high-dose systemic B12 supplementation were useful for these patients with anti CD320 Abs, supporting the autoimmune etiology of the disorder.