Anti-Neuronal Nuclear Antibody 3 Autoimmunity Targets Dachshund Homolog 1

The antigen specificity of Anti-Neuronal Nuclear Antibody-type 3 (ANNA3)-IgG is unknown. We identified Dachshund-homolog 1 (DACH1) as the ANNA3 autoantigen and confirmed it by antigen-specific assays, immunohistochemical colocalization and immune absorption experiments. Patients' median age was 63.5 years (range, 49-88); 67% were female. Neurological manifestations (information available for 30 patients) included one or more of neuropathy, 12; cognitive difficulties, 11; ataxia, 8; dysautonomia, 7. Evidence of a neoplasm was present in 27 of 30 (90%), most of neuroendocrine lineage. DACH1-IgG is rare and represents a novel proposed biomarker of neurological autoimmunity and cancer. ANN NEUROL 2022;91:670-675.