Antibodies to DNA repair proteins in headache with neurological deficits and cerebrospinal fluid lymphocytosis (HaNDL) patients.

Autoimmune mechanisms have been implicated in the pathogenesis of headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL). Pooled sera of five HaNDL patients and 30 controls (10 multiple sclerosis patients, 10 migraine patients, 10 healthy controls) were screened by protein macroarray. All sera were also individually subjected to immunoprecipitation with neuroblastoma cells and the bound antigens were identified by mass spectrometry. Antibodies to three DNA repair proteins (mitogen-activated protein kinase-4, DNA-dependent protein kinase catalytic subunit, DNA excision repair protein ERCC-6) were identified by both macroarray and immunoprecipitation methods in 3/5 HaNDL sera, but in none of the controls. The presence of DNA repair protein antibodies indicates DNA damage and provides further support for the inflammatory etiology of HaNDL.