AN AUTOIMMUNE ETIOLOGY IS HYPOTHETICALLY IN- VOLVED IN THE PHYSIOPATHOLOGY OF NARCOLEPSY, ALTHOUGH THERE IS CONFLICTING EVIDENCE.1-4 This disorder is related to abnormalities in the hypothalamic hypocre- tin (orexin) system with a characteristic deficiency in CSF Hypo-

AN AUTOIMMUNE ETIOLOGY IS HYPOTHETICALLY INVOLVED IN THE PHYSIOPATHOLOGY OF NARCOLEPSY, ALTHOUGH THERE IS CONFLICTING EVIDENCE.1-4 This disorder is related to abnormalities in the hypothalamic hypocretin (orexin) system with a characteristic deficiency in CSF Hypocretin-1 (Hcrt-1) levels in narcoleptic patients.5 The aim of our study was to investigate the presence of hypothalamic-specific antibodies in the serum and CSF of narcoleptic patients, previously tested for CSF Hcrt-1 status, by using immunohistochemistry and the screening of a hypothalamic cDNA expression library. The latter is a systematic and unbiased approach method widely used for the detection of onconeural antigens eliciting specific immune responses.