Misdiagnosis of narcolepsy caused by a false-positive orexin-A/hypocretin-1 enzyme immune assay

The diagnosis of narcolepsy is based on clinical history, sleep studies, and, in some cases, cerebrospinal fluid orexin-A/hypocretin-1 measurement. The gold standard for orexin measurement is the radioimmunoassay but other commercial kits are also available, such as the enzyme immune assay (EIA). The specificity of orexin EIA in humans is unknown. We report four cases where orexin levels were measured by EIA and resulted in false positives and the misdiagnosis of narcolepsy. Therefore, orexin EIA measurement should be strongly discouraged in a clinical setting. CITATION: Sarkanen T, Sved G, Juujärvi M, Alakuijala A, Partinen M. Misdiagnosis of narcolepsy caused by a false-positive orexin-A/hypocretin-1 enzyme immune assay. J Clin Sleep Med. 2022;18(8):2075-2078.