Children with Narcolepsy type 1 have increased T-cell responses to orexins.

Narcolepsy type 1 (NT1) is caused by severe loss of the orexin neurons, and is highly associated with HLA DQB1*06:02. Using intracellular cytokine staining, we observed a higher frequency of IFN-γ- and TNF-α-producing CD4+ and CD8+ T-cells in response to orexins in 27 children with NT1 compared to 15 healthy control children. Conversely, no such difference was observed between 14 NT1 and 16 HC adults. In addition, priming with flu peptides amplified the T-cell response to orexins in children with NT1. Our data suggests that NT1 may be caused by an autoimmune T-cell response to orexins, possibly triggered by flu antigens.