Increased Numbers of CD4 + T‐Cells in the Hypocretin/Orexin Region of Narcolepsy Type 1, 2026, Shan et al

[Jaybee00]

Narcolepsy type 1 (NT1) is presumed to be an autoimmune disorder caused by hypothalamic loss of hypocretin (Hcrt; orexin). In postmortem NT1 brains, we observed an 11‐fold increase of CD4 + T‐cells in the Hcrt region compared with control hypothalami, without a corresponding rise in CD8 + T‐cells. CD4 + and CD8 + T‐cell numbers were unchanged in other hypothalamic regions, including the paraventricular nucleus and median eminence, and in extra‐hypothalamic areas such as the substantia nigra and locus coeruleus. Hcrt‐region CD4 + T‐cells expressed the tissue‐resident memory markers CD49a and CXCR6. These findings support the autoimmune hypothesis of NT1. ANN NEUROL 2026

https://onlinelibrary.wiley.com/doi/10.1002/ana.78199

 

[Jaybee00]

Why do 'sleep attacks' happen? Study points to an autoimmune trigger in narcolepsy​

https://medicalxpress.com/news/2026-03-autoimmune-trigger-narcolepsy.html

 

[Jonathan Edwards]

It is maybe worth noting that the presence of CD4 T cells does not mean anything very specific. T cells patrol tissues and hang about if the tissue is not quite healthy, for whatever reason. rather as macrophages do. CD4 cells outnumber CD8 in at least some other situations. But it is useful to see the situation documented for narcolepsy.

 

[Violeta]

My husband has fairly extreme loss off orexin symptoms...falls asleep very easily and very often, no body warmth, and a horrible appetite.

He must have gotten it from COVID.

Thank you for the study, @Jaybee00.