These findings suggest that a certain level of CD8<sup>+</sup> T-cell reactivity combined with HLA-DQB1*06:02 expression is important for NT1 development.
In the population-stratified analysis, HLA-DQB1*06:02 conferred an increased risk for NT1 (OR: 24.1, IC: 14.6-39.5, p < 0.001) and NT2 (OR: 3.9; IC: 2.2-6.8, p < 0.001).
We compared four diffusion tensor imaging-based microstructural indices (fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [RD], and axial diffusivity [AD]) in 57 patients with NT1 (39 females, mean age 21.8 years, 51/57 H1N1-vaccinated, 57/57 HLA-DQB1*06:02-positive, 54/54 hypocretin-deficient), 54 first-degree relatives (29 females, mean age 19.1 years, 37/54 H1N1-vaccinated, 32/54 HLA-DQB1*06:02-positive), and 55 healthy controls (38 females, mean age 22.3 years).
This specific loss of hypocretin and the strong association with the HLA-DQB1*06:02 allele led to the hypothesis that NT1 could be an immune-mediated pathology.
The aim of our study was to analyze the distribution of HLA-DQB1 in Czech patients with central hypersomnias and differences between diagnostic groups of narcolepsy type 1 (NT1), type 2 (NT2), idiopathic hypersomnia (IH) and no central hypersomnia subjects (no-CH).