Abstract

Background and Aim: The involvement of the immune system in the pathogenesis of obstructive sleep apnea (OSA) is controversial. Aim of our study was to analyze the distribution of dendritic cell (DC) subsets and the expression of inflammation markers in this clinical scenario. Methods: Frequency assessment of peripheral myeloid (mDC1 and mDC2) and plasmacytoid DCs (pDCs), and of Th17 cells was investigated by flow cytometry in 50 OSA patients and in 30 age-and sex-matched healthy controls (HCs). Oxidative burst (OB) and serum levels of IL-6, IFN-g, TNF-a, IL-10 and VEGF were also evaluated. Results: mDC1, mDC2 and pDCs subsets were significantly lower in OSA (p=0.01, p=0.0003 and p<0.0001, respectively) while Th17 cells were increased (p=0.02 vs HCs). OB, IL-6, IFN-g, TNF-a, IL-10 and VEGF levels were also higher in OSA (p<0.005vs HCs). IL-6 levels correlated with disease severity, as assessed by the apnea-hypopnea index (p=0.0054), with the oxygen desaturation index (p 0.034), and with a t90 >30% (p 0.008). IL-6 expression negatively correlated with pDCs (r=-0.32, p=0.04), as Th17 cells with mDC2s (r=-0.80, p< 0.007). Conclusions: Deciphering immunological perturbations might be helpful for a better understanding of OSA pathogenesis and of its increased susceptibility to comorbidities including cancer