Fas-positive lymphocytes are associated with systemic inflammation in obstructive sleep apnea syndrome

PURPOSE: Obstructive sleep apnea syndrome (OSAS) is associated with alterations in immune system which may lead to serious complications. The aim of this study was to explore lymphocyte populations in OSAS with special attention to the Fas-positive cells. METHODS: Fifty-one patients with confirmed OSA and 20 healthy subjects were investigated. The OSA severity indices, data concerning comorbidities, and markers of inflammation and metabolic disorders were collected. Flow cytometry was used to analyze the lymphocyte profile and expression of Fas receptors (CD95). Concentration of adiponectin, IL-1β, TNF-α, and sFas were measured. RESULTS: Proportions of Fas-positive cells in the pool of CD4+ and Fas-positive in the pool of CD8+ cells in the blood of patients were significantly increased when compared with healthy subjects (74.5% vs. 65.6% and 78.8% vs.70.9%, respectively, p < 0.05). No correlation with OSA severity was found. However, the proportion and number of Fas+ cells were elevated in obese patients, in non-smokers, and in patients suffering from COPD and hypertension. There were several significant relations of Fas+ cells with inflammatory markers of systemic inflammation. CONCLUSION: Lymphocytes with the expression of Fas receptor are associated with systemic inflammation in OSAS.