Effect of continuous positive airway pressure treatment on Th17/Treg imbalance in patients with obstructive sleep apnea and a preliminary study on its mechanism

Background Obstructive sleep apnea (OSA) can be considered a chronic inflammatory disease that impacts all bodily systems, including the immune system. This study aims to assess the Th17/Treg pattern in patients with OSA and the effect of continuous positive airway pressure (CPAP) treatment. Methods OSA patients and healthy controls were recruited. OSA patients recommended for CPAP treatment were followed up for three months. Flow cytometry was employed to determine the proportion of Th17 and Treg cells. Real-time quantitative polymerase chain reaction (PCR) and western blotting were utilized to detect the mRNA and protein levels of receptor-related orphan receptor γt (RORγt) and forkhead/winged helix transcription factor (Foxp3), respectively, in peripheral blood mononuclear cells (PBMCs). Enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum levels of interleukin-17 (IL-17), IL-6, transforming growth factor-β1 (TGF-β1), and hypoxia-induced factor-1α (HIF-1α). Results A total of 56 OSA patients and 40 healthy controls were recruited. The proportion of Th17 cells, Th17/Treg ratio, mRNA and protein levels of RORγt, and serum IL-17, IL-6, and HIF-1α levels were higher in OSA patients. Conversely, the proportion of Treg cells, mRNA and protein levels of Foxp3, and serum TGF-β1 levels were decreased in OSA patients. The proportion of Th17 and Treg cells in OSA can be predicted by the apnea hypopnea index (AHI), IL-6, TGF-β1 and, HIF-1α. 30 moderate-to-severe OSA patients were adherent to three-month CPAP treatment, with improved Th17/Treg imbalance, IL-17, IL-6, TGF-β1, and HIF-1α levels compared to pre-treatment values. Conclusion There was a Th17/Treg imbalance in OSA patients. The prediction of Th17 and Treg cell proportions in OSA can be facilitated by AHI, as well as serum IL-6, TGF-β1, and HIF-1α levels. Furthermore, CPAP treatment can potentially improve the Th17/Treg imbalance and reduce proinflammatory cytokines in OSA patients.