CD4+ T-lymphocyte subsets in nonobese children with obstructive sleep apnea syndrome

Abstract

Background:To characterize the distribution of both tonsillar and circulating CD4+ T-lymphocyte subsets, and to explore their clinical relevance in nonobese children with obstructive sleep apnea syndrome (OSAS).Methods:A total of 53 children who underwent tonsillectomy for either OSAS (n = 25) or primary snoring (PS, n = 28) were prospectively enrolled. Nineteen healthy children without any symptoms were recruited as controls. We quantified the frequencies of CD4+ T-lymphocyte subpopulations using flow cytometry, serum-related cytokines using enzyme-linked immunosorbent assay, and key transcription factors using quantitative polymerase chain reaction (qPCR).Results:Tonsillar distributions of CD4+ T-lymphocyte subsets were comparable in the OSAS and PS subjects. The peripheral Th17/Treg ratio was positively correlated to severity as measured by apnea/hypopnea index (AHI), serum C-reactive protein and hypoxia-inducible factor-1α mRNA in the OSAS children (P < 0.05). And AHI was independently associated with the peripheral Th17/Treg ratio (P < 0.05). Furthermore, the response to surgery was associated with a significant reversal of the Th17/Treg imbalance and a concomitant relief of the proinflammatory profile in the OSAS subjects.Conclusion:Pediatric OSAS was associated with an altered Th17:Treg balance toward Th17 predominance. The changes in lymphocytic phenotypes that correlated with recurrent intermittent hypoxia in sleep apnea may contribute to the variance in systemic inflammation and downstream morbidities of pediatric OSAS.