The number of total leukocytes (CD45+ cells), T-lymphocytes (CD3+ cells) as well as T-helper cells (CD4+ cells) were not significantly different between the recurrence and control groups, suggesting that recurrence of OSA due to adenotonsillar regrowth may not be related to a quantitative change in these lymphocytes. This evidence concerns the gene CD4 and obstructive sleep apnea syndrome.