Obstructive sleep apnea (OSA) is a medical problem whose importance is increasing in recognition and awareness. OSA is associated with the development of hypertension and other cardiovascular diseases (1,2). OSA has pathophysiologic characteristics that are known to negatively impact immune function. Both sleep deprivation and hypoxia, hallmarks of OSA, impair immune responses (6,8,11). In addition, patients with OSA are frequently obese and obesity may be associated with increased chance of infections and immune impairment (14,15). Adipose cells are known to secrete cytokines and hormones that are involved in the immune response such as leptin, tumor necrosis factor alpha and interleukin-6 (16-19). Thus, it seems very likely that OSA may impact antigen-specific immune responses. Although it is known that characteristics of OSA impact immune function, it is not known what effects clinical OSA has on immunity.