Acute effect of nasal continuous positive airway pressure therapy on the systemic immunity of patients with obstructive sleep apnea syndrome
Nakamura, T.; Chin, K.; Shimizu, K.; Kita, H.; Mishima, M.; Nakamura, T.; Ohi, M.
Sleep 24(5): 545-553
Objectives: To investigate whether in patients with obstructive sleep apnea syndrome (OSAS) the systemic immunity is disturbed and whether it changes with nasal continuous positive airway pressure (NCPAP) therapy. Design: Polysomnography was performed on 18 OSAS patients (Group A) before NCPAP was started and again on the first night of NCPAP. Blood samples were collected at 8:00PM, 1:00AM and 6:00AM during each polysomnography. Lymphocyte subsets, lymphocyte blastformation, and natural killer (NK) cell activity were determined. Six normal subjects were also studied. A different six OSAS patients were studied over 6 days of NCPAP. Setting: N/A Patients or Participants: N/A Interventions: N/A Measurements and Results: The only immunological parameter that significantly differed between the Group A OSAS patients either before or on the first night of NCPAP, and the normal subjects was the epinephrine level. Among the Group A OSAS patients, the following immunological parameters were significantly lower at 6:00AM on the first night of NCPAP than before NCPAP was started: percentage (49.4 +- 1.9% before NCPAP vs 45.7 +- 2.0% with NCPAP, mean +- SEM, p < 0.005) and absolute count of CD4+ cells (944.1 +- 63.8 vs 829.6 +- 71.3/mm3, p < 0.05); absolute count of CD4+HLA-DR+ cells (91.9 +- 13.3 vs 75.1 +- 8.9/mm3, p < 0.05); CD4+/CD8+ ratio (2.13 +- 0.21 vs 1.91 +- 0.18, p < 0.05). The reduction in the percentage of CD4+ cells at 6:00AM was significantly correlated with the change in apnea-hypopnea index (AHI) (r = 0.729, p < 0.01). The CD4+ cell count recovered after 6 days of NCPAP. The lymphocyte blastformation and NK cell activity levels did not change with NCPAP. Conclusions: First-night NCPAP therapy reduced the CD4+ cell count after sleep, which recovered after one week of NCPAP. OSAS patients do not have immunological abnormalities.