Acute effect of nasal continuous positive airway pressure therapy on the systemic immunity of patients with obstructive sleep apnea syndrome

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. Lympho cyte subsets, lymphocyte blastformation, and natural killer (NK) cell activ ity 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 significant ly 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 t he Group A OSAS patients, the following immunological parameters were signi ficantly 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<plus/minus >63.8 vs 829.6 +/- 71.3/mm(3), p<0.05); absolute count of CD4(+)HLA-DR+ cel ls (91.9<plus/minus>13.3 vs 75.1 +/-8.9/mm(3), p <0.05); CD4(+)/CD8(+) rati o (2.13 +/-0.21 vs 1.91 +/-0.18, p<0.05), The reduction in the percentage o f CD4(+) cells at 6:00AM was significantly correlated with the change in ap nea-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 re duced the CD4(+) cell count after sleep, which recovered after one week of NCPAP. OSAS patients do not have immunological abnormalities.