Humoral immune responses to influenza vaccination in patients with obstructive sleep apnea

Study Objective. To compare humoral immune responses to influenza vaccination in subjects with obstructive sleep apnea (OSA) and in healthy volunteers (control subjects). Design. Prospective, controlled, parallel-design study. Setting. Sleep disorders center at a university hospital. Subjects. Fourteen untreated subjects with moderate-to-severe OSA (apnea hypopnea index > 15 events/hr) and 17 healthy volunteers (control subjects). Intervention. All subjects were given the influenza vaccine for the years 2004-2005 or 2005-2006. Measurements and Main Results. Blood samples were obtained before and 2-4 weeks after vaccination to measure serum antibody titers for the A/New Caledonia/20/99 (H1N1)-like and B/Shanghai/361/2002-like viral strains by using the hemagglutination inhibition assay Seroconversion was defined as an increase in the antibody titer by more than 4-fold, whereas seroprotection was defined as an antibody titer greater than 40 hemagglutination units. The mean standard error of the mean apnea hypopnea index, calculated as the number of abnormal respiratory events divided by the number of hours of total sleep time, was 56 +/- 12 events/hour in the OSA group and 1.0 +/- 0.4 oxygen desaturations/hour in the control group (p < 0.05). However, no significant differences were observed in changes in antibody concentration, frequencies of seroconversion, or rates of seroprotection between subjects with OSA and control subjects. Polysomnographic measures of OSA were not correlated with immune responses. Conclusion. Although pathophysiologic characteristics of OSA may influence immune responses, moderate-to-severe OSA did not impair humoral responses to the influenza vaccine in these subjects.