Introduction:
Obstructive sleep apnea (OSA) is a common medical disorder that is closely associated
with the occurrence of cardiovascular diseases and enhanced susceptibility to infections.
Since such inflammatory pathologies are particularly controlled by myeloid leukocytes
including neutrophils and monocytes, we hypothesize that OSA critically modulates
the phenotype and function of these innate immune cells.
Methods:
Cell counts of neutrophils and monocytes as well as phagocytic capacity and surface
expression of specific adhesion and signaling molecules of these immune cells were
analyzed in the peripheral blood of patients with and without OSA by multi-channel
flow cytometry.
Results:
OSA patients exhibited similar numbers of neutrophils and monocytes in their peripheral
blood compared to control patients. However, the absolute numbers of intermediate
and non-classical monocytes were significantly elevated in patients with OSA in comparison
to patients without OSA. Interestingly, these changes were more pronounced in patients
with advanced stages of the disease. Regarding the expression of specific key adhesion
and signaling molecules on the surface of neutrophils and monocytes, no significant
differences were observed between OSA patients and control patients. In contrast,
the phagocytic behavior of neutrophils and classical monocytes was altered in OSA
patients.
Conclusions:
Depending on disease severity, OSA promotes distinct alterations in myeloid leukocyte
availability and function critical for proper innate immune responses. Therapeutic
interventions in OSA should therefore aim at restoring immunological profiles of healthy
individuals in these patients.
