Changes of serum autoantibodies against β1 and M2 receptors in the patients of obstructive sleep apnea syndrome with chronic obstructive pulmonary disease

AIM: To study the changes of serum autoantibodies against β₁-adrenergic and M₂-muscarinic receptors in obstructive sleep apnea syndrome (OSAS) patients with chronic obstructive pulmonary disease (COPD), that is, overlap syndrome (OS). METHOD: Serum autoantibodies against β₁ and M₂ receptors in 26 cases with OS, 32 with OSAS, 30 with COPD and 28 normal subjects were determined by using enzyme-linked immunosorbent assay(ELISA). RESULTS: The positive rates and titer of β₁ and M₂ receptor autoantibodies are significantly increased in OS group (92.2％,57.7% and 1:98, 1:67), compared to OSAS (71.9%, 40.6% and 1:83, 1:30) or COPD group (70.0%, 36.7% and 1:79, 1:28) (P＜0.05), and they are higher in these groups than in the control (25.0%, 14.3% and 1:20, 1:20) (P＜0.01). CONCLUSION: Serum β₁-and M₂ receptor autoantibodies are significantly increased in the patients with COPD, OSAS or OS, compared to the control, and the highest is in OS.