The Correlation between Peripartum Cardiomyopathy and Autoantibodies against Cardiovascular Receptors

Background: Peripartum cardiomyopathy (PPCM) is characterized by left ventricular systolic dysfunction and heart failure. However, its pathogenesis is not clear. Our preliminary study revealed that autoantibodies against b1-adrenergic receptors (b1R-AABs) and M2-muscarinic receptors (M2R-AABs) participated in heart failure regardless of primary heart disease. Whether b1R-AABs and M2R-AABs participate in the pathogenesis of PPCM is still unknown. Methods: Totally 37 diagnosed PPCM patients and 36 normal pregnant women were enrolled in this study. Clinical assessment and 2-dimensional echocardiographic studies as well as the measurement of b1R-AABs or M2R-AABs by enzyme linked immunosorbent assay (ELISA) were performed. Results: The positive rates for b1R-AABs and M2R-AABs were 59.5 % (22/37) and 45.9 % (17/37) in PPCM patients, and 19.4% (7/36) (P,0.001) and 16.67 % (6/36) (P,0.001) in normal pregnant women, respectively. Both b1R-AABs and M2R-AABs had a positive correlation with serum expression level of NT-proBNP, left ventricular dimension and NYHA FC (rs: 0.496–0.892, P,0.01). In addition, a negative correlation between the activity of b1R-AABs and M2R-AABs and LVEF, LVFS was observed (rs: 20.488–0.568, P,0.01). Moreover, autoantibodies against cardiovascular receptors increased the risk of the onset of PPCM (OR = 18.786, 95 % confidence interval 1.926–183.262, P = 0.012). Conclusions: The b1R-AABs and M2R-AABs reveal a significant elevation and are correlated with the increased left ventricula