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 β1-adrenergic receptors (β1R-AABs) and M2-muscarinic receptors (M2R-AABs) participated in heart failure regardless of primary heart disease. Whether β1R-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 β1R-AABs or M2R-AABs by enzyme linked immunosorbent assay (ELISA) were performed.

RESULTS

The positive rates for β1R-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 β1R-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 β1R-AABs and M2R-AABs and LVEF, LVFS was observed (rs: -0.488-0.568, 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 β1R-AABs and M2R-AABs reveal a significant elevation and are correlated with the increased left ventricular dimension and worse cardiac contraction function. The autoantibodies of cardiovascular receptors are independent risk factors for the onset of PPCM.