The Abnormal Distribution of Peripheral B1 Cells and Transition B Cells in Patients with Idiopathic Dilated Cardiomyopathy

Abstract Background The aberrant distribution of peripheral B cell subsets is associated with the pathogenesis of a variety of inflammatory and autoimmune diseases. However, the distribution of peripheral B cell subsets in patients with idiopathic dilated cardiomyopathy (DCM) has yet to elucidated. Methods Twenty-seven idiopathic DCM patients (DCM group), 18 heart failure controls (HF group) and 21 healthy individuals (HC group) were included in this study. Peripheral B cell subsets were analyzed by multi-color flow cytometry. Level of plasma β1 cholinergic receptor (β1-AR) autoantibody was assayed by ELISA. Additionally, clinical features were also collected. Results Compared with HF and HC groups, the percentage of B1 cells were significantly decreased, whereas the percentage of transitional B cells (Tr) were significantly increased in DCM group. Notably, the percentage of B1 cells was significantly lower in patients with β1-AR autoantibody positive DCM compared with β1-AR autoantibody negative patients. Correlation analysis showed that the percentage of B1 cells was negatively correlated with N-terminal pro-brain natriuretic peptide (NT-proBNP) and positively correlated with left ventricular ejection fraction (LVEF) in patients with DCM.Conclusions The study showed that B1 cells in peripheral blood of patients with idiopathic DCM were abnormally decreased, especially in those β1-AR autoantibody positive patients, while Tr cells are significantly increased, indicating that B1 cells and Tr cells may be implicated in the pathogenesis of idiopathic DCM.