Transforming growth factor-β₁(TGF-β₁) is a multifunctional cytokine that has an important role in the regulation of cell growth, differentiation, and repair in a variety of tissues.1 In addition to its role in the cell cycle and apoptosis, TGF-β₁ induces the synthesis of extracellular matrix (ECM) and is upregulated by angiotensin II.1 2 Dilated cardiomyopathy is characterised by myocyte loss, hypertrophy of residual myocytes, increased interstitial fibrosis, and abnormalities of the cytoskeleton.3 Cytotoxic lymphocytes and macrophages are also present in the myocardium in increased numbers which may provide a source of TGF-β₁.4 Therefore in this study we have investigated whether patients with chronic heart failure caused by idiopathic dilated cardiomyopathy have increased plasma concentrations of TGF-β₁, and whether this is associated with increased macrophage gene expression for TGF-β₁compared to those with normal left ventricular function. Patients with ischaemic or hypertensive heart disease were excluded because of the potential confounding effects on TGF-β₁ concentrations of atherosclerosis and pressure overload with left ventricular hypertrophy.

Twenty patients who presented with symptoms and signs of chronic heart failure with no obvious cause and with the clinical diagnosis of dilated cardiomyopathy (by the World Health Organization criteria) were studied. All patients had right and …