['P53 is a key protein which controls cell cycle arrest and apoptosis in response to DNA damage. Auto-antibodies against p53 have been detected in some cancer patients and also in patients with autoimmune diseases. In these patients, the main cause of anti-p53 antibody occurrence was considered to be increased intracellular p53 protein in cancer cells and autoreactive lymphocytes, respectively. Intracellular p53 also increases with cardiomyocyte apoptosis during heart failure and autoreactive lymphocytes play a role in the course of idiopathic dilated cardiomyopathy (IDC) and ischemic cardiomyopathy (ICM). Based on these observations, we hypothesized that anti-p53 antibody response may also occur in patients with heart failure due to ICM and IDC.', 'The aim of this study was to evaluate anti-p53 antibodies in the serum of patients with heart failure due to IDC and ICM.', '70 eligible patients with heart failure and severe left ventricular systolic dysfunction (mean fractional shortening 12.03 +/- 3.93%) were included in the study. The aetiology of heart failure was IDC in 26 patients and ICM in 44 patients, according to the angiographic and echocardiographic findings.', 'Anti-p53 antibodies were not detected in any of the patients.'] Do serum anti-p53 antibodies occur in patients with heart failure due to idiopathic dilated and ischemic cardiomyopathies?