FAILING HEART—BASIC SCIENCE TGF-1 Gene Polymorphisms in Patients With End-Stage Heart Failure C. T. J. Holweg, BSc, a C. C. Baan, PhD, a H. G. M. Niesters, PhD, b P. J. M. J. Vantrimpont, MD, c P. G. H. Mulder, PhD, d A. P. W. M. Maat, MD, e W. Weimar, MD, PhD, a and A. H. M. M. Balk, MD, PhD e Background: The regulatory cytokine transforming growth factor (TGF)-1 is thought to play a role in atherosclerotic heart disease as well as in idiopathic cardiomyopathy. The production of TGF-1 is genetically controlled as polymorphisms in the signaling sequence of the TGF-1 gene leucine 10 3proline and arginine 25 3proline are involved in the regulation of the protein production level. We investigated whether these polymorphisms are associated with end-stage heart failure caused by dilated cardiomyopathy (CMP) or ischemic heart disease (IHD). Methods: We determined polymorphisms using sequence specific oligonucleotide probing (SSOP) in genomic DNA samples from heart transplant recipients (n = 253) and controls (n = 94). Indications for transplantation were dilated CMP (n = 109) and IHD (n = 144). Results: We found a difference in TGF-1 codon 10 genotype distribution among patients with IHD, dilated CMP, and controls (p = 0.034; 2 test). Patients with dilated CMP differed from patients with IHD (p = 0.044) and healthy controls (0.017). The genotype distribution between patients with IHD and controls was comparable. For codon 25, we found no difference in genotype distribution. Conclusions: The Leu 10 3 Pro (codon 10) polymorphism in the TGF-1 gene is associated with end-stage heart failure caused by dilated CMP and not with IHD. This observation suggests that TGF-1 is involved in the pathogenesis of CMP. J Heart Lung Transplant 2001;20:979–984. The involvement of cytokines in the pathogenesis of cardiovascular disease causing heart failure has been extensively demonstrated. Transforming growth factor–1 (TGF-1), a regulatory cytokine produced by many cell types, has been studied in relation to the pathogenesis of coronary artery disease. Both anti-atherogenic and pro-atherogenic activities of TGF-1 have been reported. 1–4 Trans- forming growth factor–1 inhibits the proliferation of many cells, including smooth muscle cells, endo- From the Departments of a Internal Medicine, b Diagnostic Insti- tute of Molecular Biology, c Cardiology and e Thoracic Surgery, University Hospital Rotterdam-Dijkzigt; and d Epidemiology and Biostatistics, Erasmus University Rotterdam, Rotterdam, The Netherlands. Submitted August 4, 2000; accepted March 27, 2001. Reprint requests: Cecile Holweg, University Hospital Rotter- dam-Dijkzigt, Department of Internal Medicine, Room Bd293, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Nether- lands. Telephone: 31-10-4635420. Fax: 31-10-4635430. E-mail: Holweg@inw1.azr.nl. Copyright © 2001 by the International Society for Heart and Lung Transplantation. 1053-2498/01/$–see front matter PII S1053-2498(01)00296-0 979