Troponin and Anti-Troponin Autoantibody Levels in Patients with Ventricular Noncompaction Hatice Betu ¨ l Erer 1 , Tolga Sinan Gu ¨ venc ¸ 2 *, Ahu Sarbay Kemik 3 , Hale Yaka Yılmaz 1 ,S ¸ eref Kul 4 , Servet Altay 1 , Nurten Sayar 1 , Yu ¨ ksel Kaya 2 , Mehmet Eren 1 1 Dr. Siyami Ersek Cardiovascular and Thoracic Surgery Research and Training Hospital, Department of Cardiology, stanbul, Turkey, 2 Kafkas University School of Medicine, Department of Cardiology, Kars, Turkey, 3 Istanbul University Cerrahpas ¸a Faculty of Medicine, Department of Biochemistry, stanbul, Turkey, 4 Bezmialem Vakıf University, Faculty of Medicine, stanbul, Turkey Abstract Ventricular hypertrabeculation/noncompaction is a morphologic and functional anomaly of myocardium characterized by prominent trabeculae accompanied by deep recessus. Dilated cardiomyopathy with left ventricular failure is observed in these patients, while the cause or pathophysiologic nature of this complication is not known. Anti-troponin antibodies are formed against circulating cardiac troponins after an acute coronary event or conditions associated with chronic myocyte necrosis, such as dilated cardiomyopathy. In present study, we aimed to investigate cardiac troponins and anti troponin autoantibodies in ventricular noncompaction/hypertrabeculation patients with/without reduced ejection fraction. A total of 50 patients with ventricular noncompaction and 23 healthy volunteers were included in this study. Noncompaction/ hypertrabeculation was diagnosed with two-dimensional echocardiography using appropriate criteria. Depending on ejection fraction, patients were grouped into noncompaction with preserved EF (LVEF .50%, n = 24) and noncompaction with reduced EF (LVEF ,35%, n = 26) groups. Troponin I, troponin T, anti-troponin I IgM and anti-troponin T IgM were measured with sandwich immunoassay method using a commercially available kit. Patients with noncompaction had significantly higher troponin I (28.9869.21 ng/ml in NCNE group and 28.11610.42 ng/ml in NCLE group), troponin T (22.1766.97 pg/ml in NCNE group and 22.7867.76 pg/ml in NCLE group) and antitroponin I IgM (1.9260.43 mg/ml in NCNE group and 1.7960.36 mg/ml in NCLE group) levels compared to control group, while antitroponin T IgM and IgG were only elevated in patients with noncompaction and reduced EF (15.8166.52 mg/ml for IgM and 16.4666.25 mg/ml for IgG). Elevated cardiac troponins and anti-troponin I autoantibodies were observed in patients with noncompaction preceding the decline in systolic function and could indicate ongoing myocardial damage in these patients. Citation: Erer HB, Gu ¨ venc ¸ TS, Kemik AS, Yılmaz HY, Kul S ¸, et al. (2013) Troponin and Anti-Troponin Autoantibody Levels in Patients with Ventricular Noncompaction. PLoS ONE 8(2): e57648. doi:10.1371/journal.pone.0057648 Editor: Toru Hosoda, Tokai University, Japan Received September 21, 2012; Accepted January 24, 2013; Published February 28, 2013 Copyright: ß 2013 Erer et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The authors have no support or funding to report. Competing Interests: The authors have declared that no competing interests exist. * E-mail: tsguvenc@gmail.com Introduction Venricular hypertrabeculation/noncompaction (NC/HT) is a primarily genetic cardiomyopathy characterized by prominent trabeculae with deep recessus separating trabeculations [1]. Left ventricular systolic dysfunction and development of idiopathic cardiomyopathy are the most important consequences of NC/HT [1,2]. However, not all patients with NC/HT demonstrate left ventricular failure, and some patients may remain asymptomatic for long periods [3]. The cause for transformation to a dilated cardiomyopathy (DCM) phenotype remains unknown despite being a topic of active research. Both cardiac troponin I (cTnI) and cardiac troponin T (cTnT) are components of myocardial troponin-tropomyosin complex and elevated serum levels are observed in dilated cardiomyopathy (DCM) patients due to myocardial necrosis, apoptosis or myocardial leakage. Elevated troponin levels are almost invariably related with poor prognosis in DCM patients [4,5]. Antibodies against various myocardial components, including cardiac troponins, were observed in patients with left ventricular systolic dysfunction and in normal individuals [6,7]. Of those, anti-cTnI antibodies were shown to be elevated in patients with idiopathic dilated cardiomyopathy (iDCM) and ischemic cardiomyopathy compared to health controls [8]. Animal studies had demonstrated that autoantibodies against cTnI could alter calcium currents in mice and produce cardiac lesions similar to the ones observed in iDCM [9]. While the evidence does not definitely demonstrate a role for autoimmu- nity in the development of DCM, it is hypothesized that immunization against myocardial compartments could accentu- ate cardiac dysfunction. While a few studies and report had shown elevated cTnT levels in NC/HT patients with accompanying neuromuscular disorders [10], a detailed investigation regarding to troponin and anti- troponin values in NC/HT patients is missing. In this study, we aimed to measure serum troponin I and T, as well as antitroponin I and T levels in a cohort of NC/HT patients with and without left ventricular systolic dysfunction. PLOS ONE | www.plosone.org 1 February 2013 | Volume 8 | Issue 2 | e57648