Macrophage Inhibitory Factor and High-Mobility Group-1 Protein in Children Undergoing Cardiopulmonary Bypass

Introduction: In recent scientific literature, 2 proteins, macrophage migration inhibitory factor (MIF) and high-mobility group-1 protein (HMG-1), have emerged as important mediators of inflammation and sepsis. Hypothesis: MIF and HMG-1 will be present in the serum of children who have undergone cardiopulmonary bypass. MIF will be present in the myocardium of children who have undergone cardiopulmonary bypass. The presence of MIF and HMG-1 in the serum and MIF in the myocardium of children undergoing bypass will correlate with clinical outcome. Methods: We will study a group of infants and children undergoing operative repair of congenital heart disease during which there is an expectation of cardiac tissue removal. Patients will have an assessment of cardiac function by echocardiography as well as blood assays for tumor necrosis factor (TNF), interleukin-6, interleukin-8, interleukin-10, MIF, and HMG-1 prior to surgery. Cardiac tissue, removed as a planned part of the procedure, will be obtained from the cardiothoracic surgeons and assayed for MIF and for apoptosis, a potential mechanism of myocardial dysfunction mediated by MIF and/or HMG-1. The patient will be admitted to the cardiac intensive care unit post operatively for routine care. Blood will be obtained at 1, 8, 24, 28, and 72 hours post operatively for the cytokine assays detailed above. The blood will be drawn from indwelling arterial or venous catheters routinely placed at the time of surgery. The amount of blood drawn (-4cc per sample) is unlikely to cause any hemodynamic compromise or result in additional blood product replacement. Sample size and Analysis Plan: 30 subjects will be enrolled to determine the presence or absence of MIF/HMG-1 in the serum and cardiac tissue pre and post cardiopulmonary bypass. Descriptive statistics of patient demographics and clinical outcome variables will be correlated to serum and myocardial concentrations of the various cytokines.