Assessment of plasma level of matrix metalloproteinase-9 in patients with sickle cell disease and its relationship to myocardial iron overload: a case–control study

Abstract

Background Cardiac iron overload is secondary to chronic blood transfusion in patients with sickle cell disease (SCD). Iron overload cardiomyopathy is a restrictive cardiomyopathy associated with systolic and diastolic dysfunction. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases responsible for tissue remodeling. Many studies offer strong evidence for the role of MMP-9 in left ventricular (LV) remodeling.Objective The authors aimed to detect the plasma levels of MMP-9 in patients with SCD and its relationship to myocardial iron overload.Materials and methods A case–control study was carried out on 75 patients with SCD and 75 age-matched and sex-matched healthy controls. Assessment of cardiac iron overload in patients by MRI T2* was performed. Plasma MMP-9 levels were measured for patients and controls using enzyme-linked immunosorbent assay.Results Patients with SCD had significantly higher levels of MMP-9 than controls. There was a highly significant relationship between plasma levels of MMP-9 and each of cardiac T2* and serum ferritin. Patients with vaso-occlusive crises (VOC) greater than 5/year had significantly higher levels of MMP-9 than those with VOC less than or equal to 5 /year.Conclusion MMP-9 seems to be a useful marker in patients with SCD. Patients with cardiac T2* less than 20 ms, serum ferritin greater than 1000 ng/ml, and recurrent VOC greater than 5/year had significantly higher MMP-9 serum levels than others.