Non-invasive evaluation of myocardial and hepatic iron overload in patients with thalassemia using magnetic resonance imaging

• Grant number: 11/23897-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2012
• End date: May 31, 2013
• Field of knowledge: Health Sciences - Medicine - Medical Radiology
• Principal Investigator: Juliano de Lara Fernandes
• Grantee: Fernanda Batista Rosa Pinto
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Thalassemia major is a genetic hemoglobinopathy relatively frequent in Mediterranean countries and in Brazil. In its homozygous form, the disease will be responsible for multiple transfusions during life. Despite an increase in life quality, these repeated transfusions lead to cumulative iron concentrations, especially in the liver. While this organ is mainly affected, cardiac complications are still responsible for complications such as heart failure. Until recently, there was no non-invasive form of evaluating iron overload in these patients. With the development of new magnetic resonance (MR) techniques, today it is possible to robustly assess both the heart and liver iron concentrations. This allowed for better therapeutical measures as well as a better understanding of the pathophysiology involved in the disease. The main method to detect iron in tissues is T2*. However, because one of the complications secondary to iron deposits is local and diffuse fibrosis, this technique will not allow the identification of this problem. In other cardiomyopathies, late gadolinium enhancement permits the identification and quantification of this complication with important prognostic information. This technique in thalassemia cardiomyopathy has not been exploited. Besides this aspect, it is also not known whether other factors can lead to increased iron uptake in the many organs affected by iron overload. One of the molecules involved in iron hemostasis is haptoglobin, responsible for the removal of iron in circulation. In normal individuals, three variants have been described with type 2-2 being associated with a reduced capacity of iron clearance. These variations in thalassemia have also not been investigated and may constitute one of the mechanisms of acceleration or slowing of iron uptake and/or fibrosis. Based on the previous hypothesis, we propose this project with the objective of evaluating the follow-up of iron deposits in the heart and liver using T2* techniques as well as late gadolinium enhancement. Added to that, we will also study these patients' polymorphisms for haptoglobin and correlate these findings to MR variables. This study has a prospective design with serial follow-up of patients and prognostic evaluation.(AU)