Transfusional Iron Overload Among Leukemia Survivors

Overview

Red cell transfusions are an important part of supportive cancer therapy. The iron in the transfused blood may build up in the body since the human body has no way to get rid of extra iron. Iron tends to build up in the liver and the heart muscle. It is unknown if iron build-up is present many years after completing cancer therapy. It is also not known if extra iron causes harm to internal organs. Researchers at St. Jude Children's Research Hospital (SJCRH) want to understand if iron build-up (called "iron overload") exists in survivors of leukemia. They also want to know if iron overload can cause injury to your organs if it is present. Liver iron accumulation has been documented in childhood cancer survivors, however, it is not known if iron associated organ toxicity is contributing to the long-term morbidity that has been well documented among these survivors. This study will investigate the prevalence of iron overload and the association of tissue iron burden with markers of organ dysfunction in leukemia survivors. This study will determine the prevalence of iron overload among long-term leukemia survivors that underwent blood transfusion. This study will use blood and magnetic resonance imaging (MRI) testing to determine iron overload of specified organs. Understanding the prevalence of iron overload could impact surveillance practices in leukemia survivors. PRIMARY OBJECTIVE: * To determine the prevalence of iron overload in the liver \[liver iron concentration (LIC) \>3mg/g using R2\* MRI measurements\] and in the heart (T2\* \<20 ms) among long-term leukemia survivors transfused with ≥50ml/kg of packed red blood cells. SECONDARY OBJECTIVES: * To examine the relationship between hepatic, cardiac, and endocrine dysfunction and transfusionally acquired iron overload as defined by R2\* and T2\* MRI among survivors of pediatric leukemias. * To investigate the association between serum ferritin, transferrin saturation, non-transferrin-bound iron, and hepcidin measurements with R2\* and T2\* MRI-defined iron overload.

Participants will have blood work drawn after an overnight fast during a routine clinic visit. They will also have an electrocardiogram (EKG) and echocardiogram (ECHO) which are often a required part of their annual visit. Magnetic resonance imaging (MRI) exams of the heart, liver, and surrounding abdominal organs will be done on all participants using a method of scanning that involves a closer study of these organs (called R2\* MRI).