By Regan Zhang, PhD Candidate at Rossi Lab, CBR
Eight years ago, John didn’t think he could live much longer, as his anemia was progressively worsening. Doctors had given him the diagnosis of myelodysplastic syndrome (MDS), a condition which leads to the decline of blood-producing bone marrow cells. Consequently, he needed red blood cell transfusions regularly in order to maintain his red blood cell count. Red blood cells are essential to carry oxygen to the tissues.
Over the last two years, John has been transfused with 80 units (bags) of red blood cells, which has caused another problem. His iron levels became significantly elevated. Iron overload is a major side-effect of blood transfusions, says Dr Heather Leitch, hematologist at St. Paul’s Hospital and Centre for Blood Research, University of British Columbia.
Excessive iron is toxic to many organs, and thus may result in liver disease, heart disease, and diabetes. The major remedy for iron overload is iron chelation therapy, which uses drugs to capture excess iron and remove it safely from the body.
Luckily for John, the highly effective oral chelation drug, deferasirox, a convenient formulation, has become accessible for patients with MDS. After just six weeks of treatment, not only did his iron levels drop, but astonishingly, John’s regular blood transfusions were no longer needed. His iron levels entirely normalized over the following months and remained normal, particularly as his need for transfusions were substantially reduced.
In a recent review article published in the journal Canadian Perspectives in Clinical Hematology, Dr Leitch describes a number of studies that report that iron chelation therapy may be beneficial for patients with MDS.
In addition to being toxic to the heart, the liver, and the pancreas, Dr Leitch points out that, due to the damaging effects of iron on DNA, iron overload may also increase the risk of progression to leukemia. Through active management of iron overload, the risks of blood transfusions can be significantly reduced.
On an even more promising note, one study found that the longer that patients with MDS received iron chelation therapy, the higher the chance there was of them becoming transfusion independent, sometimes for long periods. The biological reason for this surprising improvement in the MDS is still being investigated. Dr Leitch indicated that more has to be done to fully understand the mechanisms of this treatment, noting that “iron reduction is in some way favorably altering bone marrow failure”.
As guidelines for iron chelation treatment are still in the process of being updated in many jurisdictions, Dr Leitch believes that removing iron should be pursued as an active treatment for patients receiving blood transfusions for bone marrow failure syndromes.
Iron overload might be improved not only by iron chelators, but by other treatments for bone marrow failure syndromes that reduce transfusion requirements. Thus, iron reduction can have a significant impact on the quality of life and long term well-being of patients like John.