P0840 - Diagnosis and Management of Iron Overload in Sideroblastic Anemia

Gregory Toy, MD, Eduardo A. Rodriguez Zarate, MD
University of Utah School of Medicine, Salt Lake City, UT

Introduction: Sideroblastic anemia is characterized by decreased heme synthesis with an increase in intestinal iron absorption which deposits in the periportal hepatocytes and can lead to cirrhosis or fibrosis. The following case illustrates the importance of quantifying and treating iron overload in a patient with sideroblastic anemia.

Case Description/Methods: A 36-year-old male with a history of obesity, alcohol use, and self-reported thalassemia was referred to hepatology for an elevated ferritin of 1557 ng/mL and increased echogenicity of the liver in abdominal ultrasound. Workup of his thalassemia included electrophoresis revealing a normal hemoglobin pattern and no significant deletions or duplications in either the alpha or beta globin genes. Liver biopsy showed markedly increased iron deposition in the hepatocytes and mild steatosis. He was negative for HFE mutations. Hepatic iron concentration by weight was 171 umol/g. Bone marrow biopsy showed increased ringed sideroblasts. Based on this, he was diagnosed with sideroblastic anemia (SA). Due to his anemia, phlebotomy was not indicated, and he was recommended to start iron chelators.

Discussion: The differential diagnosis for this patient’s iron overload was broad. Thalassemia is an iron-loading anemia. However, his prior genetic workup makes this diagnosis unlikely. He also has risk factors of secondary iron overload like obesity and alcohol use. Thalassemia, obesity, and alcohol use all can cause iron overload by various mechanisms downregulating hepcidin. Obtaining a liver biopsy was important to look for the presence and grade of liver iron, steatosis, and fibrosis. This would help differentiate between primary iron overload which causes hepatocyte deposition of iron and secondary iron overload which causes iron deposition in macrophages. In terms of hepatic iron concentration (HIC), the patient would be graded as moderate iron excess. A normal subject has an HIC 10 to 36 umol/g. Hepatic fibrosis or cirrhosis develops in almost all patients with an HIC greater than 400 umol/g. For treatment of SA, risk factors for secondary SA like obesity and alcohol use should be mediated. A trial of pyridoxine is also reasonable as vitamin B6 deficiency can cause secondary SA and X-linked SA, the most common primary cause, can respond to pyridoxine. Iron chelation should also be considered to prevent progression to liver fibrosis given intolerance to phlebotomy with clinical anemia.


Disclosures:
Gregory Toy indicated no relevant financial relationships.
Eduardo Rodriguez Zarate indicated no relevant financial relationships.


Gregory Toy, MD, Eduardo A. Rodriguez Zarate, MD. P0840 - Diagnosis and Management of Iron Overload in Sideroblastic Anemia, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.