Methods for noninvasive measurement of tissue iron in Cooley's anemia.
To examine the relationship between myocardial storage iron and body iron burden, as assessed by hepatic storage iron measurements, we studied 22 patients with transfusion-dependent thalassemia syndromes, all being treated with subcutaneous deferoxamine, and 6 healthy subjects. Study participants were examined with a Philips 1.5-T Intera scanner using three multiecho spin echo sequences with electrocardiographic triggering and respiratory navigator gating. Myocardial and hepatic storage iron concentrations were determined using a new magnetic resonance method that estimates total tissue iron stores by separately measuring the two principal forms of storage iron, ferritin and hemosiderin. In a subset of 10 patients with beta-thalassemia major, the hepatic storage iron concentration had been monitored repeatedly for 12-14 years by chemical analysis of tissue obtained by liver biopsy and by magnetic susceptometry. In this subset, we examine the relationship between hepatic iron concentration over time and our current magnetic resonance estimates of myocardial iron stores. No significant relationship was found between simultaneous estimates of myocardial and hepatic storage iron concentrations. By contrast, in the subset of 10 patients with beta-thalassemia major, the correlation between the 5-year average of hepatic iron concentration and the current myocardial storage iron was significant (R = .67, P = .03). In these patients, myocardial storage iron concentrations seem to reflect the control of body iron over a period of years. Magnetic resonance methods promise to provide more effective monitoring of iron deposition in vulnerable tissues, including the liver, heart, and endocrine organs, and could contribute to the development of iron-chelating regimens that more effectively prevent iron toxicity.
Sheth
Sujit
S
Department of Pediatrics, Columbia University College of Physicians and Surgeons, Harkness Pavilion, Room HP5, 180 Fort Washington Avenue, New York, NY 10032, USA. ss125@columbia.edu
Tang
Haiying
H
Jensen
Jens H
JH
Altmann
Karen
K
Prakash
Ashwin
A
Printz
Beth F
BF
Hordof
Alan J
AJ
Tosti
Christina L
CL
Azabagic
Andjela
A
Swaminathan
Srirama
S
Brown
Truman R
TR
Olivieri
Nancy F
NF
Brittenham
Gary M
GM
D000328:Adult; D015913:Chelation Therapy; D003131:Combined Modality Therapy; D003676:Deferoxamine / Q000627:therapeutic use; D005260:Female; D005293:Ferritins / Q000032:analysis; D006446:Hemoglobin E; D006485:Hemosiderin / Q000032:analysis; D006801:Humans; D007501:Iron / Q000032:analysis*; D007502:Iron Chelating Agents / Q000627:therapeutic use; D019190:Iron Overload / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D008099:Liver / Q000737:chemistry* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009206:Myocardium / Q000737:chemistry* / Q000473:pathology; D065227:Transfusion Reaction; D017086:beta-Thalassemia / Q000150:complications / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology / Q000628:therapy
D007502:Iron Chelating Agents; D005293:Ferritins; D006485:Hemosiderin; D006446:Hemoglobin E; D007501:Iron; D003676:Deferoxamine