An ounce of caution: Superparamagnetic iron oxide nanoparticle based magnetic resonance imaging contrast–associated anaphylaxis

Abstract

Superparamagnetic iron oxide nanoparticles are increasingly used alternatives to gadolinium-based magnetic resonance imaging (MRI) contrast agents in the diagnosis of osteomyelitis in diabetic patients with renal failure. 1 Neuwelt A. Langsjoen J. Byrd T. et al. Ferumoxytol negatively enhances T2 -weighted MRI of pedal osteomyelitis in vivo. J Magn Reson Imaging. 2017; 45: 1241-1245 Crossref PubMed Scopus (6) Google Scholar Ferumoxytol is approved by the United States Food and Drug Administration and the European Medicines Agency for intravenous use for iron replacement therapy. 1 Neuwelt A. Langsjoen J. Byrd T. et al. Ferumoxytol negatively enhances T2 -weighted MRI of pedal osteomyelitis in vivo. J Magn Reson Imaging. 2017; 45: 1241-1245 Crossref PubMed Scopus (6) Google Scholar , 2 Nguyen K.L. Yoshida T. Han F. et al. MRI with ferumoxytol: a single center experience of safety across the age spectrum. J Magn Reson Imaging. 2017; 45: 804-812 Crossref PubMed Scopus (36) Google Scholar , 3 Muehe A.M. Feng D. von Eyben R. et al. Safety report of ferumoxytol for magnetic resonance imaging in children and young adults. Invest Radiol. 2016; 51: 221-227 Crossref PubMed Scopus (58) Google Scholar Ferumoxytol is composed of an iron–carbohydrate complex that minimizes dissociation and appearance of free iron into the serum. This stability allows the drug to be given in relatively large doses at rapid infusion rates while lowering the potential for immunogenic reactions as seen in low-molecular-weight iron dextran. 4 Pai A.B. Garba A.O. Ferumoxytol: a silver lining in the treatment of anemia of chronic kidney disease or another dark cloud?. J Blood Med. 2012; 3: 77-85 PubMed Google Scholar However, recent reports of severe hypersensitivity reactions have raised concern regarding its safety—these data led to a United States Food and Drug Administration–issued Black Box warning in 2015 for the risk of potentially fatal hypersensitivity reactions. 2 Nguyen K.L. Yoshida T. Han F. et al. MRI with ferumoxytol: a single center experience of safety across the age spectrum. J Magn Reson Imaging. 2017; 45: 804-812 Crossref PubMed Scopus (36) Google Scholar , 5 Varallyay C.G. Toth G.B. Fu R. et al. What does the boxed warning tell us? Safe practice of using ferumoxytol as an MRI contrast agent. AJNR. 2017; 38: 1297-1302 Crossref PubMed Scopus (36) Google Scholar We report a rare, life-threatening immediate hypersensitivity reaction potentially related to ferumoxytol MRI contrast agent.