HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit an electronic Letter to the Editor about this paper Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (17) Citing Articles via Google Scholar Google Scholar Articles by von Bonsdorff, L. Articles by Parkkinen, J. Search for Related Content PubMed PubMed Citation Articles by von Bonsdorff, L. Articles by Parkkinen, J. Related Collections Nutrition Hematology Endocrinology and Metabolism

Bleomycin-detectable Iron Assay for Non-Transferrin-bound Iron in Hematologic Malignancies

¹ Finnish Red Cross Blood Transfusion Service, Kivihaantie 7, FIN-00310 Helsinki, Finland.

² Department of Medicine, PO Box 340, Helsinki University Central Hospital, FIN-00029 Helsinki, Finland.

³ Department of Public Health, PO Box 41, University of Helsinki, FIN-00014 Helsinki, Finland.

^aAuthor for correspondence. Fax 358-9-5801429; e-mail leni.bonsdorff{at}bts.redcross.fi.

Background: A microwell modification of the bleomycin assay for determining non-transferrin-bound iron (NTBI) was evaluated and compared with a chelation method.

Methods: The bleomycin assay reagent and sample volumes were halved, and measurements were done in microwell plates. Samples from patients treated for hematologic malignancies were studied. The chelation method was based on mobilization of NTBI with a chelator and measurement of the ultrafiltered iron-chelator complex. NTBI results were also compared with transferrin saturation and the distribution of transferrin iron forms by urea-polyacrylamide gel electrophoresis.

Results: The bleomycin assay intraassay imprecision (CV) was 7.7% and 8.2% and the interassay imprecision was 18% and 9.8% for a low (0.2 µmol/L) and a high (1.5 µmol/L) control, respectively. Hemolysis increased measured NTBI. A detection limit of 0.1 µmol/L was established based on the interference of nonvisible hemolysis and on accuracy studies. In patient samples, NTBI exceeded the detection limits only when transferrin saturation was >80%. Compared with the chelation method, the bleomycin assay gave clearly lower NTBI concentrations. The chelation method also gave positive results at <80% transferrin saturation. The recovery of iron added as ferric nitrilotriacetate to serum was 33% by the bleomycin assay and 64% by the chelation assay.

Conclusions: The microwell version of the bleomycin assay is reproducible. When hemolyzed samples were excluded, bleomycin-detectable iron was found only when the transferrin saturation was >80%, suggesting high specificity. Bleomycin-detectable iron constitutes only a portion of the NTBI measured by the chelation method.

The following articles in journals at HighWire Press have cited this article:

				D. B. Van Wyck Labile Iron: Manifestations and Clinical Implications J. Am. Soc. Nephrol., December 1, 2004; 15(suppl_2): S107 - S111. [Full Text] [PDF]

				S. G. Gehrke, H. Kulaksiz, T. Herrmann, H.-D. Riedel, K. Bents, C. Veltkamp, and W. Stremmel Expression of hepcidin in hereditary hemochromatosis: evidence for a regulation in response to the serum transferrin saturation and to non-transferrin-bound iron Blood, July 1, 2003; 102(1): 371 - 376. [Abstract] [Full Text] [PDF]