Objectives: There is concern that ischemia-modified albumin (IMA) levels measured by albumin cobalt binding (ACB) assay reflect mainly albumin concentrations rather than myocardial ischemia.
Design and methods: Serum matrix and proteins were separated from a serum pool by a membrane filter. Two series of pools with albumin concentrations of 10, 20, 30, 40, 50, and 60 g/L were prepared either with human albumin or serum protein fraction. IMA values of these pools were measured in quintiplicate.
Results: There was a strong negative correlation between IMA and albumin levels in both pools. IMA change corresponding to each 10 g/L difference in albumin concentration was 37% and 48% in these pools.
Conclusions: ACB assay reflects albumin concentrations rather than IMA. Primary predictor of IMA in serum matrix is albumin concentration.
(c) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.