The diagnostic accuracy of unbound iron binding capacity (UIBC) as a test for empty iron stores. (April 2013)

• Record Type: Journal Article
• Authors: Åsberg, Arne; Thorstensen, Ketil; Mikkelsen, Gustav; Åsberg, Ann E.
• Is Part Of: Scandinavian journal of clinical & laboratory investigation. Volume 73:Number 3(2013)
• Page Start: 208
• Page End: 213
• Publication Date: 2013-04
• Subjects: Clinical biochemistry -- Periodicals; Physiology, Pathological -- Periodicals; Physiology, Experimental -- Periodicals; Medicine -- Research -- Periodicals; Clinical medicine -- Periodicals; 616.0072
• DOI: 10.3109/00365513.2013.765029
• Languages: English
• ISSNs: 0036-5513

Abstract

<abstract> <title>Abstract</title> <p> <bold> <italic>Background.</italic> </bold> Unbound iron binding capacity (UIBC) in serum, which is s-total iron binding capacity (2 times s- transferrin) minus s-iron, may be a more accurate marker of empty iron stores than serum transferrin saturation. Previously we have shown this for healthy females of childbearing age. <bold><italic>Methods.</italic></bold> Now we used receiver operating characteristic (ROC) curve analysis to compare the diagnostic accuracy of s-iron, s-transferrin, s-transferrin saturation and s-UIBC in diagnosing empty iron stores in 29, 251 female and 19, 652 male outpatients. Empty iron stores were defined as s-ferritin less than 10, 15 or 20 μg/L. <bold><italic>Results.</italic></bold> At all definitions of empty iron stores s-UIBC had a better diagnostic accuracy than the other tests in both male and female outpatients, with an area under the ROC curve of 0.85–0.97. Also in subpopulations with elevated s-CRP or low b-hemoglobin s-UIBC was more accurate than the other tests. All tests performed better in males than in females, and generally they were more accurate in adults than in children. <bold><italic>Conclusion.</italic></bold> When diagnosing empty iron stores calculation of s-UIBC is a better way to utilize the information in s-iron and s-transferrin than the calculation of s-transferrin saturation.</p> </abstract>