Performance characteristics of the Dimension RxL iron and total iron-binding capacity methods.
BACKGROUND
Measurements of serum iron and total iron-binding capacity (TIBC) can be used to aid the diagnosis of iron deficiency and iron overload states. A variety of different methods for these measurements are commercially available.


METHODS
Linearity, imprecision and hemoglobin interference of homogeneous iron and TIBC methods on a Dimension RxL analyzer were assessed. Method comparison studies were performed with a Vitros 950 analyzer.


RESULTS
The Dimension RxL iron method was linear from 40 to 1000 microg/dl. The coefficient of variation of the iron and TIBC methods were <4% and <2%, respectively, at iron concentrations of 68 and 228 microg/dl and TIBC concentrations of 206 and 384 microg/dl. Comparison of the Vitros 950 and Dimension RxL iron methods gave a slope of 0.97, an intercept of 6.0 and r=0.99. Corresponding results for the TIBC methods were 1.02, -6.6 and r=0.97, respectively. Simulation of acute iron overload in vitro did not produce the same effect on TIBC measurements as in vivo overload. Iron recovery by the Dimension RxL method was reduced 40-60% by the addition of deferoxamine at a concentration of 200 micromol/l.


CONCLUSIONS
The Dimension RxL assay provides acceptable measurements of iron and TIBC in routine patient samples. Iron measurements are unreliable in the presence of deferoxamine.
De
Barun K
BK
Department of Pathology, University of Mississippi Medical Center, Jackson, MS, USA.
Roberts
William L
WL
D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000175:diagnosis; D003676:Deferoxamine / Q000737:chemistry; D062787:Drug Overdose / Q000097:blood; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D007501:Iron / Q000097:blood* / Q000506:poisoning; D007502:Iron Chelating Agents / Q000737:chemistry; D019190:Iron Overload / Q000097:blood / Q000175:diagnosis; D033862:Iron-Binding Proteins / Q000097:blood*; D008722:Methods; D011485:Protein Binding; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results
D006454:Hemoglobins; D007502:Iron Chelating Agents; D033862:Iron-Binding Proteins; D011933:Reagent Kits, Diagnostic; D007501:Iron; D003676:Deferoxamine