Screening for iron deficiency in surgical patients based on noninvasive zinc protoporphyrin measurements

Fuellenbach, Christoph; Stein, Philipp; Glaser, Patricia; Triphaus, Chris; Lindau, Simone; Choorapoikayil, Suma; Schmitt, Elke; Zacharowski, Kai; Hintereder, Gudrun; Hennig, Georg; Homann, Christian; Stepp, Herbert; Spahn, Gabriela H.; Kaserer, Alexander; Schedler, Andreas; Meybohm, Patrick und Spahn, Donat R. (2020): Screening for iron deficiency in surgical patients based on noninvasive zinc protoporphyrin measurements. In: Transfusion, Bd. 60, Nr. 1: S. 62-72

Abstract

Background: Approximately every third surgical patient is anemic. The most common form, iron deficiency anemia, results from persisting iron-deficient erythropoiesis (IDE). Zinc protoporphyrin (ZnPP) is a promising parameter for diagnosing IDE, hitherto requiring blood drawing and laboratory workup. STUDY DESIGN AND METHODS Noninvasive ZnPP (ZnPP-NI) measurements are compared to ZnPP reference determination of the ZnPP/heme ratio by high-performance liquid chromatography (ZnPP-HPLC) and the analytical performance in detecting IDE is evaluated against traditional iron status parameters (ferritin, transferrin saturation [TSAT], soluble transferrin receptor-ferritin index [sTfR-F], soluble transferrin receptor [sTfR]), likewise measured in blood. The study was conducted at the University Hospitals of Frankfurt and Zurich. RESULTS Limits of agreement between ZnPP-NI and ZnPP-HPLC measurements for 584 cardiac and noncardiac surgical patients equaled 19.7 mu mol/mol heme (95% confidence interval, 18.0-21.3;acceptance criteria, 23.2 mu mol/mol heme;absolute bias, 0 mu mol/mol heme). Analytical performance for detecting IDE (inferred from area under the curve receiver operating characteristics) of parameters measured in blood was: ZnPP-HPLC (0.95), sTfR (0.92), sTfR-F (0.89), TSAT (0.87), and ferritin (0.67). Noninvasively measured ZnPP-NI yielded results of 0.90. CONCLUSION ZnPP-NI appears well suited for an initial IDE screening, informing on the state of erythropoiesis at the point of care without blood drawing and laboratory analysis. Comparison with a multiparameter IDE test revealed that ZnPP-NI values of 40 mu mol/mol heme or less allows exclusion of IDE, whereas for 65 mu mol/mol heme or greater, IDE is very likely if other causes of increased values are excluded. In these cases (77% of our patients) ZnPP-NI may suffice for a diagnosis, while values in between require analyses of additional iron status parameters.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0041-1132
• Sprache: Englisch