Mo1255 Diagnostic Accuracy of Zinc Protoporphyrin/Heme Ratio for Screening of Iron Deficiency Anaemia in Patients With Inflammatory Bowel Disease

Abstract

Background: Iron deficiency anemia (IDA) is commonly measured by multiple indicators. Choice of a single iron biomarker for IDA screening at population level is controversial. Zinc protoporphyrin (ZPP) has proved a sensitive and specific marker for functional iron deficiency. Our study evaluated for the first time the diagnostic value of ZPP in IDA and differential diagnosis of IDA/anemia of chronic disease (ACD). Methods: The study included 136 patients with IBD (age, 36.40 ± 13.14 years, 41 % male), who consecutively attended the Crohn Colitis Centre Frankfurt for routine evaluation between Jan 2009 and Oct 2012. Blood count, transferrin saturation (TSAT), serum ferritin (SF), C-reactive protein and ZPP were determined by routine assay. Anemia was defined in accordance with WHO criteria as hemoglobin (Hb) concentration of < 13 g/dl/12 g/dl (m/f). For the multiple-criteria model, ID was considered present when ≥2 values from SF (<30 μg/l), TSAT (<20%), and ZPP (<40 μmol/mol Hb)1 were abnormal. Anemia was classified as IDA, ACD or a mixed form (IDA/ACD)2. Results: Unlike SF, ZPP significantly correlated with Hb. Receiver operating characteristic (ROC) curves for the multiple markers used to diagnose IDA indicated a superior diagnostic accuracy of ZPP. Crucially ZPP is elevated even in ACD, indicating irondeficient erythropoiesis (fig. 1). Conclusion: ZPP is not a simple ID parameter but a marker of iron-deficient erythropoiesis. Our results confirm the utility of ZPP in detection of ID in IBD patients with inflammation and anemia, even in ACD. 1Grant KE et al. Comparison of indicators of iron deficiency in Kenyan children. Am J Clin Nutr 2012;95:1231-7 2Weiss G, Goodnough LT. Anemia of chronic disease. N EnglJ Med 2005;352:1011-23