Abstract

Zinc protoporphyrin (ZPP) is considered a reliable marker of iron-deficient erythropoiesis. The diagnostic value of ZPP as a screening parameter for iron deficiency has been shown in many different subgroups of patients with anemia. We studied the iron status in 121 renal transplant recipients. ZPP was measured by hematofluorimetry and related to the transferrin saturation (TS). Forty-four (36%) of 121 renal transplant recipients suffered from anemia (Hb < 12 g/dl). Eleven (25%) out of these 44 anemic patients had iron deficiency anemia. Elevated ZPP values (ZPP > 70 µmol/mol heme) were found in 20 (17%) patients. From these patients (n=20) with elevated ZPP 11 had iron deficient anemia, two had anemia of chronic disease, three had posttransplantation polyglobulia and four patients had elevated ZPP values of unknown origin. Sensitivity of ZPP in detecting iron deficiency anemia was l00%. The specificity in renal transplant recipients with anemia and without chronic infection was 92%. TS was reduced (TS < 20%) in 15 (12%) patients. ZPP and TS showed a significant negative correlation (r = -0.37, p < 0.001). ZPP proved to be a reliable marker of iron defïcient erythropoiesis in renal transplant recipients. The diagnostic value of this fast marker as a first line parameter in clinical screening seems to be promising and should be further investigated.

DOI: Clin. Lab.1999;45:1-6