Elevated serum transferrin receptor levels in common types of thalassemia heterozygotes in Southeast Asia: A correlation with genotypes and red cell indices

Background: Serum transferrin receptor (sTfR) measurement is a helpful test for diagnosis of iron deficiency. Increased values are detectable in thalassemia syndromes due to increased erythropoiesis. However, sTfR has never been studied in hemoglobin E (HbE) carriers and their interactions with alpha-thalassemia heterozygotes that are common in Southeast Asia. Methods: We determined sTfR concentrations using a particle enhanced immunoturbidimetric assay in 113 early pregnancies without iron deficiency. Results: Patients were genotypically classified into 6 groups: 23 normal (mean sTfR +/- SD mg/l, 0.94 +/- 0.22). 14 alpha(+)-thalassemia heterozygotes (1.06 +/- 0.45). 21 alpha(0)-thalassemia heterozygotes (1.31 +/- 0.35). 30 HbE heterozygotes (1.11 +/- 0.26), 13 HbE heterozygotes with alpha(+)-thalassemia heterozygotes (1.09 +/- 0.32), and 12 HbE heterozygotes with (alpha(0)-thalassemia heterozygotes (1.16 +/- 0.27). sTfR concentrations in all thalassemic groups were higher than controls, and significantly correlated with high red cell count, low MCV and MCH (p < 0.001). When alpha(0)- or alpha(+)-thalassemia combined with HbE, sTfR concentrations were declined compared with alpha(0)-thalassemia or hemoglobin E, respectively, suggesting more balances in alpha- and beta-globin chain production. Conclusions: Mildly increased erythropoiesis represented by increased sTfR concentrations in alpha-thalassemia and HbE heterozygotes and illustrated alpha- and beta-thalassemic gene interaction. These findings warrant further investigations on sTfR in diagnosis of iron deficiency in thalassemia carriers. (C) 2009 Elsevier B.V. All rights reserved.