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

Abstract

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 α-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 α +-thalassemia heterozygotes (1.06 ± 0.45), 21 α 0-thalassemia heterozygotes (1.31 ± 0.35), 30 HbE heterozygotes (1.11 ± 0.26), 13 HbE heterozygotes with α +-thalassemia heterozygotes (1.09 ± 0.32), and 12 HbE heterozygotes with α 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 α 0- or α +-thalassemia combined with HbE, sTfR concentrations were declined compared with α 0-thalassemia or hemoglobin E, respectively, suggesting more balances in α- and β-globin chain production. Conclusions Mildly increased erythropoiesis represented by increased sTfR concentrations in α-thalassemia and HbE heterozygotes and illustrated α- and β-thalassemic gene interaction. These findings warrant further investigations on sTfR in diagnosis of iron deficiency in thalassemia carriers.