HbE and HbF levels in HbE/βO-thalassemia are heterogeneous

Abstract

HbE/β^O-thalassemia is the syndrome resulted from compound heterozygosity of HbE and β^O-thalassemia alleles. The diagnosis of this condition relies on the detection of types and amounts of hemoglobin together with the evaluation of red blood cell morphology. The objective of the present study was to determine types and quantities of hemolglobins in the patients of HbE/β^O- thalassemia. The study was conducted in 60 HbE/β^O- thalassemic patients attending the Thalassemia Clinic, Hematology Unit, Department of Medicine, Faculty of Medicine, Maharaj Nakorn Chiang Mai Hospital. Blood samples were collected before blood transfusion after consent formed has been singed. Hb identification was performed using weak-cation exchange HPLC. HbE allele was characterized by ARMS-PCR, α-thalassemia 1 (SEA type) by Gap-PCR and Hb Bart’s by immunochromatographic strip test (IC Strip™). Based on Hb identification profile, 3 groups of samples were revealed. These included Group 1 in which 31 samples having not significantly different quantities of HbE (50.1±8.0% ) and HbF (36.2±7.2% ), Group 2 in which 13 samples having significant differences of HbE (75.5±7.5%) and HbF (11.5±7.0) and Group 3 whose Hb typing showing minute amount of fast-eluted peak in addition to HbE and HbF, the amounts of which resembling those of Group 2 (HbE = 59.8±11.2%, HbF = 23.0±8.8%). Hematologic parameters were not different among all 3 groups, except MCH. HbE allele was in heterozygous state. α- thalassemia 1 (SEA type) and Hb Bart’s were absent in all samples. The finding in this study demonstrates the heterogeneities of the quantities of HbE and HbF in HbE/β^O-thalassemia. This result has encouraged the performers to have very great care in making diagnosis of thalassemia and hemoglobinopathies relying on Hb identification.