ABSTRACT
Haemoglobin Bart’s (Hb Bart’s) level is associated with α-thalassaemia traits in neonates, enabling early diagnosis of α-thalassaemia. The study aimed to detect and quantify the Hb Bart’s using Cord Blood (CB) and CE Neonat Fast Hb (NF) progammes on fresh and dried blood spot (DBS) specimen respectively by capillary electrophoresis (CE). Methods: Capillarys Hemoglobin (E) Kit (for CB) and Capillarys Neonat Hb Kit (for NF) were used to detect and quantify Hb Bart’s by CE in fresh cord blood and dried blood spot (DBS) specimens respectively. High performance liquid chromatography (HPLC) using the β-Thal Short Programme was also performed concurrently with CE analysis. Confirmation was obtained by multiplex ARMS Gap PCR. Results: This study was performed on 600 neonates. 32/600 (5.3%) samples showed presence of Hb Bart’s peak using the NF programme while 33/600 (5.5%) were positive with CB programme and HPLC methods. The range of Hb Bart’s using NF programme and CB programme were (0.5–4.1%) and (0.5-7.1%), respectively. Molecular analysis confirmed all positive samples possessed α-thalassaemia genetic mutations, with 23/33 cases being αα/--SEA, four -α3.7/-α3.7, two αα/-α3.7 and three αα/ααCS. Fifty Hb Bart’s negative samples were randomly tested for α-genotypes, three were also found to be positive for α-globin gene mutations. Thus, resulting in sensitivity of 91.7% and 88.9% and specificity of 100% for the Capillarys Cord Blood programme and Capillarys Neonat Fast programme respectively. Conclusion: Both CE programmes using fresh or dried cord blood were useful as a screening tool for α-thalassaemia in newborns. All methods show the same specificity (100%) with variable, but acceptable sensitivities in the detection of Hb Bart.
ABSTRACT
The capillary electrophoresis (CE) is a new system that utilizes the principle of electrokinetic separation of molecules in eight electrolyte buffer-filled silica capillaries. In this study, we established the normal ranges of haemoglobin A2 (HbA2) and haemoglobin F (HbF) levels for normal individuals using this system and also the HbA2 level in beta thalassaemia and haemoglobin E (HbE) individuals.
ABSTRACT
Objective: The capillary electrophoresis (CE) is a new system that utilizes the principle of electrokinetic separation of molecules in eight electrolyte buffer-fi lled silica capillaries. In this study, we established the normal ranges of haemoglobin A2 (HbA2) and haemoglobin F (HbF) levels for normal individuals using this system and also the HbA2 level in β thalassaemia and haemoglobin E (HbE) individuals. Materials and Methods: 154 samples from normal individuals, 218 samples from β thalassaemia heterozygotes and 91 samples from HbE heterozygotes were subjected to high performance liquid chromatography (HPLC) and CE analysis. Results: The normal ranges for HbA2 and HbF by CE were 2.75% (SD 0.26%) and 0.03% (SD 0.24%) respectively, which were signifi cantly lower than that of HPLC 2.88% (SD 0.25%) and 0.58% (SD 0.61%) (p <0.001). The HbA2 level for HbE heterozygotes was 3.58% (SD 0.44%), which was signifi cantly higher than normal (p <0.001) but lower than that of β-thalassaemia heterozygotes (p<0.001) and the true HbE level was 24.28% (SD 3.38%). Conclusion: The CE system provided a fully automated and high throughput system for haemoglobin analysis. We established the normal ranges for HbA2 and HbF levels by CE. We also determined the ranges for HbA2 in beta thalassaemia and HbE heterozygotes using this system.