Cord Blood Screening for Haemoglobin E (Hb E) Syndrome by Capillary Electrophoresis

Transcription

1 Cord Blood Screening for Haemoglobin E (Hb E) Syndrome by Capillary Electrophoresis Rosline H., W. Asmuni W. Mohd Saman, Imilia Ismail, Che Anuar CY, Shafini Mohd Yusoff, Rosnah B Department of Hematology, School of Medical Sciences, Universiti Sains Malaysia, Heatlh Campus, Kelantan, Malaysia. roslin@usm.my

2 Introduction The Malaysian Thalassemia Registry (2009, August) showed a total of 4,541 registered patients of which 3,310 consist of the transfusion dependent β thalassaemia major and HbEβ thalassemia patients Hemoglobinopathy Hb E is prevalent in Malaysia and its carrier rate was 5 to 46%(1) Most of transfusion dependent thalassemia were compound heterozygous HbE/ Beta thalassemia. Study by CF. Ngim (2013) in Malaysia, showed that parent was not aware of their child carrier status until later age in 70% of the transfusion dependent patient (21/30) (2) The current poor response of voluntary thalassemia screening in Malaysia contributed to ineffective prevention. There has also been limitation in making the diagnosis of thalassemia with the existing method, high performance liquid chromatography (HPLC) especially in newborn as Hb E is not separated from Hb A2 thus resulting in uncertainty of making the diagnosis of Hb E and β-thalassemia The purpose of this study was to screen HbE syndrome from cord blood using capillary electrophoresis (CE). 1. Malaysian Thalassaemia Registry (2009, August) 2. A single centre study on birth of children with transfusion dependent thalassaemia in Malaysiaand reasons for ineffective prevention C. F. Ngim1,*, H. Ibrahim2, N. M. Lai3 andc. S. Ng4; Prenatal Diagnosis; DOI: /pd.4484

3 Method A cross sectional study was done by collecting term gestational cord blood samples from newborns delivered in Hospital USM. Consent was obtained from the mothers before delivery. 300 samples were obtained from umbilical cord immediately after birth using a syringe and needle after removing any blood from the surface of the cord with gauze to avoid maternal blood contamination. The red cell indices of the cord blood were measured using the Sysmex XE 5000 (Sysmex, Kobe, Japan) analyzer Haemoglobin analyses was performed by using CE (CAPILLARYS 2 Sebia, Lisses, France) for quantitation of HbA, HbF, and HbA2, Hb Bart s and HbE HPLC (Bio-Rad VARIANT II) was also performed at the same time for a comparison

4 Results 300 cord blood samples were examined Types of hemoglobin found were: HbA/F (63%), HbAFA2 (20%), HbAFE (10.67%), HbBart with HbAF & A2 (6%) and HbAFEBart (0.33%). Table 1 Hb E syndrome was detected in 33 (11%) and 22 (7.3%) by CE & HPLC respectively By CE, the level of HbE ranged from % in HbE syndrome Those with HbE syndrome, mean level of HbA was 9.9 ᆂ 4.9 %. Those without HbE peak, HbA and HbA2 was 20.5ᆂ 5.6 % and 0.3 ᆂ 0.2 % respectively. 12.5% of HbE syndrome has HbA of less than 5% which may need to exclude compound heterozygote HbE/Beta Mean level of HbA2 in those with normal profile was % but non-detectable peak in all those with HbE syndrome Mean of Hb A in newborns with Hb E and without E was 20.5 ± 5.6% & 9.9 ± 4.9% respectively (p<0.001) Comparing between capillary electrophoresis and HPLC, in HPLC, HbA2 range from 0.3% - 6.7% and % in those with non-detectable HbE peak and those with HbE peak respectively Table : 1 Capillary electrophoresis HbA Figure : 1 HbE HPLC

5 Discussion/Conclusion Newborn screening for hemoglobinopathies is a useful strategy for early detection of the disease Cord blood would be the best non-invasive sample to be used for the screening strategy Based on the study, capillary electrophoresis has been shown to be effective to identify the HbE peak and subsequently identify the disease Identification of HbE syndrome by HPLC is limited as it will only based on HbA2 level and the level was inconsistent HbE peak was shown to be common among our newborn and the prevalence of HbE in our study correspond to the prevalence of HbE in Malaysia (5-46%) (Malaysian Thalassemia Registry 2009) In conclusion: Implementation screening strategy in prevalent area of HbE hemoglobinopathy by cord blood sampling using CE will identify the disease early. Regular follow-up of these patients will identify those that may become transfusion dependent and appropriate management will improve the disease and social burden of the families and country Acknowledgement : Many thanks to organisng committee of Indian Ocean Rim Laboratory Haematology Congress 2014 for the support Research is supported by USM Short Term Grant (304/PPSP/ )