title: Routine screening for α-thalassaemia using an immunochromatographic strip assay for haemoglobin Bart's.
abstract: OBJECTIVE
  To evaluate an immunochromatographic (IC) strip assay for Hb Bart's as a routine screening test for α-thalassaemia in area with a high prevalence of thalassaemia and haemoglobinopathies.
  
  
  METHODS
  A total of 300 adult screen positive blood specimens were collected at an ongoing thalassaemia screening programme in northeast Thailand. Routine screening was done using red blood cell indices, osmotic fragility, and dichlorophenolindophenol tests. The IC strip assay for haemoglobin Bart's was performed on all samples. The result was evaluated against thalassaemia genotypes determined using standard haemoglobin and DNA analyses.
  
  
  RESULTS
  Of 300 subjects investigated, Hb and DNA analyses identified 32 with normal genotype. The remaining subjects carried thalassaemia with as many as 16 different genotypes. Hb Bart's was detected in all cases, with several α(0)-thalassaemia (SEA type) related disorders. Of cases with α(+)-thalassaemia, 86.1% showed a positive result; 100 out of 103 Hb E carriers, all homozygous Hb E and β-thalassaemia trait were negative. Nine out of 17 cases with β-thalassaemia/Hb E disease, and one case of double heterozygote for Hb Q-Thailand and Hb E returned positive results. The overall sensitivity and specificity of the IC strip assay for detecting α(0)-thalassaemia were 100% and 73.1%, respectively.
  
  
  CONCLUSIONS
  The results showed a high sensitivity for screening for α(0)-thalassaemia using IC strip assay for Hb Bart's. This simple method, used in combination with conventional screening protocols, should lead to a significant reduction in the number of referral cases for DNA analysis. Cost effectiveness in each population should be taken into consideration.
authors.affiliation: Biomedical Science Program, Graduate School, Khon Kaen University Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Patcharawadee
authors.initials: P
authors.lastname: Prayalaw
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Goonnapa
authors.initials: G
authors.lastname: Fucharoen
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand supan@kku.ac.th.
authors.forename: Supan
authors.initials: S
authors.lastname: Fucharoen
mesh_terms: D000328:Adult; D002846:Chromatography, Affinity; D005260:Female; D006455:Hemoglobins, Abnormal / Q000032:analysis*; D006801:Humans; D008297:Male; D008403:Mass Screening; D017085:alpha-Thalassemia / Q000097:blood / Q000175:diagnosis* / Q000235:genetics
chemical_list: D006455:Hemoglobins, Abnormal; C030448:hemoglobin Bart's
keywords: Haemoglobin Bart's; immunochromatographic strip test; α-thalassaemia