title: Applying molecular immunohaematology to regularly transfused thalassaemic patients in Thailand.
abstract: BACKGROUND
  Red blood cell transfusion is the principal therapy in patients with severe thalassaemias and haemoglobinopathies, which are prevalent in Thailand. Serological red blood cell typing is confounded by chronic transfusion, because of circulating donor red blood cells. We evaluated the concordance of serological phenotypes between a routine and a reference laboratory and with red cell genotyping.
  
  
  METHODS
  Ten consecutive Thai patients with β-thalassemia major who received regular transfusions were enrolled in Thailand. Phenotypes were tested serologically at Songklanagarind Hospital and at the National Institutes of Health. Red blood cell genotyping was performed with commercially available kits and a platform.
  
  
  RESULTS
  In only three patients was the red cell genotyping concordant with the serological phenotypes for five antithetical antigen pairs in four blood group systems at the two institutions. At the National Institutes of Health, 32 of the 100 serological tests yielded invalid or discrepant results. The positive predictive value of serology did not reach 1 for any blood group system at either of the two institutions in this set of ten patients.
  
  
  CONCLUSIONS
  Within this small study, numerous discrepancies were observed between serological phenotypes at the two institutes; red cell genotyping enabled determination of the blood group when serology failed due to transfused red blood cells. We question the utility of serological tests in regularly transfused paediatric patients and propose relying solely on red cell genotyping, which requires training for laboratory personnel and physicians. Red cell genotyping outperformed red cell serology by an order of magnitude in regularly transfused patients.
authors.affiliation: Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States of America Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
authors.forename: Pairaya
authors.initials: P
authors.lastname: Rujirojindakul
authors.affiliation: Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States of America.
authors.forename: Willy A
authors.initials: WA
authors.lastname: Flegel
mesh_terms: D000293:Adolescent; D000328:Adult; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D017707:Erythrocyte Transfusion; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D013785:Thailand; D017086:beta-Thalassemia / Q000235:genetics / Q000628:therapy