ABSTRACT
OBJECTIVE: To evaluate the usefulness of DNA methods to provide a means to precisely genotypically match donor blood units for the antigen-negative type of 35 sickle cell disease patients<. METHODS: Red blood cell units were investigated for ABO, D, C, c, E, e, K, Fyª, Fy b, Jkª, Jk b, S, s, Diª and RH variants by performing a molecular array (Human Erythrocyte Antigen BeadChipTM, BioArray Solutions), polymerase chain reaction followed by restriction fragment length polymorphism analysis and sequencing of patient samples and donor units that had been serologically matched based on the ABO, Rh and K phenotypes and the presence of antibodies. RESULTS: Matches for 21 of 35 sickle cell disease patients presented discrepancies or mismatches for multiple antigens between the genotype profile and the antigen profile of their serologically-matched blood units. The main discrepancies or mismatches occurred in the RH, FY, JK and MNS systems. Eight Rh alloimmunized patients presented RHD and RHCE variants that had not been serologically identified. According to these results better matches were found for the patients with genotyped units and the patients benefited as shown by better in vivo red blood cell survival. CONCLUSION: Molecular matching is superior to serological matching in sickle cell disease patients, decreasing the risk of transfusion reactions, especially delayed transfusion reactions to existing alloantibodies and preventing alloimmunization.
Subject(s)
Humans , Blood Group Antigens , Molecular Typing , Anemia, Sickle Cell , Isoantibodies/bloodABSTRACT
Neste século uma nova tecnologia está gradativamente se infiltrando na medicina transfusional e complementando as técnicas sorológicas: a genotipagem de grupos sanguíneos através de diferentes métodos moleculares. O futuro dos grupos sanguíneos sem dúvida envolve a biologia molecular. Neste contexto, novos procedimentos técnicos se tornam necessários para possibilitar a introdução da genotipagem de grupos sanguíneos na rotina transfusional bem como, a investigação de novos polimorfismos característicos de duas diferentes populações: doadores de sangue e pacientes. A tecnologia baseada em "microarrays" tem sido avaliada para detecção de polimorfismos de grupos sanguíneos. Com a perspectiva de que esta metodologia permitirá a realização da genotipagem de grupos sanguíneos em larga escala de forma automatizada e rápida, os objetivos deste trabalho foram: validar em uma população brasileira os chips de DNA para a genotipagem dos principais alelos de grupos sangüíneos; determinar a freqüência genotípica dos principais alelos de grupos sanguíneos em doadores voluntários de sangue e, viabilizar a criação de um banco de dados eletrônico com as características genotípicas comuns e raras de doadores voluntários de sangue, possibilitando a compatibilidade sanguínea mais exata entre doadores e pacientes portadores de anemia falciforme. Os resultados obtidos durante a validação do "microarray" mostraram concordância com os resultados da genotipagem convencional e a fenotipagem. A genotipagem de grupos sanguíneos em larga escala utilizando a plataforma HEA BeadChip possibilitou a determinação da freqüência dos principais genótipos dos sistemas de grupos sanguíneos em uma população brasileira de doadores voluntários de sangue e demonstrou agilidade na identificação de alelos raros. Esta metodologia possibilitou também a criação de um banco de dados de doadores genotipados, através do qual foi possível...
In this century a new technology is gradually infiltrating in the transfusion medicine and complementing the serological techniques: blood group genotyping through a series of molecular methods. The future of blood groups undoubtedly involvesmolecular biology. In this context, new technical procedures are necessary tomake possible the introduction of blood group genotyping in the blood bank. Themicroarray-based technology has been evaluated for detection of blood grouppolymorphisms in large scale. We evaluated the usefulness of a high-throughput genotyping based on DNA microarrays commercially available to obtain a fully typed donor database to be used for a better matching between Sickle Cell Disease (SCD) Patients and donors to prevent adverse transfusion reactions. We selected DNA samples from 144 SCD patients with multiple (receiving > 5 units) transfusions previously phenotyped for ABO, Rh(D, C, c, E, e), K1, Fya and Jka. We also selected DNA samples from 948 Brazilian blood donors whose ABO/RhDphenotype matched that of the patients. All samples were analyzed by DNA arrayanalysis (HEA BeadchipTM, BioArray Solutions) to determine polymorphismsassociated with antigen expression for 11 blood group systems (Rh, Kell, Kidd,Duffy, MNS, Dombrock, Lutheran, Landsteiner-Wiener, Diego, Colton, Scianna). Based on genotype results we were able to predict phenotype compatible donors needed in order to provide compatible units to this group of patients. Based on their ABO/Rh phenotype we were able to find in this pool of donors compatible units for 134 SCD patients...