Method for the Simultaneous Determination of Blood Group and Platelet Antigen Genotypes

Abstract

RBC and platelet (Plt) alloimmunization requires antigen-matched blood to avoid adverse transfusion reactions. Some blood collection facilities use unregulated Abs to reduce the cost of mass screening, and later confirm the phenotype with government approved reagents. Alternatively, RBC and Plt antigens can be screened by virtue of their associated single nucleotide polymorphisms (SNPs). We developed a multiplex PCR-oligonucleotide extension assay using the GenomeLab SNPStream platform to genotype blood for a plurality of blood group antigen-associated SNPs, including but not limited to: RhD (2), RhC / c, RhE / e, S / s, K / k, Kpa / b, Fya / b, FYO, Jka / b, Dia / b, and HPA-1a / b.

Description

TECHNICAL FIELD[0001]This invention relates to an ultra high throughput (UHT) multiplex PCR genotyping method. More specifically, the present invention relates to an automated method of determining a plurality of blood group and platelet antigen, preferably human platelet antigen (HPA), genotypes simultaneously from a single sample through the detection of single nucleotide polymorphisms (SNPs) for various blood group and platelet antigens.BACKGROUND OF THE INVENTION[0002]At present, there are 29 blood group systems and 6 HPA systems recognized by the International Society of Blood Transfusion (ISBT), wherein, with a few exceptions, a blood group ‘system’ may be defined by a single gene at a given locus of the human genome (Daniels, G. L. et al. Vox Sang 2003; 84:244; Metcalfe P. et al., Vox Sang. 2003; 85:240). Most people know their ABO and Rh blood group. However, the ABO and Rh blood group systems expressed on red cells simply represent antigens from only two of the 29 blood gro...

AI Technical Summary

Benefits of technology

[0014]The present invention accordingly provides an automated, or robotic, high-throughput ‘screening’ tool for blood group and platelet antigens by evaluating the alleles of the genes that express these antigens on red cells and platelets, respectively. This is done by identifying the unique nucleotides associated with the specific alleles that occupy the gene locus using a testing platform, which requires novel and specific compounds that we designed. Our robotic high-throughput platform provides important blood group and HPA genotype information within 24 hours from the start of the test. We identified the alleles of blood group antigens for; RhD, RhC, Rhc, RhE, Rhe, S, s, Duffy (Fy)a, Fyb, K, k, Kpa, Kpb, Diego (Di)a, Dib, Kidd (Jk)a, Jkb, and the platelet antigens, Human Platelet Antigen (HPA)-1a and HPA-1b, representing, but not limited to 19 of the most clinically important antigens in red cell and platelet transfusion. Additional genotyping tests for other clinically important blood group and platelet antigens may be developed, and are encompassed in the teachings of the present invention. When performed on all blood donations for all clinically important blood group and platelet antigens, our invention will provide a comprehensive database to select and confirm the antigens when required using government regulated antisera. The use of this platform as a screening tool will lessen the number of costly government regulated tests to be done by the collection facility and end user (the hospital blood bank), and meet the demand of antigen-matched blood for specific transfusion recipients.

[0018]The present invention overcomes the deficiencies of the prior art because the entire test, i.e. all steps of the method of the present invention, from PCR to computation analyses can be automated and multiplexed so that the nucleotides of a plurality of SNPs, and more preferably, the 12 SNPs of the present invention, can be identified simultaneously. This automated multiplex high throughput analysis can meet the demand of testing hundreds of blood samples, and the turn-around time of less than 24 hours, to provide valuable information to a blood collection facility before blood is shipped to the end user. This platform has the advantage over existing technology in that it reduces operator handling error. In addition, there are significant cost reductions compared with the current government-regulated serological analysis. It should be noted that present prior art technologies relating to PCR-RFLP and SSP-PCR for blood group and platelet antigens are not routinely used since they are no more cost efficient than serology. The present invention overcomes the deficiencies of the prior art and fulfils an important need in the present art for the automated, accurate, rapid and cost-effective identification of multiple blood group and HPA SNPs.

[0031]Our platform provides important genotypic information within 24 hours of donation. When performed on all blood donations for all important blood group phenotypes, our invention will provide a comprehensive database to select and confirm blood group phenotypes using government regulated antisera. The use of this platform as a screening tool will lessen the number of regulated blood group phenotype tests done by the collection facility and end user, and meet the end user demand for antigen-matched blood for transfusion recipients.

[0039]The teachings and method of the present invention are superior to the teachings of the prior art for a number of reasons, one of which is that the complete method of the present invention, from DNA extraction to result computation analyses can be automated and multiplexed so that many SNPs can be determined simultaneously. This automated multiplex high throughput analysis can meet the demand (hundreds of blood donations can be tested) and the turn-around time (<24 hours) to collate and provide valuable information to the blood collection facility before blood is shipped to the end user. This platform and method has the further advantage over existing technology in that it reduces operator handling error.

Problems solved by technology

The gold standard in the industry is to ‘phenotype’ blood for the presence of specific blood group and platelet antigens using government regulated antisera (antibodies) performed by single-test methods or by an automated platform, which is a cost ineffective method for a blood collection facility that routinely performs tests on a high volume basis.

Essentially, the current tests which employ government-approved reagents in a manual, single-test driven method are a very cost ineffective method for a blood collection facility that is often required to perform such tests on a high volume basis.

However, since much of the blood is sent to hospitals within 24-48 hours after collection, manual blood group phenotyping cannot meet the short turn-around time required to provide the end user with the information required before blood must be shipped.

The prior art does not provide the use of multiple DNA sequences as primer pairs that work simultaneously on a single sample.

Moreover, the prior art does not employ novel DNA sequences to detect blood group SNPs in an automated high-throughput fashion.

The deficiencies of these test systems are the use of a single PCR reaction for each nucleotide of a given nucleotide of each SNP, and the pooling of samples prior to the detection phase and manual post-analyte data analysis.

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