I read about a new "genetic test" that prevents"mismatched transfusions" in the CLPrime newsletter yesterday. It soulnds like it might do multiple antigens typings. It is not yet licensed in the U.S. Does anyone know more about it?

Hi Mary

I'm Neil Avent the coordinator of the Bloodgen project, which included Progenika that developed Bloodchip in the EU between 2003-2006.

Bloodchip is able to type 106 blood group specific SNPs including all clinically significant known blood group polymorphisms (ABO,RH,KEL,MNS,FY,DO,DI,CO). The Bloodchip kit also comes with Software that is able to demonstrate effectively RHD variants. The chip is undergoing CE marking in Europe for RHCE, KEL and eventually RHD diagnostics, and the process has also been initiated with the FDA.

The capacity of the chip is such that all new polymorphisms will be added, and Progenika are currently adding a large number of the HPA polymorphisms in response to customer requests, also LU antigens are being added as well. If anyone is interested in trialling the system I suggest that they contact John Otridge of Progenika inc, Boston, MA for further details. (jotridge@progenika.com). Their website gives a significant amount of detail on the kit (www.progenika.com) as does my personal URL with my recent presentations and papers (http://science.uwe.ac.uk/StaffPages/NA/).

best wishes

Neil

Is it molecular? Expensive? Time consuming?

It's a microarray using molecular methods, I think.

Hi Mary

Yes it is molecular based, you will need to start with purified DNA, and is microarray based. Progenika have yet to finalise costs, but less than 24 hour turnaround should give you 100+ blood group alleles, including almost all known RHD - the most comprehensive system I know of. It will be commercially available later this year. Feel free to contact Progenika US, they are keen to have a number of test sites in North America.

Neil

Sounds like it would be mostly used for antigen "typing" donors but would also be good for sickle cell patients--you could get a complete genotype even if they had been transfused. It might be good for testing dads of babies of sensitized moms because you can get a genotype, not just a phenotype--or even the cord blood when indicated. The turn-around-time is too long for routine use in a transfusion service, I would think.

Correct me if my understanding is wrong.

Sounds like it would be mostly used for antigen "typing" donors but would also be good for sickle cell patients--you could get a complete genotype even if they had been transfused. It might be good for testing dads of babies of sensitized moms because you can get a genotype, not just a phenotype--or even the cord blood when indicated. The turn-around-time is too long for routine use in a transfusion service, I would think.

Correct me if my understanding is wrong.

Hi Mabel

You are right, the initial target groups for implementation of BLOODchip would be those patients, and any other multi-transfused individuals. Personally speaking I think it would be also useful to genotype any Mom with antibodies so a Rh variant phenotype can be defined- they are not as rare as commonly perceived.

We are hoping that several blood banks will comprehensively genotype a cohort of their (frequent) donors, thus giving them a bank of fully typed blood. This would work well in Europe as many donors give blood every 6 months, and very often donate for decades.

Although the time scales from blood to result are relatively long, this must be measured with the amount of data obtained, and of course technology does not stand still, and these time periods will be substantially decreased. I would expect genotyping to be the norm for blood grouping of donors and patients within a decade or so.

Neil