Malcolm Needs

Yes. All changes have to be validated.

Welcome KRIS.

1:1024 is NOT a titre; it is a dilution.

Welcome Paco Belda.

Welcome Vanessa Huynh.

Welcome bloodbankem.

Welcome gaid2010.

Thanks for those suggestions, but PLEASE, don't call it anti-Kell and anti-Cellano!

True, but, in the early days, I know of at least one example that caused almost pure red cell aplasia in a BMT from a group A donor, because the contaminating anti-A was so strong.

Phew, that's a difficult one! You could begging some from one of the world's big organisations, such as the International Blood Group Reference Laboratory in the UK, somewhere like the Mayo Clinic in New York, Amsterdam, South Africa, etc, but other than that, I don't know. Some of the large reagent suppliers, such as Ortho or BioRad may possibly have some in store too.

Good point.

I must admit, we always used to use polyclonal antibodies, and there is a reason for this. Even blended monoclonal antibodies will still only recognise certain epitopes within the antigen, and while the K and k antigens tend to be single amino acid substitutions of methionine at position 193 for the K antigen, and threonine at position 193 for the k antigen, this is by no means universal. A weak expression of K is seen when either an argenine or a serine residue replace the methionine residue at position 193. As with amino acid substitutions leading to weakened expression of the K antigen, so the same can happen with the k antigen, but these substitutions may not actually be at position 193. A recent publication has shown that a substitution of Leu196Val weakens the expression of the k antigen (see Uchikawa M, Onodera T, Tsuneyama H, Enomoto T, Ishijima A, Yuasa S, Murata S, Tadokoro K, Nakajima K, Juji T. Molecular basis of unusual Kmod phenotype with K+wk-. Vox Sang 2000; 78 Suppl. 1: Abstract O011, Poole J, Warke N, Hustinx H, Taleghani BM, Martin P, Finning K, Crew VK, Green C, Bromilow I, Daniels G. A KEL gene encoding serine at position 193 of the Kell glycoprotein results in expression of KEL1 antigen. Transfusion 2006; 46: 1879-1885 and Millard GM, Lopez GH, Turner EM, Lizarazu ME, Roots NM, Liew Y-W, Flower RL, Hyland CA. Modified expression of the KEL2 (k) blood group antigen attributed to p.Leu196Val amino acid change three residues from the K/k antigen polymorphism site: implications for donor screening. Transfusion 2019; 59: 1156-1158.). Therefore, it is more likely that you may get a false negative result using a monoclonal antibody in adsorption/elution tests, than by using a polyclonal antibody, with its wider breadth of specificity to the antigen's epitopes.

I can see no reason why this would not work as a method. We used to use something very similar when testing individuals expressing the "McLeod" phenotype. However, these days it would be easier (and certainly more accurate) to perform gene sequencing on both the KEL and the XK genes. Don't forget that a true Duffy null phenotype (FY/FY), as opposed to a "GATA-1" type Fy(a-b-) is, these days, established by molecular techniques.

Welcome Michael Cortez.