This patient was always a poser to me

[David Saikin]

Any thoughts on this would be appreciated . . . patient is K1 neg and has anti-K1 (Kell). The patient always has an IgG+ DAT. Transfused every 2-3 weeks with K1 neg rbcs. Eluate is always only anti-K1. I have never understood this. The only explanation I could come up with was a possible drug-induced +DAT and the anti-K1 rode along via the Matahasi-Ogata phenomenon. Thanks to any and all for you input.

[Malcolm Needs ☆]

Hi David,

We've currently got a patient with exactly the same phenomenon from one of our hospitals on the south-east coast of England, even down to the same specificity.

Once again, I know for a fact that this patient has not received any K+ blood now for years, has been tested to death to make sure they are not a K+ themselves (possible not the best way I could have put that I think) and yet we consistently can elute anti-K from his red cells.

I was (and am ) as confused as you, but I spoke to Joyce Poole (Manager of Red Cell Reference at the International Blood Group Reference Laboratory) about the case, and she thinks that it may be a mimicking auto-antibody, rather in the same way that, very often, an apparent auto-anti-e or auto-anti-E are not actually specific for the corresponding antigen, but react preferentially with these antigens. In other words, she is suggesting that our patient (at least) has made an apparent, but not actual, anti-K that is, in fact, an auto-anti-K-like antibody.

I'm not sure if this is the correct answer, but I am certainly NOT going to argue with Joyce!!!!!!!!

:)

[David Saikin]

Thanks Malcolm