anti-K NOT detectable in Enzymes in Neutral cards   - is detectable in IAT and IAT enzymes

is there an explnation why NOT reactive in neutral cards - this is not an isolated incidence but occuring on patient and External QC samples

I was always taught that  the antigens in the Kell Blood Group System were not sensitive to the action of papain (which, pluto, I presume you are using, as you are from the UK), but that neither were the reactions between them and their cognate antibodies enhanced by the use of papain.  As a result, I am not surprised by your findings.

IAT is well-known to be the optimal technique to detect Kell Blood Group System antibody/antigen reactions, and you will note that both the techniques you have found to "work" are variants of this technique.

Most examples of anti-K are IgG, and therefore need an antiglobulin test to detect them. While enzyme-treatment of cells may or may not enhance reactivity of anti-K, it rarely turns an indirect agglutinin into a direct agglutinin. It does happen, but I've only seen it with Rh specificities where antigen density supports the process.

 

I presume that the "neutral cards" do not contain anti-IgG and therefore your findings are as expected/typical for most examples of anti-K.

You may be using a monoclonal anti-K which will work in the neutral/buffered gel cards.  Whereas, as the above posts state, the patient's anti-K will require an indirect antiglobulin test to detect.