22 January 2021 (Friday) - Anti-Kp(a)

I had a rather fraught early shift today… in retrospect it wasn’t that busy, but having had a quiet one yesterday I had been hoping for more of the same. But within an hour or so of starting work I had detected an atypical blood group antibody and had identified it.
Anti-Kp(a)
Anti-Kp(a) is rather obscure as antibodies go… with only two per cent of the population (at best) carrying the antigen it can be a challenge for those who produce antibody panels to be able to include it in their repertoire. I must admit I can’t remember having identified one myself before.

Directed at an antigen of the Kell blood group system, anti-Kp(a) can cause both haemolytic blood transfusion reactions and haemolytic disease of the foetus and newborn. Rather than copying and pasting (which would fool no one, here’s a few references…

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850705/
https://www.ncbi.nlm.nih.gov/books/NBK2270/
http://www.ijbti.com/archive/2013-archive/100012IJBTIKQR2013-rossi/100012IJBTIKQR2013-rossi.pdf

 and loads more can be found in less than thirty seconds with a search on Google.
I learned something today…

7 July 2020 (Tuesday) - Anti-M and Dosage

An interesting case today – positive antibody screen by capture. The enzyme panel was clearly negative but panels by IAT and capture were 3+ in some cells and clearly negative in others. At first sight it seemed they seemed inconclusive, but on closer inspection the positive reactions were all with cells that were homozygous for M. In the negative reactions the M was either in the heterozygous or was absent.
I’ve seen this sort of anti-M before. The word is "dosage".. but I don’t know/can’t remember why it doesn’t react at all with the heterozygous cells. I would have expected some reaction… wouldn’t I?

I asked on some of the work-related Facebook groups. A chap with whim I went to college (all those years ago) posted a rather informative PowerPoint presentation from which I leaned loads. He also corrected my incorrect usage of the terms “homozygous” and “heterozygous”. I learned something.

But

Whilst these Facebook groups can be useful, you have to be selective in deciding to whom you will listen, and who you will ignore. Am I being arrogant in feeling that more and more they seem to be crawling with people who are planning to (yet again) re-sit GCSE science, and are looking sure to fail it again.

16 February 2018 (Friday) - Anti-Kp(a)

Here’s an interesting case…. Patient presented in A&E with a G.I. bleed. The patient’s address was three hundred miles away so obviously we had no history.

Positive in cells 2, 6 and 7… a familiar pattern. Anti-K. But what’s that in cell 8? Looks like an anti-Kp(a) as well. I did the three cell screen which had a cell positive for Kp(a) but negative for K, so… anti-K and anti-Kp(a).

I know a bit about anti-K, but anti-Kp(a)? I did a little reading-up. Here’s one article on the matter. There were several others…