We had a patient several years ago who had a positive DAT and our reference lab eluted anti-K and anti-Kpa. We never detected either antibody in her plasma (we were performing an autocontrol as part of our antibody screen at the time, which is how we found it). This was the only time either antibody was detected, but we continued to give her antigen negative blood for the rest of her life. This is the only anti-K that I have ever experienced that "went away" (MINE is still quite robust after 27 years), but that is the only explanation we came up with.

We had a patient several years ago who had a positive DAT and our reference lab eluted anti-K and anti-Kpa. We never detected either antibody in her plasma (we were performing an autocontrol as part of our antibody screen at the time, which is how we found it). This was the only time either antibody was detected, but we continued to give her antigen negative blood for the rest of her life. This is the only anti-K that I have ever experienced that "went away" (MINE is still quite robust after 27 years), but that is the only explanation we came up with.

I'm not certain, but I think I have already said in another post that we followed someone with an auto-antibody for years, where we could elute off an anti-K from the patient's red cells, and yet I also know that absolutely no K+ blood was transfused over this time. Joyce Poole told me that this was rare, but not unique, and that the antibody we were eluting was an anti-K-like auto-antibody that reacted strongest with K+ red cells.

Anti-K appears in patient plasma often times when an antibody against a high frequency

Kell system is present. Often times this Anti-K is a mimicking antibody. To see if it

is a true Anti-K or a mimicking antibody one can absorb the eluate with a K- absorbing cell.

If it is mimicking the antibody will be absorbed to exhaustion. If the Anti-K does not absorb out with the K- absorbing cell then it is a true Anti-K.

Reading a few of the last responses jogged some long lost memories. In a previous life when I supervised a full service blood bank we had the majority of our donors come from the civilian employees at the local Air Force Base. We had 2 cases of short lived anti-K from donors who had never been transfused or pregnant (one was male). We speculated that since these folks worked in a "chemical rich" enviroment, that could have been the cause of the anti-K like reactions. Neither lasted more than a couple of months before vanishing. Just one more mystery for the X-Files.

It is probably best to look at the decision to remove or not remove the antibody history in terms of risk. There was evidence, however suspect, that the patient had an anti-K. If you remove the requirement of transfusing K antigen negative blood and by a very unlikely chance the patient had a transfusion reaction due to anti-K (or any harm even remotely attributable to the transfusion), then you have to convincingly explain why this was a safe or better decision for the care of the patient to your hospital QA, administrators and/or lawyers, who may only know one thing about blood-it's red!

And this from a junior member and the only response that I actually agree with.

Good For YOU!! : )

Interesting; had not heard any of that.

It is true (as many have pointed out) that it is not difficult to obtain K- blood so better to be safe than sorry. But as Malcolm pointed out, this "could" occur with a more frequent antigen than K.

While I appreiciate your comment about this perhaps not being the fault of the Tech., sadly, this is a Tech. that I would really like to get out of my dept (but she is 1 of many Generalists who rotate through given this is a medium size Community Hospital). But since I see no way to determine what really occurred, I will just leave it in.

Thanks,

Brenda

Hi Brenda

There are a number of reports in the literature of cross-reacting antibodies of bacterial origin that react with the K antigen. At least one of them describes anti-K in an infant that was about 20 months old with no history of transfusion (I could find the reference if you'd like). I have seen at least one myself in a patient with no transfusion history. The antibody was not stable in the sample over time (we attempted to use the sample for training) and it was IgM. The anti-K was not detectable in a subsequent sample. As for leaving the antibody - its a difficult decision, however transfusing K negative red cells is relatively easy considering the frequency of the antigen - I personally would leave it. Your colleague may not be at fault here and it is quite possible that it was not mis-identified or mis-detected.

Cheers

Pam

Hmmm...I am learning a lot from this post!

Thanks,

Brenda

I'm not certain, but I think I have already said in another post that we followed someone with an auto-antibody for years, where we could elute off an anti-K from the patient's red cells, and yet I also know that absolutely no K+ blood was transfused over this time. Joyce Poole told me that this was rare, but not unique, and that the antibody we were eluting was an anti-K-like auto-antibody that reacted strongest with K+ red cells.

Some years ago, I found an 'anti-K' in the serum of an elderly gentleman who had never even been in the hospital at any time in his whole life, much less transfused, until the day I crossmatched him. His DAT was positive, eluted anti-K. Antigen typing showed that his cells were K negative. This was confirmed by my reference lab. Obviously a 'K-like antibody' of some sort. As I'm reading the posts here, I'm thinking/remembering that his diagnosis was a bowel obstruction. That would go nicely with a bacterial origin, wouldn't it. Hmmm! Never saw him again, so I don't know if his 'anti-K' went away or not.

You have reminded me of the fact that I have also seen anti-K in patients who state they were never transfused; but then I have seen a number of antibodies in patients who say this. What I have also come to learn though is that patients "absolutely" do not always know they have been transfused (i.e. in OR; during war; etc). It is alarming to me that Physicians would not tell patients this (but then perhaps some of them are elderly and just don't remember).

Anyway, all of that to say that I have tended to believe that these "surprise" antibodies actually indicate patients have been transfused but did not know. But you raise an interesting point; one that I will certainly be more likely to consider going forward.

Thanks!

Brenda

Some years ago, I found an 'anti-K' in the serum of an elderly gentleman who had never even been in the hospital at any time in his whole life, much less transfused, until the day I crossmatched him. His DAT was positive, eluted anti-K. Antigen typing showed that his cells were K negative. This was confirmed by my reference lab. Obviously a 'K-like antibody' of some sort. As I'm reading the posts here, I'm thinking/remembering that his diagnosis was a bowel obstruction. That would go nicely with a bacterial origin, wouldn't it. Hmmm! Never saw him again, so I don't know if his 'anti-K' went away or not.

Sorry to be a stickler for facts, but it was a 20 DAY old baby.

Marsh WL, Nichols ME, Oyen R, Thayer RS, Deere WL, Freed PJ, Schmelter SE. Naturally occurring anti-Kell stimulated by E. coli enterocolitis in a 20-day-old child. Transfusion 1978: 18(2): 149-154.

At least with babies it is easier to get a transfusion history; it is a little more difficult with elderly patients (and often their family is not sure either).

Brenda

Sorry to be a stickler for facts, but it was a 20 DAY old baby.

Marsh WL, Nichols ME, Oyen R, Thayer RS, Deere WL, Freed PJ, Schmelter SE. Naturally occurring anti-Kell stimulated by E. coli enterocolitis in a 20-day-old child. Transfusion 1978: 18(2): 149-154.

We've seen antibodies in 'untransfused' patients quite a few times. A number of them had coronary bypass and were on the pump - they had no idea that the pump was primed with blood from donors and either their doctor didn't think it was important to tell them, or they were told when their minds were still somewhere else post-op and they didn't remember.

My elderly gent with the 'anti-K' was an excellent historian, sharp as a tack. I didn't believe his nurse when she told me he had never been hospitalized or transfused, so I persisted in questioning him, and his family. The stories they all told independently matched perfectly - never sick in his life, never served in the military, never hospitalized, almost never went to the doctor and never had been very far from home even. In the end, I had to accept that he was just one of those really interesting cases you run across now and then.

Did you check the patient's medication history. Is there any chance that the patient was started on any immuno-suppressive drugs between the two specimens?

Interesting case. Regarding the question of whether to "correct" the patient record or not: I would agree with those who caution against it. Without definitive proof as to whether the original ID of anti-K was accurate or not, I do not think you want to change the record. I think you are stuck with it.

But there is still the issue of the repeat of the "positive" specimen, coming up negative.

Brenda

Did you check the patient's medication history. Is there any chance that the patient was started on any immuno-suppressive drugs between the two specimens?