Phenotypic Unit Selection

[Everett9239]

I am currently working on revising my policy for phenotypic unit selection and was wondering, aside from sickle cell and thal patients, does anyone use phenomatched units for anyone else?  One of the techs here worked on the revision and added that we should match C, E and K groups for female patients under the age of 30 with prolonged transfusion needs and children under the age of 15 with anticipated transplant.  I cannot find any reference material that speaks to this,  The only other patient pool that I have found that may require said phenotyping would be patients with hematologic maliginancies.  Just wondering if anyone has any insight into this, or if you can point me to some referenced that may help beyond the AABB technical manual and the AABB standards.

[Deny Morlino]

I seem to recall a discussion here that the UK performs a more complete Rh typing of all(?) patients and honors the the patient's Rh results as well as K when cross matching.  Malcolm or some others from the UK can clarify that (and let me know how poor my memory actually is this morning) as well as the reasons why.

[galvania]

Swiss recommendations: (translation)

It is recommended to transfuse red cells that are Rh/K pheno-compatible for planned transfusions in the following cases:

-female infants and women of child-bearing age (birth to 50 years of age)

-when there is an allo-antibody present, regardless of specificity

-in cases of AIHA. (Where phenotype is impossible to determine by serological means, it is recommended to carry out a genotype)

-For patients requiring chrinic transfusions (eg MDS, haemoglobinopathies for example thalassaemia or sickle cell disease), it is recommended to transfuse red cells compatible for the following antigens: Rh/K, Jka, Jkb, S, s, Fya and Fyb

Anna

[Malcolm Needs ☆]

Hi Deny,

Not quite. Our Guidelines are rather like Anna's in Switzerland, except that we don't bother about S, s, Fy(a), Fy( , Jk(a) or Jk( for chronic transfusion patients.

The reasons behind this is because studies showed that if sickle cell patients are transfused with Rh and K-matched blood, they are less likely to make other antibody specificities, and those females of child-bearing potential, we don't want to stimulate them to make any antibodies, if we can help it.

[Malcolm Needs ☆]

I don't know what happened there. The smiley faces were supposed to be "bees"!

[tbostock]

I've also seen recommendations for it for myelodysplastic disorders since they are frequently transfused. I think for now (except for sickle cell) it's just a preference for how each Blood Bank wants to handle it.

We currently only match for sickle cell patients, but we may expand that now that we have automated antigen typing.

[John C. Staley]

I don't know what happened there. The smiley faces were supposed to be "bees"!

 

Malcolm, I don't recall Fy(bee) and JK(bee)! 

[Dr. Pepper]

If they caused a fatal reaction, would they be killer bees?

[kirkaw]

Although we do not do this at my current hospital, I have worked at a hospital that used phenotypically matched red cells for sickle cell patients.

In my current hospital, if we have a WAIHA patient for whom we can get an accurate phenotype, we do typically give them phenotypically matched red cells. this makes it easier upon subsequent admission. We know that we have not given the patient any cells with antigens to which they could make antibodies, so if they have a panagglutinin in their serum, we don't have to do the complete work-up again.

[Malcolm Needs ☆]

John and Phil, I refer you both to the ISBT Group that name blood group antigens!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Wonderful comments.

[Malcolm Needs ☆]

Although we do not do this at my current hospital, I have worked at a hospital that used phenotypically matched red cells for sickle cell patients.

In my current hospital, if we have a WAIHA patient for whom we can get an accurate phenotype, we do typically give them phenotypically matched red cells. this makes it easier upon subsequent admission. We know that we have not given the patient any cells with antigens to which they could make antibodies, so if they have a panagglutinin in their serum, we don't have to do the complete work-up again.

 

Are you sure kirkaw?  What about an anti-Cob, or something like that?

[kirkaw]

Malcolm, I am not certain how to answer your question. I would not venture to contradict a person as experienced as yourself. We do not see a large population of patients with WAIHA who are repeat blood users. If/when we have a WAIHA patient who requires transfusion support over many days time, we would assess each sample. If the reactivity showed marked increase in strength, we would definitely send it out for work-up each time. We do not have the resources to do adsorptions at my facility. If however, the reactivity was similar in strength and IF we had the ability to give phenotypically matched red cells, we would do that as opposed to having the sample worked up again. I have heard of some institutions doing adsorptions every 7 days instead of every 10 days but we do not have a specific policy to this nature. I guess if this ever comes up, I would consult our medical director.

My original comment regarding not working up a specimen for a WAIHA patient who had received phenotypically matched red cells stemmed from a consult I received from a trusted blood banker who said her preference is to give phenotypically matched red cells and never doing another adsorption unlessthe patient has a difficult phenotype, a reliable phenotype could not be ascertained or the patient had a transfusion reaction.

[Malcolm Needs ☆]

Sorry kirkaw, but I'm having huge trouble with my computer (the screen has gone do-lally) and so I can't really see your comment properly.  I don't want to either make a comment about your post (which may be completely reasonable and correct for all I know) which I will regret when I can see it properly or make a complete fool of myself by misunderstanding/misreading your post.  I'll have to read it at work tomorrow.  Meanwhile, from what I actually can see, you are almost certainly talking an awful lot of sense!

[Malcolm Needs ☆]

I'm glad I waited until I could read your post properly. Yes, what you say makes perfect sense actually, but, having said that, I would do regular work-ups for a short while (say a month or two), just to ensure that the patient does not make any alloantibodies.

Once it has been established that the patient is unlikely to make alloantibodies, then I would follow what you do. We see about five or six of these patients a day, and those who have not made alloantibodies within the first couple of months never seem to produce them, and your way of doing things would be perfectly safe. Indeed, in our UK Guidelines, it says that you can be more "lenient" (not the exact wording, but I don't have them to hand at the moment) with testing.

On the other hand, those that have produced an alloantibody, I would be much, much more conservative and would work up much more frequently.