Give E and c negative units?

[Malcolm Needs ☆]

4 hours ago, exlimey said:

Unless you have the right contacts......

Which suggests that most people do not, and so they remain very rare reagents for most people.

[Malcolm Needs ☆]

2 hours ago, Baby Banker said:

We do our best to avoid them having multiple antibodies by...wait for it...antigen matching.  

I agree with Ex-Limey that our sicklers who are prone to stroke have more than enough going on without having even a mild reaction.  

We have had a few patients with hyperhemolysis and they are the very devil to treat.  The ideal would be to stop transfusions, but that is a very difficult decision to make with these patients.  Also, since we are a pediatric facility, the family may decide to go elsewhere to continue transfusions.

Baby Banker, there are hundreds of blood group antigens.  You cannot match for the all, and studies in both the UK and USA have shown that, even using units from donors who have been tested at a molecular level, it gets more and more difficult, and more and more expensive, to match more than a few antigens.  It follows the Law of Diminishing Returns.

As I say, I have some knowledge of hyperhaemolysis myself, and, as you quite correctly say, the best thing to do is to stop transfusions.  However, as I said above, there are some situations in which this is clinically impossible, at which time, covering the patient with high dose IVIgG and methylprednisolone during transfusion is one of the very few options - and this would have to be done at other facilities, as well as your own, even if the family are silly enough to go elsewhere under such circumstances.

[Malcolm Needs ☆]

4 hours ago, exlimey said:

This is a very interesting thread, partly ethics, partly practical use of resources, and a large dose of "what if".  In the legal sense, the concept of "Prior Restraint" comes into play  - doing something to prevent a possible event regardless of probability.

So.....a not-so-unrealistic scenario:

The hospital has a patient with anti-K and is required to screen/type a number of units to fill a transfusion order. During the process some donors/donations are identified as K+. What should the facility do with those, knowing full well that they may stimulate an immune response in recipients ?

And.....discuss.....

As said above, we don't have to make this decision, as all of our units are typed for ABO, D, C, E, c, e and K.

[exlimey]

1 hour ago, Malcolm Needs said:

As said above, we don't have to make this decision, as all of our units are typed for ABO, D, C, E, c, e and K.

What does the Blood Center do with the K+ units ? Throw them out, or only give them to K+ patients ?

Edited September 5, 2019 by exlimey
Clarification

[SMILLER]

1 hour ago, Malcolm Needs said:

As said above, we don't have to make this decision, as all of our units are typed for ABO, D, C, E, c, e and K.

Right, but I am sure that you do not antigen type all patients and give them antigen negative units as appropriate for those antigens!

Scott

[Malcolm Needs ☆]

Within the Reference Laboratory, yes we do, although this is not the case in all hospitals, but the hospitals most certainly do follow the UK Guidelines concerning giving antigen negative blood to females of child bearing potential, and any patient who is either transfusion dependent (such as sickle cell disease patients) or is likely to become transfusion dependent (such as those with MDS or leukaemia).  It remains that a high percentage of recipients of transfusions die from their underlying pathology within about six months, so, no, not when this is likely to happen.

[Malcolm Needs ☆]

34 minutes ago, exlimey said:

What does the Blood Center do with the K+ units ? Throw them out, or only give them to K+ patients ?

They most certainly DO NOT throw them out.  They are an altruistic gift from our donors.

The units are not marked as K+ (the hospitals are aware that the antigens that appear on the unit are those for which the is negative (except for D, D, E, c, and e) and so,if there is nothing to say that the units are K Negative, they are assumed to be K Positive.  In this case, according to our Guidelines, the units should not be given to females of child bearing potential, who are not themselves K+, or to patients of either sex and any age, who are either already transfusion dependent, or likely to become transfusion dependent, unless they themselves are K Positive.

That having been said, K Positive units are more likely to reach time expiry in hospitals, than are K Negative units, as might be expected.

[John C. Staley]

10 hours ago, SMILLER said:

This goes back to some comments made earlier in this thread.  It is impractical to screen for all antigens for a particular patient that may induce an antibody response.  However, for a patient that is actively producing (or is known to have produced) an antibody for a particular antigen, transfusing known antigen positive blood would clearly not be indicated if it can be avoided.  

Scott

So...... utilizing the same scenario, are you going to screen every pretransfusion patient to determine their K status to determine if you can use those K+ units or just throw them away, it might be cheaper or just let them set on the shelf until a suitable patient comes along to use them on or are you going to extensively antigen type every patient with one antibody to determine what else they can make and then screen every unit for them for antigen compatibility???  I never had enough staff to accomplish this kind of CYA!  

 

[Ward_X]

11 hours ago, exlimey said:

This is a very interesting thread, partly ethics, partly practical use of resources, and a large dose of "what if".  In the legal sense, the concept of "Prior Restraint" comes into play  - doing something to prevent a possible event regardless of probability.

So.....a not-so-unrealistic scenario:

The hospital has a patient with anti-K and is required to screen/type a number of units to fill a transfusion order. During the process some donors/donations are identified as K+. What should the facility do with those, knowing full well that they may stimulate an immune response in recipients ?

And.....discuss.....

Anyone can have their own individualistic ethical standpoint (for example, in my day-to-day life I'm an act-utilitarian), but in the scheme of healthcare you have to abide by Hippocratic/care... therefore you just can't give blood positive for a clinically significant antigen to a pt with that antibody for giggles. It would have to be life or death, or under the jurisdiction of the BB MD to decide. Of course, sometimes in emergency situations, or if you have an unknown pt getting released blood and it turns out they do already have an antibody, that's all down to the ordering physician to adopt the responsibility of knowing the risks. On a tech basis, I don't see any of us just being like, "welp here you go, have some antigen positive blood!"

I'm not sure if this anti-K argument can apply, because that is already a pre-identified, reacting antibody. Of course you would try to give them BKN blood. When we antigen type for a pt and have a batch of 10 units for example, and 1 of those units is K+, the pt with an anti-K wouldn't be getting it. The unit is marked with a tag that lists positive for K, and you move on. The difference in this thread here is that we'd be trying to assume this anti-K pt could make an antibody to another antigen along the way, and whether to screen for this unformed antigen before giving them a unit. It's guess work, and almost retrospective.

On ‎9‎/‎4‎/‎2019 at 3:13 PM, Malcolm Needs said:

Well, yes and no Mabel.  Anti-c and anti-E grouping reagents are very easy to come by (if expensive), whereas reagent quality anti-V and/or anti-VS are both like hen's teeth, and so it would be MUCH more difficult to ensure the units are V- and/or VS-, unless you can check by molecular techniques (Leu245Val).

The point about anti-V/VS is an interesting one, and definitely dependent on the population... but I agree with @Malcolm Needs in the sense that it's extra work for an unknown benefit (at least in Western countries).

[DPruden]

I just ran across someone who thinks that a patient who has an anti-M needs to have antigen typed S- RBCs (the patient is S-).  I have been scratching my mind trying to figure out where that thought process came from!

[Malcolm Needs ☆]

9 hours ago, DPruden said:

I just ran across someone who thinks that a patient who has an anti-M needs to have antigen typed S- RBCs (the patient is S-).  I have been scratching my mind trying to figure out where that thought process came from!

No logical thought that I know.  The antigens are not even on the same carrier molecule.

[DPruden]

On ‎9‎/‎21‎/‎2019 at 2:05 AM, Malcolm Needs said:

No logical thought that I know.  The antigens are not even on the same carrier molecule.

That is what we all said at my facility, none of us could figure out why anyone would think that was necessary!

[Baby Banker]

On 9/5/2019 at 10:42 AM, Malcolm Needs said:

Baby Banker, there are hundreds of blood group antigens.  You cannot match for the all, and studies in both the UK and USA have shown that, even using units from donors who have been tested at a molecular level, it gets more and more difficult, and more and more expensive, to match more than a few antigens.  It follows the Law of Diminishing Returns.

As I say, I have some knowledge of hyperhaemolysis myself, and, as you quite correctly say, the best thing to do is to stop transfusions.  However, as I said above, there are some situations in which this is clinically impossible, at which time, covering the patient with high dose IVIgG and methylprednisolone during transfusion is one of the very few options - and this would have to be done at other facilities, as well as your own, even if the family are silly enough to go elsewhere under such circumstances.

We limit our matching to a group that is generally manageable. It has been some time ago since I looked at their recommendation, but the Sickle Cell Foundation was recommending matching further than we do.  We do find that these patients develop 'warm autoantibodies' which I think are or may be a reflection of the myriad other antigens that we do not match.  That being said, our practice has been successful in preventing stroke overall in a disadvantaged and usually overlooked (in my area) group of children. We have done a pretty good job of indoctrinating the patients and their families to get in touch with us when our patients go to another facility.  

[Baby Banker]

Looking back over, I realized that I did not specify that the patients I am talking about are the ones on chronic transfusion therapy and are transfused about every three to five weeks.  They have all either had a stroke or have been identified as being at high risk for stroke.