Jump to content

Platelet Compatibility


CARMEN DELGADO
 Share

Recommended Posts


To my understanding: if you are referring to PAS (PR) platelets, which are being, or have been phased in by blood suppliers; then give any ABO type as 60-70% of plasma has been replaced with crystalloid nutrient media. The pathogen reduction (PR) negates the CMV and irradiated necessity. 

Other BB may have a different policy though platelet availability may give you no choice. 

Link to comment
Share on other sites

On 11/4/2022 at 1:34 PM, CARMEN DELGADO said:

Since the change of platelet compatibility. What are the new acceptable Groups for an AB + recepient?

 

Carmen

Since AB+ people are considered the "universal recipient" , we give them any type platelets, usually starting with the one with the closest out date. 

Link to comment
Share on other sites

"Since AB+ people are considered the "universal recipient" , we give them any type platelets, usually starting with the one with the closest out date. "

I grant you that this is widely shared idea in our field for decades. It is also seriously wrong.  It prioritizes inventory management over patient wellbeing.  Our approach to ABO and platelets is distinctly different from ABO and red cells with no rational basis.  Antibody and complement destroy red cells and platelets equally well.  The only difference is that instead of free hemoglobin being released, it's mediators such as VEGF, IL-6 and other platelet pro-inflammatory, immunomodulatory and pro-thrombotic granule contents are released.   

ABO mismatched platelet transfusions at least double the refractoriness rate in repetitively transfused patients (see attached for references), and actually increase bleeding and mortality. 

The answer to the question is ABO identical is by far most effective and safest.  If you have to give ABO mismatched, there is probably no good answer other than washed/volume depleted O's, A's or B's, where most of the incompatible plasma is removed.  If that's not possible, postponing platelet transfusion until ABO identical is available when feasible, giving half doses of ABO identical if two patients need the one available unit, etc. are also reasonable.

Sadly, ABO mismatched platelets are probably worse than no platelets at all. They provide little or no hemostatic benefit and increased risks of bleeding, organ injury and death for the patient.  If I were the attending physician, I would generally give no platelets if ABO identical or washed O's weren't available in a stable, non-bleeding patient with a count of over 5,000.

The good news is we can improve outcomes by just doing what we do for red cells. Do not transfuse ABO incompatible antigen or antibody. It's bad for red cells, platelets and endothelial cells, all of which have complement and Fc receptors that bind immune complexes, and all of which bear ABO antigens on their surfaces.

Carr ABO mismatched refractoriness copy.pdf ABO story expanded.docx ABO endothelial cell paper.docx NEJMc2034764 copy.pdf NEJMc2034764_appendix copy.pdf

Link to comment
Share on other sites

Another point.  Since group O whole blood has proven as safe or even safer than typical component therapy (A platelets, A or AB plasma) in massive transfusion of trauma patients, perhaps group O low titer platelets would be safer than group A or B platelets for an AB patient :)?  No one knows, but worth considering.  The big problem is probably giving non-O platelets to O patients. There is evidence this increases bleeding and mortality.  Just like red cells, only O platelets for O recipients is a good practice.  The AB patient may be less of a problem, since giving some small amount of antibody may be less dangerous. A risk of hemolytic reaction of about 1 in 700 or so.  The risk of mortality in transfusing an O patient with A platelets is probably 1 in 5 (see attached).

ABO incompatible platelets intracranial bleeding 2021.pdf ABO plasma incompatible platelets and hemolytic reactions.pdf

Edited by Neil Blumberg
Link to comment
Share on other sites

I should add the good news is that when one starts prioritizing ABO identical platelets over inventory management, one reduces the platelet transfusions needed by perhaps 50%.  So our platelet shortages will disappear in large part if we stick with ABO identical as much as possible.  See attached randomized trial from eons ago :).  ABO identical reduces transfusion reactions as well, HLA and rbc alloimmunization.  Not to mention decreasing bleeding and mortality.

ABO randomized trial UR european j haematology 1993 copy.pdf ABO plt tx revisited cumulative effects.pdf Platelet transfusion worsens ICH Stroke 2020 copy.pdf

Link to comment
Share on other sites

Short answer would be any ABO type if a one time thing, along with a prayer card for no hemolysis or post-transfusion purpura. :)

 

You could make a case for type A as the anti-B is likely to be lower titer, lower biologic activity than the anti-A in group O platelets (unless low titer) or group B platelets. But this is largely theoretical hand waving.

Edited by Neil Blumberg
Link to comment
Share on other sites

@Neil Blumberg, I wish we had you at all of our facilities to educate our medical staff. Sadly, convincing Hematologists and Oncologists (at least here in America) that it is better to postpone platelet transfusions than give ABO incompatible platelets is, more often than not, rejected, especially in light of the fact that many patients are having to wait because of lack of platelet inventory to begin with. 

What we really need is a push for better transfusion therapy education in medical school. Along with this, continuing education for practitioners needs to become a priority. It is, however, quite difficult to get time with these practitioners. Even when we convince our laboratory medical directors to advocate for these issues, in my experience, clinicians rarely change. 

All that said to say, in the "trenches," the practice will likely continue to prioritize inventory over safety. 

Link to comment
Share on other sites

When the major hematology and transfusion medicine textbooks acknowledge the data showing that ABO mismatched transfusions don't provide hemostasis, actually increase bleeding, and increase platelet transfusion refractoriness, then hematologists will change their approach.  Probably some time before the heat death of the universe. Instead, one major textbook quotes methodologically unsound data from a study that classified platelet transfusions as ABO identical based upon the first transfusion, even if large numbers of  ABO mismatched transfusions were subsequently given to that patient. Total scientific nonsense.  

No doubt medical education is also to blame. I've been here 42+ years and haven't been invited to give a single talk to medical students about transfusions for many years (this is changing in 2023).  The curriculum bears little resemblance to what physicians need to know, unfortunately.  Highly dysfunctional when the single most frequently performed inpatient procedure, transfusion, doesn't have a major role in the curriculum. Ah well.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Advertisement

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.