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Group O platelets titer


ChanNicky

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Hello everyone! I work in a transfusion service where we do NOT give ABO identical platelets and we give only 1 group O platelet every 24 hours. What is the titer limit for Anti-A in group O platelets?  Has anyone heard of a study where Anti-A and/or Anti-B were titered in non-O platelets?  

Thanks

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3 minutes ago, galvania said:

the trouble with titres is that the result is method dependent - so unless the methods are identical, comparing across labs is not much use

And most of the titres quoted on this thread (if not all) are dilutions and NOT titres.  A titre is the reciprocal of the dilution - not the dilution itself.  :disbelief::disbelief::disbelief::disbelief::disbelief:

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To my knowledge there is not a shred of evidence that titers (or titres:)) have any clinical benefit in this situation. We are treating ourselves, not the patient. I understand the need to "do something."  In our case, our something is always giving ABO identical platelets, or, when this is not possible, we wash group O platelets.  Titer/titre then becomes a moot point. 

I also get that blood bankers hate to wash anything, especially platelets, but we have randomized trial data this improves survival in younger patients with leukemia.  Also avoids positive DATs, hemolysis and refractoriness to transfusion.  A culture change is needed in which we accept what we've know for decades. Transfusing a group O red cell (or platelet) to a non-O patient can very rarely result in fatal hemolysis. 

Why we keep doing this despite the ability to avoid this rare fatal complication is a mystery to me, except for inertia and inconvenience.  Of course a long standing practice that we assumed completely safe without a shred of data is hard to change.  But the evidence is quite clear that group O platelets and rbc are not universal donor unless you accept a small but real risk of death for the patient.  Not a practice to be defended in this day and age.  As hard as it will be, I hope we will all start doing that which is best for recipients.  Not what is best for inventory control or reducing wastage, which are important but lesser values.

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On ‎08‎/‎27‎/‎2018 at 9:29 AM, Neil Blumberg said:

To my knowledge there is not a shred of evidence that titers (or titres:)) have any clinical benefit in this situation. We are treating ourselves, not the patient. I understand the need to "do something."  In our case, our something is always giving ABO identical platelets, or, when this is not possible, we wash group O platelets.  Titer/titre then becomes a moot point. 

I also get that blood bankers hate to wash anything, especially platelets, but we have randomized trial data this improves survival in younger patients with leukemia.  Also avoids positive DATs, hemolysis and refractoriness to transfusion.  A culture change is needed in which we accept what we've know for decades. Transfusing a group O red cell (or platelet) to a non-O patient can very rarely result in fatal hemolysis. 

Why we keep doing this despite the ability to avoid this rare fatal complication is a mystery to me, except for inertia and inconvenience.  Of course a long standing practice that we assumed completely safe without a shred of data is hard to change.  But the evidence is quite clear that group O platelets and rbc are not universal donor unless you accept a small but real risk of death for the patient.  Not a practice to be defended in this day and age.  As hard as it will be, I hope we will all start doing that which is best for recipients.  Not what is best for inventory control or reducing wastage, which are important but lesser values.

While I appreciate this sentiment, my reality for apheresed plts is that I only receive group A or O - depending on what is there and pending outdates at the supplier.  As a small institution (24 beds) I do not have the capability for washing plts (though I have in the past at larger, tertiary care places).  Aside from myself - all the techs are generalists who would rather not do BB if they had a choice ( though for the most part they do excellently).  I guess the larger institutions get dibs on the ABO identical plts - not so for us little guys whose usage is random and rare.

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22 hours ago, David Saikin said:

While I appreciate this sentiment, my reality for apheresed plts is that I only receive group A or O - depending on what is there and pending outdates at the supplier.  As a small institution (24 beds) I do not have the capability for washing plts (though I have in the past at larger, tertiary care places).  Aside from myself - all the techs are generalists who would rather not do BB if they had a choice ( though for the most part they do excellently).  I guess the larger institutions get dibs on the ABO identical plts - not so for us little guys whose usage is random and rare.

My facility is 180ish beds in a rural area and I also have limited access to platelets. We stock 2 A Pos units on weekdays and 1 on weekends/holidays, if supply allows, and are thankful to have them. I do understand the issues about transfusing non-type specific product to patients and ideally we would transfuse only type specific. We do so if we have time to order product specifically for that patient (from blood supplier 150 miles away). My reality is also that we don't have the staff, space or the equipment to add that kind of procedure. We would have to maintain competencies on a lot of staff members who might wash a unit once or not at all over the course of a year, or call in staff to do it. Even with limiting the number of staff members that perform the procedure, we would still be trying to maintain competency for something done a limited number of times per year. It would be difficult for me to maintain competency and I'm the only full time blood banker. Who's going to check me off? Washing platelets would also require an FDA inspection, would it not? which opens another can of worms.

It's a difficult situation. We can provide A Pos platelets for everyone, usually right away, or we can tell providers that we will order type specific platelets for their patient, but its going to take time, maybe hours or tomorrow. Providers rarely want to wait, including Hem/Onc.

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I hope the lower amounts of plasma in the newer platelet products (PAS and pathogen reduced) will help reduce this risk.  We do our best to match blood types but are remote and not that big so have the same problems as others.  I am not clear on why avoiding high titer platelet donors is not any help.  I think the fatal cases were mostly from high-titer donors, but are you making the case that there has been no research to prove that avoiding them prevents fatal reactions?  Or is there actual evidence that avoiding them does not change the risk?

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There are multiple problems here that have not been adequately addressed by either the bedside practitioners and by the blood bankers/transfusion medicine community.  The problems relate to assumptions that have turned out to be false.  The first assumption is that platelet transfusion is very effective at treating or preventing bleeding.  It turns out that's not really true, at least as currently practiced.  Randomized trials show that, for example, in autologous stem cell transplant patients, prophylactic transfusion provides minimal benefit.  In acute myeloid leukemia induction therapy (really sick patients with active disease), prophylactic transfusion provides some benefit.  But at great cost to the patient.  The more platelet transfusions you receive, the less likely you are to have your disease cured in our cohort study.  So more conservative transfusion practice is actually a good idea.  There is also no big rush.  Waiting a few hours to receive a prophylactic transfusion of platelets is of no real concern in my view.  Unless there is active bleeding, or a history of bleeding at certain counts, waiting for an ABO identical platelet makes great sense.  It turns out that ABO mismatched platelets may not actually work to prevent bleeding and we have evidence they may actually make bleeding worse.  In addition, platelet transfusion predispose to nosocomial infection, thrombosis and multi-organ failure in observational studies.  And mortality.  Clinicians should think six times before giving a platelet transfusion in many settings.  The risks are vastly worse than we knew.

As for us.  We've vastly misread the efficacy and safety of platelet transfusions that are ABO mismatched.  In our surgical cohorts, the more ABO mismatched transfusions you receive, the higher the mortality rate, as well as increased bleeding.  The problem with titers is that antibody quantity is only one of the factors that influence biologic activity and clinical outcomes.  Ability to fix complement, avidity, etc. are probably as important.  There is absolutely no evidence for the common sense and likely partially true assumption that lower titer is safer.  But what titer? Some places use 1:200 and some 1:50.  No evidence. I'd obviously go with 1:50 before 1:200. But the real answer is ABO identical, even if waiting a few hours is necessary, or platelets stored without plasma (then group O would be best) or supernatant removal by washing.  I'm sure Terumo or Haemonetics could come with a simple, fast, automated washing system (it probably won't be free :) ) if they thought people would buy them.  They should and we should.  Our current practices are probably doing minimal good, great harm and are not consistent with what we now know about ABO mismatched platelet transfusions.  Hope this helps explain my passion on the subjects.

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If anyone wants references to read supporting the above rant, I'm happy to post them.  Or just go PubMed and search on Blumberg ABO platelets.  I'm afraid on this issue, the academic medical community is pretty much doing the ostrich thing :). They are waiting for definitive proof when the evidence is already more than enough to change practices.  The cavalier practice of using group O red cells as universal donor, equivalent to ABO identical, and AB plasma, in routine (as opposed to emergency) use should be stopped.

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Transfusion of ABO-mismatched platelets leads to early platelet refractoriness.

Carr R, Hutton JL, Jenkins JA, Lucas GF, Amphlett NW.

Br J Haematol. 1990 Jul;75(3):408-13.

The role of ABO matching in platelet transfusion.

Heal JM, Rowe JM, McMican A, Masel D, Finke C, Blumberg N.

Eur J Haematol. 1993 Feb;50(2):110-7.

ABO and platelet transfusion revisited.

Heal JM, Rowe JM, Blumberg N.

Ann Hematol. 1993 Jun;66(6):309-14.

Association of ABO-mismatched platelet transfusions with morbidity and mortality in cardiac surgery.

Blumberg N, Heal JM, Hicks GL Jr, Risher WH.

Transfusion. 2001 Jun;41(6):790-3.

ABO identical and washed blood transfusions as candidate strategies to reduce early mortality in acute promyelocytic leukemia.

Sahai T, Henrichs K, Refaai M, Heal JM, Kirkley SA, Schmidt AE, Mendler JH, Masel D, Liesveld J, Aquina C, Blumberg N.

ABO-immune complex formation and impact on platelet function, red cell structural integrity and haemostasis: an in vitro model of ABO non-identical transfusion.

Zaffuto BJ, Conley GW, Connolly GC, Henrichs KF, Francis CW, Heal JM, Blumberg N, Refaai MA.

 

An association of ABO non-identical platelet and cryoprecipitate transfusions with altered red cell transfusion needs in surgical patients.

Refaai MA, Fialkow LB, Heal JM, Henrichs KF, Spinelli SL, Phipps RP, Masel E, Smith BH, Corsetti JP, Francis CW, Bankey PE, Blumberg N.

Vox Sang. 2011 Jul;101(1):55-60. doi: 10.1111/j.1423-0410.2010.01464.x.

Providing ABO-identical platelets and cryoprecipitate to (almost) all patients: approach, logistics, and associated decreases in transfusion reaction and red blood cell alloimmunization incidence.

Henrichs KF, Howk N, Masel DS, Thayer M, Refaai MA, Kirkley SA, Heal JM, Blumberg N.

Transfusion. 2012 Mar;52(3):635-40. 

Is It Time to Reconsider the Concepts of "Universal Donor" and "ABO Compatible" Transfusions?

Refaai MA, Cahill C, Masel D, Schmidt AE, Heal JM, Kirkley SA, Blumberg N.

Anesth Analg. 2018 Jun;126(6):2135-2138. 

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Sorry about the incomplete references.  Here are the full references for the two missing :).

 

ABO identical and washed blood transfusions as candidate strategies to reduce early mortality in acute promyelocytic leukemia.

Sahai T, Henrichs K, Refaai M, Heal JM, Kirkley SA, Schmidt AE, Mendler JH, Masel D, Liesveld J, Aquina C, Blumberg N.

Leuk Res. 2017 Nov;62:1-3. doi: 10.1016/j.leukres.2017.09.011. 

 

 

ABO-immune complex formation and impact on platelet function, red cell structural integrity and haemostasis: an in vitro model of ABO non-identical transfusion.

Zaffuto BJ, Conley GW, Connolly GC, Henrichs KF, Francis CW, Heal JM, Blumberg N, Refaai MA.

Vox Sang. 2016 Apr;110(3):219-26. doi: 10.1111/vox.12354.

 

 

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