galvania

I would just like to add one 'grain of salt' to this debate.  You cannot detect all D variants - whether D weaks or partial Ds by serological methods alone. Neither D weaks or Partial Ds behave in a way that allow one to say that all D weaks  or partial Ds react with such and such a strength.  You will always miss some.  You will miss some D+ donors because their D antigen is so weak that it is not detected by even the most sensitive of routine serological tests - or because despite using at least two different monoclonals the donor has an extremely unusual variant that is detected by neither.  You will miss some 'D-neg' patients  because they have sufficiently large numbers of D-antigen sites that they give a normal reaction with the anti-D reagents used.  Follow the manufacturer's instructions for the reagent and method used and you will detect as many as you can hope to detect.  And before you shoot the manufacturers because their reagent/instrument gave a 4+ reaction with a partial D known to have 10'000 D-antigen sites per red cell, and discovered because the lady made an anti-D and she is pregnant - please take a minute to think about the theory behind the serology.  Maybe in years to come there will be a foolproof routine method for catching every single one……...

I would just like to add one 'grain of salt' to this debate.  You cannot detect all D variants - whether D weaks or partial Ds by serological methods alone. Neither D weaks or Partial Ds behave in a way that allow one to say that all D weaks  or partial Ds react with such and such a strength.  You will always miss some.  You will miss some D+ donors because their D antigen is so weak that it is not detected by even the most sensitive of routine serological tests - or because despite using at least two different monoclonals the donor has an extremely unusual variant that is detected by neither.  You will miss some 'D-neg' patients  because they have sufficiently large numbers of D-antigen sites that they give a normal reaction with the anti-D reagents used.  Follow the manufacturer's instructions for the reagent and method used and you will detect as many as you can hope to detect.  And before you shoot the manufacturers because their reagent/instrument gave a 4+ reaction with a partial D known to have 10'000 D-antigen sites per red cell, and discovered because the lady made an anti-D and she is pregnant - please take a minute to think about the theory behind the serology.  Maybe in years to come there will be a foolproof routine method for catching every single one……...

I would just like to add one 'grain of salt' to this debate.  You cannot detect all D variants - whether D weaks or partial Ds by serological methods alone. Neither D weaks or Partial Ds behave in a way that allow one to say that all D weaks  or partial Ds react with such and such a strength.  You will always miss some.  You will miss some D+ donors because their D antigen is so weak that it is not detected by even the most sensitive of routine serological tests - or because despite using at least two different monoclonals the donor has an extremely unusual variant that is detected by neither.  You will miss some 'D-neg' patients  because they have sufficiently large numbers of D-antigen sites that they give a normal reaction with the anti-D reagents used.  Follow the manufacturer's instructions for the reagent and method used and you will detect as many as you can hope to detect.  And before you shoot the manufacturers because their reagent/instrument gave a 4+ reaction with a partial D known to have 10'000 D-antigen sites per red cell, and discovered because the lady made an anti-D and she is pregnant - please take a minute to think about the theory behind the serology.  Maybe in years to come there will be a foolproof routine method for catching every single one……...

I would just like to add one 'grain of salt' to this debate.  You cannot detect all D variants - whether D weaks or partial Ds by serological methods alone. Neither D weaks or Partial Ds behave in a way that allow one to say that all D weaks  or partial Ds react with such and such a strength.  You will always miss some.  You will miss some D+ donors because their D antigen is so weak that it is not detected by even the most sensitive of routine serological tests - or because despite using at least two different monoclonals the donor has an extremely unusual variant that is detected by neither.  You will miss some 'D-neg' patients  because they have sufficiently large numbers of D-antigen sites that they give a normal reaction with the anti-D reagents used.  Follow the manufacturer's instructions for the reagent and method used and you will detect as many as you can hope to detect.  And before you shoot the manufacturers because their reagent/instrument gave a 4+ reaction with a partial D known to have 10'000 D-antigen sites per red cell, and discovered because the lady made an anti-D and she is pregnant - please take a minute to think about the theory behind the serology.  Maybe in years to come there will be a foolproof routine method for catching every single one……...

I would just like to add one 'grain of salt' to this debate.  You cannot detect all D variants - whether D weaks or partial Ds by serological methods alone. Neither D weaks or Partial Ds behave in a way that allow one to say that all D weaks  or partial Ds react with such and such a strength.  You will always miss some.  You will miss some D+ donors because their D antigen is so weak that it is not detected by even the most sensitive of routine serological tests - or because despite using at least two different monoclonals the donor has an extremely unusual variant that is detected by neither.  You will miss some 'D-neg' patients  because they have sufficiently large numbers of D-antigen sites that they give a normal reaction with the anti-D reagents used.  Follow the manufacturer's instructions for the reagent and method used and you will detect as many as you can hope to detect.  And before you shoot the manufacturers because their reagent/instrument gave a 4+ reaction with a partial D known to have 10'000 D-antigen sites per red cell, and discovered because the lady made an anti-D and she is pregnant - please take a minute to think about the theory behind the serology.  Maybe in years to come there will be a foolproof routine method for catching every single one……...

Okay, well, as you know from the paper, inherited weak B is rare, and the acquired weak B is even rarer.  This can be evidenced from the fact that in Race RR and Sanger R, Blood Groups in Man, 6th edition, Blackwell, 1975, only two pages of 659 are devoted to the weak B type, although Yamaguchi H, Okubo Y, Tanaka M.  A rare blood Bx analogous to Ax in a Japanese family.  Proc Jap Acad 1970; 46: 446-449 showed that the weak B type is more common amongst the populations of the Far East, than they are amongst other populations.  38 years later, Geoff Daniels, in Daniels G.  Human Blood Groups, 3rd edition, Wiley-Blackwell, 2013, still only devotes two and a half pages to weak forms of the B antigen.
This having been said, in Reid ME, Lomas-Francis C and Olsson ML.  The Blood Group Antigen FactsBook, 3rd edition, Academic Press, 2012, Martin Olsson (I presume, as he is famed for his work on the molecular study of ABO types), quotes eight different molecular backgrounds to B3, 33 different molecular backgrounds to Bx and Bm, and five different molecular backgrounds to Bel.  The overwhelming ethnicity of these individuals are from the Far East, although by no means all.
As described in the paper you provided to me, A and B antigens can weaken with certain underlying pathologies.  I have never seen this myself in a group B patient, but I did once in a group A patient with acute myeloid leukaemia, who also happened to be a Consultant Haematologist in a large London Teaching Hospital.  We were able to follow whether she was in remission or relapse from the strength of the expression of her A antigen.
It is not really known why this happens, although, as they point out in the paper you provided for me, it could be that the B transferase is altered by mutation, but, if this was the only explanation, when an individual goes into remission, it is doubtful if the mutation in the B transferase gene would resolve.  It is possible that the transferase loses its ability to attach D-galactose to all of the four (probably eight) carrier molecules.
We know that the A, B and H transferase enzymes are not working at their optimum at birth (which is why the expression of the A, B and H antigens are not at their strongest at this time of life - it is not until the age of three that the antigens are expressed at their full strength, and they can then weaken with extreme age).  However, the number of B antigen sites differs profoundly between a B adult (610,000 - 830,000) and an A1B adult (310,000 - 5650,000) (Economidou J, Hughes-Jones NC, Gardner B.  Quantitative measurements concerning A and B antigen sites.  Vox Sanguinis 1967; 12: 321-328).  This is because the A and the B transferase enzymes compete with one another for the carrier molecules.  This competitiveness can, sometimes, result in profound weakening of either the A or the B antigen on the red cells.
I hope this helps.  If not, get back to me.

You make  it sound as though the bio-Rad system does not pick up Kidd antibodies.  I can assure you that just is not the case.  If it were, then there would be a huge number of transfusion reactions in hospitals using the bio-rad system - and that is not the case.
There may be all sorts of reasons as to why these particular antibodies are not showing up.  First of all, can I suggest you try repeating manually.  As this is a trial, there may be a problem in the way the instrument has been set up - although that is a long shot.  Then, what I strongly suggest is that you contact your local bio-rad rep and let them send the samples to Switzerland.  Switzerland will need to know exactly which lot of cells and cards you were using, they will want print outs of the results from the IH1500 - and as much information about the age of the sample, whether it was frozen etc as you can give them.

You make  it sound as though the bio-Rad system does not pick up Kidd antibodies.  I can assure you that just is not the case.  If it were, then there would be a huge number of transfusion reactions in hospitals using the bio-rad system - and that is not the case.
There may be all sorts of reasons as to why these particular antibodies are not showing up.  First of all, can I suggest you try repeating manually.  As this is a trial, there may be a problem in the way the instrument has been set up - although that is a long shot.  Then, what I strongly suggest is that you contact your local bio-rad rep and let them send the samples to Switzerland.  Switzerland will need to know exactly which lot of cells and cards you were using, they will want print outs of the results from the IH1500 - and as much information about the age of the sample, whether it was frozen etc as you can give them.

OK - to clear up some confusion  (apologies for it being so late in the day!).
Ortho in Europe has glass beads.  Ortho in the States has gel which is similar to but not identical to the Bio-rad (ex-DiaMed) gel.  As the original question was about Kidd antibodies, I will stick to that.  You all know that Kidd antibodies love playing hide and seek.  BOTH techniques will miss some Kidd antibodies - but not necessarily the same ones.  So you might see some antibodies coming up in Ortho and not in Bio-Rad; and you will see others that do the opposite.  And by the way, Immucor will pick up Kidd antibodies that no one else does but it's not sure that these are real but might be artefacts caused by Paraben.  It is fair to say that some antibodies just 'prefer' one system over another.  But across the board, it evens out.

You make  it sound as though the bio-Rad system does not pick up Kidd antibodies.  I can assure you that just is not the case.  If it were, then there would be a huge number of transfusion reactions in hospitals using the bio-rad system - and that is not the case.
There may be all sorts of reasons as to why these particular antibodies are not showing up.  First of all, can I suggest you try repeating manually.  As this is a trial, there may be a problem in the way the instrument has been set up - although that is a long shot.  Then, what I strongly suggest is that you contact your local bio-rad rep and let them send the samples to Switzerland.  Switzerland will need to know exactly which lot of cells and cards you were using, they will want print outs of the results from the IH1500 - and as much information about the age of the sample, whether it was frozen etc as you can give them.

You make  it sound as though the bio-Rad system does not pick up Kidd antibodies.  I can assure you that just is not the case.  If it were, then there would be a huge number of transfusion reactions in hospitals using the bio-rad system - and that is not the case.
There may be all sorts of reasons as to why these particular antibodies are not showing up.  First of all, can I suggest you try repeating manually.  As this is a trial, there may be a problem in the way the instrument has been set up - although that is a long shot.  Then, what I strongly suggest is that you contact your local bio-rad rep and let them send the samples to Switzerland.  Switzerland will need to know exactly which lot of cells and cards you were using, they will want print outs of the results from the IH1500 - and as much information about the age of the sample, whether it was frozen etc as you can give them.

OK - to clear up some confusion  (apologies for it being so late in the day!).
Ortho in Europe has glass beads.  Ortho in the States has gel which is similar to but not identical to the Bio-rad (ex-DiaMed) gel.  As the original question was about Kidd antibodies, I will stick to that.  You all know that Kidd antibodies love playing hide and seek.  BOTH techniques will miss some Kidd antibodies - but not necessarily the same ones.  So you might see some antibodies coming up in Ortho and not in Bio-Rad; and you will see others that do the opposite.  And by the way, Immucor will pick up Kidd antibodies that no one else does but it's not sure that these are real but might be artefacts caused by Paraben.  It is fair to say that some antibodies just 'prefer' one system over another.  But across the board, it evens out.

OK - to clear up some confusion  (apologies for it being so late in the day!).
Ortho in Europe has glass beads.  Ortho in the States has gel which is similar to but not identical to the Bio-rad (ex-DiaMed) gel.  As the original question was about Kidd antibodies, I will stick to that.  You all know that Kidd antibodies love playing hide and seek.  BOTH techniques will miss some Kidd antibodies - but not necessarily the same ones.  So you might see some antibodies coming up in Ortho and not in Bio-Rad; and you will see others that do the opposite.  And by the way, Immucor will pick up Kidd antibodies that no one else does but it's not sure that these are real but might be artefacts caused by Paraben.  It is fair to say that some antibodies just 'prefer' one system over another.  But across the board, it evens out.

OK - to clear up some confusion  (apologies for it being so late in the day!).
Ortho in Europe has glass beads.  Ortho in the States has gel which is similar to but not identical to the Bio-rad (ex-DiaMed) gel.  As the original question was about Kidd antibodies, I will stick to that.  You all know that Kidd antibodies love playing hide and seek.  BOTH techniques will miss some Kidd antibodies - but not necessarily the same ones.  So you might see some antibodies coming up in Ortho and not in Bio-Rad; and you will see others that do the opposite.  And by the way, Immucor will pick up Kidd antibodies that no one else does but it's not sure that these are real but might be artefacts caused by Paraben.  It is fair to say that some antibodies just 'prefer' one system over another.  But across the board, it evens out.

OK - to clear up some confusion  (apologies for it being so late in the day!).
Ortho in Europe has glass beads.  Ortho in the States has gel which is similar to but not identical to the Bio-rad (ex-DiaMed) gel.  As the original question was about Kidd antibodies, I will stick to that.  You all know that Kidd antibodies love playing hide and seek.  BOTH techniques will miss some Kidd antibodies - but not necessarily the same ones.  So you might see some antibodies coming up in Ortho and not in Bio-Rad; and you will see others that do the opposite.  And by the way, Immucor will pick up Kidd antibodies that no one else does but it's not sure that these are real but might be artefacts caused by Paraben.  It is fair to say that some antibodies just 'prefer' one system over another.  But across the board, it evens out.

Here's the file:
 

You CAN trust the results in gel.  But as with any technique you have to understand the theory before you can interpret them correctly.  Same goes for all methods

You CAN trust the results in gel.  But as with any technique you have to understand the theory before you can interpret them correctly.  Same goes for all methods

You CAN trust the results in gel.  But as with any technique you have to understand the theory before you can interpret them correctly.  Same goes for all methods

In my experience good monoclonal anti-D reagents will pick up all but the weakest of D antigen variants (by which I mean all normal D+ and all D variants with a reasonable number of D antigens on their surface).  The positive DAT will not interfere with them unless it's caused by clinically significant cold haemagglutinin disease.  So only the very very weak D variants will come up anyway with the weak D test in an IAT but not in direct testing.  So if you did not do the weak D testing you might miss a few cases.  Those few would have to nonetheless be able to stimulate mum into making an anti-D.
I would be very interested to know exactly how many cases you see where the routine testing (using a sensitive method and good quality monoclonal anti-D reagents) is negative and the Weak D testing was positive (with a negative DAT).
I wonder if it's more or less than the number of D variant mums you miss because they group as normal D+ ...........
 
Also, for the anti-D to give you a false negative result because all the antigen binding sites are already loaded, your DAT would have to be VERY strong - and mum would have a known (hopefully), very high titre, antibody.  So you would have to carry out an eluate anyway on baby's cells and find for example that mum has a high-titre anti-D and you can elute anti-D from the baby's apparently D-negative red cells.  That's when you know that baby really is D+ and all the D sites are saturated. I've seen this twice in 'real life'.
 

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.
 
 

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. 

Not quite Tabbie - although it is difficult to explain - but I will do my best (but the explanation may not be perfect).
Rhnull individuals are incredibly rare throughout the world, and I really mean INCREDIBLY rare.  I have worked most (although not all) of my professional life in Blood Group Serology (partly at the International Blood Group Reference Laboratory, and partly at NHSBT-Tooting RCI Laboratory).  Because of the fact that the IBGRL is a World Health Organisation (international) establishment, they got/get samples of rare blood from all around the world.  Because NHSBT-Tooting RCI Laboratory covers hospitals that have an incredible mix of patient ethnicity, we also used to get a lot of VERY rare antibodies/antigens.  I think that I can say that, in 43 years in this environment, I have only seen two, maybe three families that included Rhnull individuals; that is how rare they are.
These individuals can (and do) make an antibody named anti-Rh29.  This antibody, in essence, reacts with all red cells apart from those of other individuals who have the Rhnull phenotype.  On the other hand, some individuals who have warm auto-immune haemolytic anaemia make an antibody that is very similar, if not (to all intents and purposes) identical to anti-Rh29.
Similarly, D--/D--, D../D.., D--/D.., D--/Rhnull and D../Rhnull individuals can make antibodies that look like a combination of anti-C, anti-c, anti-E and anti-e that cannot be separated (it is, needless to say, a bit - a lot - more complicated than that).  This antibody is termed anti-Rh17.  This antibody is, once again, not straightforward (as you might expect by now!).  This antibody is THE single most common specificity found in cases of WAIHA.  HOWEVER, just in case you thought things were getting easier, they are not!  The auto-anti-Rh17 you find in individuals with warm AIHA often (more often than not actually), reacts more readily with, for example E Positive red cells (or e Positive red cells, C Positive red cells or c Positive red cells) than with E Negative red cells (or e Negative red cells, C Negative red cells or c Negative red cells), irrespective of the fact that the patient is E Positive (e Positive, C Positive or c Positive).  You can tell that it is NOT anti-E (or any of the other specificities) by the fact that the antibody can be adsorbed out by E Negative red cells (it make take more adsorptions than with E Positive red cells, but you can still do it) - and, again, the same applies for other mimicking red cell antibodies.
These days, with the ability to use monoclonal Rh grouping antibodies, it is normally quite easy to tell if the antibody  is an auto- or an allo-antibody, even if the red cells are DAT Positive, because it is (usually) quite easy to sort out the patient's own Rh type.  As a result, it is VERY rare that an RCI Laboratory would bother to do too much work on it - basically, it would be a waste of time, reagents and money.
Turning to your other question, concerning how the genotype can be different from the phenotype, this situation is surprisingly much more common than you make think.
Some 68% of Black individuals are (phenotypically) Fy(a-b-), and yet, genotypically, most of these individuals are FYB/FYB, which begs the question, why are the red cells not typing as Fy(a-b+)?  Well, the answer is that there is another gene, called the GATA-1 gene that has to be present (and present in an "unmutated" form) for the antigen to be expressed on the red cell.  A large percentage of Black individuals have a mutation (and mostly as a homozygous gene mutation) that prevents the expression of the Duffy antigens on red cells, even though the blood group antigen genes are present on the chromosomes (chromosome 1 in this case, as it happens).  This is by no way the only time that a genotype does not match the phenotype.  There are loads of others (for example, Partial D Type III has gene mutations that can allow the individual to make a genuine allo-anti-D - and pretty strong anti-D at that - but, phenotypically, the person is a straightforward D Positive individual).  The same applies with e variant mutations, such as hrB and hrS.
I hope all this helps, but, if not, get back to me (or others on this wonderful site).

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.

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.