Malcolm Needs

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Do you think somebody should tell them that ABO HDFN sometimes gives a Negative DAT result in the fist two or three days of life, and that they might actually be better off looking for clinical signs, rather than performing diagnoses on the result of pathology results???????

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Do you think somebody should tell them that ABO HDFN sometimes gives a Negative DAT result in the fist two or three days of life, and that they might actually be better off looking for clinical signs, rather than performing diagnoses on the result of pathology results???????

I think that it depends upon the state of the baby.  For example, if the mother is D Negative, and has been in receipt of anti-D immunoglobulin, and the baby has a positive DAT, but is showing no other signs of HDFN, then we wouldn't perform any further testing.

If the baby has a lowish Hb, and the mother is group O and the baby group A or B, we may take a look at the mother's IgG ABO status, and then perform an eluate on the baby.

Where we might really "go to town" is if the baby is showing overt signs of HDFN, we might well go the "whole hog" and perform an elution, just in case there is a maternal alloantibody directed against a low prevalence antigen also expressed on the red cells of the father.  If this is suspected, it would be easy enough to adsorb out any IgG anti-A or anti-B on the baby's red cells, without adsorbing out the potential antigen against a paternal low prevalence antigen.  The specificity of such an antibody would be interesting, but not necessarily vital, as, should the baby require a transfusion, suitable blood should be easy to obtain.

I think that it depends upon the state of the baby.  For example, if the mother is D Negative, and has been in receipt of anti-D immunoglobulin, and the baby has a positive DAT, but is showing no other signs of HDFN, then we wouldn't perform any further testing.

If the baby has a lowish Hb, and the mother is group O and the baby group A or B, we may take a look at the mother's IgG ABO status, and then perform an eluate on the baby.

Where we might really "go to town" is if the baby is showing overt signs of HDFN, we might well go the "whole hog" and perform an elution, just in case there is a maternal alloantibody directed against a low prevalence antigen also expressed on the red cells of the father.  If this is suspected, it would be easy enough to adsorb out any IgG anti-A or anti-B on the baby's red cells, without adsorbing out the potential antigen against a paternal low prevalence antigen.  The specificity of such an antibody would be interesting, but not necessarily vital, as, should the baby require a transfusion, suitable blood should be easy to obtain.

I tend to think that there are a number of factors affecting the reaction, such as changes to the pH, rather than just dilution, that would change the equilibrium constant within the Law of Mass Action that governs antibody/antigen reactions, but pH is only one of them.

Thanks Lorna.  I'll have a look and see what I can provide but, as I see that you are working in the Isle of Man, may I suggest you get a copy of the BCSH Guideline "Pre-Transfusion Compatibility Procedures in Blood Transfusion Laboratories" from 2012 (which is available free on-line - just put in BCSH Guidelines), and these have a few at the end of the Guideline.

In addition, have a look on this site under "Library" at the top of the page, where you might find more than one thing (probably under "Education", but not only there), that will be of use to you.

Thanks Lorna.  I'll have a look and see what I can provide but, as I see that you are working in the Isle of Man, may I suggest you get a copy of the BCSH Guideline "Pre-Transfusion Compatibility Procedures in Blood Transfusion Laboratories" from 2012 (which is available free on-line - just put in BCSH Guidelines), and these have a few at the end of the Guideline.

In addition, have a look on this site under "Library" at the top of the page, where you might find more than one thing (probably under "Education", but not only there), that will be of use to you.

Sorry I'm just getting use to this site and how to reply! I am wanting to start off with easier ones and get more complicated. I'm trying to prepare for exams at a higher level which will include complicated case studies. I think both serological testing and clinical would be helpful? I am at Specialist level now but never worked in a reference lab and struggle with pan reactive panels and eluates/adsorption work and want to improve my theory so I can relate to complicated questions.  😊

Are you looking for really difficult cases, or more commonplace cases?

I CANNOT tell from the information you have given (not least because the phenotype of the reverse typing cells and the panel cells are unknown to me).

I would very strongly suggest that you send samples to a Red Cell Reference Laboratory to get this sorted out, BEFORE the patient needs a transfusion in an emergency.

From what you do tell us, I think the antibody/antibodies are unlikely to be fatally clinically significant, but it depends on the true specificity/specificities and the underlying pathology.

I tend to think that there are a number of factors affecting the reaction, such as changes to the pH, rather than just dilution, that would change the equilibrium constant within the Law of Mass Action that governs antibody/antigen reactions, but pH is only one of them.

I tend to think that there are a number of factors affecting the reaction, such as changes to the pH, rather than just dilution, that would change the equilibrium constant within the Law of Mass Action that governs antibody/antigen reactions, but pH is only one of them.

I tend to think that there are a number of factors affecting the reaction, such as changes to the pH, rather than just dilution, that would change the equilibrium constant within the Law of Mass Action that governs antibody/antigen reactions, but pH is only one of them.

actually - that should have said anti-A1 in the eluate.......
we did some adsorption and elution studies "off the books" as that's not in our SOP - but it worked! 

Came to say the same thing as @Malcolm Needs 
We actually just had a patient a week or so ago with a long standing history of being B.....and then all of a sudden we had weak reactions in gel with the anti-A and Anti-A1 in the plasma......
Sent it for ABO genotyping and they were indeed (A)B !
pretty cool stuff - this Blood Banking! 

It looks like an A subgroup B to me.  The apparent reaction with the A cells and the donor's plasma in the reverse group in the first photograph could be a weak anti-A1, but more likely it is another specificity altogether (such as an anti-P1).

Without a doubt, however, a sample from the donor should be sent to a Reference Laboratory to have the ABO type sorted out (e.g. by adsorption and elution tests, preferably using a strong human-derived polyclonal anti-A).

Nice crisp photographs, by the way.

"Nice crisp photographs, by the way." thanks 
thanks for advice 

A research team led by NHS Blood and Transplant scientists based in Bristol, at NHSBT’s International Blood Group Reference Laboratory (IBGRL), and supported by colleagues at the University of Bristol, has discovered a new blood group, MAL. 🙌 🩸

They identified the genetic background of the previously known but mysterious AnWj blood group antigen, thus allowing identification and treatment of rare patients lacking this blood group.

Louise Tilley, Senior Research Scientist, IBGRL Red Cell Reference at NHS Blood and Transplant, said: “The genetic background of AnWj has been a mystery for more than 50 years, and one which I personally have been trying to resolve for almost 20 years of my career. It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients."

hashtag#NHSBT hashtag#GiveBlood hashtag#SaveLive hashtag#NHSCareers Activate to view larger image,

A research team led by NHS Blood and Transplant scientists based in Bristol, at NHSBT’s International Blood Group Reference Laboratory (IBGRL), and supported by colleagues at the University of Bristol, has discovered a new blood group, MAL. 🙌 🩸

They identified the genetic background of the previously known but mysterious AnWj blood group antigen, thus allowing identification and treatment of rare patients lacking this blood group.

Louise Tilley, Senior Research Scientist, IBGRL Red Cell Reference at NHS Blood and Transplant, said: “The genetic background of AnWj has been a mystery for more than 50 years, and one which I personally have been trying to resolve for almost 20 years of my career. It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients."

hashtag#NHSBT hashtag#GiveBlood hashtag#SaveLive hashtag#NHSCareers Activate to view larger image,

A research team led by NHS Blood and Transplant scientists based in Bristol, at NHSBT’s International Blood Group Reference Laboratory (IBGRL), and supported by colleagues at the University of Bristol, has discovered a new blood group, MAL. 🙌 🩸

They identified the genetic background of the previously known but mysterious AnWj blood group antigen, thus allowing identification and treatment of rare patients lacking this blood group.

Louise Tilley, Senior Research Scientist, IBGRL Red Cell Reference at NHS Blood and Transplant, said: “The genetic background of AnWj has been a mystery for more than 50 years, and one which I personally have been trying to resolve for almost 20 years of my career. It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients."

hashtag#NHSBT hashtag#GiveBlood hashtag#SaveLive hashtag#NHSCareers Activate to view larger image,

A research team led by NHS Blood and Transplant scientists based in Bristol, at NHSBT’s International Blood Group Reference Laboratory (IBGRL), and supported by colleagues at the University of Bristol, has discovered a new blood group, MAL. 🙌 🩸

They identified the genetic background of the previously known but mysterious AnWj blood group antigen, thus allowing identification and treatment of rare patients lacking this blood group.

Louise Tilley, Senior Research Scientist, IBGRL Red Cell Reference at NHS Blood and Transplant, said: “The genetic background of AnWj has been a mystery for more than 50 years, and one which I personally have been trying to resolve for almost 20 years of my career. It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients."

hashtag#NHSBT hashtag#GiveBlood hashtag#SaveLive hashtag#NHSCareers Activate to view larger image,