DLabGirl

Happy Friday everyone! 
First off, Thank you Malcolm 😊 for that excellent PPT lecture! 👌 With your permission, I'd love to share it with my students; it's exactly the kind of content that helps bring these complex concepts to life (and mildly melt brains in the best way possible).
Speaking of melted brains… let's talk Anti-G differentiation, shall we? While I agree that differentiation isn’t necessary for transfusion purposes because in cases where anti-G is suspected, the recommendation is the same (D and C antigen-negative PRBCs); in the US Reference Lab world, it's a whole different dance. Differentiating anti-D + anti-C from anti-G is essential in alloimmunized patients with anti-D + anti-C for Rh Immune Globulin (RhIg) prophylaxis administration indication. Medical teams want to know if a patient is a candidate for RhIG, and if it's still indicated, especially to avoid future medical and legal complications. And so begins the beautiful (read: painstaking) double adsorption and elution process. 😫
 
The presence/development of a real anti-D indicates the patient does not require RhIg administration, whereas the presence of anti-G indicates the need for RhIg prophylaxis. That way, RhIG is avoided in patients with a real anti-D (although clinical correlation is recommended to guide every decision).
In this case, we saw what looked/reacted like anti-D and anti-C (1). Adsorption with R2R2 cells showed anti-C in the adsorbed serum (2) and anti-D and/or G in the adsorbing R2R2 cell eluate (3). Usually, we would stop and call anti-C and anti-D, if we have no reactions on C Ag Pos cells, but since suspected anti-G was in the mix, we routinely differentiate/separate it. The anti-D was confirmed in (4) by adsorbing the eluate containing the suspected (anti-D + anti-G) with an r'r unit. So far, so good. However, when we tried to separate the anti-G by elution of the adsorbing r′r cells, expecting a reaction on D and C antigen-positive cells (5), we got a negative result (Cue dramatic music).
I know, I know...at this point you’re probably wondering if we’re still in the Blood Bank or if we’ve accidentally wandered into theoretical physics. Trust me, my brain also wobbles when explaining G differentiation. It's the kind of thing that makes you rethink your career choices... for about 5 minutes... and then roll up your sleeves and start prepping another adsorption. 😅
A couple of housekeeping: We ficin treat our adsorbing cells, and sometimes use PEG in adsorption for efficiency. After briefly considering a career in something less chaotic, we retraced our steps. No PEG this time, 60-minute incubation, followed up with a DAT after each adsorption to check for antibody coating... and voilà: finally got the positive reaction we were looking for. The patient has anti-D, anti-C, and anti-G.
I can only think of a possible weak DAT strength pending elution, or PEG interference when used in adsorption. As always, this is Blood Bank, we know a million things can go wrong, and often do. But in the end, science (and a lot of perseverance) wins. 
Thanks again to everyone for your input, patience, your brains, and your sense of humor. And again, Malcolm, thanks for your lecture, teaching, dedication and inspiration!
I wish everyone a calm weekend. May your panels be clear, your DATs negative, and your eluates informative. 😉
 

Thank you for your exceptionally kind words DLabGirl, and by all means use the lecture as you wish.  The same goes for anyone else who might want to use it, with the proviso that you a) realise that it is a bit "long in the tooth", and b) I did mean that we, in the UK, would still look to ensure that there really is an anti-D present, before we do not recommend giving anti-D immunoglobulin.

Happy Friday everyone! 
First off, Thank you Malcolm 😊 for that excellent PPT lecture! 👌 With your permission, I'd love to share it with my students; it's exactly the kind of content that helps bring these complex concepts to life (and mildly melt brains in the best way possible).
Speaking of melted brains… let's talk Anti-G differentiation, shall we? While I agree that differentiation isn’t necessary for transfusion purposes because in cases where anti-G is suspected, the recommendation is the same (D and C antigen-negative PRBCs); in the US Reference Lab world, it's a whole different dance. Differentiating anti-D + anti-C from anti-G is essential in alloimmunized patients with anti-D + anti-C for Rh Immune Globulin (RhIg) prophylaxis administration indication. Medical teams want to know if a patient is a candidate for RhIG, and if it's still indicated, especially to avoid future medical and legal complications. And so begins the beautiful (read: painstaking) double adsorption and elution process. 😫
 
The presence/development of a real anti-D indicates the patient does not require RhIg administration, whereas the presence of anti-G indicates the need for RhIg prophylaxis. That way, RhIG is avoided in patients with a real anti-D (although clinical correlation is recommended to guide every decision).
In this case, we saw what looked/reacted like anti-D and anti-C (1). Adsorption with R2R2 cells showed anti-C in the adsorbed serum (2) and anti-D and/or G in the adsorbing R2R2 cell eluate (3). Usually, we would stop and call anti-C and anti-D, if we have no reactions on C Ag Pos cells, but since suspected anti-G was in the mix, we routinely differentiate/separate it. The anti-D was confirmed in (4) by adsorbing the eluate containing the suspected (anti-D + anti-G) with an r'r unit. So far, so good. However, when we tried to separate the anti-G by elution of the adsorbing r′r cells, expecting a reaction on D and C antigen-positive cells (5), we got a negative result (Cue dramatic music).
I know, I know...at this point you’re probably wondering if we’re still in the Blood Bank or if we’ve accidentally wandered into theoretical physics. Trust me, my brain also wobbles when explaining G differentiation. It's the kind of thing that makes you rethink your career choices... for about 5 minutes... and then roll up your sleeves and start prepping another adsorption. 😅
A couple of housekeeping: We ficin treat our adsorbing cells, and sometimes use PEG in adsorption for efficiency. After briefly considering a career in something less chaotic, we retraced our steps. No PEG this time, 60-minute incubation, followed up with a DAT after each adsorption to check for antibody coating... and voilà: finally got the positive reaction we were looking for. The patient has anti-D, anti-C, and anti-G.
I can only think of a possible weak DAT strength pending elution, or PEG interference when used in adsorption. As always, this is Blood Bank, we know a million things can go wrong, and often do. But in the end, science (and a lot of perseverance) wins. 
Thanks again to everyone for your input, patience, your brains, and your sense of humor. And again, Malcolm, thanks for your lecture, teaching, dedication and inspiration!
I wish everyone a calm weekend. May your panels be clear, your DATs negative, and your eluates informative. 😉
 

Happy Friday everyone! 
First off, Thank you Malcolm 😊 for that excellent PPT lecture! 👌 With your permission, I'd love to share it with my students; it's exactly the kind of content that helps bring these complex concepts to life (and mildly melt brains in the best way possible).
Speaking of melted brains… let's talk Anti-G differentiation, shall we? While I agree that differentiation isn’t necessary for transfusion purposes because in cases where anti-G is suspected, the recommendation is the same (D and C antigen-negative PRBCs); in the US Reference Lab world, it's a whole different dance. Differentiating anti-D + anti-C from anti-G is essential in alloimmunized patients with anti-D + anti-C for Rh Immune Globulin (RhIg) prophylaxis administration indication. Medical teams want to know if a patient is a candidate for RhIG, and if it's still indicated, especially to avoid future medical and legal complications. And so begins the beautiful (read: painstaking) double adsorption and elution process. 😫
 
The presence/development of a real anti-D indicates the patient does not require RhIg administration, whereas the presence of anti-G indicates the need for RhIg prophylaxis. That way, RhIG is avoided in patients with a real anti-D (although clinical correlation is recommended to guide every decision).
In this case, we saw what looked/reacted like anti-D and anti-C (1). Adsorption with R2R2 cells showed anti-C in the adsorbed serum (2) and anti-D and/or G in the adsorbing R2R2 cell eluate (3). Usually, we would stop and call anti-C and anti-D, if we have no reactions on C Ag Pos cells, but since suspected anti-G was in the mix, we routinely differentiate/separate it. The anti-D was confirmed in (4) by adsorbing the eluate containing the suspected (anti-D + anti-G) with an r'r unit. So far, so good. However, when we tried to separate the anti-G by elution of the adsorbing r′r cells, expecting a reaction on D and C antigen-positive cells (5), we got a negative result (Cue dramatic music).
I know, I know...at this point you’re probably wondering if we’re still in the Blood Bank or if we’ve accidentally wandered into theoretical physics. Trust me, my brain also wobbles when explaining G differentiation. It's the kind of thing that makes you rethink your career choices... for about 5 minutes... and then roll up your sleeves and start prepping another adsorption. 😅
A couple of housekeeping: We ficin treat our adsorbing cells, and sometimes use PEG in adsorption for efficiency. After briefly considering a career in something less chaotic, we retraced our steps. No PEG this time, 60-minute incubation, followed up with a DAT after each adsorption to check for antibody coating... and voilà: finally got the positive reaction we were looking for. The patient has anti-D, anti-C, and anti-G.
I can only think of a possible weak DAT strength pending elution, or PEG interference when used in adsorption. As always, this is Blood Bank, we know a million things can go wrong, and often do. But in the end, science (and a lot of perseverance) wins. 
Thanks again to everyone for your input, patience, your brains, and your sense of humor. And again, Malcolm, thanks for your lecture, teaching, dedication and inspiration!
I wish everyone a calm weekend. May your panels be clear, your DATs negative, and your eluates informative. 😉
 

In the UK, we would test serum/plasma samples from pregnant patients to see if there was an anti-C + Anti-G, or an anti-G on its own, but if the tests showed an anti-D+C, we didn't go any further to see if there was an anti-G there as well.  I mean, what for?  What difference does it make?

I attach a PowerPoint lecture on the subject I wrote some years ago, but I think it is still pertinent.
The G Antigen and Anti G.pptx

Do you have collect cord blood samples?  Cord red cell samples from A or B babies of type O moms (with pos DAT not due to other alloantibodies) can be preserved in Alsevers for nice student project samples. I've faked samples for immediate use by combining A or B cells from donor segment samples with type O plasma. I wash some of the excess plasma away before I give the sample to the student to work with. I don't have a specific recipe - just add a splash of plasma to cells from a couple of segments, then check a drop for a pos DAT.

I just LOVE the word "torment" Phil.
 
A teacher after my own heart!!!!!!!!!!!!!!!!!!!!

amym1586, on 22 Jul 2014 - 5:19 PM, said:
Is there a way to make a fake Lui Freeze ?
I start off my students doing a mess of typings on random "just in case" tubes from the main lab about to be discarded - CBC and coag tubes. You don't need to do 40 typings to learn how but this also gives them good practice making suspensions, reading reactions, figuring out which end of the pipet to hold etc. Save the specimens. Next day, I tell them they will do one typing that will take all day. I show them on paper what they would have done to get to that point: O on front type, A or B on back type, couldn't get that "missing" back type cell to react with a cold back type. You should have plenty of O and A specimens, maybe a few B/AB. Make pools of each type and wash. To make your weak "patient sample", spike 2-3 ml of washed packed O cells with 10 drops of A or B cells. They also do the procedure on straight O and A (or cells. It works with either human source anti-A or -B (saved from the previous day's specs) as well as reagent monoclonals. I probably should spike the mock patient sample with fewer cells as you will probably adsorb out all the antibody, but they get the point and I want it to work.
 
Other student stuff:
 
A2 or A2B with anti-A1: spike a real A or AB serum with reagent anti-A1.
 
O with weak anti-A+B: make a 12-tube serial dilution of O serum. Test each dil against A and B cells in the cold. Find the dil that gives you a w+ or 1+ in the cold. Make sure that dilution is not reacting at IS. Make up more of that dilution and give them O cells and that for their typing - the goal will be to get them to do a cold back type.
 
Typing with unexpected abs in serum: Spike your serum with reagent anti-c etc or a patient ab that will react at IS. 
 
Review your panels often. If someone has an antibody, scrounge up the stored tubes, even coags, from other depts if they save them, then pool and freeze to torment future students down the line. Freeze some specs with nice rouleaux.
 
Make DAT positive cells for eluates by adding reagent anti-D to Rh+ cells as others have suggested. Our QC reagent ab has anti-A, -B, -D, -c. After the kit ODs I use it to get a "panagglutinin" by sensitizing D+c+ cell, or auto-anti-c by sensitizing D- cells.
 
Transfusion reactions: Add 1 drop check cells to 12 or more drops non-coated cells to give mixed-field agglutination.
 
I teach PeG autoadsorption by starting them with a pseudo-patient with the above "panagglutinin" on cells and in serum. They then use some frozen samples with anti-K and a couple of old CBC tubes that I've typed and are K- for their patient serum/plasma and cells (there's no "autoantibody" in the sample now but they'll never know that).
 
Take advantage of fresh real specs when you have them (known weak Ds or weak subgroups), and in particular freeze specs with cool stuff like and-Sda or RG/Ch that you can do urine or plasma neutralization with.
 
I also take them to watch a unit being hung, show them our QA process, involve them in audits and whatever periodic QC comes due while they're in the dept.

It is an honor to be here! I'm already learning so much from all of you! Thank you!!!🙏💕

It is an honor to be here! I'm already learning so much from all of you! Thank you!!!🙏💕

It simply means that the P1 antigen is particularly strongly expressed on these red cell samples.  Therefore, if you come across a weak anti-P1, it may apparently react with these particular red cell samples, whilst apparently not with, for example, the third red cell sample shown in your antigram.  Although not identical to dosage, per se, it is fairly synonymous with dosage at a phenotypical level.
The strength of the expression of the P1 antigen is an inherited trait.

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