Clarest

I am wondering if your lab uses the buffered gel cards to test with enzyme treated panel cells in parallel with non-treated panel cells to differentiate multiple antibody specificities, i.e., observing increased or reduced/eliminated reactivity of antibodies. I am still confused whether the buffered gel card can detect IgG antibodies as there is no anti-IgG.

Hi Arno,
Thank you for the explanation! Actually I had a sample from a patient on DARA yesterday showed 1-2+ positivity with all screening and panel cells, but DAT was negative.

Yes, I agree with you Malcolm. We use child-bearing potential in our policy.

Thank you all for responding to this topic. Fortunately, the patient survived probably due to bleeding at that moment. Both poly- and mono-specific DATs were done and they (i.e. poly DAT, IgG, complement and saline control) were all weakly positive. An eluate was tested against A1, A2 and B cells and reacted with A1 and B cells, not A2 cells. The reaction strength with A1 cells was stronger than B cells. The possible explanation for eluate reacting with B cells is that the anti-A,B in this O patient's plasma coated on the A donor cells got eluted and reacted with group B reagent cells. 

Thank you all for responding to this topic. Fortunately, the patient survived probably due to bleeding at that moment. Both poly- and mono-specific DATs were done and they (i.e. poly DAT, IgG, complement and saline control) were all weakly positive. An eluate was tested against A1, A2 and B cells and reacted with A1 and B cells, not A2 cells. The reaction strength with A1 cells was stronger than B cells. The possible explanation for eluate reacting with B cells is that the anti-A,B in this O patient's plasma coated on the A donor cells got eluted and reacted with group B reagent cells. 

Thank you all for responding to this topic. Fortunately, the patient survived probably due to bleeding at that moment. Both poly- and mono-specific DATs were done and they (i.e. poly DAT, IgG, complement and saline control) were all weakly positive. An eluate was tested against A1, A2 and B cells and reacted with A1 and B cells, not A2 cells. The reaction strength with A1 cells was stronger than B cells. The possible explanation for eluate reacting with B cells is that the anti-A,B in this O patient's plasma coated on the A donor cells got eluted and reacted with group B reagent cells. 

Thank you all for responding to this topic. Fortunately, the patient survived probably due to bleeding at that moment. Both poly- and mono-specific DATs were done and they (i.e. poly DAT, IgG, complement and saline control) were all weakly positive. An eluate was tested against A1, A2 and B cells and reacted with A1 and B cells, not A2 cells. The reaction strength with A1 cells was stronger than B cells. The possible explanation for eluate reacting with B cells is that the anti-A,B in this O patient's plasma coated on the A donor cells got eluted and reacted with group B reagent cells. 

Thank you all for responding to this topic. Fortunately, the patient survived probably due to bleeding at that moment. Both poly- and mono-specific DATs were done and they (i.e. poly DAT, IgG, complement and saline control) were all weakly positive. An eluate was tested against A1, A2 and B cells and reacted with A1 and B cells, not A2 cells. The reaction strength with A1 cells was stronger than B cells. The possible explanation for eluate reacting with B cells is that the anti-A,B in this O patient's plasma coated on the A donor cells got eluted and reacted with group B reagent cells. 

Yes, I agree with you Malcolm. We use child-bearing potential in our policy.

Yes, I agree with you Malcolm. We use child-bearing potential in our policy.

Thank you Malcolm and David for sharing your experience with me.

Hi Malcolm,
Look at what I found in the link below 
http://www.transfusion.ca/Resources/CSTM-Blog/January-2017/I-will-remember-you-Malcolm-Needs
Clarest

Hi Malcolm,
Look at what I found in the link below 
http://www.transfusion.ca/Resources/CSTM-Blog/January-2017/I-will-remember-you-Malcolm-Needs
Clarest

Hi Malcolm,
1. I agree with you if we suspect there is a transfusion reaction which causes the positive DAT with IgG, it makes sense to do an elution on the new sample in case some other antibody(ies) are being detected this time but not from the previous sample.
2. Even we test an eluate once every month for the patient with an autoantibody, it is exactly as what you said the eluate shows pan- agglutination. Unfortunately, we do not perform alloadsorption on site. So, the eluate really does not mean that much for detecting underlying alloantibody(ies) developed due to transfusion reaction,  especially when the auto is strong and the eluate always shows 3 to 4+ reaction strengths. Do you think it's necessary to send to our Reference Laboratory once every month for an alloadsorption or just send out when there is a sign of hemolysis process going on?
Clarest

Hi Mabel,
We use the tube saline IAT method for crossmatch and it is allowed to skip the immediate-spin phase. So, as long as the anti-A1 does not react at 37C, we have no problem to result the compatibility of the crossmatch. Routinely, it is okay for us to give group O or B  blood for patient's with anti-A1 and that's what technologists prefer to do as it only requires immediate spin. However, for this particular patient, we just wanted to be more careful. 
Clarest

Hi tkakin,
You're right that anti-A1 typically reacts at immediate spin and that's reason for us to give group A or AB IAT crossmatch compatible red cells. On the other hand, if the group A or AB units are IAT crossmatch compatible with patient's plasma, it  proves the anti-A1 does not react at 37C.
Clarest

Thank you Malcolm. We do not usually keep group AB red cell units in our stock.

Enzyme-treated cells can be very useful in the hands of expert serologists who know the pros and cons of their use. Routine use by front-line techs is probably ill-advised.
In this case, some level of feasibility testing might be useful before switching to an enzyme-treated panel, but I would hesitate to call it "validation". Each facility should determine if such a panel is useful to them, or if it would cause more problems that it would solve.
As I mentioned in earlier in this thread - I believe these are FDA-license reagents and they do not require validation.

We call it "Passive anti-D" and put a comment "Anti-D probably due RhIG received on [date]" . If the antibody screen is still positive, we do a saline IAT crossmatch. If later on, the screen becomes negative, we just do an immediate-spin crossmatch. Sorry, we haven't startred electronic crossmatch yet.  

Per CLSI, the minimum number is 20 sample.  Make sure the Samples you select are fairly distributed in range from negative to large bleed.
 

In addition to the 20 samples, if you are not able to find weak positives, you can make your own weak positives. Just Google it.

Hi John,
 
Sorry for the confusion,. We only do the cord blood workup (ABO/Rh and DAT) on babies whose mother is Rh negative, blood group O or if the mother's plasma contains clinically significant antibody(ies).