Confirming Antigen Negative Units from Reference Lab

[Mary**]

If you receive antigen negative (i.e. K-,S-,etc.) blood from your Reference Lab do you repeat the antigen typings, Especially when they are marked "historically negative"?:fingerscr

[dcubed]

If the units are historically negative, your blood supplier should comfirm those typings. We do not routinely check their typings. If the supplied unit(s) were not compatible, then we would check the typings in our lab.

[pbaker]

We have a way for the blood center to check the historic antigen typing of the units currently on our shelf. If they notify us of historic typing or send us units from the blood center tagged as historic, we reconfirm. If they send us units tagged with antigen typing results, we do not reconfirm.

[Malcolm Needs ☆]

Those that we send out as, for example S-, K-, Fy(a-), have been typed historically and on the current donation.

If, on the other hand, we are sending out M- units for an anti-M that we know does not react strictly at 37oC, we are happy to send out historically typed M- units (to save our phenotyped stock for clinically significant antibodies), together with a print-out from our computer to show tha they have been typed for the M antigen on more than one occasion (but not on the current donation). What the Hospital Blood Transfusion Departments do then is down to them, but I know that when I worked in a Hospital Blood Transfusion Department, I wouldn't have bothered to re-type the unit - even if I had the reagents available, which was not always.

[KKidd]

Our blood center does not send out units without confirming the antigen types first. We only have the basic anti-sera (C,E,Fya,Jka,and K) and could not confirm any thing else anyway!

[Dr. Pepper]

Our blood center relies heavily on historical typings and urges us strongly to recheck all units when we get them. What's your blood supplier's opinion?

[dgibaud]

We confirm ALL antigen types marked "historical". Why? Because I've been burned before. I just happened to discover the mistake prior to transfusion. Our supplier offers "confirmed" negatives (these units are actually typed) but due to cost we always get "historically negative" which are cheaper.

[Eagle Eye]

we get antigen negative units ...but we type them again (if we have anti-sera. we do keep almost all common anti-sera eg. K, RH, Duffys, Kids, M,N,S, s)

[MARINA]

Our blood center performs antigen typing on all units asked for. They use historical typing to locate "better chance" units, but then they type them. Since this is our case, we do not retype the antigen negative units for the antigen. I have worked at several area blood banks that use the same supplier and they follow the same protocol. I am unsure of the blood banks that use the other supplier in the state.

[David Saikin]

We always retype if we have the antisera.

[AMcCord]

We always retype if we have the antisera.

Same for us.

[KathleenSL]

Our center only sends out "historical" antigen negative units if the customer has the antisera to perform the confirmatory typings themselves. The "historical" antigen negative units have a tag on them that states that the typings must be confirmed.

[rravkin@aol.com]

To re-type or not to re-type; That is the question!!

Considering the fact the such units are ordered for a specific patient demonstrating specific antibodies, or if they have historic specificities that are not demonstrating, the IAT crossmatch serfices as the check for negative antigens listed. Of course, if they are incompatible then checking the antigen types should be part of that workup.

[Malcolm Needs ☆]

To re-type or not to re-type; That is the question!!

Considering the fact the such units are ordered for a specific patient demonstrating specific antibodies, or if they have historic specificities that are not demonstrating, the IAT crossmatch serfices as the check for negative antigens listed. Of course, if they are incompatible then checking the antigen types should be part of that workup.

So should checking the supposed antibody specificity!!!!!!!!!!!

:omg::omg:

[pbaker]

You cannot rely on the crossmatch if the patient antibody is no longer detectable. A negative crossmatch does not guarantee an antigen negative unit.

[Deny Morlino]

You cannot rely on the crossmatch if the patient antibody is no longer detectable. A negative crossmatch does not guarantee an antigen negative unit.

We have had experience with this exact situation. Patient presented with only an Anti-E detectable. Transfused E-neg units. Returned a week later for additional blood transfusion. Anti-E not reacting but 4 other antibodies that had been sub-clinical (unknown to us regretfully) had strengthened and were causing issues. A larger hospital about 45 minutes away had identified all 5 antibodies about 5 years before the patient presented at our facility. A VERY big mess!

[rravkin@aol.com]

PBaker,

You make the best point. I agree with the practice that if a historical antibody is not demonstrating currently then the antigen type of the unit should be checked. But if the antibody is demonstrating the the IAT crossmatch should surfice given that the antibody was demonstrated using the same technique. I used to practice this at a previous facility.

[rravkin@aol.com]

So should checking the supposed antibody specificity!!!!!!!!!!!

:omg::omg:

That's right. Checking the original antibody specificity would be the other "part of that work up.":)

[Steven Jeff]

But if the antibody is demonstrating the the IAT crossmatch should surfice given that the antibody was demonstrated using the same technique. I used to practice this at a previous facility.

It is the practice in the UK that selected antigen negative red cells are cross-matched for a patient with clinically significant antibodies, in other words we do not rely on an IAT cross-match whether demonstrable or not. However, as Malcolm alluded to in an earlier post, the NBS in the UK provide a fantastic service in providing guaranteed antigen negative blood on request, in that we are fortunate. It is not my practice to confirm the antigen status of red cells provided by the NBS, I rely on the stated antigenicity provided by the NBS.

Steve

:)