HI all-

I have a question regarding dealing with crossmatches that are incompatible at immediate spin, yet compatible at antiglobulin. The staff had to perform a prewarmed backtype due to a cold antibody, so the reactivity at IS is likely due to this cold antibody. The antiglobulin crossmatch is compatible- however this creates a difficult situation since technically the unit is incompatible at immediate spin. The cold did not carry through to the antiglobulin phase. I would love to hear everyone's thoughts on how to approach this. This is a very small facility on the Big Island of Hawaii- they do not have a computer system, to assist with the ABO incompatibility check required by CAP. If the antiglobulin crossmatch were incompatible, it would make sense to perform a prewarmed crossmatch. We currently have them performing the second ABO reconfirmation from a different collection, and of course they reconfirm all unit ABO when they receive the units. Mahalo in advance for all your wise words

 

I would report the crossmatch as compatible and recommend use of a blood warmer for transfusion. No further workup necessary.

Some caution may be appropriate. Most "colds" are indeed clinically insignificant and mere laboratory annoyances. Most of these are autoantibodies that can be avoided by pre-warming methods. However, some can be clinically important - there are examples of anti-Vel that behave exact as LaurieD describes, but are IgM, cold-reactive alloantibodies that can cause serious in vivo hemolysis. I think one case reported by Jill Storry was actually fatal. Another nasty beastie in this category is anti-P+P1+Pk (anti-Tja, in the old vernacular).

I would suggest that a Reference Laboratory take a look at the sample (the Blood Bank of Hawaii is close ), just to give some assurance that the troublemaker is "just a cold auto". Pre-warming without an antibody ID may be dangerous. Just my two cents.

I must agree with exlimey.  See if you can identify it if at all possible before assuming it is not a problem just because it is cold reacting.  If the decision becomes transfuse or die before it can be identified then suggest running the blood through a warmer and hope for the best.

I agree with jayinsat, exlimey and John C. Staley (is this a record????????!!!!!!!!!!!!!!!!!!!!).

Hi all,

Thank you for your responses. I guess I should have mentioned that the antibody screen is negative. I actually had forgotten about anti-Vel and P,P1Pk (shame on me), but wouldn't we see a positive screen if either of those were present?  I guess we could perform cold panels in this situation, to try to identify a specificity. @exlimey, poor Blood Bank of Hawaii actually does not have a reference lab currently (no staff), our larger facility in Honolulu (where my office is) actually performs more complex antibody testing than anyone else in the state. Our small facility on Hawai'i Island would actually refer any testing to us- if we are unable to tackle the situation, we would send to the ARC in California. We would definitely suggest a blood warmer for transfusion in this situation.

Again, thanks for your responses! I usually just read through and look for guidance in all the posts, first time actually posting. 

One thing we require, before using a pre-warmed technique, is proof that there is room temperature reactivity.  You had this with the reverse type but that is often lacking in group O patients. It's not perfect for the anti-Vel etc. but it prevents the habit of doing a pre-warmed technique just to make reactivity disappear. It is a saline method so less sensitive, after all.  Using it when you are pretty sure you have a cold can be a reasonable risk to take.  Using it when you don't have a cold antibody, means taking an unnecessary risk. 

Hi Mabel,

I agree. We do expect staff to be able to explain that the reactivity is truly due to a cold before applying prewarmed technique. In the case of an O patient that we suspect has a cold reactive antibody, we would perform the IS phase of a tube screen. 

Again, thanks for the responses. I find this message board extremely helpful

 

Aloha- Laurie