ABID: Cold Agglutinin

[Brenda K Hutson]

 

I kind of "coined" a couple of bogus techniques when I worked at Stanford many years ago.

1. "Scorch and Vortex" Technique of Antibody ID (gets rid of all of those pesky antibodies)

2. "Increase the Antibody" Method of Antibody ID (i.e. if getting weak, questionable reactions that you

think "might" be an Anti-XYZ.....just give blood that is XYZ Positive.....next time, the reactions should be

clearer!

All just joking....do not try this at home or in your Lab.....LOL

And I agree with John Judd on that (except in rare instances....and in the right hands). If the cold is so strong that it is interferring with your crossmatches and you cannot obtain compatible ones....I much prefer the use of RESt absorbed plasma.

Brenda Hutson

I see several people are channeling for John Judd here.  He was asked to fill in at the last minute for another speaker at the last AABB meeting and he managed to get in a reminder to not do the pre-warmed technique (which most of us define as a saline only tube method where reagent cells and plasma sample are warmed before combining and washed with 37 degree saline before addition of anti-IgG).  He used to refer to it as the pre-fried technique because people had a tendency to use ever warmer saline if they couldn't get the antibody to "go away" by using 37 degree saline.  Most of the missed antibodies in the study he published were due to the less sensitive technique of saline testing.  The thing is, you very seldom need to do it.  If you can rule out all of the usual suspects and get AHG crossmatch compatible units by a more sensitive method that is what you should do.  Save pre-warmed for patients with a really potent cold where you have no other choice and then don't "fry" the cells.  Then you don't often need to fuss with cold panels and the like because their cold antibody will probably jump out of the tube at you--or at least interfere with the reverse type.

 

Malcolm, note that I said "often".  (and I put the period after the quote marks like you Brits do.    )

 

[kirkaw]

I understand your concern and would first want to identify a cold by running appropriate tests before jumping right to prewarm and assuming that because reactions went away that it was due to a cold.  Many years ago when I was a new supervisor, I observed exactly what you described and was bothered by it.   I reviewed past workups that were identified as cold abs and found that many were really wishy washy anti M's.   I did find one Fya  that was reacting sporadically with only double dose cells.   The way they performed antibody id was quickly changed to stop the practice of prewarming away unexplained reactions. 

I feel the same way about going from gel method to tube method (no enhancement), which happens where I work.

 

That being said, if you have a patient that has a previously identified cold, but the current antibody screen is negative in gel, what crossmatch method would you use?