Reverse Typing using IgG testing with patient with a strong cold

[ChrisH 27]

Looking for a reference to doing Reverse typing using IgG testing.  We have a A Pos patient (historical) that now has a very strong cold that we can not get rid of it.  So we sent it to our reference lab.  They cleared up the ABO discrepancy on the reverse by doing the testing at IgG.

[Malcolm Needs ★ 4,878]

I don't know for certain, but I bet they did a bit more than that.

Almost all "cold" auto-antibodies are IgM, it is true, BUT, because these antibodies almost always have a very wide thermal amplitude, they would cause "spontaneous agglutination" in tests incubated at 37oC too.

What they probably did was to either adsorb out the "cold" auto-antibody with something like rabbit erythrocyte stroma, or denaturation of the IgM molecules by a reducing agent, such as dithiothreitol (DTT), and only then performing tests using a monospecific anti-IgG reagent.

I am quite happy to be corrected.

[Ward_X 63]

If you're talking about resolving an ABO with the presence of a cold, I've seen using warmed cells/plasma, adsorbed plasma, or cord cells.

Did they use the anti-IgG for the workup, and not the discrepancy?

[Joanne P. Scannell 219]

If you know this patient is A Pos and you know the discrepant backtype is due to a cold agglutinin, why are you trying to re-establish what you already know?