Here's one for you.

70yo M with upper GI bleed, no previous transfusion history in 11 years. Negative antibody screen in 2000.

Firstly - we are a small, remote and rural lab and do not offer antibody identification as part of our service. All IDs are sent away to our 'hub' lab.

I've just tested the current sample and it's given a 1+ reaction in cell 3 in out 3 cell screen. The sample will be sent away but I thought I would do a little further investigation to put my own mind at rest as to the clinical significance - after all the patient is bleeding and there may be a requirement for blood. Possible antibodies at this point are S and Lea.

My first step, as the reaction was so weak was to respin the sample and repeat the 3 cell screen. I also put up our 2 cell rr screen just to increase the possibility of eliminating something. As the reaction was very weak I also ran the same at room temperature. The results of the 2 cell screen was a positive reaction in the first cell, not eliminating anything.

But Imagine my surprise when the RT mini-panel showed a reaction in both cells 2 and 3. There was dosage, with cell 3 reacting as 4+ and cell 2 reacting as 3+. The first cell of the rr screen was also reacting 4+. This gives the possibility now of E, c, M, S, K, Lea, Fyb and Jkb

I'm steered towards two antibodies with one being IgG and the other IgM. Of the possibilites I am elimiating E, c, K, Fyb and Jkb due to them being IgG. This leaves S or Lea (from the original screen) plus M. I am thinking that S is more likely than Lea.

So what do you think? Please bear in mind that I am not trying to identify the antibody to put it in our records, more for interest. I am going to recommend and empirical crossmatch at 37 and RT IAT and instruct the use of a blood warmer. Hopefully what is negative at 37 will also be negative at RT...

I'm also going to suggest that the patient be transferred.

I'm thinking M is more likely than S . . . do you use gel? If gel, it is more likely M.

I agree with David, but I also think that the use of a blood warmer is way OTT.

I only recommend a warmer if there is a VERY STRONG cold agglutinin . . . very strong.

There is dosage so I am almost certain that there are two antibodies there. One if definitely anti-M - the only one that fits with the picture. The other could be either S or Lea.

How strong would you consider strong? I'm wanting to err on the safe side - we are 120 miles away from the next nearest hospital which is at least 3 hours by road. Is a 4+ reaction strong enough to be considered strong?

If it doesn't work at strictly 30oC (and, don't forget that when you are using CAT, the "cold" sensitisation takes place before you put the CAT into incubate), by getting the reactants to 30oC before you mix them, then, however strong the reaction is, it is NOT clinically significant, and you don't need a blood warmer.

4+ at immediate spin and cannot be reduced effectively by prewarming.

I've never seen an anti-M giving a 4+ reaction at IS.

You don't say what the patient's blood group is......

Let us know what it turns out to be....

The reference lab called it a 'non-specific' cold. Looked pretty specific to me with decent reaction strength and even showing dosage... ** hum - they're the experts I suppose...

I've found that cold reacting antibodies were put on earth to keep Blood Bankers humble. Just when you KNOW that you will never ever again be faked out by one that 'seems' to be something significant (but isn't).........Surprise! gottcha! :confused:

Edited December 5, 201113 yr by AMcCord

I've never seen an anti-M giving a 4+ reaction at IS.

You don't say what the patient's blood group is......

Let us know what it turns out to be....

I've seen a few M's give 4+ rx in gel (IgG and Buffered cards) ; can't say I recall any 4+ in tubes. What I was referring to though was the reactivity at whcih I recommend a blood warmer for a cold aggl.

Was there any reactivity on the back type?