Learning from the experts

We perform tube testing using 4 drops of plasma for weak reverse.

Thanks, Malcom. I thought so too.

Thanks Malcom. We are trying to enhance the weak reverse, that's why we are testing at 4C. We do the test at RT first then at 4c x30', 4Cx60'.

I was informed by my senior tech that Bg antibodies react better with the older Bg positive cells. Can someone please explain the reason?

We get lots of grouping problems due to weak reverse. When we cannot resolve it at RT we incubate at4Cx60'. This leads to nonspecific reactions due to cold agglutinins. We set up a cold panel of 3 cell screen, A1 cells, A2 cells, B cells, and auto to find the specificity. Q1. If everything comes up positive at 4C, how do you resolve this? We call it NTD. Q2. Is there something else that we can do? We don't want to send samples for Geno? Q3. If you have to do cold auto adsorption, how do you remove IGM coating the RBC? Same reagents as you use for ZZAP? DTT? Q4. Most of the time these samples come to our lab for reference testing and we can not reproduce the initial results. The auto control becomes negative. The nonspecific cold agglutinins disappear. Initially, I thought it's due to cold auto adsorption but the cells are separated from the plasma. Any thoughts, what could be causing this? Antigen sites blocked? There is a lag of one week between the initial testing and the reference lab testing.

Thanks, Malcolm! We will probably defer the donor. I had the same explanation in mind but my colleagues were telling me that it's a group O donor while I thought it's a weak subgroup of A with anti-A1.

Donor Forward group: -A:0, -B:0, -A,B:0 Reverse group: A1C:0, A2C:0, BC:4 Cold panel at IS, RT, and 4C with O, A1 and A2 cells: 1+ reactions with A1 cells only Adsorption elution with polyclonal anti-A: no evidence of A antigen What next? Geno? Why there are no reactions with A2 cells?

Thank you, guys, for explaining.

For an A3B patient, is it common to get MF with anti-A reagent only and no MF with anti-A, B? We tested the sample with multiple sources of Anti-A, Anti-B and Anti-A, B. MF is seen only with -A reagent.

I was thinking about a 5 screen panel by SIAT or GEL. If everything reactive I will set up some cord and group A and B cells .

It was part of the SOP to do IS panel if everything is reacting in reverse including screening cells and auto control negative.

Hi, We have a Group A Pos patient antibody screen negative by capture. The 16 cell panel is reacting by IS (1-2) auto control negative. The patient was never transfused, not pregnant. How do you approach these cases other than running a SIAT panel at 37C?

I just answered this question. My Score PASS