A recently transfused patient develop an antibody (e.g. Kidd) with MF autocontrol, does the work-up usually include delayed transfusion reaction work-up? How about a recently transfused patient who develop WAA, does the work-up include only differential allo-adsorption, DAT, Elution when DAT IgG +,Chloroquine and EGA treatment phenotyping when the DAT IgG + or am I missing something more? Dosage is not affected with antibody having low titer, isn't it? But rather dosage is affected by the number of antigen sites right? So is the statement false that goes "Low titer of antibody results in weak reactions appearing not to react with cells having heterozygoes expression of the antigen. Thanks

1. As far as initiating a delayed transfusion reaction, that is an Institutional protocol. Historically, most places I have worked do so. Was Anti-Jka eluted? I don't want to make any assumptions. Identified could just meant he plasma/serum. I do see the MF DAT; but again, do not want to make an assumption. If not in the eluate, would not initiate a delayed Transfusion Reaction.

2. For recently transfused patient with WAA:

a. 1st, I am assuming you have identified it as being a WAA?

b. You can actually approach it 1 of 2 ways; you can perform the differential adsorption, or, you can elect to give phenotypically matched RBCs (assuming you are able to obtain the complete phenotype either by typing a pre-transfusion specimen, or, successful EGA or Chloroquine treatment). And that too is an Institutional Policy. My experience has varied with that, depending on the # of WAA patients you get, and the availability of phenotyped units. When I worked at a large Institution that constantly had warm autoantibodies, as well as very sick patients (would get patients from all over the world), it was not feasible to limit patients to phenotypically matched. So we performed allogeneic (differential) adsorptions. Where I am now, we always try to get that phenotype and give matched blood to save the time and expense of the adsorptions.

3. Not sure I totally follow your 3rd question. Are you asking if that statement is an acceptable conclusion for documentation purposes? If that is your question, I think it can be simplified to something like: Anti-XYZ reacting with homozygous cells only.

Brenda Hutson, CLS(ASCP)SBB

A recently transfused patient develop an antibody (e.g. Kidd) with MF autocontrol, does the work-up usually include delayed transfusion reaction work-up? How about a recently transfused patient who develop WAA, does the work-up include only differential allo-adsorption, DAT, Elution when DAT IgG +,Chloroquine and EGA treatment phenotyping when the DAT IgG + or am I missing something more? Dosage is not affected with antibody having low titer, isn't it? But rather dosage is affected by the number of antigen sites right? So is the statement false that goes "Low titer of antibody results in weak reactions appearing not to react with cells having heterozygoes expression of the antigen. Thanks

Hi Brenda,

Thank you for your help. I was actually asking if dosage is affected by the titer of antibody as I thought dosage is manifested when red cells

have limited number of antigen sites.

a low-titer antibody may not show a reaction with weaker reacting cells (heterozygous). Say, it reacts only 1+ with homozygous, it might not react visibly with the single dose antigen on the cells of the heterozygote. Still an attribute of the antigen, but affected by the antibody titer.

thanks Mabel