Hi, I have a question for the blood bank!!!

[sudoly]

Hi

I am Korean.
I am working at a hospital in hospital.

my job is bloodbank  manager!!!

case 1.

Antibody screen : Positive

Antibody Identification : negative

What's the reason? 

 

case 2.

2 months ago

Antibody screen : Positive

Antibody Identification : Positive

recent month

Antibody screen : Negative

1weeks ago

Antibody screen : Positive

 

This patient needs Identification?

I don't know what to do with this.

help me

 

[SMILLER]

Someone here will have better suggests than me.  In the meantime, we will need more information. 

Did the patient have a prior history? 

What antibody was ID'd  two months ago? (some antibody titres, like Kidd, can go  up and down)

If the most recent screen (from "1 week ago") was positive, what happened with the antibody ID testing?

Also, what techniques are you using?  

If your current ID testing is inconclusive, and you have exhausted all of your methods, then you need to send a specimen to a reference lab.  Even if the patient is not going to receive blood currently, you will want to know what is going on for future reference.

Regardless of current antibody ID, at the least, you will need to screen units for that antigen because of the ID from 2 months ago.

Scott

[R1R2]

Without knowing many details - 

A lot of reasons for #1 such as false positive or false negative.   Another reason is an antigen on the screening cells is not on the panel.   Would advise to go over everything again and ascertain testing was performed correctly, review antigen profiles on the screening cells to see if there is an antigen on it that is not on the panel cells (like Lua) and then give AHG compatible(and possibly antigen negative) blood. 

 

#2 - IN addition to false negative, antibody may be weak or screening cells may have weakened expression of the antigen.   Rule out all clinically significant antibodies and give AHG compatible, antigen negative blood. 

 

This is only a very short list of what may be going on.   I would advise you to find someone proficient in immunohematology to help you out before transfusing anyone. 

[Malcolm Needs ★]

Case One.  It could be a false positive (maybe your screening cells had a bacterial infection), but it is more likely that the patient has produced an antibody directed against a low prevalence antigen that is expressed on the screening cells, but not on your panel cells, particularly if your panel cells are not produced in your part of the world.  I think I am correct, for example, in saying that there is a higher percentage of the population that express the Di(a) and Mur antigens, than in the UK.  We VERY rarely see these antigens in the UK.

Case Two.  Has the patient been transfused again between the negative and positive screens?  If so, it could be, as SMILLER suggests, something like a Kidd antibody (they are sneaky little things) but can come back by something called an anamnestic response.  Alternatively, if your screening cells were close to their expiry when the screen was negative, it could be a specificity within, say, the Knops Blood Group System, as these antigens are notorious for "going off" during storage.  Either way, unless you can send a sample to a Reference Laboratory, as others say, perform an IAT cross-match and given compatible units - NOT weakly incompatible units (unless a Knops antibody is proven, as these are clinically insignificant).