Previously identified antibodies

[jalomahe]

When resulting antibody screen or antibody identification, how do you result antibodies previously identified but that are no longer at detectable levels? Do you add chartable comment to the effect that there patient has history of antibody? Do you include any comment such as a transfusion recommendation or, in the case of pregnancy, recommendation for repeat testing or ... ?

Example 1: Prenatal patient has previously identified Anti-E but now the antibody screen is negative?

 

Example 2: Pre-surgical patient has previously identified Anti-C and Anti-K but current antibody identification shows only the Anti-C. Blood bank of course honors both the C and K and provides C-, K- units but how would you report the undetectable K at this point (or do you)?

 

[David Saikin]

I put a comment attached to the negative antibody screen: "previously identified anti-*** not demonstrable at this time."

[Malcolm Needs ☆]

We do exactly the same as David.

[Dansket]

I have always followed this rule, "Record what you see, not what you think it should be."  I believe in reporting current results without a patient history disclaimer.

Edited April 28, 2014 by Dansket

[David Saikin]

 

I have always followed this rule, "Report what you see, not what you think it should be."  I believe in reporting current results without a patient history disclaimer.

 

I have found that it does not hurt to inform the MD of an ab history . . . not that a great many seem to understand the implications HOWEVER when it hits the fan, as it occasionally does, I at least have the documentation that someone should have known this information. Actually, at my instituion it would be a moot point as we would automatically set up ag negative, ahgxm compatible rbcs routinely for any in pt or preop pt.

[Malcolm Needs ☆]

I have always followed this rule, "Report what you see, not what you think it should be."  I believe in reporting current results without a patient history disclaimer.

Yes, but in this case, it is not "what you think it should be", but "what you know was there in the past", and, in the case of an anti-Jka, for example, I would ALWAYS report such a clinically significant antibody, even if no longer detectable, just because it is so clinically significant (and is well known to cause severe delayed haemolytic transfusion reactions, due to an anamnestic reaction.

The same goes for a pregnancy. Such an antibody is unlikely to affect the fetus, BUT, if the mother needs a transfusion, as they sometimes do,.....................................

[Dansket]

I have always followed this rule, "Record what you see, not what you think it should be."  I believe in reporting current results without a patient history disclaimer.

I have used this rule always with a Blood Bank Information System that is capable of storing antibody identification, controlling which blood components may be selected for transfusion, and determing crossmatch method (electronic versus serologic) by Blood Bank staff.  

[SMILLER]

Relying on IT can be taken too far.  If one determines that what you know does not jibe with what a computer is directing you do, I think you are obligated to think some more, not just assume that what you are seeing on a screen is correct and complete.

 

 

 

Scott

[jalomahe]

Thank you all and I agree that for transfusion purposes it may be a "moot point" when there are procedures in place for the blood bank staff to set up antigen negative units for all current and previously identified antibodies. MDs are perhaps not concerned because they know when it comes to transfusing the patient the blood bank will have their backs.

 

My other concern is with the prenatal patients. Antibody Screen Negative but previously id'd antibody. If you add a note/comment indicating this history, do you include in this note any comment as to whether patient should be monitered for HDFN? Do you handle it as a "critical call" and document notification of the MD? I  worry that even with the previous history comment that it doesn't click with the OB that this is an issue and instead just focuses on the "Antibody Screen Negative" result.

[David Saikin]

My OB guys are pretty astute when it comes to their pts with abs. They know the history and usually will tell me when one is coming my way. As to if a previous antibody is not discovered, I treat it like I commented above. That gives the doc the knowledge he needs now - it is not a critical call, whereas the opposite may be true, i.e., a clinically significant ab in a previously negative ab screen (esp when the pt is there to deliver).

[Malcolm Needs ☆]

Hi JALOMAHE,

With regard to antibodies in pregnancy, and whether or not the antibody will affect the fetus, I would say that the specificity, the thermal range and the history of previous pregnancies should all be taken into account.

For example, if the antibody that has since disappeared, was an anti-M, reacting in the cold and with no problems in a previous pregnancy, I wouldn't give it a second thought.

If it was an antibody known to cause HDFN, and/or was detected at 37oC, and/or had caused HDFN previously in a pregnancy with the same lady, I would not sleep until the midwife/Obstetrician knew (and signed that they had been alerted).

[EDibble]

At our facility, we report all antibodies, current and any historical ones. We have a realatively small supply of blood on hand, so it helps to explain why it may take much longer than usual to prepare compatible units for transfusion, especially if we have to obtain specially screened units from ARC, our supplier.