Jump to content

DARATUMUMAB


MERRYPATH

Recommended Posts

Anyone else encountering Blood Bank problems with the drug Daratumumab? We get positive screens in gel, auto is negative, we repeat the screen in saline. if it is negative we proceed and work in parallel with gel and saline. If the saline screen is positive we send to ARC and they do DTT treatment to get negatives...as soon as we develop a procedure we will do our own DTT treatment. I am guessing 1/3 go to ARC. Our BB Docs are letting us know when they come in system...we do Kell typings before they go to ARC if they have no transfusion history, otherwise we give Kell neg. Big headache, hard to explain, causing delays in people who are used to no problems getting transfusions. So just letting people know that when you start seeing this drug causing problems get you docs to look into it. PatO Now 60!!!

Link to comment
Share on other sites

We are working with our Pharmacy and Oncology teams to develop a process where we perform T&S and antigen typing of patient prior to administration of the drug so we have baseline info if the antibody screen becomes positive. We will be able to give antigen matched RBCs and treat similar to our patients with warm autos. So far we have not had any patients present who are on this drug - but it is only a matter of time!

Link to comment
Share on other sites

I just got notified by one of our oncologists today, that she has a patient that will begin treatment on this drug next week. I am thinking that we are going to go the way of ChrisW. We don't typically stock DTT but I am amenable to doing that but have not had a chance to do a cost analysis.

Link to comment
Share on other sites

2 questions:

For those going the DTT route, from whom do you buy this? Do you follow the 'recipe' for reconstitution outlined in the Technical manual?

Is anyone going only the route of giving phenotypically matched red cells for these patients and not using DTT treated reagent cells for the serologic workup? (This assumes that you can get a good sample for pheno/gentoyping prior to the 1st daratumumab).

Link to comment
Share on other sites

  • 2 months later...
On 1/17/2016 at 4:53 AM, kirkaw said:

2 questions:

For those going the DTT route, from whom do you buy this? Do you follow the 'recipe' for reconstitution outlined in the Technical manual?

Is anyone going only the route of giving phenotypically matched red cells for these patients and not using DTT treated reagent cells for the serologic workup? (This assumes that you can get a good sample for pheno/gentoyping prior to the 1st daratumumab).

I do not believe giving phenotype matched units allows you to ignore the reactivity that you are observing that may or may not be due to DARA.  I'm not aware of any standard that allows a blood bank to do that.

In addition, giving phenotype matched units can be a waste of a valuable resource.  If a patient needed E-, K-, Fy(a-), that's approximately 1 in 5...no problem. If they needed c-, E-, K- S- Jk(a-) now you are looking at approximately 1 in 50.  That can take time, raise the cost and remove from inventory a valuable resource for patients who actually have antibodies.

Again, I'm not aware of any standard that allows a blood bank to ignore reactivity that is observed at 37C.  Specifically, AABB standard 5.14.3.1 states: "When clinically significant antibodies are detected, additional testing shall be performed."

Section 5.14.3.3 goes on to state: "In patients with previously identified clinically significant antibodies, methods of testing shall be those that identify additional clinically significant antibodies."  No mention of just giving phenotype matched units.

Under section 5.15 "Selection of Compatible Blood and Blood Components for Transfusion", there is no mention of using phenotype matched blood in lieu of performing an antibody investigation. 

Needless to say, lol.... I'm not an advocate for just giving phenotype matched units.

Link to comment
Share on other sites

I have the AABB bulletin (Association Bulletin #16-02) sitting on the desk next to me.  Here is the direct quote regarding antibody identification:

"AFTER a patient begins taking anti-CD3: 

  • ABO/RhD typing can be performed normally
  • For antibody detection (screening) and identification, dithiothreitol (DTT)-treated cells can be used to eliminate the interference.
  • Because DTT treatment destroys Kell antigens, K negative units should be provided unless the patient is known to be K positive
  • Antibodies against other DTT sensitive blood group antigens (anti-k and anti-Yta, anti-Doa/Dob, etc) will not be detectable when the antibody screen with DTT treated cells is performed; such antibodies are encountered infrequently, however."

You will notice that is does not say; antibody screening or identification is not necessary if phenotype units are given.

It goes on to state:

"Crossmatch

  • For patients with a negative antibody screen using DTT treated cells, an electronic or immediate spin crossmatch with ABO/RhD compatible, K matched units may be performed.
  • For patients with known alloantibodies, phenotypically or genotypically matched RBC units may be provided.
  • Some clinically significant antibodies may be missed with the use of uncrossmatched phenotypically or genotypically matched units, although this will occur infrequently."

There were other bullet points, but not significant to this discussion. Again note, that under the "Crossmatch" section, it does not state that phenotype matched units can be used in lieu of performing an antibody identification.  It does however state that for patients with known alloantibodies, matched units may be provided in the uncrossmatched patient.

Warm auto cases, sickle cell cases can be an exception.  Usually though, the exception for WAA patients should occur when the frequency of transfusion is so often that it make no sense to do an antibody ID every 4th or 5th day when nothing has changed.  We will recommend that the ID be extended out a 2-3 weeks in these situations, or be performed if a change in DAT, or antibody reactivity is noted...or if a patient has a reaction.

DARA patients can not be compared to sickle cell patients who have demonstrated the propensity for developing alloantibodies, frequently need transfusions and when in crisis, usually need blood STAT.

The DARA patients that we have seen have been stable, not requiring blood on a STAT basis.  The work-up to resolve a DARA is relatively easy and can be turned-out within 3-4 hrs of receiving the sample. Every sample so far has resulted in the recommendation of giving K- units.  Simple, straight forward, complies with AABB standards and does not waste a potentially valuable resource depending on the patient's phenotype. 

 

Edited by StevenB
Link to comment
Share on other sites

I believe the section:

"For patients with known alloantibodies, phenotypically or genotypically matched RBC units may be provided."

from the referenced AABB bulletin implies that this is indeed a sufficient workaround for DARA patients, even if they have been transfused.  At least that is what our blood supplier and our reference lab is telling us.

I should have mentioned that these units are all, of course, K negative, and we have a physician's order indicating that least incompatible units are to be given.

Scott

 

Link to comment
Share on other sites

That is for the "uncrossmatched patient" with "known antibodies".  It makes no reference to the antibody identification whats so ever.  Of course, that's just my interpretation of how it is written.  Until we see it written in Standards that the antibody identification process can be skipped in lieu of giving phenotype/genotype matched units, we will continue to try to meet the Standard's requirements as they are currently written.  As mentioned earlier, there are exceptions....WAA/sickle cell...but I do not believe the DARA patient issue has risen to their level of difficulty or need.

In regards to your reference labs recommendation....  :huh:

This would be a great topic to discuss over a beer or two.  Unfortunately that's not possible!

Have a great weekend Scott.  

Link to comment
Share on other sites

We actually had a case last year that would strongly support continued performance of antibody identification in the face of a pannagluttinin/antibody to public antigen, even when providing common RBC antigen-matched RBCs. One day when we have free time (bahahahahahahahahaahaha) we plan to write it up.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Advertisement

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.