Transfusion of patients on Darzalex

[lpregeno]

I only heard about this yesterday and, wouldn't you know it, I received a pre-transfusion sample from a patient that is going to receive Darzalex. Does anyone have a procedure they use for these patients? How are you treating them once they have received treatment and need blood? ANY experience with this would  be helpful to know about.

[tbostock]

We've only had one so far.  We sent his specimen out for a antigen genotype so we can give him Rh/K matched blood at least.  We're looking at bringing in the DTT procedure if this treatment should be more common.

[galvania]

Is Darzalex the commercial name for the anti-CD38 for myeloma patients?

[suhu]

We get a list of patients from HEM/ONC, get a pre-drug sample and send it out for genotype.  The if/when screen becomes positive, we would supply phenotypically matched, but havent had this happen yet.

[StevenB]

Catching these patients untransfused is difficult.  Submit a sample for full molecular phenotype.  At a minimum, try to determine Rh and K type.  If your antibody screen is negative, select crossmatch compatible units.  If positive, the next step is to 0.2M DTT treat your panel cells to help distinguish that the observed reactivity is due to daratumumab.  The reactivity that we've seen is usually variable in saline techniques, resembling what use to be referred to as "high titered, low advidity" or HTLA antibodies. The 0.2M DTT works very well, but I would not recommend any micro reads.  Most common antibodies can be ruled-out with 0.2M DTT treatment, but not antibodies directed at the Kell system antigens.  (There are other antigens "destroyed" by the DTT treatment, but they are not pertinent to this immediate discussion.)  As such, if no underlying antibodies were detected, our transfusion recommendation is to select K- units if the patient has typed K-.   While some recommend phenotyped matched units, we do not.  Having a full phenotype does not absolve a blood bank from determining what the reactivity is due to and if any new antibodies have developed.  Requesting phenotyped matched units, without the presence of antibody is a waste of a potential resource, drives up costs unnecessarily and may result in a delay that is longer than resolving the actual work-up if the patient's type is rare enough. 

[StevenB]

On 2/5/2016 at 0:21 AM, galvania said:

Is Darzalex the commercial name for the anti-CD38 for myeloma patients?

Yes.