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Interesting question - do rabbit red cells carry CD38 ?

I thought I heard/read that removal of anti-CD38 by adsorption was not successful using human cells (which we know carry CD38). Even if rabbit red cells do carry the marker, I assume the same would apply ?

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We have been  asked by reference lab to provide informmation if patient is on CD38. It will be useful for them to process the sample.  if patient is on DARA how does reference lab process the sample. Do they use different absorption techniques? 

 

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9 minutes ago, gagpinks said:

We have been  asked by reference lab to provide informmation if patient is on CD38. It will be useful for them to process the sample.  if patient is on DARA how does reference lab process the sample. Do they use different absorption techniques? 

 

Well, in a way, yes.  They will not waste time on trying to perform alloadsorptions (as these don't work) and will probably perform genotyping from the word go, rather than trying to get a phenotype.

To be honest, the submitting hospital should give the Reference Laboratory as much information as they can about ANY patient, whether they be on ANTI-CD38 (gagpinks, they are on a monoclonal antibody - not a monoclonal antigen!!!!!!!!!!!) or not.

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On 2017-5-27 at 11:05 PM, MaryPDX said:

The only way I'm aware of is DTT treating the screening cells used.  

I agree MaryPDX, but, unless the Reference Laboratory is made aware that the patient has been on Dara, time and reagents can be wasted by trying to sort out the problem by more "traditional" means.

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4 hours ago, Mabel Adams said:

I've heard that they can decide it is some weird Lutheran antibody if they don't know it is DARA.

I haven't heard of that method Mabel.  What is the "weird" Lutheran antibody.

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A little off topic but related to DARA:  Some of my techs are reporting that hand-washing the tubes in tube testing (PeG) versus using a cell washer is more likely to give negative reactions with DARA samples.  I wonder if anyone else has experienced this?

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On 5/30/2017 at 3:26 AM, Malcolm Needs said:

I agree MaryPDX, but, unless the Reference Laboratory is made aware that the patient has been on Dara, time and reagents can be wasted by trying to sort out the problem by more "traditional" means.

I heard last week that there is another method some of the US ref labs are either using or want to start using for the Dara patients and Kell isn't affected, but I can't for the life of me remember what they said and I haven't had any luck with google. 

Has anyone heard anything similar?

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9 hours ago, MOBB said:

I heard last week that there is another method some of the US ref labs are either using or want to start using for the Dara patients and Kell isn't affected, but I can't for the life of me remember what they said and I haven't had any luck with google. 

Has anyone heard anything similar?

You may be referring to trypsin-treatment of the red cells (screening cells). Apparently CD38 is destroyed/inactivated (along with Lutheran system determinants) but Kell system antigens remain intact. Other blood group antigens are also affected by trypsin, so I think the modified approach involves testing the patients' samples against both DTT-treated and trypsin-treated cells.

To further complicate matters.....manufacturing a reliable, consistent trypsin reagent is VERY difficult. The enzyme activity of source material varies immensely and, as with other enzymes, stability is a problem.

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I work for an IRL and yes, we treat cells with DTT when we know the patient has received Daratumimab. Recently we are encountering other monoclonal antibody therapies as well, and I am eager to know if anyone has had problems with serological testing related to these therapies? And if so, how do you resolve them?

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On 6/3/2017 at 1:21 AM, Malcolm Needs said:

I haven't heard of that method Mabel.  What is the "weird" Lutheran antibody.

Plasma from patients from DARA is non-reaction with In(Lu) cells I think. CD38 maybe suppressed on In(Lu) Cells? 

On 6/20/2017 at 6:24 PM, MOBB said:

I heard last week that there is another method some of the US ref labs are either using or want to start using for the Dara patients and Kell isn't affected, but I can't for the life of me remember what they said and I haven't had any luck with google. 

Has anyone heard anything similar?

May be Kell blood group antigens excluded using In(Lu) cells that are K+k+? Or cord blood? 

Edited by dothandar

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If patient is on Dara is it safer to ask reference lab to perform X match or we can x match onsite once it's confiremed by RCI that there is no underlying alloantibody. 

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It would appear (not published) that some cells from sub-Saharan African donors MAY nor have CD38 on their red cells.  So beware if you have a negative result on cells that are ccD.ee, Fya-b- .  This might not exclude an anti-CD38.  I have seen two such cells and have had reports on others

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Thank you galvania. But what does your lab usually in terms of X match. Because if we perform xmatch its seems pointless because it would be positive. How can we ensure that units are compatible?

 

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There are two ways gagpinks.

Either you can believe your local RCI Laboratory when they say that there are no atypical alloantibodies detected (and why send them there if you don't believe their results?), or do the work yourself with DTT-treated panel cells.  NO TRANSFUSION IS 100% SAFE.

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1 hour ago, Malcolm Needs said:

There are two ways gagpinks.

Either you can believe your local RCI Laboratory when they say that there are no atypical alloantibodies detected (and why send them there if you don't believe their results?), or do the work yourself with DTT-treated panel cells.  NO TRANSFUSION IS 100% SAFE.

Thank you for your reply.  I guess i was being over cautious.  We trust RCI result but my worry was if we x match at our hospital it will be definitely incompatible  (2 or 3+).  I was over thinking that we could have missed out low frequency antibody. Just out of curiosity if we perform x match at RCI do you treat Donor cell with DTT. Of just issue least incompatible unit. 

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