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Computer Crossmatches and Revised CAP regs

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The 2017 revisions were released this week. The computer crossmatch section was revised to align with the FDA guidance. 

"If ABO typing discrepancies exist, you should not rely on a computer crossmatch.This is particularly important if there is mixed field red cell reactivity, missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

I called CAP to verify that this included resolved ABO discrepancies. Our hospital had been allowing computer crossmatches for ABO discrepancies that are resolved, and I'm not sure that our BB LIS could prevent a patient with a resolved ABO discrepancy from receiving a computer crossmatch.

Does your LIS prevent computer crossmatches for patients with MF reactions or weak reverses?

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I doubt our computer could do this either (Cerner).  I am puzzled by the requirement even when the discrepancy is resolved - it would seem to me it no longer "exists" once a valid typing is performed, or it is confirmed that an Rh Pos patient got Rh Neg blood.  Any other thoughts on this?  

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On 8/26/2017 at 6:59 PM, Byfaith said:

I doubt our computer could do this either (Cerner).  I am puzzled by the requirement even when the discrepancy is resolved - it would seem to me it no longer "exists" once a valid typing is performed, or it is confirmed that an Rh Pos patient got Rh Neg blood.  Any other thoughts on this?  

That's why I was confused and asked more than once to verify. The majority of our MF patients have received blood from us and have a history of multiple types.

The only thing I can think is to prevent hospitals from not really resolving a MF and just assuming an O or rh neg transfusion is causing the MF.

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I'm not sure how a serologic crossmatch will help?  We do require a serologic crossmatch if we have given more than 4 type O rbcs to a non-O patient before switching back to their type.

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On 8/25/2017 at 9:20 PM, MOBB said:

If ABO typing discrepancies exist, you should not rely on a computer crossmatch.This is particularly important if there is mixed field red cell reactivity, missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

The way I read this, is "if discrepancies exist".  Not if discrepancies existed (in the past).  So if you have a discrepancy and resolve it, it does not exist anymore.  So if you can't resolve the discrepancy currently with other techniques, a serologic crossmatch would be required, but if you followed through with your procedure to resolve the discrepancy, it is no longer a discrepancy.

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1 hour ago, mollyredone said:

The way I read this, is "if discrepancies exist".  Not if discrepancies existed (in the past).  So if you have a discrepancy and resolve it, it does not exist anymore.  So if you can't resolve the discrepancy currently with other techniques, a serologic crossmatch would be required, but if you followed through with your procedure to resolve the discrepancy, it is no longer a discrepancy.

I do so agree with you mollyredone.  Sadly, in the UK, it is usual to have to perform a serological cross-match, using group O red cells if there is any hint of a mixed-field (even if the patient has, for example, been typed as group A for a decade, and a unit of group O blood was transfused the previous day).  This pathetic attitude to the professional ethos of the laboratory personnel is insulting in the extreme, and, because the "mixed-field reactions" will be "reinforced" with each transfusion of group O red cells, if the patient requires frequent transfusions, the "discrepancy" will never be resolved, and precious group O units (in particular, group O, D Negative units) will be wasted unnecessarily.

Worse still is when the patient has an alloantibody, such as an anti-Fya, when group O, Fy(a-) blood has to be selected for the group A patient (in my example), when group A, Fy(a-) blood may be readily available, leaving fewer group O, Fy(a-) units readily available for a genuine group O patient, with anti-Fya, who may require it in an emergency.

Worse of all is when the patient has a complex mixture of common antibodies, or an antibody directed against a high=prevalence antigen, when there are only a certain number of group O units available in the country (and less donors, as numerous cryopreserved units may come from the same donor) and these units are wasted on patients who are patently not group O.

RANT OVER - FOR NOW!!!!!!!

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On 8/30/2017 at 9:04 AM, mollyredone said:

The way I read this, is "if discrepancies exist".  Not if discrepancies existed (in the past).  So if you have a discrepancy and resolve it, it does not exist anymore.  So if you can't resolve the discrepancy currently with other techniques, a serologic crossmatch would be required, but if you followed through with your procedure to resolve the discrepancy, it is no longer a discrepancy.

I completely agree. However, Amy from CAP did not.

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15 hours ago, Marianne said:

CAP has a webinar on Sept 20th to review the 2017 changes.  Hopefully this one will prompt much discussion and we can get some clarity, preferably in writing!

I'm looking forward to the seminar.

I'm also curious about the missing serum reactivity. Will this eliminate babies where there is no expected serum reactivity

On 8/30/2017 at 10:27 AM, Malcolm Needs said:

I do so agree with you mollyredone.  Sadly, in the UK, it is usual to have to perform a serological cross-match, using group O red cells if there is any hint of a mixed-field (even if the patient has, for example, been typed as group A for a decade, and a unit of group O blood was transfused the previous day).  This pathetic attitude to the professional ethos of the laboratory personnel is insulting in the extreme, and, because the "mixed-field reactions" will be "reinforced" with each transfusion of group O red cells, if the patient requires frequent transfusions, the "discrepancy" will never be resolved, and precious group O units (in particular, group O, D Negative units) will be wasted unnecessarily.

Worse still is when the patient has an alloantibody, such as an anti-Fya, when group O, Fy(a-) blood has to be selected for the group A patient (in my example), when group A, Fy(a-) blood may be readily available, leaving fewer group O, Fy(a-) units readily available for a genuine group O patient, with anti-Fya, who may require it in an emergency.

Worse of all is when the patient has a complex mixture of common antibodies, or an antibody directed against a high=prevalence antigen, when there are only a certain number of group O units available in the country (and less donors, as numerous cryopreserved units may come from the same donor) and these units are wasted on patients who are patently not group O.

RANT OVER - FOR NOW!!!!!!!

Malcom,

How does the UK handle computer crossmatches and missing serum reactivity? Are computer crossmatches allowed for babies with no reverse type?

I remember you stating at one point that our accredditing friends from the US and UK were comparing notes and picking the stricter ones from each side of the pond? 

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4 hours ago, MOBB said:

How does the UK handle computer crossmatches and missing serum reactivity? Are computer crossmatches allowed for babies with no reverse type?

I remember you stating at one point that our accredditing friends from the US and UK were comparing notes and picking the stricter ones from each side of the pond? 

Hi MOBB,

In fact, in the UK, as far as babies with no reverse group are concerned, unless the mother has an alloantibody (in which case we would cross-match group O antigen negative units against the mother), we don't even go as far as issuing blood via electronic issue, but just issue group O, rr, K-, CMV-, HEV-, HbS- paediatric units straight off the shelf.

With children and adults with missing reverse types, we are forced to cross-match, even if there is a reasonable reason for the missing reverse type.

I remember saying that about the accrediting agencies - and I stick by what I said!

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On 9/1/2017 at 3:40 AM, Malcolm Needs said:

Hi MOBB,

In fact, in the UK, as far as babies with no reverse group are concerned, unless the mother has an alloantibody (in which case we would cross-match group O antigen negative units against the mother), we don't even go as far as issuing blood via electronic issue, but just issue group O, rr, K-, CMV-, HEV-, HbS- paediatric units straight off the shelf.

With children and adults with missing reverse types, we are forced to cross-match, even if there is a reasonable reason for the missing reverse type.

I remember saying that about the accrediting agencies - and I stick by what I said!

Malcom,

We have a similar practice for babies under 4 months but require crossmatches starting at 4 months, yet many of the babies (especially premies) don't back type until 12 months or even later. Computer crossmatches were a huge help for this population so I'm sad to see this change, especially since we only transfuse group O products to them-they'll be MF and no reverse type! It would make more sense if we were crossmatching all groups for this population...

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On 8/31/2017 at 7:11 AM, Marianne said:

CAP has a webinar on Sept 20th to review the 2017 changes.  Hopefully this one will prompt much discussion and we can get some clarity, preferably in writing!

Definitely!  I have gotten differing answers on previous questions depending who was on the other end of the phone at CAP.

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On ‎8‎/‎30‎/‎2017 at 11:27 AM, Malcolm Needs said:

I do so agree with you mollyredone.  Sadly, in the UK, it is usual to have to perform a serological cross-match, using group O red cells if there is any hint of a mixed-field (even if the patient has, for example, been typed as group A for a decade, and a unit of group O blood was transfused the previous day).  This pathetic attitude to the professional ethos of the laboratory personnel is insulting in the extreme, and, because the "mixed-field reactions" will be "reinforced" with each transfusion of group O red cells, if the patient requires frequent transfusions, the "discrepancy" will never be resolved, and precious group O units (in particular, group O, D Negative units) will be wasted unnecessarily.

Worse still is when the patient has an alloantibody, such as an anti-Fya, when group O, Fy(a-) blood has to be selected for the group A patient (in my example), when group A, Fy(a-) blood may be readily available, leaving fewer group O, Fy(a-) units readily available for a genuine group O patient, with anti-Fya, who may require it in an emergency.

Worse of all is when the patient has a complex mixture of common antibodies, or an antibody directed against a high=prevalence antigen, when there are only a certain number of group O units available in the country (and less donors, as numerous cryopreserved units may come from the same donor) and these units are wasted on patients who are patently not group O.

RANT OVER - FOR NOW!!!!!!!

Hello Malcolm - from your text it seems that the 'usual UK practice' needs to shift.  Fortunately the proposed CAP reg does not require use of type O, only requiring a serological crossmatch.   Re: preventing a LIS from permitting an electronic/computer crossmatch I suggest creating a placeholder 'antibody' for the requirement, which can be set to disallow.  This antibody could be deleted when the requirement is resolved (awkward but possible).

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16 minutes ago, Maureen said:

Hello Malcolm - from your text it seems that the 'usual UK practice' needs to shift.  Fortunately the proposed CAP reg does not require use of type O, only requiring a serological crossmatch.   Re: preventing a LIS from permitting an electronic/computer crossmatch I suggest creating a placeholder 'antibody' for the requirement, which can be set to disallow.  This antibody could be deleted when the requirement is resolved (awkward but possible).

I could not agree more that the "usual UK practice" needs to shift.  Some of these "practices" were introduced, not so much by the BSH, MHRA, UKAS, SHOT, etc, but by NHSBT themselves - who are not an accrediting body (thank goodness, as they do not necessarily take any notice of experts within their own organisation), but are thought to be so by some who do not know any better!

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missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

I haven't worked on the bench for a long time. Have I missed something? I fail to see how a serologic crossmatch technique will provide any meaningful information about compatibility if there is "missing serum reactivity".

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12 minutes ago, tricore said:

missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

I haven't worked on the bench for a long time. Have I missed something? I fail to see how a serologic crossmatch technique will provide any meaningful information about compatibility if there is "missing serum reactivity".

So true tricore.

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On 9/6/2017 at 2:05 PM, tricore said:

missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

I haven't worked on the bench for a long time. Have I missed something? I fail to see how a serologic crossmatch technique will provide any meaningful information about compatibility if there is "missing serum reactivity".

I had the exact same thought!

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On 9/7/2017 at 6:56 AM, Baby Banker said:

I was wondering if Amy is a blood banker.

I don't know if she's a blood banker, but she was the CAP employee I was transferred to for the transfusion med checklist...I would hope that means she's a blood banker :)

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missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

I haven't worked on the bench for a long time. Have I missed something? I fail to see how a serologic crossmatch technique will provide any meaningful information about compatibility if there is "missing serum reactivity".

--I would think that CAP is just cautioning to not go overboard to type these kinds of patients--like genetic testing.

Scott

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On 10/09/2017 at 1:36 PM, SMILLER said:

missing serum reactivity, or apparent change in blood type following hematopoietic stem cell transplantation.Under those circumstances, your procedures should provide for compatibility testing using serologic crossmatch techniques."

I haven't worked on the bench for a long time. Have I missed something? I fail to see how a serologic crossmatch technique will provide any meaningful information about compatibility if there is "missing serum reactivity".

--I would think that CAP is just cautioning to not go overboard to type these kinds of patients--like genetic testing.

Scott

I hope anyone who does genetic testing knows how to tell the difference between the tissue (including white cells, etc) that are derived from the graft, and those tissues (hair, etc) derived from the recipient.

I think all sides need to read, Hult AK, Dykes JH, Storry JR, Olsson ML.  A and B antigen levels acquired by group O donor-derived erythrocytes following ABO-non-identical transfusion or minor AB)-incompatible haematopoietic stem cell transplantation.  Transfusion Medicine 2017; 27: 181-191.  Doi: 10.1111/tme.12411, which explains the whole thing about missing serum reactivity.

Edited by Malcolm Needs

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