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1 hour ago, Tabbie said:

Having read the BSH guidelines 4.7 about grouping anomalies “ reagents may cause IgG antibodies such as anti-c to be detected” Has anyone seen this or any other antibodies anti-e and what reagents did you use (A1, B cells typed as cde) ? 

Thanks

Guidelines-for-pre-transfusion-compatibility-proceduresin-blood-transfusion-laboratories.pdf

I've seen anti-c reacting with the reverse grouping cells many times.  I've only seen anti-e reacting like that a very few times.

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Thanks Malcolm

Is there a specific reason why ? There was a post and correct me if I am wrong as I can’t seem to find it again about crossmatching that was negative in patient with anti-E given E antigen positive units.

Reading Daniels Human Blood groups Anti-c antigen sites are more than anti-e together with reverse grouping temp and no enhancements ? 

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11 hours ago, Tabbie said:

Is there a specific reason why ? There was a post and correct me if I am wrong as I can’t seem to find it again about crossmatching that was negative in patient with anti-E given E antigen positive units.

Reading Daniels Human Blood groups Anti-c antigen sites are more than anti-e together with reverse grouping temp and no enhancements ? 

Well, one reason why anti-c is detected more often in the reverse group than is anti-e is simple that anti-c is a much more common antibody specificity than is anti-e.

There are two possible reasons for this.  Firstly, apart from the rarer c Negative Rh types, the most common c Negative Rh type is R1R1 (all the best people are R1R1!!!!!), and the R1R1 is not that rare, but, except in certain circumstances, it would be unusual to deliberately give an R1R1 individual R1R1 blood, unless they have already produced an anti-c.  This means that such individuals are often given blood that is c Positive (R1r, R2r, R1R2 and rr) and so their immune system is challenged.

Secondly, apart from the rarer e Negative Rh types, the most common e Negative Rh type is R2R2, and the R2R2 is comparatively rare, and, except in certain circumstances, it would be unusual to deliberately give an R2R2 individual R2R2 blood, unless they have already produced an anti-e, or anti-C.  This means that such individuals are often given blood that is e Positive (R1r, R2r, R1R1, R1R2 and rr) and so their immune system is challenged.

That having been said, anti-c is, as I said above, much more common than is anti-e, and so this also suggests that the c antigen is much more immunogenic than is the e antigen, and all of this serves to show why anti-c is detected with the reverse grouping cells, more often than is anti-e.  This is the kind of thing about which Geoff was writing.

As for your other question about E Positive units being given to patients with anti-E, you may be talking about patients with an auto-antibody that mimics anti-E, rather than someone with a genuine alloanti-E, but I would need a few more details to be certain.

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Below is the exact text from the guidelines.    I agree that potentiators added to the reverse group may detect non ABO antibodies in addition to the ABO antibodies but who adds potentiators to reverse group routinely?   One reason that anti c is mentioned may be that reverse group cells are usually Rh neg.   I have seen strong IgG anti c react in reverse group with no potentiators. 

 

 

Other reverse grouping anomalies: Potentiators in the reverse grouping reagents may cause IgG antibodies such as anti-c to be detected in the reverse group.

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Now reading the JPAC 1.2: Specifications, performance evaluation and quality control of blood grouping reagents and lab reagent inserts 😀 there seems to be a mix of human and murine products just wondering for example why anti-Lea is made from murine IgA as it’s biochemistry is built on type 1 chains can a human equivalent not be made ?

Edited by Tabbie
adding more

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16 minutes ago, Tabbie said:

Does anyone use Alsevers instead of Cellstab and why which test would it be used for ? 

When I was working in RCI at NHSBT-Tooting Centre, we used to store our liquid reagent cells in Cellstab, but wash them an resuspend them in Dil2 for use.  We found the reactions we got were much, much sharper (I don't mean that the reactions were more sensitive to detecting weak antibodies, although we believed that they were, but that it was far easier to "see" the reactions as clear reactions, rather than "fuzzy" reactions), and, in addition, it meant that we didn't detect reactions caused by antibodies directed against the preservatives in the Cellstab.  We were able to show this with multiple photographs.

Despite all the evidence, we were told that we couled not continue to do this, as we were not standardised with the other NHSBT RCI Laboratories (standardisation is everything these days, even if it means dumbing down, rather than bringing everyone up to an excellent standard, and because it was more expensive.  The only problem was that we were able to show that it was actually LESS expensive, because it meant less testing, and no testing for antibodies against preservatives.

This did not fit with management theory, however, and so we had to stop.  Since then we got "fuzzy" reactions, leading to many cases of repeat testing, and many cases of antibodies against preservatives and, hence, more expensive testing in terms of reagents, staff time and fairly simple investigations into moderate or even complex investigations, but hey, what did we know!  At least we are now standardised (and expensive)!

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