For those of you who detect anti-Cw and nothing else out of the ordinary with either a two cell or three cell screen in the plasma of a dce/dce patient, would you:

a) give rr by electronic issue?

give rr by immediate spin cross-match?

c) give rr cross-match compatible blood?

d) test the rr units for the Cw antigen?

e) other?

:confused::confused:

We would do "c".

Thanks.

Something unusual, if not absolutely unique has occurred; I've had a thought!

For those of you who detect anti-Cw and nothing else out of the ordinary with either a two cell or three cell screen in the plasma of a dce/dce patient, would you:

a) give rr by electronic issue?

give rr by immediate spin cross-match?

c) give rr cross-match compatible blood?

d) test the rr units for the Cw antigen?

e) other?

I am just interested.

:confused::confused:

We would select an Rh Negative unit, do an AHG crossmatch, and test unit for Cw antigen.

Thanks BSIPHERD.

We give AHG crossmatch compatible units.

Thanks clmergen.

Something unusual, if not absolutely unique has occurred; I've had a thought!

For those of you who detect anti-Cw and nothing else out of the ordinary with either a two cell or three cell screen in the plasma of a dce/dce patient, would you:

a) give rr by electronic issue?

give rr by immediate spin cross-match?

c) give rr cross-match compatible blood?

d) test the rr units for the Cw antigen?

e) other?

I am just interested.

:confused::confused:

Thanks for answering my question.

The reason I asked the question is because there are still quite a few people around who think that Cw is an allele at the C/c locus, and that Cw only ever travels with the C gene. As a consequence, some people would do an immediate spin cross-match or even electronic issue of rr blood when the patient has an anti-Cw.

Although exceptionally rare, there are cases of donors and patients who are C-, Cw+ (we picked up an Ro donor a bout three years ago who was found to be Cw+).

Going back to the original question, surely the answer depends on what country you are in and whose cells you use. Different countries have different requirements as to which antigens have to be present in their secreening cells, and of these, which have to be present in the homozygous state. Most manufactureres of commercial screening cells don't just make cells for one country but worldwide (and yes, TimOz - I agree with you 1000% about the need for non-European antigens on the screening cells) - so you need to choose cells that meet your own specific regulations. If you can get everything you need in 2 cells, then fine. If not, then you need to use 3 or even 4 (in switzerland, the majority of labs use a 4-cell screen for patient testing)

Although exceptionally rare, there are cases of donors and patients who are C-, Cw+ (we picked up an Ro donor a bout three years ago who was found to be Cw+).

Although exceptionally rare, there are cases of donors and patients who are C-, Cw+ (we picked up an Ro donor a bout three years ago who was found to be Cw+).

Just to confirm what you say, Malcolm - I've seen 2 cases of C-Cw+ over the last 5 years

I have used both the 2 and 3 cell Ortho screen and I personally love the 3 cell screen for several reasons. the Main reason is if you have an Anti-D you will have 1 cell negative to rule out some antigens. The same reasoning goes for multiple antibodies. If you have 1 negative cell to begin ruling out, then you can select cells that are homozygous for the remaining cells on your panel and decrease the time spent doing a complete panel. Any money save using a 2 cell panel will be spent in Tech time.

John Judd did a large study (222,000 antibodies) in 1997and concluded that if you use 2 screening cells that are R1R1 and R2R2 and one of these is homozygous for Jka is adequet for antibody detection. Ortho and Immucor both have this product. The paper was titled "Commmentary: testing for unexpected red cell antibodies-two or three reagent red cell samples?"

So, I did a Google search, and this was first on the list for 2 cell vs 3 cell antibody screen.   

We have been doing a 2 cell screen for over a decade, I was hoping to find a published study that indicates this is unsafe and we are missing antibodies.  To me, it intuitively feels like we should be.

We are using BioRad.  I am neither knocking nor endorsing any company, we have two IH-1000 and those are the cells we use.

Their 2 cell screen says:

• R1R1 (CDe/CDe) and R2R2 (cDE/cDE)
• Homozygous expression of Jka

Their 3 cell screen says:

• R1R1 (CDe/CDe), R2R2 (cDE/cDE), and rr (cde/cde), Jk(a+b-), Jk(a-b+), Fy(a+b-), Fy(a-b+), M+N-, M-N+, S+s-, S-s+, Le(a+b-), Le(a-b+)

How are we not missing weakly reacting Fya, or Fyb, or Jkb...?  The two cell screen is only (planned) to be homozygous for Jka.

On 10/13/2009 at 9:43 AM, Sue Miller said:

John Judd did a large study (222,000 antibodies) in 1997and concluded that if you use 2 screening cells that are R1R1 and R2R2 and one of these is homozygous for Jka is adequet for antibody detection. Ortho and Immucor both have this product. The paper was titled "Commmentary: testing for unexpected red cell antibodies-two or three reagent red cell samples?"

Oddly when I fist viewed this thread, the second page didn't load.  Now I see a paper I would have liked to have seen.

Any chance someone with better Google Fu than I can hunt this paper down?

Thanks

11 hours ago, Cliff said:

Oddly when I fist viewed this thread, the second page didn't load.  Now I see a paper I would have liked to have seen.

Any chance someone with better Google Fu than I can hunt this paper down?

Thanks

It was in a 1997 ARC Immunohematology.  I found it through PubMed.

Immunohematology.pdf

I remember reading this paper in 1997 and sharing it with my Transfusion Service Medical Director (the best medical director I ever had).  We had recently gone to immediate spin crossmatching and had switched to a 3 cell screen as a stipulation of going to the IS XM by this medical director because it made her more comfortable with the that decision.  After reading this article she considered it a valid argument but was unwilling to go back to the 2 cell screen.  Her peace of mind, real or imagined, was more important than the money we would have saved.  

I would be hard-pressed to justify the use of a 3-Cell screen with automated testing, not so for manual tube testing.

On 8/7/2018 at 4:08 PM, Dansket said:

I would be hard-pressed to justify the use of a 3-Cell screen with automated testing, not so for manual tube testing.

Why????  

These quotes are from page 91 of the 1997 ARC Immunohematology publication, "The inconstant degree of agitation that different workers use in resuspending RBC buttons after centrifugation. This can significantly affect the sensitivity of tube tests and explains many instances of variability seen in the performance of proficiency tests", and "Incorrect technique is the most likely cause of unwanted negative tests. Standardized column technologies, such as the gel test, eliminate many of the variables inherent in test tube methods".

John Judd also published a white paper through ORTHO regarding use 2-cell versus 3-cell antibody screen reagents probably prior to the ARC Immunohematology publication in 1997.  In that white paper, he concluded that difference in test results between 2-cell and 3-cell reagents was attributable to variation in technique between personnel performing the tube tests and not due to antibody screen cells reagent.

I believe manual tube testing is the 800lb dinosaur in the room of a 21st century Transfusion Service.  The rest of the Clinical Laboratory discontinued manual testing in the 20th century.  Automated testing is not just an answer for high volume testing but is critical safety enhancement in even the smallest Transfusion Service.

 

37 minutes ago, Dansket said:

I believe manual tube testing is the 800lb dinosaur in the room of a 21st century Transfusion Service.  The rest of the Clinical Laboratory discontinued manual testing in the 20th century.  Automated testing is not just an answer for high volume testing but is critical safety enhancement in even the smallest Transfusion Service.

 

I take it that you have discussed this with the likes of Geoff Daniels, Joyce Poole, Nicole Thornton etc, plus the equivalent blood group serology greats of the USA, the Netherlands, etc, almost all of whom swear by manual tube testing, as do I.

Yes, without a doubt, if you are not competent in this technique through lack of proper training and constant practice, then it has many pitfalls, but to condemn a technique outright as being almost prehistoric is a bit rich, with all due respect.

Edited August 10, 20186 yr by Malcolm Needs

3 hours ago, Malcolm Needs said:

I take it that you have discussed this with the likes of Geoff Daniels, Joyce Poole, Nicole Thornton etc, plus the equivalent blood group serology greats of the USA, the Netherlands, etc, almost all of whom swear by manual tube testing, as do I.

I don't condemn Standard Tube Testing as much as I abhor the intrinsic variability (increased risk) introduced by workers who were never shown or who never mastered the technique (as practiced by the expert serologists you referenced) to be able to produce consistent results particularly with weak (<=2+ agglutination).  Discussions with experts does nothing to address this issue, whereas automated testing completely eliminates the issue of manual (technique-dependent) testing methods.

22 hours ago, Dansket said:

 

 

22 hours ago, Dansket said:

I believe manual tube testing is the 800lb dinosaur in the room of a 21st century Transfusion Service.  The rest of the Clinical Laboratory discontinued manual testing in the 20th century.  Automated testing is not just an answer for high volume testing but is critical safety enhancement in even the smallest Transfusion Service.

 

I could not agree with you more especially since I was one of the first in the intermountain west to bring automation into my transfusion service in 1999.  It was quite a battle then.  I sure hope it's easier now.

Automation comes with it's problems too.  We had solid phase for our last instruments, now we're on gel.  We have a 2+ cut-off to call someone Rh Pos.  Now we are changing the types of lot's of people from Rh Neg to Rh Pos because gel is more sensitive.

Plus, we seem to get a lot of "gel junk".  This is new to us, so we started doing full peg panels on anything the machine interpreted as positive.  Almost all of the panels were negative.  We switched to a peg 2 cell screen.

Then there is what our techs are calling sprinkles.  A clear negative reaction, but a few tiny clumps sprinkled above the button.  I'm afraid they'll change these to negative before sending them across the interface.  They likely are negative though.

No method is perfect.

6 hours ago, Cliff said:

Plus, we seem to get a lot of "gel junk".  This is new to us, so we started doing full peg panels on anything the machine interpreted as positive.  Almost all of the panels were negative.  We switched to a peg 2 cell screen.

I've been using Gel for all routine testing since 1995 and ProVue since 2004-5.  

All our specimens (EDTA) are initially centrifuged for 3 minutes in a Stat Spin Express centrifuge.  You should use only platelet-poor plasma when testing in Gel.  Standard laboratory centrifugation does not give you platelet-poor plasma.

Part of our standard routine for resolving ABO Plasma Grouping discrepancies and weakly positive antibody screens is to centrifuge the specimen three (3) more times for a total of 9 minutes of high-speed centrifugation and retest in Gel. This will reduce but not entirely eliminate the "sprinkles". 

To me, "sprinkles" in Gel correspond to the "sticky cells" seen in microscopic reading of standard tube tests. I don't think "sprinkles" are clinically significant.  We standardized reading of gel cards using lighted 35mm photographic slide viewer.  This viewer has the milky plastic background see in X-Ray viewers and that is used by ProVue.

Edited August 12, 20186 yr by Dansket
added images to show slide viewer

I do not think that it's really that hard to get consistent results from tech to tech with tube testing. But it requires adequate training and oversight, just as you need for automated testing, in order to provide appropriate patient care.

Interesting note above about platelet-poor-plasma and gel though.

Scott