Blood Type Question

[Brenda K Hutson]

I have no previous experience with Alba Bioscience Reagents (have read some of the previous discussions on this website). So, need input on this blood type:

1. 19 yr old pregnant woman (1st pregnancy)

2. GEL Card Anti-D shows kind of diffuse agglutination up the column (with a little

at bottom and top)

3. Alba Bioscience "blend" is W+ positive at the Weak D phase (so that is kind of a

flag for me; expect a true Weak D to be stronger??)

4. Alba Bioscience Delta D is Negative (performed Immediate Spin only)

Thanks,

Brenda Hutson, CLS(ASCP)SBB

[Malcolm Needs ☆]

My only experience with Alba reagents is with their Weak D/Partial D anti-D panel, which is excellent, but I'd be a bit worried about calling this one a straightforward Weak D (unless the lady is an R2r, as Weak D Type 2 can be very weak indeed).

I'd have it checked by a Reference Laboratory (but, then, as a Reference Laboratory Manager, I would say that, wouldn't I??????????????!!!!!!!!!!!!!!!!!).

[David Saikin]

I have had a few pts like yours . . . it is plain that they have some form of D ag - one of my pts had a macro+ fetal bleed screen. I tell the OB Docs that we are going to consider their pt as Rh= even though we know there is "some" D present. I have run them with the Alba Partial D panel - they are not a match BUT 3 of the 4 women type the same with this panel (and they are not related and 2 work herre in the hospital).

[Mabel Adams]

You might contact the Quotient technical specialist, Rebecca Bullock. She posts on here so you can probably send her a private message. She has been very helpful to me with two strange D typings both of whom had made anti-D. I think they are collecting odd samples of D for further research on their partial D kit. If you can't reach her, let me know and I will give you her email.

One of my patients is pregnant and appears to have anti-C, D & G yet has some sort of D antigen. I ended up writing something up for the doctor that explained what our test results were with various reagents, the history on her I garnered from various other labs that had tested her and a description of weak and partial D antigens in somewhat general terms. I told the MD she should be treated as Rh neg as a recipient and pregnant person but as Rh positive as a blood donor.

[Malcolm Needs ☆]

One of my patients is pregnant and appears to have anti-C, D & G yet has some sort of D antigen. I ended up writing something up for the doctor that explained what our test results were with various reagents, the history on her I garnered from various other labs that had tested her and a description of weak and partial D antigens in somewhat general terms. I told the MD she should be treated as Rh neg as a recipient and pregnant person but as Rh positive as a blood donor.

Bravery above and beyond the call of duty, in my opinion!!!!!!!!!!!!!!!!!!!!!

:judge::judge::judge::judge::judge:

Edited May 9, 2012 by Malcolm Needs

[JOANBALONE]

Is it possible to send the sample for genotype?

[David Saikin]

It is always possible to send for molecular studies BUT - the cost is prohibitive (in my estimation). Even if you can determine what D variant is present, you are not going to change the way you treat the pt).

[Barbarakym]

:

4. Alba Bioscience Delta D is Negative (performed Immediate Spin only)

Thanks,

Brenda Hutson, CLS(ASCP)SBB

I have a question for you? Why do you care? We gave up weak D (exception listed below) a long time ago. You can not tell the difference between mosaic (can and will sometimes make anti-D as we found out) and weak D at the bench level....

SO we only do IS. If machines (gel or?) are used anything less than 2+ (validaded this) is done on tube and if tube is neg at IS we call them NEGATIVE. Period.

NOW EXCEPTION: AABB standards require that RH NEG babies of RH NEG moms need to have a weak D done to tell if mom needs rhogam. They ALSO say there must be a method in place to tell the difference between what looks like a Wk D from a fetal maternal bleed which makes them look like they are Positive..... THUS what we do is IF the baby is RH neg of RH NEG mom, we test the baby for weak D. IF the baby is weak D positive we give the mom rhogam. BUT we call the baby RH Inconclusive (so as not to give them a positive interpretation if they come back later). We give RH inconclusive also when DAT is positive and you can't do the weak D.. so we have mechanism in place and no one questioned it.

We would rather call someone Neg than positive and have them develop antibody. Which in our large facility we had happen 5 or 6 times in a 2 year period. Weak D testing not required except in above exception. But that exception is to be sure mom gets rhogam.

[John C. Staley]

It is always possible to send for molecular studies BUT - the cost is prohibitive (in my estimation). Even if you can determine what D variant is present, you are not going to change the way you treat the pt).

But David, Malcolm needs the work. It's budget time and the books are a little thin!

:haha:

[Malcolm Needs ☆]

Oh so true John!

[David Saikin]

But David, Malcolm needs the work. It's budget time and the books are a little thin!

:haha:

OK - I'll consider sending Malcolm my reference Molecular studies (how does the US dollar fare vs the EURO?)

[Malcolm Needs ☆]

David, the UK does not dabble in this new fangled EURO! We still have pounds and pence (although, personally, I think we should still have pounds, shillings and pence)!!!!!!!!!!!!!!

[B.Bullock]

I have had a few pts like yours . . . it is plain that they have some form of D ag - one of my pts had a macro+ fetal bleed screen. I tell the OB Docs that we are going to consider their pt as Rh= even though we know there is "some" D present. I have run them with the Alba Partial D panel - they are not a match BUT 3 of the 4 women type the same with this panel (and they are not related and 2 work herre in the hospital).

David,

Mabel is correct. Quotient is interested in performing further research on patient or donor samples which have been tested using our Partial D Kit, but give patterns that differ from the patterns on the Partal D Kit insert. We know that those patients are infrequent, but they are out there, and we would like to test them further so that we can expand the known pattern insert. I think you said that some of your patients work at your hospital and may be available? The additional testing we would perform would be at no cost to you, since we are currently doing this research. Please contact me using the Quotient Technical Service line 888-228-1990.

[DOGLOVER]

I see in one post above where someone has a policy about gel typing for D having to be at least 2+. What is everyone doing about tube typing. Do you call 1+ positive or do you require a weak D test be done if under @+. We are having a discusiion about this with some disagreement. Thanks for the input from this great group.

[Malcolm Needs ☆]

Hi Doglover,

As a Reference Laboratory, we would "go the whole hog", however weak the reaction, BUT, as other people have said, molecular work in the UK does not cost the hospital anything, if we send it for such work, rather than the hospital sending it direct (which costs an arm and a leg). Mind you, if we send a lot of rubbish for testing, we are left in no doubt that this is what we have done!!!!!!!!!!!!!!

That having been said, we can lay claim to discovering something like five or six new Weak/Partial D's in the last few years.

Edited May 10, 2012 by Malcolm Needs
Forgot the last bit.

[Mabel Adams]

We recently had two patients that type pretty weakly with anti-D at IS that both have made anti-D. One we know we transfused with D pos blood a few years back; the other we know was transfused elsewhere and their records show that she was D pos by older molecular testing so I assume she also got D pos blood. We have gotten so we tend to transfuse any that react weakly at IS in tube with neg blood. I think we would consider anything below about 2+ especially since we now use the Quotient anti-D and it seems a bit more sensitive. This is not the same as doing weak D tests on everyone--we do those on babies of Rh neg moms, apparently Rh neg patients with Rh pos autologous units and people that we are trying to resolve weird D typings.

[Malcolm Needs ☆]

That having been said, we can lay claim to discovering something like five or six new Weak/Partial D's in the last few years.

Well, what do you know! We've just had a report back from the International Blood Group Reference Laboratory, and one of our patients is a DNB. This, of course, is not new, BUT, the D mutation was found on a DcE haplotype, whereas it has only previously been reported in association with DCe!!!!!!!!!

:excited::excited:

[Eagle Eye]

It is always possible to send for molecular studies BUT - the cost is prohibitive (in my estimation). Even if you can determine what D variant is present, you are not going to change the way you treat the pt).

when I want to send my patient for RH genotyping, my boss tells me same exact thing!!!!!!!!

[JOANBALONE]

Our blood center charges about $150 for complete genotype. What are others being charged?

JB

[Eagle Eye]

Our blood center charges about $150 for complete genotype. What are others being charged?

JB

This sounds right for completed genotype which doesn't include RH panel....In other words if you need to know partial D or other Rh variant, you need to order separate panel which costs almost X3 (~$450).

[Brenda K Hutson]

I care because we reported it out as Rh Positive (based only on GEL result; which is a Policy I am changing; will require 2 types on ALL new patients, regardless of extent of Testing Ordered). But then 1 of my Trainers used the specimen to train a student; they obtained different results (as per my description). So, we are trying to resolve it (and have also asked the patient to come back for a redraw).

I also care because as I mentioned, I do not have experience with the Alba Bioscience Reagents so I am trying to understand and learn; how they work and how to interpret the results.

Brenda

I have a question for you? Why do you care? We gave up weak D (exception listed below) a long time ago. You can not tell the difference between mosaic (can and will sometimes make anti-D as we found out) and weak D at the bench level....

SO we only do IS. If machines (gel or?) are used anything less than 2+ (validaded this) is done on tube and if tube is neg at IS we call them NEGATIVE. Period.

NOW EXCEPTION: AABB standards require that RH NEG babies of RH NEG moms need to have a weak D done to tell if mom needs rhogam. They ALSO say there must be a method in place to tell the difference between what looks like a Wk D from a fetal maternal bleed which makes them look like they are Positive..... THUS what we do is IF the baby is RH neg of RH NEG mom, we test the baby for weak D. IF the baby is weak D positive we give the mom rhogam. BUT we call the baby RH Inconclusive (so as not to give them a positive interpretation if they come back later). We give RH inconclusive also when DAT is positive and you can't do the weak D.. so we have mechanism in place and no one questioned it.

We would rather call someone Neg than positive and have them develop antibody. Which in our large facility we had happen 5 or 6 times in a 2 year period. Weak D testing not required except in above exception. But that exception is to be sure mom gets rhogam.

[AMcCord]

I see in one post above where someone has a policy about gel typing for D having to be at least 2+. What is everyone doing about tube typing. Do you call 1+ positive or do you require a weak D test be done if under @+. We are having a discusiion about this with some disagreement. Thanks for the input from this great group.

Our policy says that all anti-D reagents must react 2+ or stronger (whether tested on the Echo or by tube) to be called Rh Pos. Exception: babies whose moms are candidates for RhoGAM - if they react to anti-D, irregardless of strength, we give mom RhoGAM.

[Barbarakym]

Our policy says that all anti-D reagents must react 2+ or stronger (whether tested on the Echo or by tube) to be called Rh Pos. Exception: babies whose moms are candidates for RhoGAM - if they react to anti-D, irregardless of strength, we give mom RhoGAM.

Same here.