Weak D testing on donors

[csjuarez]

The system we are using to do ABO-Rh testing on donors (Ortho AutoVue) claims that the Anti-D clone used will detected virtually all "weak D" -- does this meet the weak D testing requirement in AABB Standards, or must we still do "Weak D" testing (in tubes) which is in actuallity probably not as sensitive as the original test?

I've submitted this question to AABB, but haven't gotten a response yet. Any opinions or experience on this issue out there?

[David Saikin]

I think you should pose that question to the FDA, as their rule states Weak D testing must be done. Of course, if you can substantiate that claim by validation studies, they may let you off, but I don't think you can or that they will let you.

[Kochman]

Ortho AutoVue is not available in the US nor have the claims made for it been reviewed by FDA. Furthermore, specific performance would depend on the source of the Anti-D in the gel card.

[rknan]

Sir,

In our experience The blend which has IgG and IgM detects both D and weak D antigens and there fore it is not found necessary to do the Weak D testing separately.

Thankyou.

[dcross]

In Australia, it is a requirement to test donors with an anti-D which detects the D VI variant.To my knowledge, the only monoclonal anti-D which detects the DVI variant is the Diagast. In Australia, we follow the uropean standard but I would be surprised if the FDA standard is any different in this regard

[johna]

Sir,

In our experience The blend which has IgG and IgM detects both D and weak D antigens and there fore it is not found necessary to do the Weak D testing separately.

Thankyou.

--------------------------------------------

I would seriously question that any anti-D reagent can be touted as having the ability to detect "all" weak D antigens. From a reference laboratory perspective we've encountered occasional weak D specimens which react with some but not all IgG/IgM blends even after the weak D test is performed.

[sramakrshn]

As per the Standards for Blood Banks & Blood Transfusion Services in India. We

adopting the following Procedure as laid down:

" The Rh(D) type should be determined with Anti-D reagent from two

different sources using a validated method.It is preferable to use

one IgM and other a blend i.e., IgM+IgG. If blood is typed as D-Negative

it should be tested to detect weak "D" using IAT method.When the test

for "D or D" Weak is positive, the label should read Rh(D) positive.

When the test for "D or D" weak is Negative the label should read

Rh(D) Negative"

[galvania]

In Australia, it is a requirement to test donors with an anti-D which detects the D VI variant.To my knowledge, the only monoclonal anti-D which detects the DVI variant is the Diagast. In Australia, we follow the uropean standard but I would be surprised if the FDA standard is any different in this regard

In the DiaMed cards, a number of different anti-D clones are used and you can chose between anti-D that are DVI+ or anti-D that are DVI-. Scangel similarly have a choice with both DVI positive and DVI negative anti-D reagents

[Mau Feitio]

In my hospital The Rh(D) type only in donors is determined with Anti-D reagent from two

different sources using a validated method.. If blood is typed as D-Negative

it should be tested to detect weak "D" using IAT method.

[irshadaad]

THE DIAMED IS PROVIDING Rh DVI- IN THEIR CARDS IN CASE WE GET NEGATIVE ITS MUST TO CONFIRM WEAK D WITH A SECOND CARD PROVIDING DVI+ ITS QUITE SATISFACTORY I DONT CONSIDER THE CLAIM OF Ortho AutoVue IS TRUE ,I THINK YOU SHOULD GO FURTHER FOR CONFIRMATION OF ALL THE NEGATIVE FOR A WEAK D...I THINK ALL THE STANDARDS ADVISE US TO DO THE CONFIRMATORY FOR Rh NEGATIVE TO RULE OUT WEAK D.......