Baby weak D and gel testing

[pbaker]

I received a call from a pathologist at a smaller hospital that uses gel technology.  They are a very basic lab that only does ABO/Rh and antibody screens, no IDs or other fancy testing.  Tube testing is their back up method.  Since they have not had any issues in several years, they are wanting to get rid of tube testing and just go with gel.  It has been several years since I worked with gel so I am coming to my experts (you guys) for help. 

 

Is gel sufficient to perform weak D testing on newborns of Rh negative mothers for the purposes of Rhogam eligibility?

[Malcolm Needs ☆]

Yes, indeed it is very sensitive, but you need to make sure that the clones of anti-D used in the gel cards are capable of detecting weak and partial D types.  Of course, no clones will detect ALL weak and partial D types, but as long as they detect the more common types, then the test is okay.  Don't forget that, after all, the anti-D reagents used in the tube testing will also not detect ALL weak and partial D types, but is also a less sensitive test.

[BankerGirl]

pbaker:  We have a small hospital in our area that decided it was more cost effective to just give all RH negative mothers RhIG rather than worry about performing a weak D on the baby.  They don't deliver many babies, and if they were to buy anti-D reagent it would expire long before they could make use of it.  I believe that they perform a fetal screen to catch large fetal bleeds, but they do not perform KB testing.

[Abraham]

We have been Gel users for about 20 years. We see about 1-2 Gel negative, Weak D tube testing positive patients per year..

[Malcolm Needs ☆]

Are the anti-D clones detecting the same epitopes Abraham?

[Likewine99]

I have done weak D testing on babies in gel for many years and we found it more sensitive than the Ortho tube reagents.

 

Email me at Mary.Mendel@Mercy.Net and we can discuss in more detail.  

[Dansket]

Have been using ORTHO BioCLone Anti-D antiserum in both manual gel (1996) and in ProVue (2005) for Weak D testing on newborn blood samples (presented data for Weak D testing in manual gel at 1997 AABB annual meeting in Denver).

[David Saikin]

Ortho gel anti-D does not detect DVI.  We use tube anti-D for weak D testing on our cord bloods that type negative with the gel.