Recovering Anti-D from an eluate of an RH negative patient

[mimi03]

This has happened twice in the last few days , where we are picking up Anti-D in the Eluate of an Rh negative patient. Patient has received RhoGam but no transfusions.

[Malcolm Needs ★]

Have you considered that your patient could be a particularly low-grade weak D, a partial D of some kind (such as an RoHar), which would explain the anti-D in the eluate as a result of the RhoGam, or that what you are detecting in the eluate is not an anti-D, but is an anti-LW?

I also assume that the last wash is totally negative?  Sorry to ask this.

Edited September 23 by Malcolm Needs

[exlimey]

On 9/23/2022 at 3:42 PM, Malcolm Needs said:

 

How about a "Del" ? Fits the description perfectly.

One the other hand, "twice in the last few days" is worrying. While not impossible, it's highly unlikely that a facility would encounter more than one of these anomalies (zebras) in such a short period. I assume Malcolm's question regarding the Last Wash is an allusion to some laboratory artifact - bad technique, bad reagents, etc.

[Bet'naSBB]

What eluate kit do you use?

If you use one with a "working wash" - try repeating your eluate, washing with normal saline instead...........usually takes care of it.

We see this quite a bit - especially with Rh's and K's.  Our Medical Director refers to it as the "Ogata Phenomenon"

https://www.bbguy.org/education/glossary/glm06/

 

[Malcolm Needs ★]

While the Ogata-Matuhasi phenomenon has been recognised since the early 1960's, it is, that notwithstanding, a very rare phenomenon to actually come across in practice.

With all due respect to you Bet'naSBB, if you "see this quite a bit", I would be a bit worried as to why.

[mimi03]

Thanks everyone for your replies and comments. Yes to Malcolm, the last wash was negative. The Elution kit we use is from Gamma, the Elu-kit.

One correction though, I only had one eluate recover the anti-D, the other one was a warm auto.

We no longer stock the DTT, I wish we did, so I am not able to confirm if it is anti -LW. I really suspect it is.

[Malcolm Needs ★]

1 hour ago, mimi03 said:

We no longer stock the DTT, I wish we did, so I am not able to confirm if it is anti -LW. I really suspect it is.

If you have any, you could try D Negative Cord or Neonatal red cells, which express the LW antigen comparatively strongly (certainly compared with adult D Negative red cells).