Can Del person produce anti-D?

[Yanxia]

Dweak person can't produce anti-D, I don't know if Del have all the D epitope as Dweak.

[David Saikin]

Shily

Weak D+ individuals CAN produce anti-D. It depends on the nature of their D antigen. If they are missing a piece of the D mosaic, they can product ab to those portions they are missing. I would expect that Del individuals that fit that description would also be D antibody makers.

[Yanxia]

Thank you, David Saikin.

Original Du is divided into Dweak which express all D epitope and D partial which will lack one or several D epitope. This is in China's text book says, maybe we have the different name of it.

[bbbirder]

Shily,

DELs are more common in Asians than other groups, so you are more likely to encounter them than we are in the US. From what I read, DELs will normally be typed as RhD neg (at least by all typing sera licensed in the US). They usually only get investigated if they were a donor who caused anti-D formation in the recipient. They can only be detected by absorption/elution or molecular testing.

Do you do more investigations of RhD negative patients or donors than we usually do in the US so that you identify the DELs?

Because DELs routinely get typed as RhD neg, they will get transfused with RhD neg blood, so are not likely to be exposed to RhD positive blood. However, there is an article in Transfusion Oct 2005 that is titled "A comprehensive analysis of DEL types: partial DEL individuals are prone to anti-D alloimmunization." So I guess the answer is, Yes, DELs can make anti-D. (I did not read this full article yet, but it looks like there are 6 different kinds of DELs, so they type may play a role.)

The entire "D variant" topic is really interesting, and very complex.

Linda Frederick

[Mabel Adams]

Sounds like the Chinese definitions of D variants might be more useful. Here, Weak D is the term used for any antigen detectable only by an antiglobulin technique, regardless of whether it is partial or complete but just with less antigen on the cell. From serologic testing we can't tell the difference for certain unless they have made anti-D.

Thirty years ago, these people were called Du positive (they were called Rh neg, Du pos by some techs and Rh pos, Du pos by others). Then they were called Rh pos (or D pos), Du variant for awhile. Now the preferred term is weak D, but even that isn't clear-cut as some places are choosing to treat anyone reacting less than 2+ (tube) as Rh neg. What we need are antisera that give us positive only with the people we want to treat as pos and neg with those we want to treat as neg. We would probably have to have different antisera for donors than for recipients. Maybe genetic testing will resolve this dilemma.

[Yanxia]

Thank you, Linda!

Thank you, Mabel!

Del is a very hot topic in China recently, it is under investigation, we do weak D test use 3 kind of anti-D in IAT, not do Del test routinely.

I encountered a pregnant women, her blood type is ccEe and D negative. There are anti-D and anti-C in her serum, because the sample is exhausted, I can't detect if anti-G in it.

I do the absorb and elute test, the result is not good, I run two kind of anti-D reagent the same time, one is + -,the other is negative.

[galvania]

Hello Shily

If you are using 2 types of anti-D, I presume that at least 1 of them is monoclonal. I'm never very happy about using monoclonals for absorption elution tests. Not because of the antibodies, but you never know what other things have been mixed with them to turn them into a reagent that might then have an influence on the test. I hope the lady's baby comes through OK

Anna

[jschang]

Hello shily

I had investigated 48 RHD negative pregnancy women ( 26 DEL negative, 22 DEL positive ) and 104 RHD negative pre-surgery patients (35 DEL negative, 69 DEL positive). 6 pregnancy women produced anti-D with RHD positive baby are DEL negative, 5 transfused patients produced anti-D with RHD negative but DEL positive RBCs. Not anyone DEL positive patient or women produced anti-D.

This is our primary investigation in DEL transfusion. We need more molecular evidences to prove this investigation.

[Yanxia]

Thank you, Jschang. I am very happy to meet you here.

I have checked the reported Del phenotype, I can't find ccEe with Del positive which I remembered have read in some book. Maybe I am wrong.

One day I phoned Mr. Xiang, he is my teacher in Shanghai. He said adsorb and elution test is a very difficult test which frequently get fale positive result.