Just curious to know how many labs interpret a Bioclone Anti-D tube reaction of 1+ as Rh Neg.  The insert does state any agglutination is considered a positive result for D antigen. 

 

On 3/29/2019 at 10:41 AM, Malcolm Needs said:

dothandar, an excellent post if I may say so (although I don't absolutely agree 100% with the terminology you use).

I agree that Weak D Types 1, 2 and 3 are to be regarded as D Positive, if the following two papers are to be followed - which I think they should (Daniels G.  Variants of RhD – current testing and clinical consequences.  British Journal of Haematology 2013; 161: 461-470 and Sandler SG, Flegel WA, Westhoff CM, Denomme GA, Delaney M, Keller MA, Johnson ST, Katz L, Queenan JT, Vassallo RR, Simon CD.  It’s time to phase in RHD genotyping for patients with a serological weak D phenotype.  Transfusion 2015; 55: 680-689).  However, as individuals of all three weak D types have, very, very rarely produced allo-anti-D (see Daniels G.  Human Blood Groups.  3rd edition, 2013, Wiley-Blackwell), they could all be put into your computer as WKDV.

Sorry, I am mucking you about - it really is an excellent post!

A powerpoint slide from 2018 AABB case presentation by Woo JS, et al. included a page of reported anti-D cases (see attached picture) So there would be 7 total cases of anti-D production in Weak D type 1,2, and 3,  including the case that was presented. The authors also have footnote that some of these anti-D has both auto- and allo- antibody characteristics. 

On 4/3/2019 at 5:47 AM, Patty said:

Just curious to know how many labs interpret a Bioclone Anti-D tube reaction of 1+ as Rh Neg.  The insert does state any agglutination is considered a positive result for D antigen. 

 

Since we have capability for molecular tests in this lab, we would refer to molecular testing for the following populations, (if D typing is <2+)

2) Women with child-bearing potentials

3) Potential transplant recipients

If you do not have molecular testing capability, I suppose you can call them D- (to be conservative) 

For the following population of patients, we interpret any positive reaction as D+ (if the DAT is negative) 

1) Males (<18 year old)  (exception  is our local Children's Hospital) 

2) Female with no child bearing potential 

3) blood or organ donors 

 

 

 

 

 

Edited April 6, 20196 yr by dothandar

1 hour ago, dothandar said:

So there would be 7 total cases of anti-D production in Weak D type 1,2, and 3,  including the case that was presented.

Thanks for that - another EXCELLENT post.

I would say that not all cases of Weak D Type 1 with an allo-anti-D have been published.  I found one myself, and sent it to the IBGRL for confirmation.  It was confirmed and so I asked Joyce Poole if I should publish it as a case study, and she said no, because it wasn't new (the patient ws - the situation wasn't).

Edited April 6, 20196 yr by Malcolm Needs

1 hour ago, Malcolm Needs said:

Thanks for that - another EXCELLENT post.

I would say that not all cases of Weak D Type 1 with an allo-anti-D have been published.  I found one myself, and sent it to the IBGRL for confirmation.  It was confirmed and so I asked Joyce Poole if I should publish it as a case study, and she said no, because it wasn't new (the patient ws - the situation wasn't).

Since it is widely publicized to consider Weak D Type 1,2 or 3 as D+, I think it will be a good idea to document anti-D production in Weak D type 1,2 or 3; at least as an abstract to professional organization if not as a full case report. Each case may count as "exception" and if there were too many exceptions, the hypothesis (or proven theory) may be challenged.  That is just "my feeling" anyways. I can be very wrong since I am not an expert . 

Edited April 6, 20196 yr by dothandar

Just when we thought it might be safe to say we had a somewhat definitive answer..........

I wonder if the committee that came up with the recommendations for treating Rh weak Ds - Type 1, 2 and 3 as Rh pos had access to this data??         

I wonder if this is going to change this recommendation any time soon?? 

I wonder if this is worse than the allo-anti-Ds we are going to see with the now widespread policy of starting all traumas  (except children and females of child bearing potential)  with RH pos blood before getting a blood type?  That is not a benign policy either.  

We were just starting molecular testing and were just starting to call these patients Rh pos and not giving RhIg - now I don't know which way to go!  

cswickard, I seem to have started something here, which I certainly did not intend to start.

Allo-anti-D in individuals with Weak D Types 1, 2 or 3 are incredibly rare.  The one I saw was the only one I saw in 43 years, most of which were spent in Reference Laboratories, so I have seen countless examples of these Weak D Types.