noelrbrown

I think you will find that dichloro-diphenyl-trichloroethane will destroy a lot more than just the Kell Blood Group System antigens!!!!!!!!!!!  

If you use DDT, you won't last long either!!!!!!!!!!  SORRY, I couldn't resist it!!!!!!!!!!

Heterozygous versus Homozygous expression for the antigen is key especially in the MNS system.  You should know what the status is of the cell you are using so that you can compare apples to apples.

Heterozygous versus Homozygous expression for the antigen is key especially in the MNS system.  You should know what the status is of the cell you are using so that you can compare apples to apples.

Be aware that most Anti AB these days is a blend of anti A and Anti B monoclonal and is not strictly an anti AB.

Be aware that most Anti AB these days is a blend of anti A and Anti B monoclonal and is not strictly an anti AB.

We are using the ELUclear Kit (Hemo bioscience) and the 0.8% reagent red cells (Ortho/J&J, whoever they are now) and have no problems ... and we do a lot of eluate preps/testing.

There is a very good reason not to use pooled cells.  Many antibodies only react with cells with a double dose of the relevant antigen.  That does not mean that these antibodies are not clinically significant.  If you mix cells together, even if, for example cell I is Jka+b- and the other Jka-b+, you are diluting out the concentration of each antigen and you will miss the antibody if it is there.  Same goes for weak antibodies in general.  Pooled cells are OK if you are only looking for the type of antibody that jumps out of the tube at you - as for example for donors, and even then, it's not ideal.  You would need a good system for detecting DPs!  I don't know anybody who tests ante-natals only using pooled cells.  If they are they should be closed down!

Would you mind sharing your procedure?  I don't suppose you have found a way to automate it on one of Ortho's machines, have you?  I keep thinking we could jury-rig about any test if we call it a crossmatch.

Sounds like poor advice from the IRL, I think what they meant to say was that the CD38 antigen is weakly expressed on Cord cells.  The Kell system is completely removed by DTT treatment so you should give K neg blood as you have no way to exclude anti K, BTW that also means JSa, Jsb, Cellano etc. also Lu null cells do not express CD38 either.

Sounds like poor advice from the IRL, I think what they meant to say was that the CD38 antigen is weakly expressed on Cord cells.  The Kell system is completely removed by DTT treatment so you should give K neg blood as you have no way to exclude anti K, BTW that also means JSa, Jsb, Cellano etc. also Lu null cells do not express CD38 either.

Unfortunately the answer is, it depends...  If the anti CD47 is a human antibody, then it will cause a positive DAT as CD47 is expressed on most cells in the body including erythrocytes.  If the anti CD47 is mouse or goat then it will not as this antibody will bind to CD47 but will not cause the same interference we see with Daratumamab.  I believe recent therapies involve blocking some of the CD47 receptors. 

Hi gagpinks,
As a UK Biomedical Scientist, if it is the last thing I do, it will be to teach you to use the correct nomenclature!
I can assure you that NHSBT Reference Laboratories DO NOT perform titres on samples of anti-c (or anti-D) from pregnant women, but, instead, perform quantification, and they are reported as IU/mL, and only because the computer system we use will not allow us to report them in the correct nomenclature (IUmL-1)!  Okay, rant over!
I would say that, without a doubt, there is an element of IgM in this lady's anti-c (unless, of course, there is another, as yet unidentified IgM antibody against another antigen expressed by the reverse grouping B red cells) as the reverse grouping B red cells have the Rh phenotype rr.  This may mean that the quantification results are falsely high, because the rr red cells used to perform the quantification are enzyme treated with bromelin to decrease the zeta potential and allow the red cells to come into closer proximity with each other, and this would enhance a reaction with an IgM anti-c, just as well as it would an IgG anti-c.
That having been said, there is no guarantee (at this time) that there is not an element of IgG anti-c present, and as this situation cannot be guaranteed, the pregnancy should be treated as if the entire anti-c is IgG, and that the quantification results are accurate; in other words, the case should, at least for now, be treated as if severe HDFN is a possibility.
So, what to do?  Well, one thing that you should do is send a sample of maternal peripheral blood to the IBGRL for foetal genotyping, to determine if the foetus carries the RHc gene (it almost certainly will, as the biological father is unlikely to also be c Negative, as the mother must be - although it is possible - but then, why would the mother have made an anti-c).  Assuming, therefore, that the foetus carries the RHc gene, and will express the c antigen on its red cells, then, again, you have to treat the pregnancy as if severe HDFN is a possibility.
The other thing that should be done at this stage, either by your own laboratory (if you have the reagents and the SOP, with staff competent in the technique - UKAS, you understand!), or by the Reference Laboratory (more likely) is to treat the maternal plasma with dithiothreitol (or a similar reducing agent - but please, not 2ME - unless you have lost your sense of smell!) to denature the IgM anti-c molecules, to see if there is an element of IgG anti-c present.  If there is an element of IgG present, then, once again, the pregnancy should be treated as if severe HDFN is a possibility.  This could be an unusual, but not unique case, of an antibody causing clinically significant HDFN, where the antibody has been formed after 28 weeks of gestation.
Come what may, the maternal antibody should be monitored from now until delivery as a minimum every two weeks, and, of course, the foetus should also be monitored by MCA Doppler (or something similar) until delivery, just to be on the safe side.
Sorry I can't give you a more definitive answer, but this is both a rare and interesting case.
One thing that I would ask, and that is, if the antibody screen was negative at 28 weeks of gestation, why were you sent another sample at 30 weeks of gestation?  Did the lady have a potential sensitising event, such as a fall?
Malcolm

Unfortunately the answer is, it depends...  If the anti CD47 is a human antibody, then it will cause a positive DAT as CD47 is expressed on most cells in the body including erythrocytes.  If the anti CD47 is mouse or goat then it will not as this antibody will bind to CD47 but will not cause the same interference we see with Daratumamab.  I believe recent therapies involve blocking some of the CD47 receptors. 

Hemo bioscience is selling ready to use DTT ( frozen), see our web site for details.  

Unfortunately the answer is, it depends...  If the anti CD47 is a human antibody, then it will cause a positive DAT as CD47 is expressed on most cells in the body including erythrocytes.  If the anti CD47 is mouse or goat then it will not as this antibody will bind to CD47 but will not cause the same interference we see with Daratumamab.  I believe recent therapies involve blocking some of the CD47 receptors. 

Unfortunately the answer is, it depends...  If the anti CD47 is a human antibody, then it will cause a positive DAT as CD47 is expressed on most cells in the body including erythrocytes.  If the anti CD47 is mouse or goat then it will not as this antibody will bind to CD47 but will not cause the same interference we see with Daratumamab.  I believe recent therapies involve blocking some of the CD47 receptors. 

Unfortunately the answer is, it depends...  If the anti CD47 is a human antibody, then it will cause a positive DAT as CD47 is expressed on most cells in the body including erythrocytes.  If the anti CD47 is mouse or goat then it will not as this antibody will bind to CD47 but will not cause the same interference we see with Daratumamab.  I believe recent therapies involve blocking some of the CD47 receptors. 

Be careful as the diluents used to suspend the cells will be different.  For gel card assays you need a Low Ionic strength diluent.  Diluents often contain potentiators and will have been validated for use in the appropriate card system.  I am not saying they won't work and they probably will however you should perform validation to ensure you don't miss a significant antibody. 

Be careful as the diluents used to suspend the cells will be different.  For gel card assays you need a Low Ionic strength diluent.  Diluents often contain potentiators and will have been validated for use in the appropriate card system.  I am not saying they won't work and they probably will however you should perform validation to ensure you don't miss a significant antibody. 

Be careful as the diluents used to suspend the cells will be different.  For gel card assays you need a Low Ionic strength diluent.  Diluents often contain potentiators and will have been validated for use in the appropriate card system.  I am not saying they won't work and they probably will however you should perform validation to ensure you don't miss a significant antibody. 

Hemo bioscience is going to be launching ready for use DTT in the next 2-3 weeks.  We plan on pushing it through our email list and will update our web site with product codes.

We do 3-part DATs in gel only. Polyspecific, IgG and Buffer cards. Beautiful reactions, clear cut.
For the buffer cards we do 50 uL cells (0.8%) and 25 uL of the anti-C3b, C3d (Immucor).
Pos QC = Complement Control Cells
Neg QC = A2 cells.
We normally use Immucor Complement Control Cells but with the recent shortage, we validated Hemobioscience which works just as well.
No problems with CAP surveys.