Hematopoietic stem cell transplantation with bidirectional incompatibility

[mpmiola]

Dear friends, I ask for help in this case!

 

Receiver: B +

Donor: A +

 

After 7 days of the transplantation we identify an anti-B in the receptor that remained detectable for 2 years. He disappeared three years. Today, five years after the doctor thinks the anti-B should be present. I think not. Who is right?

 

I ask:

 

1 - How long does the B lymphocyte donor can replicate in the recipient and produce memory antibody?

 

2 - The syndrome passenger lymphocyte is for how long?

 

3 - No stimulus lymphocyte should not stop producing the antibody?

 

Can someone explain this occurrence?

 

Already, thank you.

[galvania]

:devilish: This sounds like an assignment question to me!  Q1 - patient disappeared for 3 years - would his anti-B be present  5 years later? - no because he's probably dead........ :devilish:

[mpmiola]

Galvan.

Thanks for contributing!

The patient did not die. It is being watched since his transplant that took place 5 years ago.

The anti-B antibody is that disappeared after two years of transplantation. What I think is expected and our doctor does not.

You know for how log a donor lymphocyte can replicate the receiver, producing anti-B antibodies?

 

 

Edited September 17, 2015 by mpmiola

[galvania]

OK - so - I completely misunderstood your post.  What you mean is that the patient had anti-B which was detectable for two years then the anti-B disappeared.   And the doctor thinks it should still be detectable.  Is that right?

So what does the rest of the patient's blood group look like?  Are there any mixed field reactions?  (Would you see them in the technique you are using?)  How is the patient's DAT?

[Malcolm Needs ☆]

Can I just be clear in my own mind here please?

 

We are talking about a BMT/SCT, rather than a solid organ transplant?

[mpmiola]

Anna

Sorry, I have difficulty with English.

There are mixed field reactions. I'm using gel-test. The DAT is negative. The eluate is also negative.

 

How to explain?

[mpmiola]

 

Malcolm, thanks for participating.

 

Yes, a case of SCT with ABO incompatibility.

 

Do you know if the donor B cells can produce antibodies autonomous way and for an indefinite period in the receiver?

[Yanxia]

I think we should take into consideration  immune-tolerance and blood group substance's neutralization here

[Malcolm Needs ☆]

The donor's transplanted lymphocytes will probably continue to produce a certain amount of anti-B, but it may be a such a low that it is not detectable by normal serological techniques.  This applies particularly if the recipient is a secretor.

 

If you Lewis type the recipient, the Lewis type will remain that of the recipient, even after the transplant (as the Lewis antigens are not intrinsic to the red cell membrane and are "made" in another part of the body and then adsorbed onto the red cell surface).  If, therefore, the recipient was Le(a-b+) before the transplant, they will be Le(a-b+)  transplant (whatever the donor's Lewis type may be).  If, therefore, the recipient is Le(a-b+), they will also continue to secrete B substance.  On the other hand, if the recipient was Le(a-b-) prior to the transplant, they will continue to be Le(a-b-) after the transplant, and the easiest way to know whether or not they secrete B substance is to test their saliva, to see if it is capable of inhibiting HUMAN anti-B (NOT monoclonal anti-.

 

If the recipient was Le(a+b-), and still is Le(a+b-), that means that the recipient was (and is) a non-secretor, and so would only secrete a minimal amount of B substance - if any.

 

So, as about 80% of people are secretors (give or take a percentage point or two!), the chances are that any anti-B produced by the donor's transplanted B lymphocytes (and, ultimately, by the transplanted memory cells) will be adsorbed out by the recipient's B substance in the plasma.

 

In addition, as shily correctly states, there is immune tolerance (nowadays known as "accommodation"), which means that, although the donor's B lymphocytes may still be producing anti-B, the amount produced will be considerably reduced.

 

So, how do you prove that there is any anti-B being produced, if there is non being detected by normal serological techniques?  Well, if there is still secretion of B substance, this will be adsorbed onto the surface of the red cells (despite the fact that are actually group A red cells (!!!!!!!!!!!!!!!!!), and you should be able to react the red cells of the recipient (in other words - the donor's red cells - are you still following me??????!!!!!!!!!!!!!!!) with human anti-B and then eluate it back off again (adsorption and elution testing).

 

The bottom line is that, if the recipient was a secretor to start with (and still will be now), I think that YOU would be right, rather than your doctor!

 

When I was an awful lot younger, I wrote a paper about this.  Needs ME, McCarthy DM, Barrett J.  ABH and Lewis antigen and antibody expression after bone marrow transplantation.  Acta Haematologica 1987; 78: 13-16.  Whether or not you can still get this is another thing entirely!!!!!!!!

 

         

[mpmiola]

Malcolm

I'm asking me. How can a human being be so wise?

Thank you for sharing your wisdom. I learned a lot from this post.

I hope to have the pleasure of meeting you in person one day!