Jump to content

Anti-A1


Liz

Recommended Posts

An A(sub)B recipient is to receive a kidney from an AB donor. The recipient does not have anti-A1. He is most probably A2B but it has not been confirmed. 

Question: the probability that he forms anti-A1 is ~25% to 35%; what is the probability that the Anti-A1, if formed, will react at 37C?

 

Link to comment
Share on other sites

Yes, but so do individuals, and the pathology of the individuals, and the details behind this is still being "discovered".  For example, the idea of "accommodation" has really only been realised since the transplantation of solid organs that are ABO on the major side (although it was suspected long before that).

Link to comment
Share on other sites

Thank you for mentioning this important concept which few know of. I presented accommodation at the meeting to decide whether to transplant or not. 

The literature is limited on iABO KT with A2B and AB but sufficient. We will transplant. They considered this case ABO mismatched but compatible as anti-A1 is absent.  May end up publishing they said. But I am just happy that he found a kidney. He is a young man and the live donor is his mum. Will keep you posted.

Thank you. 

Link to comment
Share on other sites

Malcom, you replied to Liz’s question that the chance of the patient developing anti-A1 was almost zero due to immunosuppression followed by accommodation.

Am I correct in assuming the immunosuppression is due to the drugs transplant patients take?

I had never heard of "accommodation" and my quick google search suggests that accommodation occurs when a transplanted organ has normal function despite the presence of alloantibodies. These antibodies are capable of binding to the antigen and activating compliment, but for some reason they don't. My search went on to state that accommodation is more likely if the antibodies are removed (temporarily) by plasma exchange just prior to transplant, which has resulted in several successful ABO-incompatible transplants!!!!

It seems reasonable that variability in an individual’s accommodation potential exists. Is it a stretch to link accommodation to the variability in individuals forming (or not forming) antibodies. Are the ramifications known? For example if an individual has a high degree of accommodation, i.e. good for transplants and transfusion; does it mean having an immune system that may not be as effective at identifying and killing pathogens? Understanding accommodation seems useful for the immunohematology field as well as organ transplant, yet this is the first I have heard of it. If you could please provide further explanation or references I (and I would guess others) would appreciate it.

Link to comment
Share on other sites

Hi Ensis01,

Yes, the immunosuppression would be due to the drugs.

To be perfectly honest, my own knowledge of "accommodation" is pretty sketchy, and most of it comes second hand from Dr Geoff Daniels, and it may well be (in fact it is very probable) that Liz knows more about this than do I, but here are some references that may help:

Takahashi K.  Accommodation in ABO-incompatible kidney transplantation: why do kidney grafts survive.  Transplant Proc 2004; 36 (Suppl 2): 193S-1936S.
 
Chung BH, Lim JU, Kim Y, Kim J-I, Moon IS, Choi BS, Park CW, Kim Y-S, Yang CW.  Impact of the baseline anti-A/B antibody titer on the clinical outcome in ABO-incompatible kidney transplantation.  Nephron Clin Pract 2013; 124: 79-88.  doi:  10.1159/000355855.
 
Shimmura H, Tanabe K, Ishikawa N, Tokumoto T, Takahashi K, Toma H.  Role of anti-A/B antibody titers in results of ABO-incompatible kidney transplantation.  Transplantation 2000; 70 (9): 1331-1335.
 
Park WD, Grande JP, Ninova D, Nath KA, Platt JL, Gloor JM, Stegall MD.  Accommodation in ABO-incompatible kidney allografts, a novel mechanism of self-protection against antibody-mediated injury.  Am J Transplant 2003; 3 (8): 952-960.
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Advertisement

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.