Hey Boston,
If I am not mistaken, you are discussing 2 different things : IgA and PRA. Hopefully this helps:
What is IgA?IgA is an antibody, part of our natural defenses against infection. We all have plenty of IgA in our blood and also in the inner lining of our intestine and airways where it works in our defense. If you have IgA nephropathy, a very small proportion of all the IgA in your body sticks in your kidneys and sets off inflammation which damages the kidneys. The rest of the IgA in your body works normally so you have normal resistance to infection.
What will happen if I have a transplant? Will IgA nephropathy damage my new kidney?
We know that IgA may stick in the glomeruli of your new kidney if you have a transplant. The immunosuppressive treatment which you receive to stop you rejecting your kidney does not prevent this happening. But this is not as serious as you might think. Although IgA gets into the kidney it usually does not cause much in the way of inflammation or damage to the kidney. The recurrence of IgA nephropathy may eventually contribute to the failure of the transplant but this is nearly always a very slow process as it is in your original kidneys. Overall the chance of a successful kidney transplant is still very good indeed if your original kidney problem was IgA nephropathy. (this is from
http://www.igan-world.org/infopatients.htm)
Regarding PRA: The body can also create antibodies against the tissues of other human beings. Normally, we do not do this. However, it can happen when we are exposed to the tissues of other human beings, such as with a blood transfusion, a pregnancy, or an organ transplant. The antibodies that the body can create after these "sensitizing" events are called anti-human antibodies, or "alloantibodies".
If you have anti-human antibodies in your blood which react with the tissue type of a kidney donor, then you cannot receive a kidney transplant from that donor. The antibodies in your blood would attack and damage the kidney immediately after transplantation. Treatment such as plasmapheresis can keep this from happening. (this is from
http://www.umm.edu/transplant/kidney/highpra.html)
Let me know if this clears things up, or makes it more confusing!
Karol