Summary
Recipient immune cells recognise donor MHC as foreign, requiring matching and immunosuppression.
In depth
Hyperacute (preformed antibodies), acute (T cells, weeks) and chronic (months to years). Immunosuppressants include ciclosporin and tacrolimus (calcineurin inhibitors). Graft-versus-host disease occurs in bone marrow transplants.
Matching HLA reduces rejection. Immunosuppression increases infection and cancer risk. Tolerance induction is a goal.
Key idea: transplant rejection is the immune system doing its normal job against foreign MHC.
Recipient T cells recognise donor HLA (direct pathway) or processed donor peptides (indirect). Matching HLA-A, B and DR reduces rejection, and kidney matching also checks ABO and uses crossmatch tests for preformed antibodies. Living donors and identical twins give the best results; the first successful kidney transplant between twins was in 1954 by Murray (Nobel Prize 1990).
Immunosuppression typically combines calcineurin inhibitors, antiproliferatives (mycophenolate) and steroids, and increases risk of infection and cancer. Graft-versus-host disease occurs when donor immune cells attack the recipient after bone marrow transplants. Xenotransplantation with genetically engineered pig organs is under trial.
Example: the cornea is relatively safe to transplant because the eye is immune-privileged and lacks blood vessels.
Frequently asked questions
What is Transplant Rejection?
Recipient immune cells recognise donor MHC as foreign, requiring matching and immunosuppression.
Which area of biology covers Transplant Rejection, and how advanced is it?
Transplant Rejection is one of the 52 topics in Immunology & Disease. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Blood Groups and Transfusion, Immune Checkpoint Therapy, HIV and AIDS.
Can you give an example of Transplant Rejection?
Identical twins can accept kidneys without drugs.
What should I learn before Transplant Rejection?
Work through the Beginner topics in Immunology & Disease first, such as Immune System, Viruses, Innate Immunity, then return to Transplant Rejection. Advanced topics assume the Intermediate vocabulary.
What topics are related to Transplant Rejection?
The closest topics to Transplant Rejection are Blood Groups and Transfusion, Immune Checkpoint Therapy, HIV and AIDS, Immunodeficiency. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Transplant Rejection?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Transplant Rejection. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Transplant Rejection different from Blood Groups and Transfusion?
Transplant Rejection: Recipient immune cells recognise donor MHC as foreign, requiring matching and immunosuppression. Blood Groups and Transfusion: ABO and Rh antigens on red cells determine compatible donors, since mismatches trigger agglutination. Read both side by side and note what each one explains.
How should I study Transplant Rejection step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Blood Groups and Transfusion and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.