Rejection of a transplanted kidney is brought about mainly by
- A. T lymphocytes recognising the foreign antigens on the graft
- B. histamine released by mast cells
- C. phagocytosis by neutrophils alone
- D. the failure of the graft's own blood supply
Explanation
The donor tissue carries different major histocompatibility antigens, and T cells attack the graft as they would a virus infected cell, which is why patients take immunosuppressive drugs for life and why donors are tissue matched first. This is a cell mediated response, so antibody plays a smaller part. A transplant from an identical twin needs no suppression, because the antigens are the same.