超急性拒絶反応
- 移植直後から24時間以内に起こる激しい拒絶反応。
- 腎移植の時は、ドナーの血清とレシピエントのT細胞を使って抗体抗原反応が起きないか調べる。抗原はHLA class Iである。(HIM.1777)
- 移植腎で超急性拒絶反応が起こったときは次の病理像が見られる：neutrophils, immunoglobulin, and complement in vessel walls
- 反応機序：液性免疫。レシピエントの抗HLA抗体の存在による
- 治療法：臓器摘出
| hyperacute rejection | Antibody mediated due to the presence of preformed antidonor antibodies in the transplant recipient.
Occurs within minutes after transplantation. |
| acute rejection | Cell mediated due to cytotoxic T lymphocytes reacting against foreign MHCs.
Occurs weeks after transplantation. Reversible with immunosuppressants such as cyclosporin and OKT3. |
| chronic rejection | Antibody-mediated vascular damage (fibrinoid necrosis);
Occurs months to years after transplantation. Irreversible. |