Hyperacute in minutes, acute in weeks, chronic over years
Expansion
| Type | Timing | Mechanism | Treatment |
|---|---|---|---|
| Hyperacute | Minutes to hours | Preformed antibodies against donor antigens, causing thrombosis | None; prevented by cross-matching |
| Acute | Days to months | T cell mediated (cellular), or antibody mediated | Responds to increased immunosuppression |
| Chronic | Months to years | Fibrosis and vascular narrowing, incompletely understood | Poorly responsive |
Chronic rejection has organ-specific names worth knowing: bronchiolitis obliterans in lung, accelerated coronary atherosclerosis in heart, vanishing bile duct syndrome in liver, and chronic allograft nephropathy in kidney.
Graft versus host disease is the mirror image: donor immunocompetent cells attack the recipient. It occurs after bone marrow transplantation and, rarely, after transfusion of non-irradiated blood into an immunosuppressed patient. It targets skin, gut and liver, causing rash, diarrhoea and jaundice.
Matching: ABO compatibility and HLA matching improve outcome, with HLA-DR most important, followed by B then A. The requirement is why living related donation gives better results and why highly sensitised patients are difficult to transplant.