[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Immunology](https://durgical.com/en/immunology/) › [Transplant, tumors and immunotherapy](https://durgical.com/en/immunology/#a-transplant) › Transplant rejection: hyperacute, acute, chronic

[Immunology](https://durgical.com/en/immunology/) · [Transplant, tumors and immunotherapy](https://durgical.com/en/immunology/#a-transplant)

# Transplant rejection: hyperacute, acute, chronic

- Process

The body sees a donated organ as foreign and attacks it, within minutes, weeks or slowly over years.

Updated 2026-11-01

**See it in 3D:** [Kidneys](https://durgical.com/en/anatomy/kidney/) · [Liver](https://durgical.com/en/anatomy/liver/)

## Key points

- Hyperacute (minutes to hours): preformed antibodies against ABO or HLA (type II hypersensitivity); complement, thrombosis and ischemia; the graft is removed. Prevented by crossmatch.
- Acute cellular (weeks to months): recipient T cells against donor MHC; lymphocyte infiltrate and vasculitis; usually reversible with more immunosuppression.
- Acute antibody-mediated: new donor-specific antibodies; C4d deposits in graft capillaries.
- Chronic (months to years): intimal thickening and fibrosis of graft vessels; irreversible and the main cause of late graft loss.
- Chronic rejection by organ: kidney, interstitial fibrosis and arteriopathy; lung, bronchiolitis obliterans; heart, accelerated coronary vasculopathy; liver, vanishing bile ducts.

## What it is

Rejection is the recipient's immune response against donor antigens, mainly HLA (MHC) molecules and ABO blood group antigens. Its timing tells the mechanism: preformed antibodies act in minutes, T cells and new antibodies act in weeks to months, and slow vascular and fibrotic damage builds over years. ABO matching, HLA typing, crossmatch tests and immunosuppressive drugs reduce the risk.

## Key facts

- Graft types: autograft (self), isograft (identical twin), allograft (same species), xenograft (other species).
- Corneas are rarely rejected because they have no blood vessels.
- Rejection must be told apart from drug toxicity (calcineurin inhibitor nephrotoxicity) and infection (CMV, BK virus); a graft biopsy settles it.

## Step by step

- Donor tissue carries HLA molecules that the recipient's T cells have never seen as self.
- Direct recognition: recipient T cells react to intact donor MHC on donor dendritic cells (drives acute rejection).
- Indirect recognition: recipient antigen-presenting cells process donor HLA and show it on their own MHC (drives antibodies and chronic rejection).
- Activated CD4 T cells release IL-2 and other cytokines; CD8 T cells kill graft cells.
- B cells make donor-specific antibodies that fix complement on the graft endothelium.
- Repeated injury leads to vessel narrowing, fibrosis and slow loss of function.

## Types of rejection

| Type | Timing | Mechanism | Pathology | Outcome |
| --- | --- | --- | --- | --- |
| Hyperacute | Minutes to hours | Preformed anti-ABO or anti-HLA antibodies, complement (type II) | Thrombosis of graft vessels, ischemic necrosis; graft turns mottled and cyanotic | Graft removed; prevented by ABO matching and crossmatch |
| Acute cellular | Weeks to months (most often in the first 6 months) | CD8 and CD4 T cells against donor MHC (type IV) | Lymphocytic infiltrate, tubulitis, endothelialitis | Usually reversible with steroids or T-cell–depleting antibodies |
| Acute antibody-mediated | Weeks to months, or later | New donor-specific anti-HLA antibodies, complement | Capillary inflammation, C4d staining | Treated with antibody-removal strategies; worse prognosis |
| Chronic | Months to years | T cells, antibodies and non-immune injury together | Intimal proliferation and fibrosis of vessels, parenchymal atrophy | Irreversible; main cause of late graft failure |

## Memory aid

Minutes means ready-made antibodies; weeks means T cells waking up; years means vessels slowly scarring.

## Test yourself

Think of the answer, then tap the question to see it.

## What causes hyperacute rejection and how is it prevented?

Preformed antibodies against donor ABO or HLA antigens; it is prevented by ABO matching and a pretransplant crossmatch.

## Which immune cells drive acute cellular rejection?

Recipient T cells (CD8 cytotoxic and CD4 helper) reacting against donor MHC molecules.

## What biopsy marker suggests antibody-mediated rejection?

C4d deposits in the graft capillaries, a footprint of complement activation by antibodies.

## What is chronic rejection of a lung transplant called?

Bronchiolitis obliterans (chronic lung allograft dysfunction).

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/immunology/transplant-rejection-hyperacute-acute-chronic/)

## See it in 3D

The structures of Durgical's 3D anatomy where it is found.

- [Kidneys](https://durgical.com/en/anatomy/kidney/)
- [Liver](https://durgical.com/en/anatomy/liver/)

## Related

- [MHC/HLA class I and II](https://durgical.com/en/immunology/mhc-hla-class-i-and-ii/)
- [Type II hypersensitivity (antibody against cells)](https://durgical.com/en/immunology/type-ii-hypersensitivity/)
- [Type IV hypersensitivity (delayed, T cells)](https://durgical.com/en/immunology/type-iv-hypersensitivity/)
- [ABO and Rh blood groups, hemolytic disease of the newborn](https://durgical.com/en/immunology/abo-and-rh-blood-groups-hemolytic-disease-of-the-newborn/)
- [Graft-versus-host disease](https://durgical.com/en/immunology/graft-versus-host-disease/)
- [Immunosuppressants by mechanism (classes)](https://durgical.com/en/immunology/immunosuppressants-by-mechanism/)

## Microorganisms

- [Cytomegalovirus](https://durgical.com/en/microbiology/cytomegalovirus/)

[← All of immunology](https://durgical.com/en/immunology/)

Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given.

Sources: [Transplant rejection](https://medlineplus.gov/ency/article/000815.htm) (MedlinePlus, U.S. National Library of Medicine, 2026); [Complement](https://medlineplus.gov/ency/article/003456.htm) (MedlinePlus, U.S. National Library of Medicine, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/immunology/transplant-rejection-hyperacute-acute-chronic/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/immunology/transplant-rejection-hyperacute-acute-chronic/