Organ rejection
Hyperacute
[edit | edit source]- Minutes to days
- Occurs due to high level pre-formed anti blood group or anti-HLA antibodies binding to endothelium of the graft (antibody-mediated reaction). Initiates a cascade of events culminating in vascular thrombosis and ischaemic necrosis of the graft.
- Severe, untreatable, thrombotic reaction
- Very rarely seen in modern times due to screening
- Assessed by screening serum against a panel of regional donors
- Non-sensitised patient = 0%
- Sensitized = 100% and will need desensitization therapy
- Near-universal graft loss, can try plasmapheresis and Ig infusion if diagnosis is made early
- Preventable with typing, AB screening and cross-match
Acute
[edit | edit source]- Defined as an acute deterioration in allograft function with characteristic pathological findings
- Diagnose with biopsy
- Usually occurs five days (up to 10 days) after transplant
- Either ABMR or T-cell mediated or both
- Prevented by suppressing T cells
- Management
- Cell-mediated: pulse corticosteroids
Chronic
[edit | edit source]- Long-term fibrotic process related to accumulation of T-cells and macrophages
- Indolent/repetitive ABMR or TCMR or non-immune insults
Approach to suspected rejection
[edit | edit source]- Organise a biopsy
- Banff criteria on biopsy helps to diagnose, and will tell you whether it's T-cell or ABMR