Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Transplant rejection

11,091 views

Published on

Published in: Health & Medicine, Technology

Transplant rejection

  1. 1. BALAJI.R ALTHEANZ 09’
  2. 2.  Rejection is a complex process in which “recepient immune system recognize the graft as foreign and attacks it”.  It involves 1. Cell mediated immunity 2. Circulating antibodies
  3. 3.  It is caused by T-cell mediated reactions.  Destruction of grafts occurs by 1. CD8+ CTLs 2. CD4+ helper cells  Delayed hypersensitivity is triggered by CD4+ helper cells.  2 pathways 1. Direct pathway 2. Indirect pathway
  4. 4.  It is called humoral rejections.  2 types 1. Hyperacute 2. Acute HYPERACUTE:  Presence of preformed antidonor antibodies.  Transplant rejection has already occurred.
  5. 5. ACUTE:  Initial exposure to class I&II HLA antigens.  Antibodies causes injury by 1. Complement dependent cytotoxicity 2. Inflammation 3. Antibody dependent cell mediated cytotoxicity.
  6. 6.  Rejection reactions 1. Hyperacute 2. Acute a. cellular b. humoral 3. Chronic
  7. 7.  Occurs within minutes or hours after transplantation.  Kidney becomes 1. Cyanotic 2. Mottled 3. Flaccid  Immunoglobulin and complement deposition occurs.  Neutrophils accumulate leading to occlusion of capillaries & fibrinoid necrosis.
  8. 8.  Cellular – mononuclear cell infiltrate  Humoral – vasculitis ACUTE CELLULAR:  Seen within initial months after transplantation.  Mononuclear cells accumulates in glomerular and peritubular capillaries leading to FOCAL TUBULAR NECROSIS.  Treatment – cyclosporin.
  9. 9.  Also known as rejection vasculitis.  Necrotizing vasculitis characterised by intimal thickening.  Presence of complement breakdown product C4d – indicator of humoral rejection.  Treatment – B cell depleting agents.
  10. 10.  Immunosuppressive agents 1. Cyclosporin 2. Azathioprine 3. Steroids 4. Rapamycin 5. Monoclonal antibodies.
  11. 11. ANOTHER METHOD:  Prevention of host T cells from receiving co-stimulatory signals (B7- 1&2) from dendritic cells. DISADVANTAGES:  EBV induced lymphoma  HPV induced squamous cell carcinoma  Kaposi sarcoma
  12. 12.  Hematopoietic stem cell transplants are used for 1. Hematological malignancy 2. Aplastic anemia 3. Thalassemia 4. Non hematological cancers PROBLEMS: 1. Immunodeficiency 2. GVH disease
  13. 13.  Occurs in any situation in which “immunologically competent cells or their precursors are transplanted to immunologically crippled recipients and the transferred cells recognize allo-antigens in the host”.  It may be 1. Acute 2. Chronic
  14. 14.  Days to weeks after allogenic bonemarrow transplantation.  Clinical features 1. Generalised rash 2. Jaundice 3. Ulceration of gut 4. Bloody diarrhea
  15. 15.  Follow acute syndrome or occur insidiously.  Clinical features 1. Cutaneous injury 2. Cholestatic jaundice 3. Esophageal strictures 4. Depletion of lymphocytes  It is a life threatning condition.  Treatment – bonemarrow transplants.

×