transplantation tahir.ppt by Dr. Tahir khan

Transplantation immunology

1. Transplantation immunology
Tahir khan

2. Transplant Immunology Outline
•Introduction
•Graft compatibility
•Graft rejection

3. Transplant Immunology Outline
•Introduction

4. Introduction
Transplantationthe moving of cells, tissues, and
organs from one site to another
Graft the transplanted organ
Donor person from whom graft is taken
Recipient (host)person who gets the graft
•1954 -first transplant (living kidney)
•1960s -liver, heart transplants

5. •Surgical difficulties
•Graft rejection
•Organ shortage
Introduction
Transplantation problems

6. Transplant Immunology Outline
•Introduction
•Graft compatibility

7. Compatibility
Rejection = recipient recognizes graft as foreign,
and destroys it
Autograftwithin same person
Isograft between identical twins
Allograftbetween genetically different people
Xenograftbetween different species

8. •Histocompatible: antigenically similar to the host
•Histoincompatible: antigenically different from the host
•MHC antigens are the most important
•ABO antigens are also important
•Minor histocompatiblity antigens are less important
Compatibility
Histocompatibility

9. Transplant Immunology Outline
•Introduction
•Graft compatibility
•Graft rejection

10. •Any two people (except identical twins) will express
some HLA proteins that are different.
•Every recipient will recognize, and react against, at
least some foreign antigens in the graft
•Rejection is complex, with lots of killing mechanisms.
Rejection

11. •Direct pathway of recognition
•Indirect pathway of recognition
Rejection
How do recipient cells know which cells to kill?

12. Direct Pathway Indirect Pathway

13. •T-cell-mediated rejection
•Antibody-mediated rejection
Rejection
Two mechanisms of rejection

14. •CD8+ CTLs kill graft cells directly
•CD4+ cells trigger a delayed hypersensitivity reaction
Rejection
T-cell mediated rejection

15. •Hyperacute rejection
•Acute rejection
•Chronic rejection
Rejection
Clinical types of rejection

16. Clinical manifestations of graft rejection
I.Hyperacute rejection: very quick
II.Acute rejection: about 10 days (cell mediated)
III.Chronic rejection: months-years (both)

17. Rejection Response