Kidney Transplant Immunology Flashcards
What happens with antibody production in kidney transplantaion
Very early graft loss - 48 hours - hyperacute rejection
Preformed antibodies present in 1% of the population
Activation of clotting and complement leading to intravascular thrombosis, ischemia, and subsequent necrosis
What is the solution for antibody producition
transplant cross-match or immunoadsorption
Cross-match: take cell from donor (usually spleen). Take sera from recipient. See whether lysis is present.
Immunoadsorption: makes blood go through column to adsorb antibodies
Describe MHCs in humans
Class I: A, B, C
Class II: DR, DQ, DP
Very polymorphic = high variability
MHC I: all cells except RBC
MHC II: only APCs
What are the effects of complement and clotting facotrs
Occlusion of the blood supply to an organ induces ischemia reperfusion injury (tissue damage caused when blood supply returns to tissue after a period of ischemia. Absence of oxygen and nutrients creates a condition in which the restoration of circulation results in inflammation and oxidative damage through the induction of oxidative stress). Activation of the complement and clotting systems: damage and also increased immunogenicity (ability to induce a humoral or cell-mediated immune responses).
Ex ‘vivo’ normothermic perfusion now standard for renal transplant - restores circulation and allows an organ to regain function prior to transplantation.
What is allorecognition
T cells in the periphery recognise peptide derived from pathogens and transformed cells in the context of self-MHC; however, they can recognise donor MHC molecules.
What do MHC incompatible cells do
Induce uniquely strong immune responses. Reflects the uniquely high precursor frequencies of T cells with direct anti-MHC allospecificity.
What do DCs do
link between the innate and adaptive immune systems.
Present mainly in tissues exposed to the external environment (immature-antigen capture)
Most potent APCs (mature)
Normally activated by TLRs
DCs are transplanted with graft. Foreign DCs are activated due to complement and clotting factors.
