Quiz 2 additional Flashcards
How are T cells activated in direct allograft recognition?
How are T cells activated in indirect allograft recognition?
What type of allograft recognition is more common during acute rejection? What response is triggered?
Direct allograft recognition
Allospecific CTLs directly kill donor cells
What type of allograft recognition is more common in the form of chronic rejection? What response is triggered?
Indirect allograft recognition
Inflammation induced by Th1 cells promotes slow tissue destruction and organ dysfunction
What are the three types of allograft rejections?
Hyperacute
Acute
Chronic
What characterizes a hyperacute allograft reaction?
Occurs in minutes to hours
Requires previous exposure; is mediated by pre-existing antibody to alloantigen (i.e. ABO, Rh)
Rare due to pre-screening
What type of allograft rejection are blood transfusion reactions classified as?
Hyperacute rejection
What characterizes an acute allograft rejection?
Occurs in days to weeks
Mediated by T cells, chiefly CTL mediated damage & massive inflammation (Th1 and alloantibodies can participate)
Necrotizing vasculitis, interstitial lymphocyte infiltrate, endothelitis
What characterizes a chronic allograft rejection?
Occurs in months to years
Largely Th1 and macrophage mediated (some alloantibody)
Thickening of vascular wall, interstitial fibrosis, vesicle occlusion
Frequency and magnitude of what event predicts likelihood and time of onset of chronic rejection?
Acute rejection
Which two drugs are classified as Calcineurin inhibitors?
Cyclosporine
Tacrolimus (FK-506)
Which two dugs are inhibitors of IL-2R signaling?
Rapamycin (sirolimus)
Basiliximab (anti-IL2R)
Which drug is responsible for inhibition of costimulation (B7:CD28)?
Belatacept (CTLA4-Ig)
Which two drugs are classified as proliferation inhibitors?
Azathioprine
Mycophenolate mofetil
Which two drugs are responsible for T cell depletion?
Thymoglobulin (anti-CD3)
Alemtuzumab (anti-CD52)
Which two drugs are responsible for T cell depletion?
Thymoglobulin (anti-CD3)
Alemtuzumab (anti-CD52)
What is the general mechanism of calcineurin inhibitors?
CNIs block NFAT activation, which is critical as a TF in T cell activation
Which of the HLA alleles are tested for matches before transplants?
HLA-A
HLA-B
HLA-DR
What characterizes graft versus host disease (GVHD)?
Donor T cells can react to host (acute and chronic activation) *Can exhibit graft vs tumor effect
Most often occurs in hematopoietic SC/BM transplants
What are the 3 hallmarks of GVHD?
Skin: Macropapular rash
Liver: Hepatomegaly & jaundice
Gi tract: Diarrhea
