Transplant Reactions

Question 1

Describe hyperacute rejection

Answer 1

Within minutes. Preexisting recipient antibodies activate complement. Type II hypersensitivity rxn. Thrombosis, ischemia and fibrinoid necrosis

Question 2

Describe acute rejection

Answer 2

Takes weeks to months.
Cellular type: type IV hypersensitive reaction. CD8 and or CD4 cells activated against donor MHCs
Humoral type: similar to hyperacute but antibodies develop after transplant

Question 3

Describe chronic rejection

Answer 3

Months to years. Both type 2 and type 4 hypersensitivity. APCs present donor peptides, including allogeneic MHC, and CD4 T cells respond

Question 4

Describe graft vs host disease

Answer 4

Maculopapular rash, jaundice, diarrhea, hepatosplenomegaly. Risk increased by HLA mismatch. Type 4 hypersensitivity. Grafted T cells attack host cells