What type of transplant rejection is characterized by systemic symptoms and a CD8 response?

• A. Acute rejection
• B. Chronic rejection
• C. Hyperacute rejection
• D. Graft-versus-host disease

Answer: (D)

The type of transplant rejection characterized by systemic symptoms and a CD8 T-cell response is graft-versus-host disease (GVHD). This occurs when immunologically competent cells from the donor recognize the recipient’s tissues as foreign and mount an immune response against these tissues.

In GVHD, the activated CD8 T-cells from the graft attack the recipient's organs, leading to systemic symptoms such as fever, rash, diarrhea, and liver dysfunction. This response is distinct from other rejection types, which primarily involve the recipient's immune system reacting against the donor tissue rather than the donor's immune cells attacking the recipient.

Acute rejection involves a more typical immune response characterized by CD4 and CD8 T-cell responses, primarily focused on the recognition of foreign antigens presented by recipient tissues. Chronic rejection typically manifests through a gradual and progressive deterioration of the graft, often mediated by both cellular and humoral immunity, but does not show the immediate systemic symptoms seen in GVHD.

Hyperacute rejection occurs almost immediately upon transplantation due to pre-existing antibodies in the recipient that react against the donor tissue, leading to rapid graft failure; it is characterized by sudden onset rather than systemic symptoms.

Understanding the immune mechanisms and cell involvement in these different types of transplant rejection helps clarify why