Transplant

Question 1

What interleukin fascilitates acute rejection?

Answer 1

Clinical importance: Activation of a particular T cell by a foreign HLA peptide results in clonal proliferation of that type of T lymphocyte, a process that is mediated by IL-2 and leads to acute rejection

Question 2

What are absolute contraindications for transplant?

Answer 2

Absolute contraindications for organ donation include incurable or metastatic malignancy, sepsis, transmissible spongiform encephalopathies (e.g., Creutzfeldt-Jakob disease), and cardiac arrest that occurred before brain death, none of which apply to this patient.

Question 3

Preformed antibodies against class I HLA of the graft are responsible for ____________rejection

Answer 3

Preformed antibodies against class I HLA of the graft are responsible for hyperacute rejection

Question 4

Abdominal pain, hypertension, generalized fatigue, and an increase in creatinine within 6 months of renal transplantation are concerning for __________ rejection of the renal allograft.

Answer 4

acute

Question 5

What staining results would we expect for an acute cellular rejection

Answer 5

The biopsy confirms an acute cellular rejection (the absence of C4d staining indicates no antibody deposition).

C4d stainng looks for antibody deposition which we would see in hymoral rejection

Question 6

Acute liver transplant rejection can occur within 6 months after transplantation and may manifest with vomiting, jaundice, rising bilirubin, and pain in the graft region. What imaging modality would you start with?

Answer 6

US!
Since clinical findings for acute liver transplant rejection are nonspecific, duplex ultrasound of the liver should be performed to rule out possible vascular complications (e.g. portal vein thrombosis, bleeding), biliary complications (e.g., leak, stricture), and liver infection (e.g. perihepatic abscess).

Question 7

What group of immunosuppressant drugs act by inhibiting IL-2 to precent rejection?

Answer 7

Calcineurin inhibitors

A group of immunosuppressant drugs that act by inhibiting interleukin-2 production and IL-2 receptor expression, reducing T-cell activation. Examples include tacrolimus and cyclosporine.

Question 8

Prophylaxis against the most common opportunistic pathogens, such as Pneumocystis jirovecii and human cytomegalovirus (CMV), should be administered in posttransplant patients on immunosuppressive therapy.

What can we give?

Answer 8

Trimethoprim-sulfamethoxazole

Question 9

What prophylaxis must we think about for post-transplant patients?

Answer 9

CMV and ipprotunitsitc pathogens Pneumocystis jirovecii

Question 10

< 48 hours after transplantation, usually within minutes to hours

Answer 10

Hyperacute rejection

Question 11

< 6 months after transplantation, usually within weeks to months

Answer 11

Acute rejection

Question 12

> 6 months after transplantation, usually after a few years

Answer 12

Chronic rejection

Question 13

What rejection: on biopsy Dense interstitial lymphocytic infiltrate with vasculitis

Answer 13

acute

Question 14

What rejection: on biopsy Small vessel thrombosis → ischemia → graft necrosis

Answer 14

hyperacute

Question 15

What kind of rejection does not require removal of the graft?

Answer 15

Acute rejection

Question 16

What is this describing: recipient’s preformed cytotoxic antibodies against donor’s class I HLA molecules or blood group antigens → activation of the complement system and adhesion to cells → thrombosis of vessels → graft ischemia and necrosis

Answer 16

Humoral rejection (type II hypersensitivity reaction)

THIS IS HYPERACUTE

Question 17

What is the pathophysiology behing acute rejection?

Answer 17

Acute cellular rejection (type IV hypersensitivity reaction)
Donor MHC class II antigens react with recipient CD4+ T cells, which then differentiate into Th1 helper T cells → cytokine (INF-γ) release → macrophage recruitment → parenchymal and endothelial inflammation
Donor MHC class I antigens react with recipient CD8+ T cells → direct cytotoxic cell damage

Acute humoral rejection (type II hypersensitivity reaction): recipient antibodies, formed before or after transplantation, react against donor HLA antigens

Question 18

What types of hypersensitivities are seen in acute rejection?

Answer 18

type IV and II

Acute cellular rejection (type IV hypersensitivity reaction)
Donor MHC class II antigens react with recipient CD4+ T cells, which then differentiate into Th1 helper T cells → cytokine (INF-γ) release → macrophage recruitment → parenchymal and endothelial inflammation
Donor MHC class I antigens react with recipient CD8+ T cells → direct cytotoxic cell damage
Acute humoral rejection (type II hypersensitivity reaction): recipient antibodies, formed before or after transplantation, react against donor HLA antigens

Question 19

What type of pathophysiology do we see in chronic rejection?

Answer 19

A mix of type II and IV hypersensitivity

Combination of humoral rejection (type II hypersensitivity reaction) and cellular rejection (type IV hypersensitivity reaction)
Donor MHC class II antigens react with recipient CD4+ T cells → differentiation into Th1 helper T cells → cytokine (INF-γ) release → macrophage recruitment → parenchymal and endothelial inflammation

Question 20

an immunological response that occurs when donor T lymphocytes in the graft recognize the recipient as foreign, resulting in a systemic inflammatory reaction

Answer 20

Graft versus host disease