Transplantation

• What is the term for the transplantation of cells, tissues, or organs from one body site to another in the same individual?

  AUTOGRAFT

  
• What is the term for transplantation between genetically identical individuals?

  ISOGRAFT
• What is the term for transplantation between genetically different members of the same species?

  ALLOGRAFT
• What is the term for transplantation between different species?

  XENOGRAFT
• What are the three key factors that successful transplantation depends on?

  MHC matching, ABO compatibility, and immunosuppressive therapy

  
• What is the primary use of isografts and autografts?

  They are used in rescue therapy for malignancies
• What is a disadvantage of using isografts and autografts?

  Possible contamination with malignant cells
• What is a characteristic of allografts regarding graft survival?

  Graft survival depends on the degree of genetic similarity and immunosuppressive treatment

  
• What is a significant risk associated with allografts?

  High risk of rejection
• What is a major advantage of xenografts?

  Unlimited supply of organs
• What is a significant disadvantage of xenografts?

  High risk of rejection and zoonotic disease transmission
• How is graft rejection classified?


  Based on the time the rejection process develops
• What are the three types of graft rejection?

  Hyperacute rejection, acute rejection, chronic rejection
• What mediates hyperacute rejection?

  Preformed antibodies

  
• When does hyperacute rejection typically occur?

  Minutes to hours post-transplant
• Who is at risk for hyperacute rejection?

  Multiparous women, individuals with previous unsuccessful grafts, multiple transfusions, and xenograft transplantation
• What are the cardinal features of hyperacute rejection?

  Immediate graft failure, leukocytes in peritubular capillary, thrombosis, C4d+/-, and circulating antibodies

  
• What is the outcome of hyperacute rejection?

  Irreversible graft function
• What are some prevention and treatment options for sensitized patients experiencing hyperacute rejection?

  Removal of antibodies, inhibition of antibody production, inhibition of complement cascade, intravenous Ig, and splenectomy

  
• What is plasmapheresis used for?

  Removal of antibodies
• What are some CD20-specific monoclonal antibodies used for inhibition of antibody production?

  Ocrelizumab, Rituximab, Ofatumumab, and Epratuzumab

  
• What is the role of BAFF in B-cell activation?

  BAFF acts as an anti-apoptotic survival factor critical for maturation of the B-cell lineage
• What is the function of eculizumab?

  Inhibition of the complement cascade
• What does intravenous Ig do in the context of hyperacute rejection?

  Neutralizes circulating anti-HLA antibodies and inhibits complement activation

  
• What is the purpose of splenectomy in sensitized patients?

  It removes a major source of lymphocytes, including antibody-secreting B cells
• What are the cardinal features of acute rejection?

  Loss of graft function a few days post-transplant, leukocyte infiltration, thrombosis, C4d+, and anti-donor antibodies

  
• What is the outcome of acute rejection?

  Often reversible with appropriate treatment
• What are the cardinal features of chronic rejection?

  Slow, progressive loss of graft function, leukocyte infiltration, thrombosis, C4d+, and anti-donor antibodies

  
• What is the outcome of chronic rejection?

  Often reversible with appropriate treatment
• What characterizes hyperacute rejection in terms of immunology?

  Preformed immunoglobulin, complement activation, thrombosis, and inflammation

  
• How do acute and chronic rejection differ immunologically?

  They involve recognition of the allogeneic graft as foreign by host CD4+ and CD8+ T cells

  
• What occurs during graft-versus-host disease (GVHD)?

  Donor immune cells attack the recipient tissues

  
• What are common symptoms of graft-versus-host disease?

  Fever, liver dysfunction, skin rash, diarrhea, and bone marrow hypoplasia

  
• Where is the rash typically distributed in graft-versus-host disease?

  On surfaces of limbs, face, neck, palms of hands, and soles of feet

  
• What gastrointestinal symptoms can occur in graft-versus-host disease?

  Diarrhea, abdominal cramps, nausea, and anorexia
• What liver symptoms can occur in graft-versus-host disease?

  Right upper quadrant pain, jaundice, raised LFTs, and hepatomegaly

  
• What is the most effective way to prevent graft-versus-host disease?

  Donor T-cell depletion

  
• What are the risks associated with donor T-cell depletion?

  High incidence of disease relapse and increased incidence of graft rejection
• What are some management strategies for gastrointestinal symptoms in graft-versus-host disease?

  Strict monitoring of fluids, daily weights, close monitoring of electrolytes, and checking stools for occult blood
• Why is hemoglobin and hematocrit monitored in patients with graft-versus-host disease?

  To assess for hemorrhaging