questions 9

Transplant

Topic updated on 05/20/17 5:05pm

Snapshot
  • A 60-year-old-man presents with nausea and vomiting to his primary care physician. Medical history is significant for a liver transplantation approximately 2 weeks prior to presentation. On physical examination there is scleral icterus and mild ascites. A liver biopsy shows lymphocytic infiltrates in the interstitium. (Acute rejection)
Introduction
  • Transplantation is a process by which
    • cells, tissues, or organs (a graft) from the donor are transplanted into a host (or recipient)
  • The immune system's ability to recognize and respond to foreign antigens bring challenges to transplantation
  • There are several types of grafts
    • autograft
      • tissue is moved from one location to another in the same person
        • e.g., skin graft and using the saphenous vein to replace a coronary artery
      • the graft will not be considered foreign and thus
        • will not require lifelong immunosuppresion
    • syngeneic graft (isograft)
      • tissue is transplanted from one genetically identical donor to the host
        • e.g., transplantation between monozygotic twins
    • allograft
      • tissue is transplanted from one genetically different donor of the same species to the host
        • e.g., kidney transplant
    • xenograft
      • tissue is transplanted from a donor of a different species to the host
        • e.g., porcine heart valve
Transplant Rejection
 
Transplant Rejection
Rejection Type
Pathogenesis
Comments
Hyperacute
  • Type II hypersensitivity reaction where
    • pre-existing recipient antibodies attack the donor antigen resulting in
      • complement activation
      • endothelial damage
      • inflammation
      • thrombosis
  • Time
    • minutes to hours
  • Findings
    • capillary thrombosis which
      • prevents graft vascularization
Acute
  • Cellular rejection
    • type IV hypersensitivity reaction where
      • recipient CD8+ T-cells react to donor antigens after activation by antigen presenting cells
  • Humoral rejection
    • just like in hyperacute rejection; however,
      • the antibodies are formed after transplantation occured
  • Time
    • weeks to months
  • Findings
    • graft vessel vasculitis with
      • lymphocytic infiltrates
Chronic
  • Type II and IV hypersensitivity reaction secondary to
    • CD4+ T-cells responding to the host's antigen presenting cells
  • Time
    • months to years
  • Findings
    • cytokine secretion after T-cell activation leads to
      • smooth muscle proliferation
      • interstitial fibrosis
      • parenchymal atrophy
Graft-versus-host disease
  • Type IV hypersensitivity reaction secondary to
    • the donor's T-cells attacking the recipient's cells leading to
      • organ dysfunction
  • Time
    • variable
  • Findings
    • maculopapular rash
    • jaundice
    • diarrhea
    • hepatosplenomegaly
 
Tissue Compatibility Testing
  • ABO blood typing
  • Tissue typing
    • used to see if HLA antigens match and focuses on
      • HLA-A
      • HLA-B
      • HLA-DR

References



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Qbank (6 Questions)

TAG
(M1.IM.18) A 32-year-old Caucasian female required a kidney transplant 3 years ago. She presents with elevated creatinine levels (2.6 mg/dl) and an elevated blood pressure (160/90 mmHg). A biopsy is taken of the transplanted kidney. Following histological findings, a diagnosis of chronic graft rejection is made. Which of the following is NOT a likely finding? Topic Review Topic

1. Interstitial fibrosis
2. Glomerular destruction
3. Tubular atrophy
4. Graft arteriosclerosis
5. Glomerular crescents

PREFERRED RESPONSE ▶
TAG
(M1.IM.42) A 40-year-old male with a history of chronic alcoholism recently received a liver transplant. Two weeks following the transplant, the patient presents with a skin rash and frequent episodes of bloody diarrhea. A colonoscopy is performed and biopsy reveals apoptosis of colonic epithelial cells. What is most likely mediating these symptoms? Topic Review Topic

1. Donor T-cells
2. Recipient T-cells
3. Donor B-cells
4. Recipient B-cells
5. Recipient antibodies

PREFERRED RESPONSE ▶
TAG
(M1.IM.52) Several weeks following a kidney transplantation, a 50-year-old Caucasian female presents for evaluation of the transplanted organ. Biopsy shows inflammation involving the endothelial cells of the kidney vasculature and the presence of mononuclear cells in the interstitium. Which cells are most likely responsible for this presentation? Topic Review Topic

1. Donor T-cells
2. Recipient T-cells
3. Preformed recipient antibodies
4. Donor antibodies
5. Deposition of antibody immune complexes

PREFERRED RESPONSE ▶
TAG
(M1.IM.74) A 45-year-old female is undergoing renal transplantation for management of chronic renal failure secondary to glomerulonephritis. The transplant surgeon placed the donor kidney in the recipient and anastamosed the donor renal artery to the recipient's external iliac artery as well as the donor ureter to the recipient's bladder. After removing the clamps on the external iliac artery, the recipient's blood is allowed to perfuse the transplanted kidney. Within 3 minutes, the surgeon notes that the kidney does not appear to be sufficiently perfused. Upon further investigation, an inflammatory reaction is noted that led to clotting off of the donor renal artery, preventing blood flow to the transplanted organ. Which of the following best describes the pathophysiology of this complication? Topic Review Topic

1. Type I hypersensitivity reaction
2. Type II hypersensitivity reaction
3. Type III hypersensitivity reaction
4. Type IV hypersensitivity reaction
5. Graft-versus-host disease

PREFERRED RESPONSE ▶
TAG
(M1.IM.76) A 62-year-old female with a history of uncontrolled hypertension undergoes kidney transplantation. One month following surgery she has elevated serum blood urea nitrogen and creatinine and the patient complains of fever and arthralgia. Her medications include tacrolimus and prednisone. If the patient were experiencing acute, cell-mediated rejection, which of the following would you most expect to see upon biopsy of the transplanted kidney? Topic Review Topic

1. Sloughing of proximal tubular epithelial cells
2. Lymphocytic infiltrate of the tubules and interstitium
3. Drug precipitation in the renal tubules
4. Granular immunofluorescence around the glomerular basement membrane
5. Crescent formation in Bowman’s space

PREFERRED RESPONSE ▶
TAG
(M1.IM.77) A physician is describing a case to his residents where a kidney transplant was rapidly rejected from the recipient minutes after graft perfusion. The physician most likely describes all of the following manifestations EXCEPT? Topic Review Topic

1. Graft mottling
2. Graft cyanosis
3. Low urine output with evidence of blood
4. Histological evidence of arteriosclerosis
5. Histological evidence of vascular damage

PREFERRED RESPONSE ▶
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