Chapter 14 - Organ Transplantation

Question 1

3 types of transplant rejection?

Answer 1

Hyperacute
Acute
Chronic

Question 2

Cause of hyperacute rejection?

Answer 2

Hyperacute rejection is a vascular thrombosis that occurs within minutes of reestablishing blood supply to the organ; caused by pre-formed antibodies

Question 3

Prevention of hyperacute rejection?

Answer 3

ABO matching and lymphocytotoxic crossmatch (thus not seen clinically)

Question 4

Timing of acute rejection?

Answer 4

Occurs after the first 5 days, usually within the first 3 months

Question 5

Acute rejection episodes can occur even though the patient is on maintenance immunosupression - current maintenance protocols?

Answer 5

Tacrolimus, mycophenolate mofetil, +/- prednisone

Question 6

Signs of organ dysfunction suggest acute rejection - what confirms it?

Answer 6

Biopsy

Question 7

In the case of liver transplant, what is the first step in working up suspected acute rejection?

Answer 7

R/o biliary obstruction by U/S and vascular thrombosis by Doppler

(Technical problems are more common than immunologic rejection in the case of the liver)

Question 8

In the case of heart transplant, signs of functional deterioration occur too late to allow effective therapy - what is done to mitigate this?

Answer 8

Routine ventricular biopsies (via jugular, SVC, and right atrium) at set intervals

Question 9

First line therapy for acute rejection? Next steps?

Answer 9

Steroid boluses

If unsuccessful, antilymphocyte agents (OKT3) have been used, but high toxicity is a problem

Newer anti-thomyocyte serum is tolerated better

Question 10

Timing of chronic rejection?

Answer 10

Seen years after transplant with gradual, insidious loss of organ function - poorly understood and irreversible

Question 11

What should be done in patients suspected of having chronic rejection?

Answer 11

Biopsy in case it is a delayed and treatable case of acute rejection