Pestana Chap 13 - Organ Transplantation

Question 1

Are brain-dead patients organ donor candidates? Can patients with specific infections (like hepatitis) be donors? Can patients with metastatic cancer be donors?

Answer 1

1) Virtually all brain-dead patients are potential candidates, regardless of age
2) Donors with specific infections (like hepatitis) can be used for recipients who have the same disease
3) Even donors with metastatic cancer can donate corneas

Question 2

What is the general rule for choosing a potential donor?

Answer 2

The general rule for regular physicians is that all potential donors are referred to the harvesting teams, and they will exclude the few that cannot be used at all

Question 3

What is the only absolute contraindication to organ donation?

Answer 3

A positive HIV status

Question 4

What are 3 ways in which transplant rejection can occur?

Answer 4

1) Hyperacute
2) Acute
3) Chronic rejection

Question 5

What is hyperacute rejection? What is it caused by? What is it prevented by?

Answer 5

1) Hyperacute rejection is a vascular thrombosis that occurs within minutes of reestablishing blood supply to the organ
2) It is caused by preformed antibodies
3) It is prevented by ABO matching and lymphocytotoxic crossmatch, and thus it is not seen clinically

Question 6

When does acute rejection occur? Do episodes occur even with immunosuppression?

Answer 6

1) After the first 5 days, and usually within the first 3 months
2) Yes

Question 7

What do current maintenance protocols for acute rejection include? What is suggestive of acute rejection and what confirms it?

Answer 7

1) Tacrolimus and mycophenolate mofetil, with or without prednisone
2) Signs of organ dysfunction suggest acute rejection, and biopsy confirms it

Question 8

In terms of liver transplantation, are technical problem or immnologic rejection more common? What is therefore the first order of business when liver function deteriorates after transplant (rising gamma-glutamyltransferase [GGT], alkaline phosphatase, and bilirubin?

Answer 8

1) Technical problems

2) Rule out biliary obstruction by ultrasound and vascular thrombosis by Doppler

Question 9

What is done in the case of heart transplant to allow effective therapy in the event of deterioration and why?

Answer 9

In the case of the heart, signs of functional deterioration occur too late to allow effective therapy, thus routine ventricular biopsies (by way of the jugular, superior vena cava, and right atrium) are done at set intervals

Question 10

What is first line therapy for acute rejection? What if this is unsuccessful and what is a problem with this alternate therapy? What alternative is tolerated better?

Answer 10

1) Steroid boluses
2) If unsuccessful, antilymphocyte agents (OKT3) have been used, but their high toxicity is a problem
3) Newer antithymocyte serum is tolerated better

Question 11

What efforts are under way to diagnose rejection without the need for biopsies?

Answer 11

Efforts are under way to come up with cellular MRI as a noninvasive way to diagnose rejection, without the need for biopsies

Question 12

What is chronic rejection? Is it understood and reversible? Do we have treatment for it? Why do patients get a biposy for chronic rejection?

Answer 12

1) Chronic rejection is seen years after the transplant, with gradual, insidious loss of organ function
2) It is poorly understood and irreversible
3) Although we have no treatment for it, patients suspected of having it have the transplant biopsied in the hope that it may be delayed (and treatable) case of acute rejection