Expanding the envelope: can we increase the organ donor pool through the appropriate application of infectious disease principles?

Editorial Expanding the envelope: can we increase the organ donor pool through the appropriate application of infectious disease principles? The remarkable success that has been achieved in organ transplantation over the past few decades stands out as one of the outstanding achieve- ments of biomedical science during this period: a clear-cut instance of a successful, multidisciplinary collaboration among surgeons, pediatri- cians, and internists; clinicians and basic scientists; nurses and doctors; organ procurement groups and patient advocacy organizations. A revolution has occurred: transplantation has been transformed from an extraordinary exercise in human immunobiology to the most practical way of rehabilitating patients with a wide variety of illnesses resulting in heretofore fatal heart, lung, liver, and kidney disease. Indeed, many of the problems that face us today are a result of the success of this revolution, particularly the serious imbalance that currently exists between the availability of organs and the increasing numbers of individuals who would benefit from them. Great effort has been expended to increase the donor pool, including the use of non-heart-beating donors, living unrelated donors, and living donors contributing ``partial organs'' (e.g., a single lobe of the liver or lung). The shortage of donors has also stimulated a relook at strategies that might allow organ procurement from donors with a variety of infections that have disqualified them from donation in the past. Although these attempts should still be regarded as experimental, requiring informed consent, human studies committee approvals, as well as the expedited sharing of information with the transplant community, there appears to be considerable promise in this effort. Bacterial infection in the donor has been addressed in a report of the successful transplantation of kidneys from a donor who died as a conse- quence of enterococcal sepsis (1). In reviewing this issue, it appeared that there are some appropriate guidelines that can be fashioned and that can potentially lead to the procurement of more organs for successful transplant. At present, the following guidelines regarding the use of cadaveric donors in the face of bacterial infection appear to be reasonable: 1. All microorganisms are not equal in terms of virulence, adherence to metastatic sites, invasiveness, or rate of response to antimicrobial therapy. Thus infection in the donor with relatively bland organisms, such as enterococci, Staphylococcus epidermidis, and Acinetobacter, does not preclude organ procurement, provided the following rules are observed: a. Treatment with full doses of a bactericidal antimicrobial program aimed at the infecting organism for a minimum of 48 h is necessary before the question of organ procurement can be raised. If signs of patient response can be seen, this can be very encouraging in deciding to proceed. If, because of resistance of the bacteria, bactericidal therapy is not possible, then the donor should be regarded as unacceptable. b. Certain infecting organisms, because of virulence, tendency to adhere to endothelial surfaces, and the ability to spread hematoge- nously to other sites, render a particular donor undesirable. Thus, infection of the donor with such organisms as Salmonella species, Staphylococcus aureus, and Pseudomonas aeruginosa, would, at least for the present, preclude the use of organs from such donors. c. Infectious processes in the donor associated with ongoing blood- stream infection (high-grade bacteremia) would rule out a prospective donor unless a course of bactericidal therapy had been administered for 10±14 days, and the bacteremia had been cleared. Conversely, processes associated with only transient bacteremia would require a shorter duration of therapy in addition to clinical evidence of a response. d. There may be occasions when one organ is unsuitable for transplantation, but other organs can be safely obtained and used. For example, terminal pneumonia may block the use of the lungs for transplant, but since bacteremia is uncommon, other organs can be safely used provided an adequate bactericidal regimen has been administered. 2. The major concern is the avoidance of blood stream infection, particularly with Staphylococcus aureus, Pseudomonas, salmonellae, Candida species, and other vasculotropic organisms. Although the majority of positive blood cultures of the donor at the time of organ procurement are probably contaminants, disastrous seeding of the fresh vascular 115 Copyright ß Blackwell Munksgaard 2002 Transplant Infectious Disease . ISSN 1398-2273 Transpl Infect Dis 2002: 4: 115±116 Printed in Denmark. All rights reserved

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Expanding the envelope: can we increase the organ donor pool through the appropriate application of infectious disease principles?