1. Donor Organ Selection Criteria: What is Ideal? A Consensus (?) Discussion

2. Hunsicker’s Law Heat of discussion ~ 1/(relevant data)

3. Histology will be an important consideration in evaluation of the donor IF: Preimplantation biopsy correlates with short and long term clinical outcomes. The information is “marginally useful,” i.e. adds significantly to predictions based on demographic and clinical data. The incremental predictive value is sufficiently important to offset any cost of incremental cold ischemia time.

4. We don’t really have the answer to these questions (Hayry Rule). Therefore, more studies are needed.

5. How can we acquire additional needed information? No information on outcomes is obtained from organs that are discarded, but these organs can shed light on optimal methods for performing the biopsies. The most important information will be on organs that are accepted by some groups but not by others (statistically “the marginal donors”). We need to collect clinical and histological data on a national basis (adequate numbers). This might be done best by a consortium of OPOs.

6. In Which Donors Should a Biopsy be Done? We should start to establish this by looking at the characteristics of the statistically “marginal donors,” i.e., those in whom there is currently no consistency in acceptance. These criteria should be modified over time based on new information about impact of histological findings on short and long term outcomes. Obvious lesions identified at donor nephrectomy warrant biopsy. PROPOSED STUDY INTERNATIONAL.

7. How Should the Kidney Be Biopsied? Wedge vs. needle biopsy: –difference in numbers of glomeruli –difference in numbers of vessels –difference between subcortical and deeper tissue Are we more interested in: –visibly abnormal tissue –visibly normal tissue One or both kidneys?

8. How Should Donor Organ Histology Be Done? Essentially every OPO has access to at least one pathology department in which optimal histology can be done. To get best information at least biological cost: –At least for studies, biopsies should be done using “push processing,” not by frozen sections. –Biopsies should be read in a timely fashion by a qualified renal histopathologist. –Proposed study should also include centers that use almost all donors.

9. What Recipient Outcomes Should be Examined? The most important outcomes are long term clinical outcomes: –patient survival, –graft survival, –post-transplant renal function and histology. However, impact of predictors on DGF is important, also. This information may be important in adjusting compensation or payer evaluation of center outcomes.

10. How Should Pathologists Report Results of Biopsy to Clinicians? It would be an error for the pathologist to report acceptability or non-acceptability to the clinician. Acceptability is a function of clinical data, histological data, and status of the recipient. We might want to develop a “prognostic score” that could be integrated with other prognostic information and with recipient status.

11. Grading Scheme for Donor Biopsies Rapid paraffin processing/vs. frozen section study, with some continuous variable outcomes, and adequate n’s to be convincing. Who to biopsy? Retrospective data. What can we decide before this study? Should we make a grading schema before the study is complete. Provisional grading schema to be decided now for study - Randhawa/Racusen. Funding of study? NIH? Gov? Corporate?

12. Grading Scheme for Donor Biopsies Randhawa/Racusen to have most input into first full draft of schema for study (which could also be used for other purposes). Most controversial area of Randhawa proposal was grading of ATN. ATN changes usually subtle and diffuse in the sense of affecting every nephron. However no grading system in man exists, and perhaps what is appropriate for early biopsies (donor and implantation) is not the same as for later bx,

13. Future Directions The most important thing about a donor kidney is not how the kidney functioned, or what the kidney looked like, in the donor. Rather, what counts is how the kidney will function and what it will look like in the recipient. We need to find markers of the response of donor kidneys to death and transplantation: –predictors of extent of tubular injury –predictors of recovery from tubular injury