The Banff Conferences on Allograft Pathology
1991 - Present
History and General information about the Banff
Conferences on Allograft Pathology, the Banff Consensus Process and Funding
On December 18th, 1990
I received a letter from Paul Keown
telling me that the ISHLT had just published a
consensus classification of heart and lung transplant biopsy
interpretation and suggesting that we do the same for the kidney. I was
enthusiastic from the beginning and so was Lorraine Racusen who said it was
the most interesting project I had ever suggested to her. We decided to
undertake it together and I began to look around for a location for the
My wife Elaine had been to conferences at the
Banff Centre and suggested that as a
venue. On Easter Sunday in April 1991 we happened to be in Banff and on a whim
I stopped by the Banff Centre. The office was open despite
the holiday because they were running a conference that day and so we began
planning the meeting there for the first week of August.
The first meeting was very small. Actually it
was interdigitated with a ISN Disaster Relief Task Force meeting which I
conducted the same weekend. The people involved in the the transplant
pathology meeting included Paul Keown, Bryan Myers, Lennie Ramos, Pekka
Hayry, Eva von Willebrand, Steen Olsen, Byron Croker, Phil Halloran,
Margaret Billingham, Doug Wilson, Lorraine Racusen, and me. You can see a
video here (Banff Faces video).
The main genesis of the idea of the new
classification came from the joint observations Steen Olsen and I had made
on protocol biopsies. At Steen's hospital protocol biopsies were carried
out in every transplant before discharge from the hospital and then often
later in the transplant course. The protocol biopsy studies from Aarhus
played an important role in our thinking about thresholds for rejection,
especially with regard to tubulitis.
The protocol biopsy study which James Burdick
and I conducted at Johns Hopkins began in January 1983 continued until I
moved to Canada in 1987.
The articles below reflect these protocol biopsy
studies that were an important background and the main motivation for the
creation of the Banff schema in 1991:
Characteristics of early routine renal allograft biopsies.
The assumption that renal allograft histology should be perfectly normal
during quiescence in the absence of rejection or nephrotoxic insults has not
been adequately investigated. To study this, routine renal allograft
biopsies were performed at approximately 1 and 4 weeks, when patients often
had normal function or stable acute tubular necrosis (ATN). These were
compared with biopsies from other patients during autologous ATN or
clinically evident allograft rejection. There were two new findings: (1)
Almost all biopsies contained an interstitial infiltrate, so that only the
presence of vasculitis provided a clear distinction between rejection and
quiescence. Most of the biopsies with infiltrates were from patients who had
never received cyclosporine, so that an infiltrate does not necessarily
signify toxicity due to this drug. (2) A major proportion of the cells in
some biopsies appeared to express both the helper/inducer and the cytotoxic/suppressor
phenotype, and a similar finding after in vitro stimulation suggests that
this represents a cell population that is activated in some way.
Primary acute renal failure ("acute tubular necrosis") in the transplanted
kidney: morphology and pathogenesis.
University Institute of Pathology, Aarhus Kommunehospital, Denmark.
"Acute tubular necrosis" (ATN)
in the transplanted kidney, when properly differentiated from other causes
of acute renal failure, appears to be a relatively benign condition. It has
been widely assumed to be pathologically identical to ATN in the native
kidney, but its histopathologic features have not been studied in detail.
Because immunosuppressive therapy with cyclosporine adds an additional layer
of complexity to the morphologic changes observed, in the present study we
have confined our observations to patients immunosuppressed with steroids
and azathioprine. Thirteen renal allograft biopsies from patients with ATN
and 5 biopsies from patients with normal allograft function were compared
with the previously obtained series of 57 native kidney ATN biopsies and 20
control biopsies. Both qualitative and quantitative differences between
transplant and native kidney ATN were found. Compared with native kidney ATN,
transplant ATN showed significantly less thinning and absence of proximal
tubular brush border and less variation in size and shape of cells in
individual tubular cross-sections. There were also significantly fewer casts
and less dilatation of Bowman's space and a significantly greater number of
polarizable crystals presumed to be oxalate in transplant ATN. In native
kidney ATN the tubular injury sites were mostly characterized by
desquamation of individual epithelial cells leaving areas of bare basement
membrane (the "non-replacement" phenomenon). In transplant ATN, sites of
tubular injury, although rare and affecting only short tubular segments,
were characterized by the actual presence of identifiable necrotic tubular
cells, a finding seldom seen in native kidney ATN. There also was a greater
interstitial infiltrate of mononuclear inflammatory cells in transplant ATN
compared to native kidney ATN. Electron microscopic studies of 9 transplant
ATN biopsies showed a mild reduction in proximal tubular brush border
compared with controls but this alteration was significantly less than that
observed in native kidney ATN. There was no significant alteration in
proximal or distal basolateral infoldings and this contrasted sharply with
the marked reduction in basolateral infoldings of the plasma membrane
observed in native kidney ATN. Disintegrated necrotic cells were found by
electron microscopy in transplant ATN whereas these were not observed in
native kidney ATN. There were significantly more cells with apoptosis
(shrinkage necrosis) in transplant ATN than in native kidney ATN. There were
significantly more cells with apoptosis (shrinkage necrosis) in transplant
ATN than in native kidney ATN. On the other hand, there were significantly
greater numbers of "non-replacement" sites in the distal tubules in native
kidney ATN compared to transplant ATN.
It was clear to us that interstitial
inflammation by itself was completely nonspecific and did not constitute
rejection unless accompanied by substantial tubulitis beyond a certain
threshold or by arteritis. This message of the nonspecificity of
interstitial infiltrate alone was considered so important in the description
of the new classification that the editor of KI insisted that we emphasize
this very early in the manuscript ("so it will be seen and understood even
by the reader who never gets beyond the first page"). The
published paper in 1993 reflected this suggested structure.
One can follow the progress of the meeting
publications. There was a significant flaw in the original 1993 paper:
it regarded tubulitis in atrophic tubules as having the same significance as
tubulitis in nonatrophic tubules. By 1995 it became common practice to
score tubulitis only in nonatrophic tubules and this requirement became part
Banff 1997 classification published in 1999.
The 1995 meeting focused on making the Banff
lesion scoring the same as CADI so there was no difference between the two
assessments. The 1997 meeting modified the classification so that the
concepts of the Banff and the NIH CCTT classifications were aligned and the
two were merged in the 1997 Banff Working Classification.
More recently the classification has incorporate
antibody mediated rejection and has begun to address genomics, telepathology,
maintenance of competence and training courses, and many other subjects.
The Banff conferences have attracted an increasingly wide assortment of
stakeholders to the meeting including pathologists, clinicians, surgeons,
basic scientists, and representatives of other important organizations in
transplantation like the ISHLT and the Immune Tolerance Network, regulatory
agencies and government bodies, and pharmaceutical companies.
Constant vigilance has been necessary over these
past 18 years to maintain the scientific rigor the meeting required. Often
that rigor came mainly from the program we put together for the meeting, the
selections of speakers and the goals and objectives for the meeting, the
ideas about what each meeting should try to accomplish and who should lead
various aspects of the process. Lorraine Racusen was the prime mover in
these aspects of the meeting many years emphasizing cutting edge topics in
transplantation. In addition to formal seminar-style sessions and
facilitated discussions, poster sessions have provided an excellent format
for data presentation and networking for both junior and senior
Other solid organs beyond the kidney have always
been there at the Banff meetings. Margaret Billingham represented the heart
in the first meeting in 1991, but the other organs have become increasingly
active in recent years creating their own Banff classifications of their
respective areas, or moving the science of transplantation along by
improving existing classifications.
There are now Banff classifications of liver,
pancreas and composite tissue allograft pathology. We are most grateful to
those who have led these non-renal areas of the meeting, Jake Demetris in
liver, Cynthia Drachenberg in pancreas, Rene Rodriguez in heart, and Linda
Cendales in composite tissue.
The Banff Consensus Process
There was no professional facilitator. In the
beginning I did most of the facilitation. In later years Lorraine Racusen,
Bob Colvin, and sessions chairs have also played an important role in
The other solid organs - liver, pancreas,
composite tissue, heart, lung - have tended to follow the structure of the
kidney consensus process in their own deliberations at the meeting.
The author line in
the manuscripts reflected the actual work of creating them, with the
individuals who facilitated and structured discussions at the meeting and
who actually wrote the paper being included first, and the other authors
being listed alphabetically after that.
Authorship included everyone who provided
substantive and useful input, even those who were not at the meeting. From
the beginning we have favored participation by young people, and those from
developing countries. There has been a successful effort from the start to
make the classification truly international.
An amusing aside is that in the beginning most
feedback on the papers was provided by fax and in the years 1991-93 I spent
about $15,000 a year on fax charges. With the advent of Email this cost
dropped to essentially zero by 1994.
Funding for the Banff Meetings
Funding for the Banff meetings has been unusual
in a very positive way from the very beginning: Those involved in organizing
the meeting donate their time and are supported from elsewhere so there are
essentially no administrative costs. Also from the beginning many speakers
paid their own way to the meeting or found their own support.
Michele Hales who coordinated the Banff meetings
from 1991 to 2007 had a University of Alberta position supported by the
National Kidney Foundation (US) as Assistant Director of
cyberNephrology, a joint project of the University and the NKF.
Victoria Sheldon who has coordinated the Banff
meetings since 2007 is a full time University undergraduate student and a
part time employee of
Corporate donations to the Banff meetings are
made payable to the University of Alberta and kept in a University account
with all the usual oversights required by University procedures. Copies of
past budgets are available on request. I (Kim Solez) am the contact for
corporate donations, assisted by Dr. Michael Mengel and Victoria Sheldon.
Corporate donors are acknowledged on the
for the meeting, in the printed program, and in the publications
from the Banff meetings.
As noted, most speakers cover their own costs.
This arrangement has worked well for eighteen years and allows us to put on
a consistently excellent, unique standard-setting meeting while keeping
costs to a minimum.
We are particularly enthusiastic about providing
financial assistance to young participants and those from countries that
have not been represented in the past in the process.
I hope this background description is useful to
you and that you enjoy the other facets of the website.
Thanks to Everyone!
Finally I would like to thank everyone involved
for the financial assistance we have received from individuals, corporations and granting agencies over the post 18 years. We could not
have done it without you!
The intellectual ferment of Banff is even more
important, and for this I thank all of you who have contributed your time
and ideas over the years to help us make important new decisions and move
science and medical practice forward.
The next eighteen years will be even more
exciting than the past eighteen have been, as our activities expand still
further. Thanks to everyone for participating and contributing!
Kim Solez, M.D.
Director of Banff Conferences for Allograft
Cell phone: 780-710-1644
|Copyright © 1991 - 2013 Banff Conferences on
Allograft Pathology All rights reserved.
November 04, 2016 03:28:19 PM