Formally established in 1990, the Division of Transplant Pathology plays
an integral part in the comprehensive transplant program at the University
of Pittsburgh Medical Center and its satellite center in Palermo,
Italy. The mission of the Division is to provide up-to-date
laboratory services emphasizing continued excellence in patient care,
to provide expert consultation, to foster an academic environment
devoted to education and training, and to conduct basic and clinically
oriented research in transplantation pathology. A nucleus of
professionals with expertise in pathology, immunology and molecular
biology is actively involved in many transplantation related research
projects at the Thomas E. Starzl Transplantation Institute.
The Division offers a wide range of laboratory tests and tissue analyses
for patients and experimental studies. Routine histology, specialized
immunocytochemistry and in situ hybridization procedures are performed
on tissues from patients under consideration for transplantation, on
native organ resections and on post-transplant biopsies. These
procedures assure consistency of analysis and continuity of patient care. Post-transplant
monitoring assays deal with lymphocyte reactivity and cytokine production
and detection of cytomegalovirus, Epstein-Barr virus, and Hepatitis viruses,
among other infectious agents.
The division has established and maintains an active telepathology consultation
service. We developed a specific HIPPA-compliant software with
Diversified Services, Inc. that is used to triage and respond to cases. We
have also recently integrated robotic microscope capabilities (Trestle
Systems) into the software applications.
Drs. Zeevi and Duquesnoy are the Co-Directors of the UPMC-Presbyterian Tissue
Typing Laboratory, which offers histocompatibility-testing services
to the organ transplantation program at the University of Pittsburgh
Medical Center. In 2004, this laboratory performed donor workups
as follows: kidney transplants from living donors (98), non-living
donors (100), liver transplants from living donors (38), non-living
donors (256), transplant of pancreas (29), kidney/pancreas (23), heart
(53), intestine (48), lung (50), and double lung (20).
The Division offers comprehensive consultation in liver, kidney, and
solid organ transplantation pathology to community and university-based
physicians. The scope of this service encompasses the evaluation
of liver, heart, intestinal and kidney disease in prospective transplantation
candidates, donor recipient histocompatibility issues, the examination
of native explanted organs, and the evaluation of post-transplant biopsies
or resections to evaluate the causes of allograft dysfunction such as
infection, ischemia, rejection, technical complications, recurrent disease
and post-transplant malignancies. These consultation services are
also available through the Internet (http://path.upmc.edu/divisions/transpath/hepa00.html).
For the period of July 1, 2004 through June 30, 2005, the professional
workload on outside consultation cases was:
Anthony J. Demetris, M.D.: 286 cases
Michael A. Nalesnik, M.D.: 315 cases
Parmjeet Randhawa, M.D.: 269 cases
Tong Wu, M.D., Ph.D: 234 cases
Erin Ochoa, M.D.: 107 cases
The Division has a strong commitment to research in transplantation. Each
professional is actively engaged in research projects frequently in collaboration
with members of other departments, in particular, Transplant Surgery. Over
the year, faculty of the Division contributed 62 refereed publications,
invited reviews and book chapters. Thirty-two invited lectures
and scientific meeting presentations were given outside the institution,
including 15 talks abroad. Several members serve on grant review
committees and editorial boards of major professional journals.
Current research activities deal with a variety of projects:
Studies on the role of IL-6 in liver disease have shown that this
cytokine is essential for maintaining biliary tree integrity and liver
mass under conditions of biomedical stress, such as obstructive cholangiopathy. Using
IL-6 deficient mice, a model of accelerated development and decompensation
of biliary cirrhosis has been established. Analysis of IL-6/gp/30-dependent
transcription factor activation is being used to determine how these
signaling pathways contribute to the phenotype observed.
Experimental animal and clinical studies show that the development
of cirrhosis and decompensation are heavily influenced by oxidative
stress in hepatocytes, which up regulates the cyclin-dependent kinase
inhibitor, p21. This in turn, inhibits hepatocyte proliferation
and accelerates the development of cirrhosis and decompensation.
The Research Histology Laboratory of the Division serves as the Core
Liver Tissue Laboratory for the Immune Tolerance Network (ITN). Specific
Web-based software has been developed to communicate results to investigators
throughout the world on a real time basis. Data management tools
are being developed for this application.
The division also maintains a robust clinical database, as a part
of EDIT (Electronic Data Interface for Transplantation). This
database links histology diagnoses and histologic finding with a multitude
of clinical, serologic, matching, donor and outcome parameters. The
database is an invaluable resource for clinical and patient-based research
Dendritic cells play an important role in inflammatory diseases, including
allograft rejection, and steatohepatitis, as well as in tolerance to
solid organ allografts. IL-6/gp130 signaling plays an important
role in their maturation. Continuing studies are investigating
the role of IL-6 dependent co-factors in dendritic cells maturation.
During rejection, cardiac allografts undergo a stress response, which
leads to an increased expression of heat shock proteins and the infiltration
of hsp-dependent autoreactive lymphocytes. Heat shock proteins
also play a role in transplant immunity associated with chronic rejection.
Serological studies deal with the characterization of antibodies against
private and public HLA epitopes and their correlation with amino acid
residues. Screening of sera from highly sensitized patients permits
the identification of potential donors with acceptable mismatches and
the assessment of the relative immunogenicity HLA antigens.
A computer algorithm has been developed (HLA Matchmaker) that assesses
donor- recipient HLA compatibility at the amino acid structural level. The
algorithm makes intralocus and interlocus comparisons of amino acid
triplets of HLA class I antigens.
Lung Transplantation is the only therapeutic option for many fatal
lung diseases. The current immunosuppression protocols based
on systemic cyclosporine or tacrolimus are not adequate to control
rejection. A unique option is to target a high concentration
of the immunosuppressive drugs to the lung allograft without increasing
the systemic levels that might be toxic. Studies are conducted
in lung transplant patients that receive aerosol CsA and in control
patients on the role of various cytokines and effector molecules that
can cause allograft damage and dysfunction. We also evaluate
the impact of aerosol CsA on suppressing alloreactive T cells, on the
alloantibody formation and release of soluble donor derived HLA antigen. We
are correlating the laboratory finding with the clinical parameters
and determining whether these tests can be used as early markers of
Based on in vitro and in vivo evaluation or cytokine production, it
has been possible to characterize individuals as "high" or "low" producers
for a given cytokine. Such polymorphisms correspond to allelic
variation that can be determined by DNA genotyping. We are interested
to study what the relationship is between cytokine polymorphism and
clinical outcome after organ transplantation. High may develop
more acute producers of proinflammatory cytokines such as TNF- rejection
and require augmented immunosuppression. Iin contrast, patients
with and high IL-10 genotype (a suppressive cytokine) may experience
less low TNF- rejection. Cytokine polymorphisms may also influence
other post-transplantation outcomes such as infections and allergic
side effects of immunosuppressive agents.
Post-transplant lymphoproliferative disease cytokine analysis of autologous
EBV infected B cells has indicated Th2 type responsiveness during PTLD
and Th1 type responses in normal EBV seropositive individuals.
Autologous lymphokine-activated killer (LAK) cell therapy has been
successfully used to treat lymphoproliferative disorders arising in
organ transplant patients.
The clinical profile of patients with BK virus infection in the renal
allograft is defined. DNA sequencing of viral strains is being
used to define mutations and genomic rearrangements, which may be relevant
to the pathogenesis of an extremely refractory interstitial nephritis
seen in these individuals. Quantitative PCR assays have been
developed to measure viral load in biopsy samples and body fluids to
better manage the immunosuppression levels in these patients. The
interplay between host and viral immune factors in this disease is
being investigated by DNA microarray technology. Drugs with antiviral
activity are being screened in an in-vitro culture model for possible
future use in the clinical arena.
Studies on human hepatocytes have shown that IL-6 and HGF regulate
the activity of cytosolic phospholipase A2 (cPLA2) in cultured human
hepatocytes. The regulation of cPLA2 by cytokines and growth
factors may play a role in the pathophysiology of inflammatory and
non-inflammatory liver diseases.
Image analysis approaches are being applied to biopsy interpretation. Semi
automated morphometry is being coupled with a neural network approach
to evaluate fibrosis stage in chronic hepatitis, and image recognition
algorithms in conjunction with multispectral analysis are being applied
to the problem of rejection evaluation in kidney biopsies.
Human hepatobiliary cancers show increased expression of cyclooxygenase-2
(COX-2). Studies have demonstrated that activation of Akt is
an important mechanism by which COX-2 promotes hepatobiliary cancer
growth. Interruption of the COX-2 and prostaglandin signaling
pathways is being targeted for the chemoprevention and treatment of
human hepatobiliary cancers.
Peroxisome proliferator activated receptor-gamma (PPAR-gamma) ligands
have been shown to inhibit human cholangiocarcinoma growth via a p53-dependent
mechanism. These pharmacological agents may represent promising
therapeutic agents for the treatment of human cholangiocarcinoma.
Targeting p27kip1 to improve hepatocyte transplantation research. In
characterizing the cell-cycle regulatory role of the cyclin-dependent
kinase inhibitor, p27kip1, it was discovered that p27 knockout mice
exhibit pronounced multi-organomegaly with no increased spontaneous
carcinogenesis in the liver.
Optimizing outcome after pediatric heart transplantation. This
project focuses on different aspects of pediatric heart transplantation
and how to optimize outcomes and minimize drug-related complications.
The Division is strongly devoted to teaching and training in transplantation
pathology. Professional staff directed graduate students and
medical students in subjects, such as Cancer Biology, Digestion & Nutrition,
Immunology & Inflammation, Kidney Pathology, and Molecular Pathology. Visitors,
including fellows and pathologists from Turkey, Peru, Columbia, India,
Nigeria, and Canada, came to the Division for further training in transplant
The division also heads the Banff Working Group on Liver Allograft Pathology. This
group sets international guidelines for liver allograft biopsy interpretation
and meets every two years to present new findings in the field and discuss
Many pathology residents have rotated through the Division to receive
training in transplantation, hepatic and renal pathology. This
rotation is designed to provide a basic understanding of the molecular,
cellular and histopathologic mechanisms of transplant immunity, allograft
rejection opportunistic infections, organ preservation injury, recurrent
disease, drug toxicity graft versus host disease and lymphoproliferative
disease. During this rotation, the residents attended various transplant
conferences, research meetings and special lectures.
The Division conducts weekly interdisciplinary conferences on heart,
kidney, kidney/pancreas, intestine, liver and native liver pathology. Conferences
in conjunction with Transplant Surgery deal with liver transplant tumors
and Transplant Grand Rounds. There are also bimonthly meetings
to discuss research progress within the Division and weekly journal clubs.
Transplant Pathology Internet Service (TPIS)
Transplant Pathology Internet Services (TPIS): An Interactive Platform
for the Standardization of Transplantation Pathology Practice TPIS
is a worldwide web-based venture of the Division of Transplantation
Pathology and was originally designed to foster collaboration among
transplant institutions. It has grown to over 2,500 pages and has evolved
into an educational and interactive medium promoting both communication
and standardization of transplant pathology practice. It performs this
role using a three-pronged approach:
The first and largest component of TPIS is didactic and follows classical
web-based design. Twenty-nine separate transplant-related histologic
grading systems are incorporated with hyperlinked photomicrographs, serving
as a de facto standard for biopsy interpretation. One hundred sixty-five
separate consult cases, stripped of patient identifiers, are presented
with full discussion. In addition, separate didactic sections covering
the handling and pathology of all major transplant organs are presented.
A full- length textbook, abstracts and a separate with all references
hyperlinked to PubMed Immunopathology module provide complementary information
for the transplant pathologist. Several video lectures are also available
on the site.
The second component comprises interactive education. A case conference
module containing 101 separate transplant-related cases represents a
major portion of this section. Users can contribute cases or join in
discussions of cases. (A separate electronic forum also serves an educational
purpose, but has found its main use as a collaborative tool). A separate
histopathologic testing module that can be modified for self-assessment
or centralized scoring was added to conduct pathologist standardization
testing for an international clinical drug trial. This approach, which
can also be used for continuing medical education, has widespread applicability
for multi-center studies involving pathologists.
The third component that encourages standardized practice is an interactive
portion directed toward altering the practice of the individual pathologist.
In the simplest case, TPIS serves as a download site for specialized
software. At present we are offering software that performs HLA matching
using the CREG approach and written within our group, and we are also
offering telepathology software on a contractual basis. A second approach
uses Java applets to perform medical calculations, allowing the user
to perform calculations directly through the web browser. We have integrated
five separate formulas that calculate creatinine clearance based on different
clinical variables and offer all of these within our site. Similar calculations
can be performed for determination of hepatic iron index. Finally, we
are developing webware, based on the ImageJ applet from the NIH that
allows the pathologist to perform problem-directed image analysis such
as area measurement or nuclear counting directly through the browser. The
creation of such small, easy to use modules will not only offer additional
tools to the practicing pathologist but will serve to enhance image interpretation
and offer a new standard of practice for anatomic pathology.
In the last year, TPIS received 4,607,135 hits with an average of 12,622
(or 3501) pages viewed per day, transferring 108.116 gigabytes of data.
Definitive and freely available information-rich sites such as TPIS are
likely to become powerful voices in molding the practice of pathology
in the immediate future. We are presently upgrading our case database
to allow selection based upon individual Banff criteria of rejection. This
will provide the foundation for a novel and powerful teaching tool.