Diagnostic and Therapeutic Applications of Microarrays in Liver Transplantation

INTERLIVER is a prospective observational study of the relationship of the molecular phenotype of 300 liver transplant biopsies to the histologic phenotype and the clinical features and outcomes. A segment of a biopsy performed as standard-of-care for indications, or by center protocol, will be used for gene expression study.

The current standard for biopsy-based diagnoses of dysfunction of liver transplants is histology (the Banff system), an arbitrary international empirical consensus based on lesions and rules, similar in principle to the kidney, heart, and lung histology systems. Recent data-driven approaches using molecular and conventional technologies indicate that such systems frequently produce incorrect diagnoses - perhaps 40-50% in abnormal kidney or heart transplant biopsies and even more in lung biopsies, with great potential for harm to patients due to inappropriate treatment. To address this unmet need and improve diagnostics in the area of organ transplantation, the Alberta Transplant Applied Genomics Centre (ATAGC, University of Alberta) has developed a new diagnostic system - the Molecular Microscope® Diagnostic System (MMDx) that interprets biopsies in terms of their molecular phenotype, and combines the molecular and histopathological features of transplant biopsies, plus clinical and laboratory parameters, to create the first Integrated Diagnostic System. The MMDx, developed first in kidney transplant biopsies because phenotypes are well established, will now be adapted to liver transplant biopsies. The present study will develop a Reference Set of liver biopsies, adapt the MMDx system to assess and report molecular phenotype of liver biopsies; and validate and refine this system in 300 unselected prospectively collected for clinical indications and a standard of care biopsies from North American and European Centers. In addition to demonstrating the real-time feasibility and potential value of this System in patient care, the study will develop and optimize a transparent and user-friendly reporting format to communicate this information to clinicians and obtain detailed feedback to improve its utility. Thanks to increasing interest and support from participating centers, INTERLIVER has already received 856 biopsies from 740 participants and will extend the Reference Set to 900 biopsies.