Molecular transplantation pathology: the interface between molecules and histopathology

In the last decade, high-throughput molecular screening methods have revolutionized the transplantation research. This article reviews the new knowledge that has emerged from transplant patient sample-derived 'omics data by examining the interface between molecular signals and allograft pathology.

State-of-the-art molecular studies have shed light on the biology of organ transplant diseases and provided several potential molecular tests with diagnostic, prognostic, and theranostic applications for the implementation of personalized medicine in transplantation. By comprehensive molecular profiling of patient samples, we have learned numerous new insights into the effector mechanisms and parenchymal response during allograft diseases. It has become evident that molecular profiles are coordinated and move in patterns similar to histopathology lesions, and therefore lack qualitative specificity. However, molecular tests can empower precision diagnosis and prognostication through their objective and quantitative manner when they are integrated in a holistic approach with histopathology and clinical factors of patients.

Despite clever science and large amounts of public money invested in transplant 'omics studies, multiparametric molecular testing has not yet been translated to patient care. There are serious challenges in the implementation of transplant molecular diagnostics that have increased frustration in transplant community. We appeal for a full collaboration between pathologists and researchers to accelerate transition from research to clinical practice in transplantation.