Pathological Biomarkers in Toxicology

The introduction of the autopsy/necropsy service and use of the microscope to investigate disease in humans and animals were important milestones in the development of postmortem morphologic end points, recognizable as pathological biomarkers for diagnosis. Later, the integration of special histopathologic techniques, such as electron microscopy, confocal laser scanning microscopy, immunohistochemistry and in situ hybridization resulted in increased accuracy of diagnoses. These techniques facilitated the transition of diagnostic pathology toward a prognostic and therapeutically oriented discipline and increased involvement in research and development of biomarkers. Morphologic pathology has been accepted as the gold standard in the validation of specificity and sensitivity of established biomarkers as well as many novel biomarkers under investigation. Examples of gross and microscopic pathological biomarkers are provided herein.