Determining whether or not a pathologic finding should be regarded as adverse has posed a conundrum for histopathologists for longer than I have been in the business. Much of the problem stemmed from the lack of a workable definition of adverse that could be useful to the pathologist and toxicologist and also acceptable to regulatory authorities. Definitions of adverse have been presented in a variety of laws, regulations, and in the scientific literature, but none have really caught on. The most recent foray into the fray from an ILSI HESI committee may finally succeed. Keller et al. (Tox Sci. 126(2), 291-297, 2012) recently presented what appears to be a workable hybrid of the previous endeavors. In their paper, an adverse effect is defined as “A change in morphology, physiology, growth, development, reproduction, or life span of a cell or organism, system, or (sub)-population that results in an impairment of functional capacity, an impairment of the capacity to compensate for additional stress, or an increase in susceptibility to other influences.” Hopefully, pathologists will find this definition useful in preparation of their reports. At least we will have a foundation to work from and a reference to provide to regulatory authorities representing an opinion from industry, academia, and government.
Dr. Jeff Engelhardt