Research Relevant Conditions and Pathology in Nonhuman Primates

Abstract

Biomedical research involving animal models continues to provide important insights into disease pathogenesis and treatment of diseases that impact human health. In particular, nonhuman primates (NHPs) have been used extensively in translational research due to their phylogenetic proximity to humans and similarities to disease pathogenesis and treatment responses as assessed in clinical trials. Microscopic changes in tissues remain a significant endpoint in studies involving these models. Spontaneous, expected (ie, incidental or background) histopathologic changes are commonly encountered and influenced by species, genetic variations, age, and geographical origin of animals, including exposure to infectious or parasitic agents. Often, the background findings confound study-related changes, because numbers of NHPs used in research are limited by animal welfare and other considerations. Moreover, background findings in NHPs can be exacerbated by experimental conditions such as treatment with xenobiotics (eg, infectious morphological changes related to immunosuppressive therapy). This review and summary of research-relevant conditions and pathology in rhesus and cynomolgus macaques, baboons, African green monkeys, common marmosets, tamarins, and squirrel and owl monkeys aims to improve the interpretation and validity of NHP studies.

Hericium erinaceus mycelium‐Derived Polysaccharide Alleviates Ulcerative Colitis and Modulates Gut Microbiota in Cynomolgus Monkeys

“…The monkey model in this study not only over additional model but of a higher class as monkeys are phylogenetically closer to humans. [ 29 ] Thus, it is a step further in the clinical application process in having experimental models which more accurately mimics the human condition. It could therefore be speculated that findings based on this higher animal model have a higher potential for translation into clinical practice.…”

The Common Marmoset—Biomedical Research Animal Model Applications and Common Spontaneous Diseases

“…Other less prevalent diseases occur in marmosets and a complete inventory of spontaneous diseases in marmoset was recently reviewed. 113…”

The Histology of Background Pathological Processes in Cynomolgus Monkeys (Macaca fascicularis) from Control Groups in Toxicology Studies

“…Samples of the studied organs were fixed in a 10% neutral buffered formalin, dehydrated through a series of alcohol solutions with increasing concentrations and cytosols, and embedded in paraffin HISTAMIX (BioVitrum, Russia). [3][4] μm sections prepared on a Rotary Microtome Microm HM355S (Thermo Scientific) were stained with eosin and hematoxylin using a standard technique, as well as Perls's staining was used to detect hemosiderin. We also used polarizing microscopy to confirm the presence of exogenous pigment in the lungs.…”

“…Nonclinical safety studies with biopharmaceuticals usually use nonhuman primates, primarily cynomolgus monkeys (M. fascicularis), as a test system, since, due to their close phylogenetic relationship with humans, primates are often the only relevant animal species for assessing the safety of targeted drugs [1,2]. However, in some cases, clinically healthy monkeys have some background pathology changes [3,4] which develop either before administration of the drug or during the experiment and, in turn, when identified in a histological examination, may affect the accuracy of the results of an evaluation of toxicity studies. The correct interpretation of pathomorphological abnormalities is of utmost importance, since, in some cases, it can affect the general conclusion on a safety study of a drug and the characteristics of its toxicological profile.…”