title: Spontaneous cardiomyopathy in cynomolgus monkeys (Macaca fascicularis).
abstract: A previously undescribed spontaneous cardiomyopathy was identified by routine light microscopic examination of the heart from four clinically healthy purpose-bred cynomolgus monkeys that ranged from four to nine years of age and included 2 males and 2 females. Special stains of Sirius red, Masson's trichrome, and Mallory's phosphotungstic acid hematoxylin (PTAH); and immunohistochemistry using anti-CD68, troponin-I, and desmin antibodies were used to facilitate lesion characterization and assess cardiomyocyte viability. Microscopically, the apical to mid-ventricular myocardium to subendocardium had foci of cardiomyocyte disarray with cytoplasmic pallor to stippling and karyomegaly, vacuolization of the perimyseal connective tissue, a meshwork of fibrous tissue that concentrated around medium-sized blood vessels and dissected between or less often replaced affected cardiomyocytes; and a minimal, predominantly macrophage infiltrate. The disrupted cardiomyocytes were immunoreactive to desmin and troponin-I antibodies and had a normal cross-striation pattern by PTAH, indicating the chronic cardiomyopathy was not associated with active cardiomyocyte damage. The consistent distribution and morphology of the cardiomyopathy suggested a common etiology and pathogenesis. The features were reminiscent of chronic catecholamine-induced experimental cardiomyopathy and stress cardiomyopathy in monkeys and humans, respectively. This report documents another spontaneous heart lesion in clinically healthy monkeys for consideration during interpretation of toxicology studies.
authors.affiliation: Roche Pharmaceuticals, Pathology Department, Non-clinical safety, Palo Alto, CA 94304, USA. tanja.zabka@roche.com
authors.forename: Tanja S
authors.initials: TS
authors.lastname: Zabka
authors.forename: Michael
authors.initials: M
authors.lastname: Irwin
authors.forename: Mudher A
authors.initials: MA
authors.lastname: Albassam
mesh_terms: D000818:Animals; D009202:Cardiomyopathies / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D003094:Collagen / Q000378:metabolism; D005260:Female; D006651:Histocytochemistry; D008252:Macaca fascicularis; D008297:Male; D008992:Monkey Diseases / Q000378:metabolism / Q000473:pathology*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology
chemical_list: D003094:Collagen