Estudo morfológico e imunohistoquímico (Troponina C) na detecção de lesões cardíacas secundárias à doença renal crônica em cães

Abstract

Acute or chronic abnormalities in cardiac function can lead to lesions in kidneys or heart and cause the Cardiorenal syndrome. This study had the objective to (1) to verify, based on morphology, the correlation between Chronic Kidney Disease (CKD) and cardiovascular injury, as well as to reveal the extent of the lesion in dogs; because initial regressive changes often cannot be discerned with hematoxylin and eosin staining (H&E) alone, and (2) to verify the reliability of immunohistochemistry with anti-cTnC human antibody, to detect heart lesions in dogs with renal failure. Cardiac fragments from 22 dogs were submitted to immunohistochemistry, which revealed reduction of cTnC levels in the cytoplasm of cardiomyocytes. This decrease in immunoreactivity occurred usually on the same myocytes with specifics changes in H&E stain, ranging from mild cell swelling to increased eosinophilia, loss of striation, cell lysis and karyolysis that sometimes was accompanied by a inflammatory infiltrate. In 10 cardiac fragments vascular injury was observed, ranging from mild swelling to necrosis of endothelial cells, with deposition of eosinophilic material (staining positively for collagen in Masson’s trichrome) in the vessel wall and mineralization. Grossly, there were left ventricular hypertrophy and extra-renal lesions of uremia, including glossitis and ulcerative stomatitis, uremic pneumo and gastropathy, and intercostal mineralization. The evaluated kidneys had lesions of differtnmet intensity, irregular surface, fibrosis and altered cortico-medullary relationship, hyalinization and glomerular sclerosis, marked tubular cell necrosis and mineralization, mononuclear infiltration, and interstitial fibrosis. In this study, the cardiac vascular lesions were correlated with changes resulting from long term uremia and/or combination of metabolic and cellular changes of the Cardiorenal syndrome type 4, wherein the chronic kidney impairment can induce chronic lesions in the heart