Association of increased erythrocyte osmotic resistance with haematological and histopathological findings in dogs with a congenital extrahepatic portosystemic shunt

Abstract

The aim of the study was to investigate changes in erythrocyte osmotic resistance in relation to haematological and histological changes in dogs with a congenital portosystemic shunt. Osmotic fragility tests with complete blood counts and liver histological examinations were performed in 12 dogs with single extrahepatic portosystemic shunt confirmed by surgical exploration. Laboratory results were compared with those from 30 healthy dogs. Dogs with portosystemic shunt had a significantly increased erythrocyte osmotic resistance (P < 0.01) with 5%, 50% and 90% haemolysis corresponding to 0.45%, 0.35% and 0.30% NaCl solution, respectively. Statistical analyses revealed no correlation between haematological indicators and the osmotic fragility test results. Increased osmotic resistance was significantly associated with hepatic lipogranulomas. Based on these results, dogs with a congenital portosystemic shunt have a significantly increased erythrocyte osmotic resistance suggesting impaired red blood cell deformability. Osmotic resistance test that until now was not studied in canine hepatopathies seems to be independent of routinely performed haematological tests. Portosystemic vascular anomaly, osmotic fragility, liver biopsy, caninePortosystemic shunt (PSS) is the most common vascular anomaly in dogs. Persistent communication in single PSS allows blood to bypass the liver and be delivered directly from the portal bloodstream into systemic circulation. All laboratory abnormalities are related to secondary metabolic changes due to progressive liver atrophy (Mathews and Bunch 2005).In human medicine, chronic liver diseases are associated with increased erythrocyte osmotic resistance (OR) due to accumulation of membrane cholesterol as a result of impaired lipid metabolism. This change in membrane composition with an increased surface area to volume ratio morphologically corresponding to target cells, has a direct effect on red blood cell deformability (Vassiliadis et al. 2010). Target cells are commonly also seen in dogs with chronic liver disorders, but the alterations in erythrocyte OR in hepatopathies have not been described, yet. A similar tendency for increased erythrocyte osmotic resistance in a portosystemic shunt could suggest a similar pathogenesis to impaired erythrocyte deformability in humans with chronic liver disease. Liver biopsy is the gold standard in the diagnostics of hepatic disorders.The aim of this study was to investigate changes in erythrocyte osmotic resistance in dogs with a single extrahepatic portosystemic shunt, and to determine associations with alterations in the haematology profile and liver histopathological findings.

Changes in Leukogram and Erythrogram Results in Bitches with Vaginitis

“…Acanthocytes were also detected in dogs with hemangiosarcoma, glomerulonephritis, as well as disseminated intravascular coagulation [ 28 ]. Leptocytes and codocytes were noted in hepatic insufficiency, especially in dogs and cats with portocaval shunts [ 27 , 29 ]. Sepsis leads to decreased red blood cell deformability in rats and mice [ 30 , 31 ] and altered erythrocyte morphology, with the formation of echinocytes, sphero-echinocytes, and spherostomatocytes [ 32 ].…”