The effect of preanalytical phase on the stability of the osmotic fragility and morphological changes in erythrocytes in cattle (Bos taurus)

Abstract

Hereditary spherocytosis in cattle is a disorder that results from a nonsense mutation in SLC4A1 gene that encodes band 3 membrane protein. This membranopathy leads to a production of spherically-shaped RBCs with reduced deformability and shorter lifespan in circulation. The laboratory diagnosis of hereditary spherocytosis commonly rely on erytrocyte osmotic fragility test (OFT), which is time and work consuming and can be influenced by the preanalytical factors. The aim of the study was to determine the effect of the preanalytical phase on the stability of the osmotic fragility and morphological changes of bovine erythrocytes. The blood was collected from the tail vein from Holstein-Friesian cows (n = 20) into tubes with EDTA or lithium heparin. The erythrocyte resistance to hemolysis was measured by osmotic fragility test immediately after blood collection and 24, 48 and 72 hours after storage at 4oC or room temperature. The thin blood smears were also prepared, stained and examined for cell morphology.The results showed that bovine erythrocyte osmotic fragility remains stable during 24 hours storage at 4oC regardless of the anticoagulant used. It suggests the possibility of performing OFT the day after blood collection when storing blood at 4oC. It was also found that bovine erythrocytes stored at room temperature have reduced osmotic resistance. However, heparin better preserves osmotic resistance of bovine erythrocytes at room temperature. Erythrocytes that are stored undergo changes during the storage period. The microscopic examination of cell morphology revealed the transformation of bovine discocytes into different stages of echinocytes, which rapidly occurs during the first three days of storage.