Assessment of Dependence of Erythrocyte Lysis Rates on Amount of Microspherocytes in Hereditary Spherocytosis

Abstract

INTRODUCTION: Hereditary spherocytosis (HS) is a disease, which belongs to congenital membranopathies and runs with hemolytic anemia of different severity. In patients with HS, morphologically transformed erythrocytes — microspherocytes — appear in blood in different quantities. Erythrocyte lysis rates in patients with HS are significantly higher than in individuals with no hematologic diseases in history, however, there are no studies demonstrating the relationship between the amount of microspherocytes and erythrocyte lysis rates. AIM: Was to establish correlation between erythrocyte lysis rates and the amount of microspherocytes in patients with HS. MATERIALS AND MATERIALS: Study material was venous blood of 15 patients with HS (the main group) and of 14 “healthy” individuals (control group). Venous blood was taken into test tubes with K3EDTA as an anticoagulant for calculation of morphometric parameters of erythrocytes, and into test tubes with Li-heparin for determination of erythrocyte lysis rates. Morphometric parameters of erythrocytes were calculated using VideoTesT-Morphologia hardware and software complex. For each erythrocyte, average surface area, average diameter, thickness and sphericity index were determined Erythrocyte lysis rate was determined with use of glycerol reagent (glycerol test) on Vitalon-400 semi-automatic biochemical analyzer, and was assessed by reduction of optical density of the incubation medium and expressed as the difference between the initial and final optical densities multiplied by 1 000 (standard units). Statistic data processing was carried out using parametric and non-parametric statistical methods, and Spearman correlation analysis was performed by Spearman method using Sigma-Plot 11.0 software. RESULTS: Erythrocyte lysis in glycerol test occurred faster in patients with HS than in “healthy” persons due to instability of membrane of microspherocytes which make a significant proportion of erythrocytes in peripheral blood of patients with HS. CONCLUSIONS: A proportional dependence was established between the amount of microspherocytes and increase in the rate of erythrocyte lysis, which indicates their instability typical of HS. This dependence permits to use the automated glycerol test with graphic record of erythrocyte lysis rate for detection of microspherocytes in blood of patients with HS, when morphometric hardware and software complex is not available in clinical diagnostic laboratories.