2015
Volume 15, Number 2, pp. 45–53
Decreased expression of CD47 and CD55 surface molecules on density-based subsets of red cells of β-thalassaemia intermedia patients compared to red cells of healthy blood donors
Angela Risso,1 Elena Mansutti1 and Jitendra N. Mehrishi2
1Dept of Agriculture and Environment Sciences, Cell Biochemistry Unit, Università di Udine, Italy
2The Cambridge Blood, Umbilical Cord Blood Stem Cells for Cell–Gene Thalassaemia, Sickle Cell Disease Therapy and Cultivated RBC Research Initiative, Cambridge, United Kingdom
The main cause of morbidity and mortality in β-thalassaemia patients is iron overload, due to blood transfusions and increased erythropoietin (EPO) plasma concentration, since high EPO levels increase iron absorption through downregulation of hepcidin. Determining transfusion protocols and timing requires examining medical and chemico-clinical parameters. We report data on the properties of density-based subsets of red blood cells (RBCs) of two Italian patients affected by β-thalassaemia intermedia, examined at different times. The separation of RBCs by density showed a higher than normal number of dense RBCs (ρ > 1.1092 g/cm3) and very dense RBCs (ρ ≥ 1.117 g/cm3). In each subset, when compared to the one from healthy blood, the viability and the expression of two membrane molecules, CD55 and CD47, able to prevent uncontrolled lysis and macrophagocytosis respectively, were lower. Analyses of the densities and of the membrane integrity in β-thalassaemic red cells should help assessing the number of damaged cells and improving transfusion timing. Dense cells can be detected even with modest equipment in resource-limited laboratories and could be of diagnostic value, as already demonstrated for sickle-shaped RBCs.
Keywords: erythrocytes, membrane molecules, Percoll gradient separation