The Expression of CD47 and its Association with Other Biochemical Storage

Abstract

Background: CD47 is an integrin associated protein which decreases with PRBCs (packed red blood cells) prolonged storage that possibly leads to less effective blood transfusion. Electrolyte imbalance occurs due to inactivation of Na+/K+ ATPase pump in low temperature which in turn leads to continuous increase of extracellular potassium, which is considered life threatening for patients with renal failure or those with massive transfusions. The objective of the present study is to evaluate the expression of CD47 by flow cytometry with other biochemical storage changes (pH, sodium and potassium ions) in CPD/SAGM packed non-leucoreduced Group (A) versus CPD/SAGM leucoreduced Group (B) red blood cell units at different storage times (on day 7, 14, 28 from date of red blood cells collection).Subjects and Methods: Nearly 450 ml of whole blood is obtained into quadruple blood bags and further subdivided into 20 non-leucoreduced units and 20 leucoreduced units. Non-leucoreduced and leucoreduced units are stored at 4 ± 2•C. Samples are taken from each packed red blood cell unit at days 7, 14 and 28 and tested for Na+ and K+ ions, pH and CD47 marker by flow cytometry.Results: Both leucoreduced and non-leucoreduced units show a highly significant decrease in Na+, pH and CD47 expression and a highly significant increase in K+ level. However, there was no statistically significant difference found between the 2 studied groups regarding Na+ and K+ levels, pH and CD47 expression on packed red cells except for Na+ on 28 th day which was slightly higher in leucoredced than non-leucoreduced units. Conclusion:Red cell storage lesion is an inevitable process. Our study showed a highly statistically significant decrease in CD47 by flow cytometry in both leucoreduced and non-leucoreduced PRBCs along the storage period from day 7 to day 28.