An in vitro comparison of Red Blood Cell haemolysis in neocyte-enriched and leucocyte-poor blood

Abstract

Introduction Red blood cell concentrates (RBCC) have a shelf life of 42 days when stored at 1-6 ºC. This may lead to shortages and wastage as biological changes develop due to storage lesions leading to the unit having to be discarded. Pooled neocytes could potentially extend the shelf life of the RBCC unit. Patients with chronic anaemia depend on regular blood transfusions which could lead to transfusion complications. This study was conducted in an attempt to improve the longevity of stored red blood cells (RBC), through isolating neocytes and comparing the rate of haemolysis, biochemical changes and viability with filtered blood. Methodology Thirty filtered units were processed from fresh whole blood. Two transfer bags were attached to the filtered blood cell unit by using a sterile heat sealer. The neocytes and the additives were extracted from the filtered blood unit. These were centrifuged and the two transfer bags were placed on separate scales. The additive was separated into one satellite bag while the concentrated neocytes were separated into the second satellite bag. The Saline Adenine Glucose Mannitol nutrients were added to the neocyte-enriched bag and the transfer tube between the two bags was sealed. The nutrient transfer bag was then discarded and the neocyte bag was the final required product. Both unit types were stored for 42 days and every 14 days samples were analysed for RBC count, mean corpuscular volume, mean corpuscular haemoglobin concentration, haemoglobin, sodium and plasma haemolysis using standardised techniques. Results Although the red cell count was decreased in the filtered blood unit compared to the neocyte-enriched unit, this difference was not significant (p = 0,27). In both unit types the mean corpuscular volume increased (p = 0,87), while the mean corpuscular haemoglobin concentration decreased over all time points (p = 0,44). Sodium levels decreased over the storage period (p = 0,14) while the percentage plasma haemolysis increased steadily in both units (p = 0,65). The haemoglobin remained stable for both neocyte-enriched and filtered blood. Conclusion The outcome of this study demonstrated that neocyte-enriched blood did not have a survival advantage when compared to pre-stored leucocyte reduced RBC using the conventional manual collection method. These results are similar to previous studies which utilised multiple methods to collect a high neocyte yield. Feasibility was highlighted as the main challenge as many of these methods have proven to be too expensive and too laborious.