Red blood cells undergo a series of biochemical fluctuations during 35–42-day storage period at 1°C to 6°C. The sodium/potassium pump is immobilised causing a decrease in intracellular potassium with an increase in cytoplasmic sodium levels, glucose levels decline, and acidosis occurs as a result of low pH levels. The frailty of stored erythrocytes triggers the formation of haemoglobin-containing microparticles and the release of cell-free haemoglobin which may add to transfusion difficulties. Lipid peroxidation, oxidative stress to band 3 structures, and other morphological and structural molecular changes also occur leading to spheroechinocytes and osmotic fragility. These changes that transpire in the red cells during the storage period are referred to as “storage lesions.” It is well documented that gamma irradiation exacerbates storage lesions and the reports of increased potassium levels leading to adverse reactions observed in neonates and infants have been of particular concern. There are, however, remarkably few systematic studies comparing the in vitro storage lesions of irradiated and nonirradiated red cell concentrates and it has been suggested that the impact of storage lesions on leucocyte reduced red blood cell concentrate (RBCC) is incomplete. The review examines storage lesions in red blood cells and their adverse effects in reference to blood transfusion.

BackgroundStorage lesions occur in red blood cell products when potassium ions, haemoglobin and lactate dehydrogenase are released into the extracellular plasma due to post-irradiation storage or cellular degeneration. The South African blood transfusion establishments do not comply with the universal leucocyte-reduction policy due to cost and the current HIV pandemic. Various studies regarding storage lesions have been completed in well-developed countries but not in Cape Town, South Africa.ObjectiveThis study aimed to determine cellular degeneration occurring in non-irradiated and irradiated red blood cells (RBC) by comparing the measured biochemical and haematological indices during storage of up to 42 days.MethodEighty whole blood units were collected from voluntary, non-remunerated donors. Blood components tested weekly until expiry were whole blood, RBC concentrate, leucocyte-reduced RBC concentrate (pre-storage) and paediatric RBC concentrate (n = 20). Ten units per product were irradiated and 10 were not. Evaluations included potassium, sodium, glucose, lactate dehydrogenase, phosphate, haemoglobin, haematocrit, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentrate, mean cell volume and plasma haemoglobin. Plasma haemolysis levels were calculated using an approved formula.ResultsThe haemolysis levels evaluated on Day 35 and Day 42 were higher than the recommended 0.8%, whereas results for the non-irradiated components up to expiry were all below 0.8%.ConclusionThis study confirms that gamma irradiation aggravates the RBC storage lesions. The products tested yielded similar results to other studies in developed countries, however the South Africa transfusion medicine policy should remain unchanged.