Background

Irradiation of blood products is most commonly used for reducing the risk of the transfusion-associated graft-versus-host disease (TA-GvHD) by preventing T-cell proliferation. In recent times, there have been strong efforts by governmental authorities in many countries to replace radioactive irradiators by x-ray irradiators for reasons of safety and sustainability. However, there is still limited data available on the quality of x-ray irradiated standard and pediatric units of red blood cells.

Methods

Red blood cells in additive solution PAGGS-M (Macopharma) were produced from whole blood (500 ml) in CPD anticoagulant (70 ml) by centrifugation and subsequent leukodepletion. RBC were x-ray irradiated using the RADGIL2 (Gilardoni) with > 25 Gy according to German guidelines. Pedriatric units were prepared by splitting a regular unit into four pediatric units after irradiation. Non-irradiated units served as controls. Relevant quality parameters were evaluated in x-ray irradiated and non-irradiated standard and pediatric units (n=12 each) of packed red blood cells at different time points of storage

Results

As expected, extracellular potassium was considerably elevated in irradiated packed red blood cells. The level of extracellular potassium was equal in standard and pediatric units and it was comparable (or slightly lower) in x-ray irradiated compared to gamma irradiated units (61.0 ± 1.9 mmol/l versus 69.5 ± 4.0 mmol/l) at the end of shelf life.

Hemolysis rate was increased in pediatric units but when irradiation is performed within 7 days after donation there is no difference between irradiated and control units up to 14 days after irradiation. All units met the criteria of German guidelines (hemolysis < 0.8%) at the end of the shelf life.

Conclusion

Extracellular potassium is of major concern in irradiated packed red blood cells. Potassium levels were similar in x-ray and gamma irradiated units, showing that x-ray is a good alternative to gamma irradiation. Early irradiation and short storage after irradiation are favorable, especially in pediatric units to reduce levels of extracellular potassium and rate of hemolysis.

Offenlegung Interessenkonflikt:

No conflict of interest.