Quality of red blood cells washed using an automated cell processor with and without irradiation

Sterile washing of red blood cells (RBCs) and use of an additive solution permits longer postwash storage. The effect of irradiation during this extended storage time is unclear.

RBCs were washed 14 days after collection using an automated cell processor and stored in saline-adenine-glucose-mannitol. To determine how long washed and irradiated RBCs could be stored, units were irradiated 1, 4, 5, and 7 days after washing and in vitro quality was assessed. Determined limits of postwash storage time for washed and washed and irradiated RBCs were validated. Quality assessment included percent recovery, hemoglobin (Hb), hemolysis, extracellular K(+) , and adenosine triphosphate. Immunoglobulin (Ig)A levels were measured in the nonirradiated arm.

RBCs irradiated 1 and 4 days after washing had unacceptably high hemolysis by Day 7 postwash, not meeting the acceptance criterion (<0.8% hemolysis in 98% of units with 95% confidence). Therefore, a 48-hour maximum storage time after irradiation was chosen. Storage limits tested in the validation phase were as follows: washing on Day 14 and subsequent storage for 7 days (washed RBCs) and washing on Day 14, irradiation on Day 19, and subsequent storage for 48 hours (washed and irradiated RBCs). All units met criteria for Hb, hematocrit, hemolysis, and sterility for washed RBCs. However, RBCs were washed with less than 2 L of saline, and IgA levels in 27 of 40 units were too high to be suitable for transfusion to IgA-deficient recipients.

The extended expiry for washed and washed and irradiated RBCs met requirements for all indications except transfusion to IgA-deficient recipients.