Background/Case Studies: Recent supply chain disruptions have impacted the manufacturer of 1.6% NaCl (saline solution) used in automated cell washing instruments in the manufacturing of deglycerolized products. The immediate availability of deglycerolized red blood cell (DRBC) products is critical for patients with multiple alloantibodies or antibodies to high-incidence antigens. In response, an alternative method for manufacturing DRBC using only 12% NaCl and 0.9% NaCl with 0.2% dextrose solutions was validated.
Study
Design/Methods: A total of 8 high-glycerol cryopreserved red cell units were deglycerolized during the validation period. The cryopreserved RBC units chosen were close to expiration to simulate “worse case” scenario units. All of the DRBC units had expiration dates that were within a year of the validation period. The vendor protocol for high-glycerol deglycerolization was modified to substitute the 1.6% NaCl for 0.9% NaCl with 0.2% dextrose; resulting with this alternative method using 2 bags of 1000mL 0.9% NaCl with 0.2% dextrose. After processing, the DRBC units were evaluated for RBC % recovery, specific gravity, and hemolysis using the vendor provided hemoglobin color comparator.
Results/Findings: The average red cell percent recovery for the DRBC units was 86%. The hemolysis level for each unit was measured using the vendor’s “Free Hemoglobin Visual Comparator”. The comparator measures hemoglobin on a scale of 1-8, with 1-4 being within acceptable level. The average hemoglobin level for all units processed was 3. Specific gravity was accessed using a clinical refractometer, the acceptable range being any value below 1.020. Each unit measured below the acceptable threshold of 1.020 for specific gravity indicating the glycerol was effectively removed. Details on the individual unit results are listed in Table 1 seen below.
Conclusions: The average red cell percent recovery satisfied the current quality control standard of 80%. The percent recovery and “Free Hemoglobin Visual Comparator” results indicate there was no significant increase in cell lysis despite the change in NaCl concentrations.
The specific gravity for each unit was within the acceptable range; indicating that sufficient removal of glycerol from the red cells was achieved. This alternative method can be seen as a viable option for maintaining rare RBC availability, as the trial units did not display excess hemolysis or increased glycerol retention.
