The Preparation of Frozen Red Blood Cells and a Procedure for Deglycerolizing Frozen RBCs using COBE 2991 Blood Cell Processor

Choi, Kyung Hwan; Rhu, Jong Ha; Park, Hae Ryoun; Kim, Hyun Ok

Abstract

BACKGROUND: The cryopreservation of red blood cells (RBCs) has not ever been applied to the clinical services in Korea. The aim of this study was designed to supply the frozen-thawed RBCs as a routine service through estimation of efficiency and safety after freezing, thawing and washing.
METHODS
Fifteen fresh packed RBCs were frozen with 40 percent(wt/vol) glycerol. After frozen storage at -70degrees for at least one month, the RBCs were thawed and washed in the COBE 2991 blood cell processor. We measured the blood cell count, RBC recovery rate, K+, LDH, specific gravity, osmolarity, and the percentage of hemolysis in the supernatant after deglycerolization. Autologous transfusions were done to the four voluntary donors with deglycerolized autologous blood for clinical assessment.
RESULTS
The freeze-thaw-wash recovery rate of RBC was 76.8+/-10.0%, which is not enough to pass the AABB standard. But the recovery rate was increased up to 87.0+/-2.1% with the 4 stepwise predilution technique. The supernatant plasma specific gravity, osmolarity, and K+ were 1.006+/-0.001, 292+/-3 mOsm/KgH20, and 1.1+/-0.2mEq/L, respectively. The Hb ATP and 2,3-DPG were 3.6+/-0.8nmol/g and 13.4+/-4.5nmol/g. In simulated study, the free hemoglobin was 2.8+/-1.1mg/dL and 0.4+/-0.2% of total hemoglobin. In four autologous transfusion cases, plasma haptoglobin level was 96.0+/-40.8 mg/dL (reference range 30~200 mg/dL) and urine hemoglobin was not observed after 2~6 hours later after transfusion.
CONCLUSION
The results of this study indicated that technical experiences for freezing, thawing and washing were established for clinical use of frozen RBCs in Korea.