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.