Evaluation of two distinct cryoprotectants for cryopreservation of human red blood cell concentrates

Cryopreservaton of packed human red blood cells requires the use of cryoprotectants.

The study assessed physiological parameters of 40 RBC units frozen with either 40% glycerol or 6.7% HES.

After thawing, they were suspended in NaCl or in 6% HES. Tests of Hct, Hb, Na+ and K+ ions, ATP, 2,3-DPG, pH and erythrocyte stability were measured 30 minutes and 24 hours after thawing.

Hct was lower after thawing but did not differ significantly between two groups. Hb was lower after thawing, but was statistically significant higher in the HES group (43.8 g/unit vs 35.4 g/unit). K+ concentration increased after thawing and was significantly higher after 24 hours in the glycerol group (29.0 mEq/l vs 8.7 mEq/l). ATP concentration in the HES group was significantly lower (2.15 micromol/g) in comparison with the glycerol group (6.30 micromol/g) 24 hours after thawing. 2,3-DPG levels did not differ significantly between the methods. Stability of RBCs frozen in glycerol were better (94.58%) than RBCs frozen in HES (80.75%) measured 24 hours after thawing. ATP is better protected in erythrocytes frozen in glycerol than in HES.

Erythrocytes frozen with HES preserved more hemoglobin than with glycerol. Membrane permeability for Na+ and K+ ions was preserved better with HES. HES compared to glycerol offered better protection for erythrocytes.