Red blood cell preservation by droplet freezing with polyvinylpyrrolidone or sucrose-dextrose and by bulk freezing with glycerol.

BACKGROUND: Red blood cell (RBC) preservation is essential to transfusion medicine. Many blood group reference laboratories need a method to preserve rare blood samples for serologic testing at a later date. This study offers a comparison of three common cryoprotective agents and protocols used today: bulk preservation with glycerol and droplet freezing with sucrose-dextrose (S+D) or polyvinylpyrrolidone (PVP). STUDY DESIGN AND METHODS: Human blood from 14 volunteers was collected and frozen at set intervals over 2 weeks with PVP, S+D, or glycerol. The frozen RBCs were later thawed and the percentage of surviving RBCs was determined. Detailed protocols and an instructional video are supplied. RESULTS: Over a 2-week period, RBCs preserved with glycerol and thawed with a widely used protocol showed a recovery of 41 ± 16% (mean ± standard deviation) while those thawed with a modified glycerol protocol showed a recovery of 76 ± 8%. RBCs preserved by droplet freezing with S+D showed a recovery of 56 ± 11% while those preserved by droplet freezing with PVP showed a recovery of 85 ± 6%. Recovery values were similar with ethylenediaminetetraacetic acid or heparin anticoagulants, differing freezing rates, and varying droplet volumes. CONCLUSION: Droplet freezing with PVP offered the greatest recovery. While bulk freezing with glycerol can also be effective, droplet freezing may be a more convenient method overall. It requires less effort to thaw, needs much less storage room, and allows blood group laboratories to be frugal with thawing rare samples.

A practical strategy to reduce the risk of passive hemolysis by screening plateletpheresis donors for high-titer ABO antibodies.

BACKGROUND: Hemolytic transfusion reactions (HTRs) can occur from ABO-incompatible platelet (PLT) transfusions. After a series of cases at our institution, a procedure to screen all plateletpheresis donors for high-titer ABO antibodies was implemented. STUDY DESIGN AND METHODS: Plasma samples from plateletpheresis donors were screened using pooled 0.8% A1 and 0.8% B red blood cells (RBCs) in buffered gel. Dilutions of 1 in 150, 1 in 200, and 1 in 250 were sequentially evaluated. A component testing positive for high-titer ABO antibodies was restricted to ABO-identical or group O recipients or washed. RESULTS: At the initial dilution of 1 in 150, half of group O components were labeled as high titer. At the current dilution of 1 in 250, 25% of group O components are labeled as high titer. No PLT-associated HTR has been reported since screening began. CONCLUSION: Universal screening for high-titer ABO antibodies in plateletpheresis donors can be implemented efficiently to reduce the risk of HTRs. The cutoff for classifying a unit as high titer depends on the serologic method used and may be customized by the individual facility. Our screening method uses one gel test per donation regardless of blood group and a plasma dilution of 1 in 250 with pooled A1/B RBCs in buffered gel.

RH genotyping in a sickle cell disease patient contributing to hematopoietic stem cell transplantation donor selection and management.

African individuals harbor molecular RH variants, which permit alloantibody formation to high-prevalence Rh antigens after transfusions. Genotyping identifies such RH variants, which are often missed by serologic blood group typing. Comprehensive molecular blood group analysis using 3 genotyping platforms, nucleotide sequencing, and serologic evaluation was performed on a 7-year-old African male with sickle cell disease who developed an "e-like" antibody shortly after initiating monthly red blood cell (RBC) transfusions for silent stroke. Genotyping of the RH variant predicted a severe shortage of compatible RBCs for long-term transfusion support, which contributed to the decision for hematopoetic stem cell transplantation. RH genotyping confirmed the RH variant in the human leukocyte antigen-matched sibling donor. The patient's (C)ce(s) type 1 haplotype occurs in up to 11% of African American sickle cell disease patients; however, haplotype-matched RBCs were serologically incompatible. This case documents that blood unit selection should be based on genotype rather than one matching haplotype.