Red Blood Cells Derived from Whole Blood Treated with Riboflavin and UV Light Maintain Adequate Cell Quality through 21 Days of Storage

Effects of pre-freeze pathogen reduction with riboflavin and UV light on red cells stored post-thaw in AS-3 additive solution

BACKGROUND

Pathogen reduction technology (PRT) may improve the safety of RBCs for transfusion. As the Czech Republic considers PRT, we asked what effects riboflavin and UV light PRT pre-freezing has on the post-thaw recovery and properties of cryopreserved RBCs (CRBCs) after deglycerolization and liquid storage.

STUDY DESIGN AND METHODS

24 Group O whole blood (WB) units were leukoreduced and then treated with riboflavin and UV light PRT (Mirasol, Terumo BCT, USA) before cryopreservation (T-CRBC); 20 similarly-collected units were untreated controls (C-CRBC). Units were processed to RBCs and then cryopreserved with 40% glycerol (wt/vol), frozen at -80°C, stored >118 days, reconstituted as deglycerolized RBC units in AS-3, and stored at 4 ± 2°C for 21 days. One treated unit sustained massive hemolysis during the post-thaw wash process and was removed from data analysis. The remaining units were assessed pre-PRT, post-PRT, and post-thaw-wash on days 0, 7, 14, and 21 for hematocrit, volume, hemoglobin per transfusion unit, pH, % hemolysis, hemoglobin in the supernatant, potassium, phosphorus, NH₃ , osmolality, ATP, and 2,3-diphosphoglycerate.

RESULTS

PRT with leukoreduction caused a 5% loss of RBC followed by a 24% freeze-thaw-wash related loss for a total 28% loss but treated units contained an average of 45 g of hemoglobin, meeting European Union guidelines for CRBC. T-CRBCs displayed higher post-wash hemolysis, potassium, and ammonia concentrations, and lower ATP at the end of storage.

CONCLUSIONS

Cryopreserved RBCs from Riboflavin and UV light-treated WB meet the criteria for clinical use for 7 days after thawing and provide additional protection against infectious threats.

New ultraviolet C light-based method for pathogen inactivation of red blood cell units

BACKGROUND

Pathogen inactivation (PI) technologies for platelet concentrates and plasma are steadily becoming more established, but new PI treatment options for red blood cells (RBCs), the most commonly used blood component, still need to be developed. We present a novel approach to inactivating pathogens in RBC units employing ultraviolet C (UVC) light.

METHODS

Whole blood-derived leukoreduced RBCs suspended in PAGGS-C, a third generation additive solution, served as test samples, and RBCs in PAGGS-C or SAG-M as controls. Vigorous agitation and hematocrit reduction by diluting the RBCs with additional additive solution during illumination ensured that UVC light penetrated and inactivated the nine bacteria and eight virus species tested. Bacterial and viral infectivity assays and in vitro analyses were performed to evaluate the system's PI capacity and to measure the RBC quality, metabolic, functional, and blood group serological parameters of UVC-treated versus untreated RBCs during 36-day storage.

RESULTS

UVC treatment of RBCs in the PAGGS-C additive solution did not alter RBC antigen expression, but significantly influenced some in vitro parameters. Compared to controls, hemolysis was higher in UVC-treated RBC units, but was still below 0.8% at 36 days of storage. Extracellular potassium increased early after PI treatment and reached ≤70 mmol/L by the end of storage. UVC-treated RBC units had higher glucose and 2,3-diphosphoglycerate levels than controls.

CONCLUSION

As UVC irradiation efficiently reduces the infectivity of relevant bacteria and viruses while maintaining the quality of RBCs, the proposed method offers a new approach for PI of RBC concentrates.

Assessing quality of blood components derived from whole blood treated with riboflavin and ultraviolet light and separated with a fully automated device

BACKGROUND

Combining pathogen reduction and automated separation of whole blood (WB), together with the use of improved additive solutions, may increase reproducibility and extend shelf-life of blood components.

MATERIALS AND METHODS

Forty WB units were collected from volunteer donors and randomised 1:1 into two groups: 1) pathogen reduction with riboflavin and ultraviolet light (PRT); or 2) no treatment (Control). After two hours (h) at room temperature, all units underwent fully automated separation into red blood cell concentrate (RBCC), plasma and leukopack components. RBCCs were leukoreduced and stored in phosphate-adenine-glucose-guanosine-saline-mannitol (PAGGSM) solution while plasma units were shock frozen within 8 h of collection and stored at ≤ -25°C. RBCCs were sampled on day 1 and weekly thereafter until day 42, while plasma was sampled on days 1 and 30. The main study objective was to assess the in vitro quality of separated RBCCs using biochemical and haematological parameters. Plasma protein content after one cycle of freeze-thaw was also analysed.

RESULTS

The quality of RBCCs was largely comparable between the PRT and Control groups, except for a significantly higher degree of haemolysis and extracellular potassium levels in the PRT group after 35 days of storage. While potassium concentration was significantly higher in the PRT group at all timepoints, the degree of haemolysis exceeded the accepted European threshold (i.e., <0.8% of red cell mass in ≥ 90.0% of tested units) after day 35. Most plasma protein levels were significantly lower in the PRT than the Control group at both day 1 and day 30.

DISCUSSION

Pathogen reduction with riboflavin and ultraviolet light treatment of WB can be combined with fully automated separation to obtain RBCCs that may be stored for up to 35 days in PAGGSM solution with acceptable quality, comparable to that of RBCCs from untreated blood. The relative differences between factor concentrations in plasma from the PRT and the Control groups were similar during the 30-day storage.