Preparation of cryoprecipitate from riboflavin and UV light-treated plasma.

BACKGROUND AND OBJECTIVES: The Mirasol® pathogen reduction technology system for plasma is based on a riboflavin and UV light treatment process resulting in pathogen inactivation due to irreversible, photochemically induced damage of nucleic acids. This study was undertaken to evaluate the possibility of making pathogen reduced cryoprecipitate from riboflavin and UV light- treated plasma that meets the quality requirements specified by UK and European guidelines for untreated cryoprecipitate. MATERIALS AND METHODS: Cryoprecipitate was made from riboflavin and UV light-treated plasma. Plasma units were thawed over a 20 h period at 4°C, and variable centrifugation settings (from 654 g for 2 min to 5316 g for 6 min) were applied to identify the optimal centrifugation condition. Plasma proteins in cryoprecipitate units were characterized on a STA Compact, Diagnostica STAGO and Siemens BCS analyzer. RESULTS: Neither the centrifugation speed or time appeared to have an effect on the quality of the final cryoprecipitate product; however the initial solubilization of the cryoprecipitate product was found to be easier at the lower centrifugation setting (654 g for 2 min). Cryoprecipitate units prepared from Mirasol-treated plasma demonstrated protein levels that were less than levels in untreated products, but were on average 93 IU/unit, 262 mg/unit and 250 IU/unit for FVIII, fibrinogen and von Willebrand ristocetin cofactor activity, respectively. CONCLUSION: Cryoprecipitate products prepared from Mirasol-treated plasma using a centrifugation method contain levels of fibrinogen, FVIII and von Willebrand ristocetin cofactor activity, that meet both the European and UK guidelines for untreated cryoprecipitate. Flexibility in centrifugation conditions should allow blood banks to use their established centrifugation settings to make cryoprecipitate from Mirasol-treated plasma.

Quality of proteins in riboflavin and UV light-treated FFP during 1 year of storage at -18°C.

BACKGROUND: The Mirasol® Pathogen Reduction Technology (PRT) System for plasma combines riboflavin (vitamin B(2)) and UV light energy to reduce pathogens in plasma products. This study evaluated protein quality of apheresis derived plasma products treated with riboflavin and UV light and stored at -18°C for up to 1 year. Comparisons were made to paired, untreated controls after 6 months and 1 year of storage. METHODS: This study evaluated the in vitro protein quality of apheresis derived plasma products processed between 8 and 8.5 h from collection and stored at -18°C for 6 months and 1 year. Plasma (205±5 mL) was combined with 35±5 mL of 500 µM riboflavin, and exposed to UV light (6.24 J/mL). A total of 14 plasma units were used for this study. Plasma units were analyzed using standard coagulation assays immediately following treatment, and after 6 months and 1 year of storage at -18°C. RESULTS: Fibrinogen, Total protein, Factors II, VIII, IX, X and XII were modestly affected by storage for 1 year at -18°C. The average percent protein retention in treated plasma samples after 1 year of storage in comparison to controls held under similar conditions were: Total Protein, 103%, Factor II, 88%, Factors VII and XI, 62%, Factor V 60%, Factor VIII and IX, 77%, Fibrinogen, 75%, Factor X, 85% and Factor XII, 82%. CONCLUSION: Results after 6 months (double the EU guidelines recommended storage time) and 1 year (four times longer than the EU guidelines recommended storage time) of storage at -18°C demonstrated that all proteins were well preserved. Values observed for treated products stored under these conditions are within the same range as those reported for other pathogen inactivated plasma products.

Protein stability of previously frozen plasma, riboflavin and UV light-treated, refrozen and stored for up to 2 years at -30 °C.

BACKGROUND: The Mirasol pathogen reduction technology system for plasma is based on a riboflavin and UV light treatment process resulting in pathogen inactivation due to irreversible, photochemically induced damage of nucleic acids. The objective of this study was to evaluate the in vitro protein quality of previously frozen FFP, thawed, Mirasol-treated and refrozen for a final storage period of up to 2 years at -30 °C. MATERIALS AND METHODS: All plasma products were held at 4 ± 2 °C, and frozen within 8h after the start of collection. FFP was stored frozen at -30°C for eight time intervals before riboflavin and UV light treatment and refrozen to -30 °C and stored for varying time intervals for a total storage period of up to 2 years at -30 °C. Results were compared to paired, untreated units thawed and stored for the same time intervals. RESULTS: The overall mean values for all time points in riboflavin and UV light treated plasma samples indicates that all proteins were well preserved following a period of frozen storage for 2 years at -30 °C. Factors V, VII and XI, retained 70%, 65% and 53% activity, respectively. All other protein factors, anticoagulant and inhibitor proteins demonstrated retention between 74% and 100%. CONCLUSION: Riboflavin and UV light-treated FFP maintained both coagulant and anticoagulant in vitro protein quality after double freeze/thaw storage at -30 °C for up to 2 years, a finding that may offer processing flexibility to blood centers.