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

BACKGROUND: The Mirasol system for whole blood (WB) is a non-toxic, non-mutagenic pathogen reduction technology (PRT) that treats WB units with riboflavin (vitamin B2) and ultraviolet (UV) light to alter nucleic acids, thereby reducing pathogen infectivity and inactivating white blood cells. This study evaluates the quality of red blood cells (RBCs) derived from WB treated with the Mirasol system. STUDY DESIGN AND METHODS: Paired units of WB were collected from 61 healthy donors. One unit per donor was treated with riboflavin and UV light and the other was used as an untreated control. RBCs were processed from the WB units and stored in AS-3 at 1-6°C for 21 days and sampled for in vitro analyses of RBC quality parameters. RESULTS: Several statistically significant differences were observed between test and control units, but values were overall within normal clinical ranges. After leukoreduction, the residual leukocyte count and RBC recovery met FDA requirements. The RBC units derived from treated WB maintained haemolysis below 1% through 21 days of storage. CONCLUSION: RBCs derived from WB treated with the Mirasol system meet accepted FDA guidelines for RBC quality through 21 days of storage at 1-6°C.

Reduction of Leishmania donovani infectivity in whole blood using riboflavin and ultraviolet light.

BACKGROUND: Leishmaniasis is a vector-borne disease caused by the protozoan parasite Leishmania sp. that is transmitted by sandflies. Travelers to endemic areas, and US military personnel stationed in the Middle East, are at risk for contracting the disease. STUDY DESIGN AND METHODS: Whole blood (WB) units were spiked with human monocytes infected with L. donovani amastigotes to a final concentration of approximately 10(5) infected cells/mL. After riboflavin (RB) addition, units were exposed to 80 J/mLRBCs ultraviolet (UV) light. One pretreatment (collected after RB addition) and one posttreatment sample were collected, serially diluted in culture medium, and incubated at 22°C for up to 5 weeks. Parasite viability was determined by microscopic observation for replicating promastigote forms. RESULTS: Mirasol treatment of 3 units of L. donovani-infected WB with RB and UV light resulted in a parasite reduction of 2.3 ± 0.12 log. CONCLUSIONS: Partial reduction of L. donovani can be achieved in WB using RB and UV light. This technology may be useful when potential donors are exposed to Leishmania sp. during residence, travel, or military deployment to an endemic area.

Development of a riboflavin and ultraviolet light-based device to treat whole blood.

BACKGROUND: In the United States, blood components are commonly used for patients in need of massive transfusion after blood loss. In combat situations, when severe traumatic injuries occur far from a hospital, fresh whole blood is a valuable transfusion therapy because components may not be available. The risk of infectious or immunological complications from fresh whole blood transfusions could be mitigated by a system that reduces pathogen loads and inactivates white blood cells (WBCs). Such a system is in development and utilizes riboflavin and ultraviolet light to provide pathogen reduction and WBC inactivation. STUDY DESIGN AND METHODS: The system has been tested with in vitro and in vivo animal studies to evaluate WBC inactivation and pathogen reduction, and with in vitro studies to assess the function of the treated blood products. RESULTS: Elimination of viable WBCs with the system is equivalent to gamma-irradiation. Results have been reported for reduction of Babesia microti, Trypanosoma cruzi, HIV, and bacteria, and preliminary results for Babesia divergens are available. Treated whole blood, platelets, and plasma maintain coagulation function. Treated red blood cell components exhibit low hemolysis and high adenosine triphosphate levels at the end of storage. CONCLUSIONS: Treatment with riboflavin and ultraviolet light is a promising alternative to gamma-irradiation. Effectiveness of the system against a variety of pathogens has been established, and further studies are planned. The in vitro studies of function indicate that treated whole blood, as well as components from treated whole blood, will provide acceptable hemostasis and perform well in the next phase of in vivo studies.

Evaluation of potential immune response and in vivo survival of riboflavin-ultraviolet light-treated red blood cells in baboons.

BACKGROUND: Pathogen reduction methods have the potential to modify blood components, resulting in immunologic reactions or compromised blood components. This study evaluated the hypothesis that there is no immune response to riboflavin-and-ultraviolet [UV]-light-treated red blood cells (RBCs), as observed by serology and by survival of RBCs in circulation. STUDY DESIGN AND METHODS: Three baboons were in each treatment group: 1) untreated (negative control), 2) quinacrine mustard (QM)-treated (positive control), and 3) riboflavin-and-UV light-treated (test group) RBCs. In the immunization phase, autologous test or control RBCs were injected subcutaneously on Days 0, 21, 42, and 49. Plasma samples from these days were tested against test or control RBCs by flow cytometry and standard serology. On Day 56, autologous (51)Cr-labeled test or control RBCs were injected. Blood samples were taken over 21 days after injection to determine RBC survival (t(1/2)). RESULTS: Untreated and riboflavin-and-UV-light-treated RBCs showed no evidence of significant immunoglobulin G (IgG) binding after incubation with autologous plasma. RBC-bound IgG was detected on QM-treated RBCs after incubation with autologous plasma. This antibody was inhibited by QM, as demonstrated by a hapten inhibition study. t(1/2) values for the untreated and riboflavin-and-UV-light-treated RBCs were 7.3 +/- 0.8 and 7.5 +/- 1.7 days, respectively; the t(1/2) value for QM-treated RBCs was 2.3 +/- 2.9 days. CONCLUSION: Treatment with riboflavin and UV light did not render RBCs immunogenic. Positive controls indicated that immunization promoted an immune response. In the (51)Cr-labeled RBC survival phase of the study, riboflavin-and-UV-light-treated RBCs exhibited behavior similar to negative control RBCs. Detrimental immunologic or functional side effects were not observed.