Cryopreservation of platelets treated with riboflavin and UV light and stored at -80°C for 1 year.

BACKGROUND: The combination of pathogen reduction technologies (PRTs) and cryopreservation can contribute to building a safe and durable platelet (PLT) inventory. Information about cryopreserved riboflavin and UV light-treated PLTs is scarce. STUDY DESIGN AND METHODS: Twenty-four buffy coat (BC) PLT concentrates were grouped into 12 type-matched pairs, pooled, and divided into 12 non-PRT-treated control units and 12 riboflavin and UV light PRT-treated test units. Both were cryopreserved with 5% DMSO and stored at -80°C for 1 year. The cryopreservation method used was designed to avoid the formation of aggregates. PLT variables (PLT recovery, swirling, pH, MPV, and LDH) and hemostatic function measured by thromboelastography (TEG) were analyzed before cryopreservation (day 1) and post-cryopreservation at day 14 and months 3, 6, and 12 of storage at -80°C. The analyses were carried out within 1-h post-thaw. RESULTS: No aggregates were found in either PLT group at any time. Swirling was observed in both groups. MPV increased and mean pH values decreased over time (p < .001), but the mean pH value was never below 6.4 in either group after 12 months of storage at -80°C. PLT recovery was good and clotting time became significantly shorter over the storage period in both groups (p < .001). CONCLUSION: Our cryopreservation and thawing method prevented aggregate formation in cryopreserved riboflavin-UV-light-treated PLTs, which exhibited good recovery, swirling, pH > 6.4, and procoagulant potential, as evidenced by a reduced clotting time after 12 months of storage at -80°C. The clinical relevance of these findings should be further investigated in clinical trials.

Haemostatic function measured by thromboelastography and metabolic activity of platelets treated with riboflavin and UV light.

BACKGROUND: Pathogen reduction technology (PRT) may damage platelet (PLT) components. To study this, metabolic activity and haemostatic function of buffy coat (BC) PLT concentrates, with or without riboflavin and UV light PRT treatment, were compared. MATERIAL AND METHODS: Twenty-four BC PLT concentrates, leukoreduced and diluted in additive solution, were grouped into 12 type-matched pairs, which were pooled and divided into 12 non-PRT-treated BC PLT concentrates (control units) and 12 riboflavin and UV PRT-treated BC PLT concentrates (test units). Haemostatic function and metabolic parameters were monitored by thrombelastography at days 1, 3, 7 and 14 post collection in both PLT groups. RESULTS: Loss of PLT discoid shape, glucose consumption, lactate production, and decrease in pH were greater in the PRT-treated PLTs than in control PLTs over time (p<0.001). PLT haemostatic function evaluated by clot strength was also significantly weaker in PRT-treated PLTs compared with the excellent clot quality of control PLTs at day 7 (maximum amplitude: 41.27 vs 64.27; p<0.001), and even at day 14 (21.16 vs 60.39; p<0.001) of storage. DISCUSSION: Pathogen reduction technology treatment accelerates and increases platelet storage lesion, resulting in glucose depletion, lactate accumulation, PLT acidification, and discoid shape loss. The clots produced by control PLTs at day 14 were still remarkably strong, whereas at day 7 PRT-treated PLTs produced weaker clots compared to the control group. Clinical trials investigating the efficacy of PRT-treated PLTs transfused at the end of the storage period (day 7), when the in vitro clot strength is weaker, are needed.

Use and safety of riboflavin and UV light-treated platelet transfusions in children over a five-year period: focusing on neonates.

BACKGROUND: There are very few published reports about the use and safety of pathogen reduction technology (PRT) based on riboflavin and UV light for platelet (PLT) transfusion in children. STUDY DESIGN AND METHODS: A two-part study was conducted: 1) a study investigating the safety of PLTs treated with riboflavin and UV light-PRT transfused to 379 children and 1,980 adults over a 5-year period; 2) an observational study evaluating the efficacy of PLT use in 132 neonates transfused with PRT-treated PLT compared with 99 neonates receiving standard PLTs over two 5-year periods. RESULTS: The rate of adverse reactions related to transfusions with PRT-treated PLTs was found to be slightly higher in adults than in children, although not statistically significant (0.19% vs. 0.12%; p = 0.85). All PLT transfusion events in children were mild. From 2013 to 2017, 379 children received 4,236 riboflavin and UV light-treated PLTs. Hemato-oncology patients received the most PLT transfusions (61.2%), followed by critically ill children in the Pediatric Intensive Care Unit (PICU) (24.6%), and neonates in the Neonatal Intensive Care Unit (NICU) (10.5%). A significant increase in PLT transfusions was found in 132 neonates transfused with 458 PRT-treated PLTs compared with 99 neonates receiving 176 standard PLTs, measuring PLT use/patient (p = 0.031) and total PLT dose/patient (p = 0.041). CONCLUSIONS: Riboflavin and UV light-based PRT for PLTs seems to be safe for children. Neonates required a higher number of PLT transfusions when these were PRT-treated rather than standard. A long-term follow-up for chronically transfused children and randomized clinical trials are needed.

Our experience in riboflavin and ultraviolet light pathogen reduction technology for platelets: from platelet production to patient care.

BACKGROUND: Pathogen reduction technology (PRT) enhances blood component safety, but its implementation is hampered by loss of blood quality and cost. STUDY DESIGN AND METHODS: A retrospective study was conducted to investigate the efficacy, safety, and cost of 9673 riboflavin and ultraviolet light-treated platelet (PLT) transfusions given to 1211 patients during a 3-year period. The results were compared with the efficacy, safety, and cost of 6424 nontreated PLT transfusions administered to 1500 patients during a 3-year comparison period before PRT implementation. RESULTS: Despite a similar PLT transfusion dose per unit for both periods (pre-PRT period 3.26 vs. PRT period 3.19), the mean number of PLT concentrates per patient (4.2 vs. 7.8; p = 0.006) and the total dose of PLTs received by patients were higher in the PRT period (13.6 vs. 24.8; p = 0.0002). Hematology and medical and surgical patient categories had the highest PLT use per patient. However, febrile (2.5% vs. 1.2%; p = 0.02) and allergic (0.16% vs. 0.08%; p = 0.01) reactions were lower during the PRT period. The blood center saved €284,805.58 due to a reduction of outdated PLTs from 16.8% to 0.72% after PRT implementation. CONCLUSIONS: Although PRT can improve PLT safety, it can increase the amount of PLTs required for transfusion in some patient categories. The cost of PRT can be partially offset by the savings associated with a lower rate of PLT outdates. This cost reduction can be a key factor in settings where inventory management is challenged by a high percentage of wasted PLTs due to outdating.

Strategies for reducing the risk of transfusion-transmitted leishmaniasis in an area endemic for Leishmania infantum: a patient- and donor-targeted approach.

BACKGROUND: In the Balearic Islands, as in other areas of the Mediterranean basin, there is a significant proportion of asymptomatic Leishmania (L.) infantum-infected blood donors, who may represent an important threat to transfusion safety. The Balearic Islands blood bank, located in an area endemic for L. infantum, carried out a study of donors and patients to investigate the impact of this infectious disease on blood safety in the region. MATERIALS AND METHODS: Twenty asymptomatic Leishmania-infected blood donors were followed-up between 2008 and 2011 to investigate the evolution of Leishmania infection in asymptomatic carriers. Their blood was periodically tested for anti-Leishmania antibodies by western blot and for Leishmania DNA by quantitative polymerase chain reaction (qPCR). Additionally, the prevalence of L. infantum infection was investigated in a group of 68 multiply transfused patients to ascertain the risk of transfusion-transmitted leishmaniasis (TTL) in the region, taking into account regular blood component production practices such as pre-storage leucodepletion and pathogen reduction technology. RESULTS: All 20 donors remained asymptomatic over the study period (2008-2011). Most donors had repeatedly positive qPCR results, either persistently or intermittently, but showed no symptoms of Leishmaniasis. Levels of parasitaemia were remarkably low in asymptomatic donors, with values ≤1 parasite/mL. Despite multiple transfusions received over 15 years, no transfused patient studied was infected with L. infantum. DISCUSSION: L. infantum-infected donors can remain asymptomatic for at least 3 years. In our region, no cases of TTL were detected, despite an active search in multiply transfused patients. This seems to be related to two independent variables: (i) a low concentration of the parasite in the peripheral blood of asymptomatic carriers and (ii) the application of methods with proven efficacy against TTL, such as leucodepletion and pathogen reduction technology.

The effectiveness of riboflavin and ultraviolet light pathogen reduction technology in eliminating Trypanosoma cruzi from leukoreduced whole blood.

BACKGROUND: The parasitic Chagas disease is caused by the protozoan Trypanosoma cruzi, which is mainly transmitted by insect vectors. Other infection routes, both in endemic and in nonendemic areas, include organ and marrow transplantation, congenital transmission, and blood transfusion. Asymptomatic chronic chagasic individuals may have a low and transient parasitemia in peripheral blood and, consequently, they can unknowingly transmit the disease via blood transfusion. Riboflavin and ultraviolet (UV) light pathogen reduction is a method to reduce pathogen transfusion transmission risk based on damage to the pathogen nucleic acids. STUDY DESIGN AND METHODS: In this study, we tested the effectiveness of this technology for the elimination of T. cruzi parasites in artificially contaminated whole blood units (WBUs) and thus for decreasing the risk of T. cruzi transfusion transmission. The contaminated WBUs were leukoreduced by filtration and treated with riboflavin and UV light. The level of pathogen reduction was quantified by a real-time polymerase chain reaction (qPCR) and a real-time reverse transcription-polymerase chain reaction (RT-qPCR) as a viability assay. RESULTS: The RNA (cDNA) quantification of the parasites showed a more than 99% reduction of viable T. cruzi parasites after leukoreduction and a complete reduction (100%) after the riboflavin and UV light treatment. CONCLUSION: Riboflavin and UV light treatment and leukoreduction used in conjunction appears to eliminate significant amounts of viable T. cruzi in whole blood. Both strategies could complement other blood bank measures already implemented to prevent the transmission of T. cruzi via blood transfusion.

Where do Trypanosoma cruzi go? The distribution of parasites in blood components from fractionated infected whole blood.

BACKGROUND: Platelets (PLTs) are the blood component most frequently involved in Trypanosoma cruzi transfusion transmission cases reported in the literature, although whole blood (WB) and red blood cells (RBCs) have also been incriminated. However, there is little knowledge of the parasite distribution among blood components. STUDY DESIGN AND METHODS: The aim of this study was to investigate in which blood component T. cruzi parasites concentrate the most, after fractionating artificially T. cruzi-infected WB. The T. cruzi parasite load was studied by a specific quantitative real-time polymerase chain reaction (qPCR) in WB, buffy coat (BC), PLT concentrates, RBCs before and after leukoreduction, and plasma (PL). RESULTS: The parasite load in WB experimentally infected with 1.5 × 10(6) parasites (2.78 × 10(3) parasite equivalents/mL) was unevenly distributed among the separated blood components. The highest level was found in the BC (6.94 × 10(3) parasite equivalents/mL) and RBCs before leukoreduction by filtration (2.51 × 10(3) parasite equivalents/mL), after which RBCs presented a 99.9% reduction in parasite levels. Both PL and PLTs, partially leukoreduced by centrifugation but nonfiltered, had low parasite levels, the lowest concentration being in PL. CONCLUSIONS: The highest parasite concentration was detected in the BC, followed by RBCs before leukoreduction. There is a notable risk of transfusion-transmitted Chagas disease associated with nonleukoreduced RBCs. Leukoreduction may be an effective prevention strategy for transfusion-transmitted T. cruzi infection, especially in endemic countries and in nonendemic countries with a high rate of immigration from Latin America.

Transfusion-transmitted leishmaniasis: a practical review.

In the Balearic Islands, as in other areas in southern Europe, there are a significant proportion of asymptomatic Leishmania infantum-infected blood donors. Theoretically, these donors may represent an important challenge for blood transfusion safety. However, despite an active search of multiply transfused patients, there have been, so far, no cases of transfusion-transmitted leishmaniasis (TTL) in our region. On the other hand, there is scarce evidence of the TTL in the literature. A review of asymptomatic Leishmania-infected blood donors' studies in endemic areas and TTL reports published in the English literature were performed, to ascertain the factors that determine the real risk of transfusion transmission of Leishmania.

Evidence of meaningful levels of Trypanosoma cruzi in platelet concentrates from seropositive blood donors.

BACKGROUND: According to the reported cases of transfusion-acquired Trypanosoma cruzi infection, the risk of T. cruzi transfusion transmission appears to be higher with platelet (PLT) products than with other blood components. The aim of this study was to investigate by quantitative real-time polymerase chain reaction (qPCR) the parasitic load detected in leukoreduced plasma and PLT concentrates collected by apheresis from seropositive T. cruzi blood donors and compare them with peripheral whole blood (WB). STUDY DESIGN AND METHODS: During 2011 to 2013, a prospective study was carried out in a group of blood donors originating from Chagas-endemic areas but who are now living on the island of Majorca, Spain. Leukoreduced plasma and PLT concentrates were collected by apheresis from seropositive blood donors with detectable parasitemias in peripheral WB. RESULTS: Seropositivity was found in 23 of 1201 donors studied (1.9%), and T. cruzi DNA with less than 1 parasite equivalent/mL was detected in peripheral WB in 60.86% (14 of 23) of these. The study in blood components obtained by apheresis from these donors showed that T. cruzi DNA with a mean ± SD parasitic load of 5.33 ± 6.12 parasite equivalents/mL was detected in 100% of the PLT concentrate samples. Parasite DNA was undetectable in the extract taken from plasma collected from donors with a positive qPCR in peripheral WB. CONCLUSION: The higher parasitic load found in PLT concentrates compared to plasma and peripheral WB would explain the higher transfusion transmission risk of Chagas disease associated with PLT transfusions described in the reported cases of transfusion-acquired T. cruzi infection.

Practical issues that should be considered when planning the implementation of pathogen reduction technology for plateletpheresis.

Pathogen reduction technology (PRT) is associated with increased blood safety through the inactivation of virus, bacteria and parasites. Dilution of platelet (PLT) concentrates in platelet additive solution (PAS) is a requirement for applying PRT, and that it is associated with various practical issues: increasing PLT target yields to compensate for loss of PLTs through PRT, extended apheresis donation time due to PAS addition at the end of the procedure, and the appearance of PLT aggregates. We proposed to program higher target PLT yields for plateletpheresis donations to compensate for PLTs lost due to PRT processing. To verify the feasibility of this approach, a paired study of the Amicus 3.11 and Trima 5.22 apheresis separators was performed using 196 procedures carried out on the same 98 donors. The Amicus 3.11 presented a higher collection efficiency (CE: 78.02 vs. 69.63; p < 0.0001) and collection rate (CR: 8.3 vs. 7.00; p < 0.0001); it was also faster (56.92 vs. 62.60; p < 0.0001) than the Trima 5.22 apheresis device. However, analysis of the donor group with higher pre-procedure PLT counts showed similar productivity results for the Amicus and Trima. The percentage of PLT aggregates detected was higher with the TA than the AM (8.62% vs. 3.88%, p = 0.04). Overall, both separators are entirely suitable for collecting hyper-concentrated PLTs that are subsequently diluted in PAS for PRT, without excessively increasing the donation time. PLT aggregation can occur after apheresis collection but most of them disappear by day 1. Further investigation is needed to study the clinical impact of PLT aggregation.

Role of Riboflavin- and UV Light-Treated Plasma in Prevention of Transfusion-Related Acute Lung Injury.

INTRODUCTION: Risk reduction strategies for transfusion-related acute lung injury (TRALI) include the preferential use of male donors to provide fresh frozen plasma (FFP). Implementing this measure based on FFP quarantine program is a very complex process. To improve FFP inventory management and the availability of FFP from male donors, the Mirasol Pathogen Reduction Technology(®) (PRT) system for FFP using riboflavin and UV light was adopted in our region in 2012. METHODS: The percentage of male/female FFP units issued and TRALI cases in patients receiving FFP in the period before implementing riboflavin and UV light (2010-2011) was compared with the period post implementation of riboflavin and UV light (2012-2013). RESULTS: In 2010 and 2011, there was one FFP transfusion-related TRALI case reported per year, when the proportion of male/female FFP distributed to the hospitals was 60/40. During 2012 and 2013, there have been no FFP transfusion-related TRALI cases, when the proportion of male/female FFP distributed to the hospitals was around 97/3. Mirasol PRT allows quick availability (24 h from collection) compared to quarantined FFP (≥3 months from collection). CONCLUSION: Thanks to its readiness, simplicity and feasibility, riboflavin- and UV light-treated FFP implementation can facilitate the preferential use of FFP from male donors as a TRALI prevention strategy.

Reducing the financial impact of pathogen inactivation technology for platelet components: our experience.

BACKGROUND: Pathogen inactivation (PI) technology for blood components enhances blood safety by inactivating viruses, bacteria, parasites, and white blood cells. Additionally, PI for platelet (PLT) components has the potential to extend PLT storage time from 5 to 7 days. STUDY DESIGN AND METHODS: A retrospective analysis was conducted into the percentage of outdated PLT components during the 3 years before and after the adoption of PLT PI technology in our institution. The PLT transfusion dose for both pre-PI and post-PI periods was similar. A retrospective analysis to study clinical safety and component utilization was also performed in the Balearic Islands University Hospital. RESULTS: As a result of PI implementation in our institution, the PLT production cost increased by 85.5%. However, due to the extension of PLT storage time, the percentage of outdated PLT units substantially decreased (-83.9%) and, consequently, the cost associated with outdated units (-69.8%). This decrease represented a 13.7% reduction of the initial cost increase which, together with the saving in blood transportation (0.1%), led to a saving of 13.8% over the initial cost. Therefore, the initial 85.5% increase in the cost of PLT production was markedly reduced to 71.7%. The mean number of PLT concentrates per patient was similar during both periods. CONCLUSIONS: The extension of PLT storage time can substantially contribute to reducing the financial impact of PI by decreasing the percentage of outdated PLTs while improving blood safety. Since the adoption of PI, there have been no documented cases of PLT transfusion-related sepsis in our region.