Conventional Platelets Research Articles

P‐BB‐17 | Biochemical Parameters at Day 7 of Storage of Pathogen Reduced (UVA/Amotosalen) and Conventional Platelets in Additive Solution With or Without Irradiation

P‐BB‐17 | Biochemical Parameters at Day 7 of Storage of Pathogen Reduced (UVA/Amotosalen) and Conventional Platelets in Additive Solution With or Without Irradiation

Transfusion outcomes between regular and low yield pathogen reduced platelets across different patient populations in a single institution.

Pathogen reduction technology (PRT) effectively mitigates bacterial contamination in platelets but is more likely to produce low yield units. Although low dose transfusion using conventional platelets has not been associated with increased bleeding, these findings have not been reproduced with PRT-treated platelets. Platelet transfusions in a tertiary adult hospital were retrospectively reviewed. Comparisons were made between PRT-treated regular (PRT-PR) and low (PRT-PL) yield platelets. Outcomes examined included the number of platelets and RBCs transfused, transfusion-free interval, and corrected count increment (CCI). Subgroup analyses were also performed on hematology-oncology inpatients and outpatients, as well as non-hematology-oncology patients. Platelet utilization per patient remained mostly unchanged (mean 2.9-4.3units per patient per month) even when the frequency of PRT-PL transfusion increased. Among 1402 patients examined, the number of platelets and RBCs transfused was not significantly different between patients first transfused with PRT-PR versus PRT-PL (mean number of platelet units=2.8 vs. 3.1, p=0.38; mean number of RBC units=4.8 vs. 4.3, p=0.93). Among 10,257 platelet transfusions examined, the transfusion-free interval (hazard ratio=1.05, 95% confidence interval 1.00-1.10) and CCI (10.2 vs. 11.0, p=0.70) were comparable between PRT-PR and PRT-PL units. Similar findings were observed in all subgroups, except for shortened transfusion-free intervals among hematology-oncology inpatients. PRT-PR and PRT-PL units may be used in an equivalent manner to maintain an adequate platelet inventory, since there was only a minor difference in time between transfusions.

Multinational Analysis of Children Transfused With Pathogen Inactivated Platelets.

Pathogen inactivated (PI) platelets are a technological advancement in blood safety; however, the pediatric experience is not well characterized. We studied pediatric patients who received transfusions of PI platelets across several centers and countries to determine if transfusion reaction rates differed when compared with conventional platelets. This is a retrospective multisite study conducted during 2 time periods. The study period started at the time each site began using PI platelets on a widespread basis, and the control period was a similar timespan before PI introduction. Suspected acute transfusion reactions were compared. The study included 3839 pediatric patients who were 0 to 18 years of age who received >7930 platelet transfusions, in total, across 4 centers in 3 countries between 2013 and 2019. The age distribution of patients in the study and control period was not significantly different (P = .190). There was not a difference in the percentage of patients who had any type of transfusion reaction between the time periods (1.0% and 1.1%, P = .803). There were fewer patients with mild allergic reactions in the study period compared with the control period (0.2% and 0.7% of patients with reactions, respectively, P = .018). Pediatric patients have the same rate of acutely suspected transfusion reactions when receiving PI or conventional platelet transfusions. Subgroup analysis found fewer mild allergic reactions in the study period, which was contemporaneous to the addition of using platelet additive solution more broadly. Future studies of PI platelets should include children to better assess transfusion efficacy and hemostatic outcomes.

How do we implement pathogen reduction technology, while maintaining an adequate platelet inventory for our patients?

Despite the significantly reduced infectious disease risk through robust and sensitive laboratory assays, comprehensive donor screening and good manufacturing practices, new and emerging infectious agents and bacterial contamination continue to pose a threat to the blood supply. Pathogen Reduction (PR) technology is an option to mitigate the risk of platelet transfusion transmitted infections. Here we describe our structure and strategies to implement PR technology. Pre-implementation and phased approach implementation processes from our hospital-based donor center, components processing laboratory, transfusion service, clinicians, nursing, and patient perspectives are described. Communication and reassessment of collection settings occurred between the donor center and components processing laboratory (CPL). During Phase 1, CPL consistently processed approximately 56% of monthly apheresis platelets (AP) collections by PR and the remaining 44% as conventional platelets (CP). Phase 2 increased the amount of AP undergoing PR from 56% to approximately 78%. A phased implementation and maintenance of a dual inventory may provide flexibility to blood collection, blood manufacturing, and transfusion service processes. Our dual inventory of PR and CP allows our transfusion service a readily available platelet inventory. A collaborative hospital-based donor center, component processing laboratory, and transfusion service are essential to the productivity and maintenance of the dual platelet inventory.

Platelets treated with pathogen reduction technology: current status and future direction.

Allogeneic platelets collected for transfusion treated with pathogen reduction technology (PRT), which has been available in some countries for more than a decade, are now increasingly available in the United States (US). The implementation of PRT-treated platelets, also known as pathogen-reduced platelets (PRPs), has been spurred by the need to further decrease the risk of sepsis associated with bacterial contamination coupled with the potential of this technology to reduce the risk of infections due to already recognized, new, and emerging infectious agents. This article will review available PRP products, examine their benefits, highlight unresolved questions surrounding this technology, and summarize pivotal research studies that have compared transfusion outcomes (largely in adult patients) for PRPs with non-PRT-treated conventional platelets (CPs). In addition, studies describing the use of PRPs in pediatric patients and work done on the association between PRPs and HLA alloimmunization are discussed. As new data emerge, it is critical to re-evaluate the risks and benefits of existing PRPs and newer technologies and reassess the financial implications of adopting PRPs to guide our decision-making process for the implementation of transfusing PRPs.

Blood utilisation and transfusion reactions in adult patients transfused with conventional or pathogen-reduced platelets.

SummaryPathogen‐reduced (PR) platelets are routinely used in many countries. Some studies reported changes in platelet and red blood cell (RBC) transfusion requirements in patients who received PR platelets when compared to conventional (CONV) platelets. Over a 28‐month period we retrospectively analysed platelet utilisation, RBC transfusion trends, and transfusion reaction rates data from all transfused adult patients transfused at the Yale‐New Haven Hospital, New Haven, CT, USA. We determined the number of RBC and platelet components administered between 2 and 24, 48, 72 or 96 h. A total of 3767 patients received 21 907 platelet components (CONV = 8912; PR = 12 995); 1,087 patients received only CONV platelets (1578 components) and 1,466 patients received only PR platelets (2604 components). The number of subsequently transfused platelet components was slightly higher following PR platelet components (P < 0·05); however, fewer RBCs were transfused following PR platelet administration (P < 0·05). The mean time‐to‐next platelet component transfusion was slightly shorter following PR platelet transfusion (P = 0·002). The rate of non‐septic transfusion reactions did not differ (all P > 0·05). Septic transfusion reactions (N = 5) were seen only after CONV platelet transfusions (P = 0·011). These results provide evidence for comparable clinical efficacy of PR and CONV platelets. PR platelets eliminated septic transfusion reactions without increased risk of other types of transfusions with only slight increase in platelet utilisation.

Cold-stored whole blood platelet function is preserved in injured children with hemorrhagic shock.

Recent data demonstrate the safety of uncrossmatched cold-stored whole blood (WB) transfusion in pediatric trauma patients. The hemostatic capabilities of platelets within the cold-stored WB unit have been demonstrated via in vitro studies and animal models. However, platelet function has not been evaluated in pediatric recipients of cold-stored WB transfusions. Injured children, 2 years or older and 10 kg or greater with hemorrhagic shock received up to 30 mL/kg of cold-stored, low titer (<50) anti-A and -B, leukoreduced, group O- WB during their initial resuscitation. Patients were included if (1) they received WB and no conventional platelets, and (2) platelet count and thromboelastography maximum amplitude were measured both before and after transfusion. These data and relevant clinical outcomes (mortality, intensive care unit length of stay [LOS], hospital LOS and ventilator days) were compared to a historical cohort of pediatric trauma patients who received uncrossmatched red blood cells (RBC) and conventional room temperature platelets. Twenty-two children were included in the study; 14 in the component cohort versus 8 in the WB cohort. Neither posttransfusion platelet count (129 × 109/L vs. 135 × 109/L) nor function (thromboelastography maximum amplitude, 59.5 mm vs. 60.2 mm) differed significantly between children receiving cold-stored platelets within the WB unit versus children who received conventional warm platelets. Median (interquartile range) weight-adjusted platelet transfusion volume in the historical cohort was 4.6 (2.5-7.7) mL/kg vs. 2.4 (1.3-4.0) mL/kg in the WB cohort (p = 0.03). There was no difference between groups in age, race, mechanism of injury, Injury Severity Score, vital signs, and severe traumatic brain injury (TBI). Outcomes, including mortality, intensive care unit LOS, hospital LOS, and ventilator days, were not significantly different between groups. No difference was seen in posttransfusion platelet number or function in severely injured children receiving cold-stored WB platelets as compared to those receiving conventional room temperature-stored platelets. Larger cohorts are required to confirm these findings. Therapeutic, level IV.

Ultraviolet light-based pathogen inactivation and alloimmunization after platelet transfusion: results from a randomized trial.

The current study explored whether pathogen-reduction treatment of platelet components before transfusion would decrease the risk of alloimmunization. Study participants were patients with hematologic cancer who were included in two parallel, randomized clinical trials testing pathogen-reduction treatment versus conventional platelets using the Mirasol or Intercept pathogen-reduction systems. Patients who had a baseline, pretransfusion sample and a follow-up, posttransfusion sample were included in the study (n = 179 patients in each study arm). Human leukocyte antigen antibody levels were determined using a commercial multianalyte, bead-based assay. The rate of human leukocyte antigen Class I alloimmunization at the clinical sites in recipients of conventional platelets was low at the highest assay cutoff (range, 1.2%-5.9%). Consistent with prior studies, human leukocyte antigen antibodies were first detected from 3 to 35 days after transfusion. There were no statistically significant differences between alloimmunization rates in patients who received pathogen-reduction treatment versus conventional platelet transfusions. Although he difference was not statistically significant, the effect size for protection from alloimmunization was greatest for high-level human leukocyte antigen Class I antibodies (approximately threefold) in the Intercept-treated patients compared with those who received conventional platelets. In the Mirasol study, only two patients and one patient in the control group developed medium-level or high-level antibodies, respectively, so it was impossible to determine an effect size for potential protection. The current study was not sufficiently powered to determine whether pathogen-reduction treatment provides protection from human leukocyte antigen alloimmunization in platelet transfusion recipients. The data presented will be useful in the design of future trials and endpoints powered to detect a protective effect.

Apheresis platelets in additive solution: Is it a good alternative to conventional group-specific apheresis platelets?

Introduction: India is among the medium developed countries with a population over 1.25 billion with areas of difficult terrains, landslides, and there is requirement of platelets for dengue outbreaks,cancer patients or patients needing intensive care. Use of nongroup-specific platelets is common and the incompatible plasma comes with complications at times. Thus, finding group-specific platelets have always been difficult. Arranging group-specific donor is really a challenge, especially in cases of international patients, outstation patients, and patients that require numerous platelet transfusions, more so in hospital-based blood banks that have limited voluntary apheresis blood donor registry. Materials and Methods: This study was conducted in multispecialty tertiary health-care hospital of Delhi/NCR where the majority of patients are from a different place or different state or a different country. To make do with the available donors who are often replacement donors of a group different from the patient, platelet additive solution (PAS) was used to replace the incompatible plasma. Use of PAS was implemented on all apheresis prepared using storage solution for platelets (SSP+, Macopharma, France) using apheresis platform. PAS was added after collection of hyperconcentrated platelets units. Control group (n = 10) included patients receiving group-specific platelets during the study. Results: A total of 130 apheresis units were prepared on PAS during the study. 126 units were issued to 77 patients. 99.2% of donors under study were male and 47.7% in age group 18–30 years and 31.5% of blood Group O positive. Final platelet volume prepared was 300 ± 20 ml. Mean platelet volume and product pH were within normal range. Conclusion: Use of PAS for apheresis platelets eliminates the need for group-specific platelets converting all single-donor apheresis platelets to universal platelets, thereby helping in better management without compromise in patient safety.

PHP259 - Tasks Involved In Platelet Production And Transfusion From The U.S. Hospital Perspective: Two Process Frameworks

Platelet production (PP) and transfusion are complex processes, largely due to pathogen testing. Pathogen reduction (PR) is a new technology that has the potential to improve PP efficiency by simplifying these processes. Objectives of this project were to 1) develop frameworks detailing tasks involved in each process: one from the hospital blood donor center (BDC) perspective describing PP tasks, and the other from the hospital transfusion service (TS) detailing tasks for platelet procuring and administration (PA); and 2) assess the impact of PR on these processes. Identification of tasks involved in producing and procuring conventional (non-PR) platelets was informed through literature review and discussion with clinical experts. Major tasks were identified in both processes, along with possible branching of pathways within each process. The frequency of tasks was assessed for conventional vs. PR PP, with categorization by type to identify which task groupings were major contributors to the complexity of the process. Major PP tasks include apheresis donation, processing, bacterial culturing, infectious disease testing, storage, shipping to hospital, and returns. PP comprises 14 tasks with conventional platelets vs. 12 tasks with PR platelets. Major PA tasks include receipt of shipment, storage, point-of-issue (POI) bacterial testing, physician ordering, administration to patient, and adverse event (AE) management. PA comprises 15 tasks with conventional platelets vs. 13 tasks with PR platelets. POI is task-intensive, requiring up to 6 additional steps per test repeated every 24 hours, ranging from 2-6 tests/platelet unit depending on platelet age. Noninfectious AE tasks are similar for both conventional vs PR however infectious AE are expected to be reduced or eliminated with PR. The PP frameworks can be used in hospital operations research to simplify and improve PP efficiency. PR platelets represent a means of reducing tasks, and potentially costs, of producing and administering platelets.

Refrigerated storage of platelets initiates changes in platelet surface marker expression and localization of intracellular proteins

Platelets (PLTs) are currently stored at room temperature (22°C), which limits their shelf life, primarily due to the risk of bacterial growth. Alternatives to room temperature storage include PLT refrigeration (2-6°C), which inhibits bacterial growth, thus potentially allowing an extension of shelf life. Additionally, refrigerated PLTs appear more hemostatically active than conventional PLTs, which may be beneficial in certain clinical situations. However, the mechanisms responsible for this hemostatic function are not well characterized. The aim of this study was to assess the protein profile of refrigerated PLTs in an effort to understand these functional consequences. Buffy coat PLTs were pooled, split, and stored either at room temperature (20-24°C) or under refrigerated (2-6°C) conditions (n = 8 in each group). PLTs were assessed for changes in external receptor expression and actin filamentation using flow cytometry. Intracellular proteomic changes were assessed using two-dimensional gel electrophoresis and Western blotting. PLT refrigeration significantly reduced the abundance of glycoproteins (GPIb, GPIX, GPIIb, and GPIV) on the external membrane. However, refrigeration resulted in the increased expression of high-affinity integrins (αIIbβ3 and β1) and activation and apoptosis markers (CD62P, CD63, and phosphatidylserine). PLT refrigeration substantially altered the abundance and localization of several cytoskeletal proteins and resulted in an increase in actin filamentation, as measured by phalloidin staining. Refrigerated storage of PLTs induces significant changes in the expression and localization of both surface-expressed and intracellular proteins. Understanding these proteomic changes may help to identify the mechanisms resulting in the refrigeration-associated alterations in PLT function and clearance.

Enhancing electrochemical performance of LiFePO4 by in situ reducing flexible graphene

Well-dispersed graphene materials reduced by Ac under hydrothermal condition were used as conductive additives to improve intrisic disadvantage of promising LiFePO4 battery materials, which was synthesized at surface of graphene sheets. The as-prepared LiFePO4/graphene composites were characterized by X-ray powder diffraction (XRD), scan electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge tests. The results show that, compared with conventional LiFePO4 platelets, the composite deliver excellent electrochemical performances, due to flexible graphene-based porous conducting network. We believe that such a facile process will provide a new pathway for further enhancing its energy storage efficiency.

Release of immune modulation factors from platelet concentrates during storage after photochemical pathogen inactivation treatment

Blood platelets (PLTs) are critical for hemostasis, and they contain biologically active constituents with the potential to modulate inflammatory responses. This study examined the effects of photochemical pathogen inactivation treatment (PCT) on the release of cytokines and/or chemokines from PLT components. Double-dose apheresis PLT components were suspended in plasma-PLT additive solution mixtures and divided into paired therapeutic units. One unit served as an untreated control and the other unit was treated with PCT. PLT concentrations, pH, and levels of cytokines and/or chemokines (CD62p, platelet-derived growth factor-AB, interleukin [IL]-8, soluble CD40 ligand [sCD40L], IL-1beta, and tumor necrosis factor alpha) were measured during 7 days of storage in PLT component supernatants and PLT lysates. PLT content, pH, and cytokine and/or chemokine content and release from PLT component prepared with PCT were not different (p > 0.05) from paired control components during storage. Levels of sCD40L, however, increased significantly during storage while decreasing in parallel within PLT lysates, although no differences were detected between paired PCT and control PLT component. PCT did not increase the release or secretion of PLT chemokines and/or cytokines over a 7-day period compared to conventional PLT component.

Platelet dose consistency and its effect on the number of platelet transfusions for support of thrombocytopenia: an analysis of the SPRINT trial of platelets photochemically treated with amotosalen HCl and ultraviolet A light

The SPRINT trial examined efficacy and safety of photochemically treated (PCT) platelets (PLTs). PCT PLTs were equivalent to untreated (control) PLTs for prevention of bleeding. Transfused PLT dose and corrected count increments (CIs), however, were lower and transfusion intervals were shorter for PCT PLTs, resulting in more PCT than control transfusions. PLT dose was analyzed to determine the impact of the number of PLTs transfused on transfusion requirements. Transfusion response was compared for patients with all doses of >or=3.0 x 10(11) and the complementary subset of patients with any dose of fewer than 3.0 x 10(11). Analyses included comparison of bleeding, number of PLT and red blood cell (RBC) transfusions, transfusion intervals, and CIs between PCT and control groups within each PLT dose subset. Mean PLT dose per transfusion in the PCT group was lower than in the control group (3.7 x 10(11) vs. 4.0 x 10(11); p<0.001). More PCT patients received PLT doses of fewer than 3.0 x 10(11) (n=190) than control patients (n=118; p<0.01). Comparisons of patients receiving comparable PLT doses showed no significant differences between PCT and control groups for bleeding or number of PLT or RBC transfusions; however, transfusion intervals and CIs were significantly better for the control group. When patients were supported with comparable doses of PCT or conventional PLTs, the mean number of PLT transfusions was similar. Lower CIs and shorter transfusion intervals for PCT PLTs suggest that some PLT injury may occur during PCT. This injury does not result in a detectable increase in bleeding, however.

Routine Use of Platelet Components Prepared with Photochemical Treatment (INTERCEPT Platelets™): Impact on Clinical Outcomes and Resources.

Background: In 2003 the Blood Transfusion Center (BTC), Cliniques Universitaires Mont Godinne (CUMG) initiated routine use of INTERCEPT Platelets (I-P) for support of thrombocytopenia. To examine the impact of I-P on patient (Pt) outcomes and resources, the rate of acute transfusion reactions (ATR) for platelet (PLT) and red cell (RBC) transfusions (txn) and the effect on platelet use were compared for 18 months before I-P adoption, when only conventional platelets (C-P) were used, and for 18 months after adoption of I-P. Since preparation of RBC did not change, the rates of PLT-ATR and RBC-ATR in the 2 periods were used to assess the impact of I-P on ATR.Methods: In both periods, PLT were collected on the Amicus Separator™ (Baxter) with process leukocyte reduction. For C-P, T-Sol™ (Baxter) with a ratio to plasma of 70:30 % was used; and for I-P, Intersol™ (Baxter)with a ratio to plasma of 65:35 % was used. I-P containing 2.5 to 6.0 x 1011 plts in 300 mL were treated with amotosalen (150 μM) plus UVA (3 J/cm2) to inactivate pathogens and leukocytes. As for C-P, I-P units were issued the day (d) after collection and stored for either 5 or 7 d. Clinical services reported febrile and non-febrile ATR occurring within 24 hr of txn to the BTC. HLA and PLT antibodies (AB+/AB−) were determined by the BTC in pts with suspected alloimmunization.Results-Table: The number of patients transfused with PLT and RBC increased by 13% and 8%, respectively, after I-P adoption; and the mean plt dose increased by 3.6% (4.14 vs 4.29 x 1011). The relative distribution of components by primary care indications was similar in the 2 periods. After adoption of I-P, the incidence of ATR decreased significantly (p=0.002), largely due to fewer ATR in pts without AB detected (AB-). I-P adoption did not substantially increase component utilization, did not require addition of personnel to the BTC, nor delay time of PLT issue. I-P did not affect the number of plt donors required to support the CUMG patient population. I-P replaced gamma irradiation for prevention of txn-associated GVHD, avoided use of routine bacterial testing, and replaced CMV serology. Adoption of I-P facilitated extension of PLT storage from 5 to 7 d, with a decreased rate of component expiration from 7.2% to 3.7%.Conclusions: Use of I-P resulted in a decreased incidence of ATR to PLT txn. The average dose of I-P was minimally higher than C-P, and the number of PLT txn/pt was slightly increased. Adoption of I-P did not adversely impact donor recruitment, utilization of resources, or BTC personnel resources to prepare components. I-P replaced other technologies, thus reducing the net cost impact of adoption.Impact of I-P Adoption On Component Use and ATRComponentC-PC-RBCI-PC-RBCPeriodBeforeBeforeAfterAfterUnits Transfused3,5299,5514,05111,493Hematology3,070 (87%)4,202 (44%)3,524 (87%)4,942 (43%)Oncology141 (4%)382 (4%)81 (2%)575 (5%)CV Surgery140 (4%)2,388 (25%)203 (5%)2,528 (22%)Other178 (5%)2,579 (27%)243 (6%)3,448 (30%)Patients35315814021719Units/Pt10.06.010.16.7Febrile ATR1.3%0.4%0.9%0.4%AB+/AB−18/2119/14Urticaria6453Sepsis1100

Safety and Efficacy of Pathogen-Inactivated Platelets Transfused in Routine Use to Pediatric Patients: An Interim Report.

Background. A pathogen inactivation (PI) process to treat platelet concentrates (INTERCEPT, Baxter Healthcare Corporation and Cerus Corporation) is certified for use in Europe (CE Mark 2002). No labeling restriction exists regarding pediatric patients. In the three clinical trials supporting regulatory approval, patient age eligibility was ≥ 16 years (yrs). We initiated an ongoing study to specifically examine the safety and efficacy of transfusion (txn) of PI platelets (plts) in a pediatric population. This is an observational, single arm, open label study that will evaluate 500 transfusion episodes.Methods. Buffy coat plts are collected, pooled, leuko-depleted, and PI-treated with 150 uM amotosalen and 3,9 joules/cm² UVA illumination. Amotosalen was removed by overnight adsorption. Plts did not require gamma irradiation. Plt txns are ordered according to hospital guidelines and patients (pts) are managed according to hospital clinical practice. Eligible pts are thrombocytopenic, expected to develop thrombocytopenia requiring plt txn, diagnosed with a condition associated with thrombocytopenia or receiving therapy that will result in severe thrombocytopenia. Plt txn are given for prophylactic and therapeutic needs. Safety assessed by txn reaction within 24hrs of txn completion and efficacy assessed by count increment [CI] and corrected count increment [CCI] ≤1.5hr post txn are monitored.Results. Pts range in age from 1 to 16 yrs. One hundred fifty-eight PI-treated plt concentrates have been transfused into 21 pts (13 leukemias, 7 solid tumors and 1 aplastic anemia). Plt concentrates are transfused as units of 0.5 x 1011 plts. Txn episodes per patient (receipt of one or more concentrates) range from 1 to 45. One of the frequently transfused patient (45 txn episodes) had a prolonged cytopenia (resistant leukaemia) and had a refractory thrombocytopenia. The number of platelets transfused per episode range from 1.0 to 6.8 x 1011 (2 to 13.6 units). Six txn reactions in 6 pts have been noted and include fever (5), urticaria (1) and itching (2). For the patients experiencing fever, bacterial cultures were done on patient blood samples and plt concentrate samples; all cultures were negative. Mean plt CI was 44,400 per μL (range −11,000 to 216,000). Mean plt CCI was 11,780 (range −3,020 to 45,170). If we exclude the refractory patient from this CI and CCI analysis the mean plt CI was 58,000 per μL (range −11,000 to 216,000). The mean plt CCI was 14,250 (range −2,750 to 45,170).Conclusions. To date, txn of PI plts in this pediatric oncology pt population has been safe and efficacious, with no transfusion reactions specifically related to PI observed. Post-txn plt count increment, corrected count increments and hemostasis have been similar to that observed with conventional platelets. The introduction of PI platelets has not resulted in increased platelet component utilization.

Routine Use of Platelet Components Prepared with Photochemical Treatment (INTERCEPT Platelets) : Impact on Clinical Outcomes and Costs.

Background: In 2003 the Blood Transfusion Ctr (BTC), Cliniques Universitaires Mont Godinne (CU-MG) initiated routine use of INTERCEPT Platelets (I-P) for transfusion support of thrombocytopenia. To examine the impact of I-P on patient outcomes and costs, the rate of acute transfusion reactions (ATR) for platelet (PLT) and red cell (RBC) transfusions (txn) were compared for 285 days (d) before I-P adoption, when only conventional platelets (C-P) were used, and for 255 d after adoption of I-P for routine use. Since preparation of RBC did not change, the relative rates of PLT-ATR and RBC-ATR in the 2 periods were used to assess the impact of I-P on ATR.Methods: In both periods, PLT were collected on the Amicus Cell Separator (Baxter) with process leuko-reduction. For C-P, T-Sol (Baxter) with a ratio to plasma of ~ 70:30 % was used; and for I-P, Intersol (Baxter)with a ratio to plasma of ~ 65:35 % was used. I-P containing 2.5 to 6.0 x 1011 plts in ~ 300 mL were prepared with an integrated processing set using amotosalen (S-59, 150 uM) and UVA (3 J/cm2) to inactivate pathogens and leukocytes. As for C-P, I-P were issued the d after collection and were stored for up to 5 d. The Hematology Service reported PLT and RBC ATR (febrile and non-febrile ATR occurring within 24 hr of txn) to the BTC. HLA and PLT antibodies (AB+/AB−) were determined by the BTC in pts with suspected alloimmunization. Factors impacting costs for PLT, before and after adoption of I-P, were assessed by the BTC.Results: Days of observation before and after adoption of I-P were similar (Table). More pts received I-P, due to an increase of CV surgery pts after I-P adoption. The mean plt dose was 2% lower with I-P (4.06 vs 4.15 x 1011), and the number of PLT txn/pt was 8% higher for I-P. The rate of ATR to PLT txn with I-P showed a declining trend (p =0.08) , while the rate of ATR to RBC txn was similar in the 2 periods (p = 0.55). Before and after I-P, 16.5 and 9.3 % of pts receiving plt had PLT ATR, respectively. The decrease was largely due to fewer ATR in pts without AB detected (AB-). Adoption of I-P did not require addition of personnel to the BTC, nor delay time of PLT issue. I-P did not affect the number of plt donors required to support the CU-MG patient population. I-P replaced gamma irradiation for prevention of txn-associated GVHD and avoided use of routine bacterial testing for PLT.Conclusions: Use of I-P resulted in a trend of decreased incidence for ATR to PLT txn on a per txn and per pt basis compared to RBC ATR. The average dose of I-P was minimally lower than C-P, and the number of PLT txn/pt was slightly increased. Adoption of I-P did not adversely impact the cost of donor recruitment or donor utilization nor the cost of BTC personnel. I-P avoided the cost of gamma irradiation and routine bacterial cultures. I-P offer the potential to reduce patient care costs due to reduced ATR.Impact of I-P AdoptionComponentC-PC-RBCI-PC-RBCPeriodBeforeBeforeAfterAfterDays285285255255Patients103na129naHem-Onc47%na44%naCV Surgery35%na47%naTXN (units)1466511019904895ATR : No. TXN (%)23 (1.57%)18 (0.35%)18 (0.90%)21 (0.42%)AB+/AB-6/133/156/74/17TXN/Patient14.2na15.4nana = not available

Therapeutic efficacy and safety of platelets treated with a photochemical process for pathogen inactivation: the SPRINT Trial

AbstractWe report a transfusion trial of platelets photochemically treated for pathogen inactivation using the synthetic psoralen amotosalen HCl. Patients with thrombocytopenia were randomly assigned to receive either photochemically treated (PCT) or conventional (control) platelets for up to 28 days. The primary end point was the proportion of patients with World Health Organization (WHO) grade 2 bleeding during the period of platelet support. A total of 645 patients (318 PCT and 327 control) were evaluated. The primary end point, the incidence of grade 2 bleeding (58.5% PCT versus 57.5% control), and the secondary end point, the incidence of grade 3 or 4 bleeding (4.1% PCT versus 6.1% control), were equivalent between the 2 groups (P= .001 by noninferiority). The mean 1-hour posttransfusion platelet corrected count increment (CCI) (11.1 × 103PCT versus 16.0 × 103control), average number of days to next platelet transfusion (1.9 PCT versus 2.4 control), and number of platelet transfusions (8.4 PCT versus 6.2 control) were different (P< .001). Transfusion reactions were fewer following PCT platelets (3.0% PCT versus 4.4% control;P= .02). The incidence of grade 2 bleeding was equivalent for PCT and conventional platelets, although posttransfusion platelet count increments and days to next transfusion were decreased for PCT compared with conventional platelets.

Evaluation of platelets prepared by apheresis and stored for 5 days. In vitro and in vivo studies.

To evaluate the effect of storage on apheresis platelets collected with a closed-system blood cell separator, an in vitro investigation was performed, with measurements of pH, lactate, ATP, the ratio of ATP to the total adenine nucleotide content, and adenylate kinase. Unmodified apheresis platelets and apheresis platelets with plasma added were compared with conventional platelets stored in PL-1240 or PL-732 plastic containers. During 6 days of storage, there were similar changes in all variables with one exception: the extracellular activity of adenylate kinase was lower in apheresis platelets with plasma than in the other three groups (p less than 0.01). In vivo studies were carried out with 111Indium-labeled autologous platelets in eight volunteers. Apheresis platelets with 100 mL of plasma added were stored in two 1000-mL containers (PL-732) at 22 degrees C during agitation. Platelets from one of the containers were labeled with 111Indium and transfused into the volunteer within 24 hours. Platelets from the other container were labeled after 5 days of storage and transfused into the same donor. There were no significant differences between apheresis platelets stored for 1 day and those stored for 5 days: the mean percentage of recovery was 58.4 and 57.6 percent, t1/2 was 69 and 67 hours, and the survival time was 5.5 and 5.6 days, respectively.