Leukoreduced Apheresis Platelets Research Articles

Comparing transfusion reactions between pre-storage and post-storage leukoreduced apheresis platelets: an analysis using propensity score matching

Transfusion reactions induced by platelet transfusions may be reduced and alleviated by leukocyte reduction of platelets. Although leukoreduction of apheresis platelets can be performed either pre-storage or post-storage, seldom studies directly compare the incidence of transfusion reaction in these two different blood products. We conducted a retrospective study to compare the transfusion reactions between pre-storage and post-storage leukoreduced apheresis platelets. We reviewed the general characteristics and the transfusion reactions, symptoms, and categories for inpatients who received pre-storage or post-storage leukoreduced apheresis platelets. Propensity-score matching was performed to adjust for baseline differences between groups. A total of 40,837 leukoreduction apheresis platelet orders were reviewed. 116 (0.53%) transfusion reactions were reported in 21,884 transfusions with pre-storage leukoreduction, and 174 (0.91%) reactions were reported in 18,953 transfusions with post-storage leukoreduction. Before propensity-score matching, the odds ratio for transfusion reactions in the pre-storage group relative to the post-storage group was 0.57 (95% confidence interval [CI] 0.45–0.72, P < 0.01); the odds ratio after matching was 0.63 (95% CI 0.49–0.80, P < 0.01). A two-proportion z-test revealed pre-storage leukoreduction significantly decreases the symptoms of chills, fever, itching, urticaria, dyspnea, and hypertension as compared with those in post-storage leukoreduction. Pre-storage leukoreduced apheresis platelet significantly decreased febrile non-hemolytic transfusion reaction as compared with post-storage groups. This study suggests pre-storage leukoreduction apheresis platelet significantly decreases the transfusion reaction as compared with those in post-storage leukoreduction.

Financial analysis of large-volume delayed sampling to reduce bacterial contamination of platelets.

Effective and financially viable mitigation approaches are needed to reduce bacterial contamination of platelets in the US. Expected costs of large-volume delayed sampling (LVDS), which would be performed by a blood center prior to shipment to a hospital, were compared to those of pathogen reduction (PR), point-of-release testing (PORt), and secondary bacterial culture (SBC). Using a Markov-based decision-tree model, the financial and clinical impact of implementing all variants of LVDS, PR, PORt, and SBC described in FDA guidance were evaluated from a hospital perspective. Hospitals were assumed to acquire leukoreduced apheresis platelets, with LVDS adding $30 per unit. Monte Carlo simulations were run to estimate the direct medical costs for platelet acquisition, testing, transfusion, and possible complications associated with each approach. Input parameters, including test sensitivity and specificity, were drawn from existing literature and costs (2018US$) were based on a hospital perspective. A one-way sensitivity analysis varied the assumed additional cost of LVDS. Under an approach of LVDS (7-day), the total cost per transfused unit is $735.78, which falls between estimates for SBC (7-day) and PORt. Assuming 20,000 transfusions each year, LVDS would cost $14.72 million annually. Per-unit LVDS costs would need to be less than $22.32 to be cheaper per transfusion than all other strategies, less than $32.02 to be cheaper than SBC (7-day), and less than $196.19 to be cheaper than PR (5-day). LVDS is an effective and cost-competitive approach, assuming additional costs to blood centers and associated charges to hospitals are modest.

Supplemental findings of the 2017 National Blood Collection and Utilization Survey.

This report provides supplemental results from the 2017 National Blood Collection and Utilization Survey on characteristics of the donor population, autologous and directed donations and transfusions, platelets, plasma and granulocyte transfusions, pediatric transfusions, severe donor-related adverse events, cost of blood units, hospitals policies and practices, and inventory, dosing, and supply. Weighting and imputation were used to generate national estimates including number of donors, donations, donor deferrals, autologous and directed donations and transfusions, severe donor-related adverse events, platelet and plasma collections and transfusions, number of cross-match procedures, irradiation and leukoreduction, and pediatric transfusions. Between 2015 and 2017, successful donations decreased slightly by 2.1% with a 10.3% decrease in donations by persons aged 16-18 years and a 14.4% increase in donations by donors aged >65 years. The median price paid for blood components by hospitals decreased from $211 to $207 for leukoreduced red blood cell units, from $523 to $517 for leukoreduced apheresis platelet units, and from $54 to $51 for fresh frozen plasma units. Plasma transfusions decreased 13.6%, but group AB plasma units transfused increased 24.7%. Between 2015 and 2017, blood donations declined slightly because of decreases in donations from younger donors, but the number of donations from older donors increased. The price hospitals pay for blood has continued to decrease. Plasma transfusions have decreased, but the proportion of plasma transfusions involving group AB plasma have increased.

A dual-center evaluation of platelet culture vials to detect the presence of microorganisms in platelets.

Microorganism contamination of platelets results in a high risk of transfusion-related sepsis. Here, the ability of culture vials (BD BACTEC Platelet Aerobic/F and Platelet Anaerobic/F vials, Becton, Dickinson and Company) to detect microorganisms in leukoreduced apheresis platelets (LRAPs) and leukoreduced whole blood platelet concentrates (LRWBPCs) was assessed. LRAPs or LRWBPCs were inoculated into Aerobic/F and Anaerobic/F vials and placed in a blood culturing system (BD BACTEC FX System, Becton, Dickinson and Company) for growth/monitoring over 7 days to detect preexisting contamination during false-positive testing. Subsequently, platelets were seeded with microorganisms at approximately 10 CFU/mL or approximately 1 CFU/mL to simulate contamination. Aerobic/F and Anaerobic/F vials were inoculated with platelets (sets of 12). Microorganism growth was detected in the BACTEC FX instrument over 7 days. Overall, 2925 vials were tested. Of the 1905 vials included in the microorganism detection phase, 63 (3.3%) Aerobic/F and 16 (0.8%) Anaerobic/F vials were both BACTEC FX and subculture negative. From the remaining 1827 vials, two (0.1%) Anaerobic/F vials were false positive; no false positives were observed in Aerobic/F vials, and no false negatives occurred in either vial type. Of the remaining 1825 vials (99.9%), 955 Aerobic/F and 870 Anaerobic/F vials were true positives. The mean-time-to-detection range was 8.5 to 77 hours. All true-positive Aerobic/F and Anaerobic/F vials showed 100% agreement with subculture for positive identification of seeded microorganisms. Aerobic/F and Anaerobic/F vials facilitate contamination detection in LRAPs and LRWBPCs down to approximately 1 CFU/mL. These results support the use of Aerobic/F and Anaerobic/F vials for quality control testing of platelets before transfusion.

Feasibility of Flow Cytometric Identification and Isolation of Pre-Platelets to Understand Its Function and Role in Cancer Metastasis

Background:It is known that platelets interact with tumors to support malignant cell growth and stimulate epithelial to mesenchymal transition (Li, et al. "The Role of Platelets in Tumor Growth, Metastasis, and Immune Evasion", Platelets, pp. 547-561, Academic Press, 2019). P-selectin which is secreted from alpha granules has been implicated as the major perpetrator of this tumor cell and platelet communication. (Kim et al, PNAS 95(16): 9325-9330, 1998). Higher numbers of alpha granules are found in newly released young platelets from megakaryocytes, also known as pre-platelets, than mature platelets. Given their potential role in cancer metastasis, the ability to identify and isolate pre-platelets from mature plateletsforassessment of overall functionality and biology is important. Of note, identification and measurement of pre-platelets based on higher RNA content has been in clinical use for various clinical conditions for several years. Here we evaluated the feasibility of identifying and sorting pre-platelets by flow cytometric analyses in multiple platelet apheresis samples from heathy donors. Study Design and Methods Apheresis samples from adult healthy donors at Roswell Park Comprehensive Cancer Center were obtained and analyzed in accordance with an IRB approved protocol. Platelets sampled from apheresis products were collected with the use of an apheresis device known to yield a leuko-reduced platelet concentrate. All components were irradiated with 2500 cGy immediately after the collection and stored on platelet agitator at 22°C. A 4 mL aliquot was withdrawn from each bag for sorting essays.Pre-platelets were distinguished from mature platelets based on the presence of higher RNA levels. The cell permeant RNA dye TO (BD Biosciences, San Jose, CA) was used to identify pre-plapletes by flow cytometry according to published protocol (Ando et al Blood97 (4): p915-921, 2001).The optimal concentration of TO dye was determined by titration at decreasing dilutions and acquisition on a LSR-II flow cytometer (BD Biosciences, San Jose, CA). Confirmation of flow cytometry-based assay was determined by processing 5 healthy donor whole blood samples by both flow cytometry and using an XE-5000 automated hematology analyzer (Sysmex America, Mundelein, IL). The percentage of pre-platelets was measured as a percent of total platelets by both techniques. Platelet sorting was performed on 12 leuko-reduced apheresis platelet products on a FACSAria II (BD Biosciences, San Jose, CA). Platelets were identified by co-staining with CD41a. Platelet activation was assessed before and after sorting based on P-selectin (CD62P) surface expression. Flow cytometry analysis was performed using FCSExpress v6. Results: We determined that flow cytometric sorting of pre-platelets optimally required TO (0.5 µg/mL) for optimal staining for gating of pre-platelets. A two way, paired simple t test resulted in a p value of 0.09 when compared to standard gating strategy per XE-5000 automated hematology analyzer. Among all 14 samples evaluated, the percentage of preplatelet to apheresis sample pre-platelet ratio was estimated between 2.8% to 8.2%. Interestingly P-selectin ratio of pre-platelets was significantly higher than mature platelets (median: 67% vs 52%). ConclusionThis study is the first to demonstrate the feasibility of identifying and sorting pre-platelets using a novel flow cytometric method with TO staining. Isolation of these rare platelet precursor cells (pre-platelets) with known higher P-selectin expression are an essential first step to understanding the potential pre-eminent role of these cells in cancer evasion and metastasis. Disclosures Wang: Abbvie: Other: Advisory role; Kite: Other: Advisory role; Jazz: Other: Advisory role; Astellas: Other: Advisory role, Speakers Bureau; celyad: Other: Advisory role; Pfizer: Other: Advisory role, Speakers Bureau; Stemline: Other: Advisory role, Speakers Bureau; Daiichi: Other: Advisory role; Amgen: Other: Advisory role; Agios: Other: Advisory role.

Financial impact of alternative approaches to reduce bacterial contamination of platelet transfusions.

Bacterial contamination of platelets remains the leading infectious risk from blood transfusion. Pathogen reduction (PR), point-of-release testing (PORt), and secondary bacterial culture (SBC) have been proposed as alternative risk control strategies, but a comprehensive financial comparison has not been conducted. A Markov-based decision tree was constructed to model the financial and clinical impact of PR, PORt, and SBC, as well as a baseline strategy involving routine testing only. Hospitals were assumed to acquire leukoreduced apheresis platelets on Day 3 after collection, and, in the base case analysis, expiration would occur at the end of Day 5 (PR and SBC) or 7 (PORt). Monte Carlo simulations assessed the direct medical costs for platelet acquisition, testing, transfusion, and possible complications. Input parameters, including test sensitivity and specificity, were drawn from existing literature, and costs (2018 US dollars) were based on a hospital perspective. The total costs per unit acquired by the hospital under the baseline strategy, PR, PORt, and SBC were $651.45, $827.82, $686.33, and $668.50, respectively. All risk-reduction strategies decreased septic transfusion reactions and associated expenses, with the greatest reductions from PR. PR would add $191.09 in per-unit acquisition costs, whereas PORt and SBC would increase per-unit testing costs by $31.79 and $17.26, respectively. Financial outcomes were sensitive to platelet dating; allowing 7-day storage with SBC would lead to a cost savings of $12.41 per transfused unit. Results remained robust in probabilistic sensitivity analyses. All three strategies are viable approaches to reducing bacterially contaminated platelet transfusions, although SBC is likely to be the cheapest overall.

Improved yield of minimal proportional sample volume platelet bacterial culture.

Reports of septic transfusion reactions (STRs) after transfusion of culture-negative platelets (PLTs) justify more effective prevention strategies. Pathogen reduction technologies or performance of additional point-of-issue testing are proposed strategies to enhance safety through Day 5 of storage. Trima leukoreduced apheresis PLTs (APs) were collected during two study periods (45 and 31 months) using standard procedures, with target settings adjusted during the second period to maintain split rate after increased culture volume. Primary testing for bacterial contamination was performed using BacT/ALERT 3D with sampling from the mother bag 24 to 36 hours after collection. Two culture approaches were compared: in PeriodA, an 8-mL sample in one aerobic culture bottle (CB), and in PeriodB a minimal proportional sample volume (PSV) of at least 3.8% of mother bag volume into one to three aerobic CBs (7-10 mL per bottle). In Periods A and B, 188,389 and 159,098 AP collections were tested, respectively. The true-positive (TP) rate in PeriodA was 0.90 per 10,000 collections and in Period B was 1.83 per 10,000 (p<0.05). In PeriodB, 12 of 29 (41%) TP results had discrepant CB results (DCBRs; at least one of multiple bottles without growth). The false-positive rate in PeriodB, 15.05 per 10,000 collections, was significantly higher than that of PeriodA, 3.66 per 10,000. One contaminated collection resulting in STR(s) was reported in each study period. Implementation of PSV was operationally successful and did not impact the AP split rate. Proportional sample volume improved the sensitivity of primary testing and identified collections that could have escaped detection had only a single bottle with 8- to 10-mL volume been used. PSV may represent another approach to enhanced PLT safety for 5-day storage without a requirement for secondary testing.

Application of a portable microscopic cell counter for the counting of residual leukocytes in leukoreduced apheresis platelet concentrates in a hospital blood bank

While a portable microscopic cell counter has been evaluated to enumerate residual white blood cells (WBCs) in red blood cells and platelet concentrates at blood centers, it has not yet been assessed in a hospital blood bank. We investigated the performance of this device and evaluated its accuracy, along with its benefits in time management.Residual WBCs from each of 100 apheresis platelet specimens were measured manually using a Nageotte chamber, along with flow cytometry methods and an ADAM-rWBC automated instrument (NanoEnTek, Seoul, South Korea). The efficiency was calculated by measuring the time required for the analysis of one specimen ten times consecutively.Flow cytometry and the ADAM-rWBC were able to detect four sporadic cases that had residual WBCs exceeding 1/μL that were not detected by the manual method. Analysis time was the shortest with the ADAM-rWBC, followed by flow cytometry and the manual method.Our data suggest that hospital blood banks require quality control of residual WBCs; among the methods evaluated in this study, the portable microscopic cell counter offers the best time efficiency.

Results of lookback for Chagas disease since the inception of donor screening at New York Blood Center

Chagas disease is a parasitic infection by Trypanosoma cruzi, typically transmitted via infected triatomine bug fecal contamination of bite sites. Other routes of infection include congenital, oral, organ transplantation, and blood product transmission. From 2007 until 2011, New York Blood Center screened donations for the presence of T. cruzi antibodies using a Food and Drug Administration-approved test. Confirmatory testing was performed and recipients of units donated by confirmed-positive donors were investigated via lookback. A total of 204 donors were T. cruzi antibody positive representing 0.019% of all donors during this time period (1,066,516 unique donors screened). Of the enzyme-linked immunosorbent assay-reactive donors, 77 were confirmed positive by radioimmunoprecipitation assay (0.007%). At least 154 units from 29 of the confirmed-positive donors had been transfused to 141 recipients. At the time of lookback, 48 of the 141 recipients were alive and seven underwent T. cruzi screening. Two recipients were found to be immunofluorescence assay (IFA) positive. Both IFA-positive recipients received a leukoreduced apheresis platelet unit (two separate donations) from the same confirmed positive donor, a 72-year-old immigrant from Argentina. Lookback analysis was able to identify the first two cases of probable transfusion-transmitted T. cruzi infection since implementation of the national screening program, which increases the total number of reported cases in the United States to 8.

In vitro and in vivo quality of leukoreduced apheresis platelets stored in a new platelet additive solution

Platelets (PLTs) stored in additive solutions (PASs) may reduce the risk of several plasma-associated adverse transfusion reactions such as allergic reactions and potentially transfusion-associated lung injury. The objective of this study was to determine the in vitro characteristics and the in vivo radiolabeled recovery and survival of apheresis PLTs (APs) stored in a new PAS and compare the latter to Food and Drug Administration (FDA) criteria. Hyperconcentrated APs were collected from healthy subjects in a paired crossover study comparing PAS (35% plasma) and 100% plasma-stored APs (Part 1) up to 7 days and, in Part 2, to determine the in vivo recovery and survival of PAS stored AP at 5 days compared to fresh PLT controls. In vitro and in vivo assays were performed following standard methods. Sixty-six and 25 evaluable subjects successfully completed Parts 1 and 2, respectively. pH for PAS AP was maintained above 6.6 for 5 days of storage. P-selectin values were consistent with published values for commonly transfused PLT products. The PAS in vivo PLT recovery (54.3 ± 8.1%) was 86.7% of the fresh control, and survival (6.4 ± 1.3 days) was 78.0% of the fresh control, both meeting the FDA performance criteria. APs stored in PAS with 35% plasma carryover maintained pH over 5 days of storage and met current FDA criteria for radiolabeled recovery and survival. The use of PAS for storage of single-donor PLTs in clinical practice represents an acceptable transfusion product that reduces the volume of plasma associated with PLT transfusion.

Effect of storage on levels of nitric oxide metabolites in platelet preparations

Nitric oxide (NO), a potent signaling molecule, is known to inhibit platelet (PLT) function in vivo. We investigated how the levels of NO and its metabolites change during routine PLT storage. We also tested whether the material of PLT storage containers affects nitrite content since many plastic materials are known to contain and release nitrite. For nitrite and nitrate measurement, leukoreduced apheresis PLTs and concurrent plasma (CP) were collected from healthy donors using a cell separator. Sixty-milliliter aliquots of PLT or CP were stored in CLX or PL120 Teflon containers at 20 to 24°C with agitation and daily samples were processed to yield PLT pellet and supernatant. In a separate experiment, PLTs were stored in PL120 Teflon to measure NO generation using electron paramagnetic resonance (EPR). Nitrite level increased markedly in both PLT supernatant and CP stored in CLX containers at a rate of 58 and 31 nmol/L/day, respectively. However, there was a decrease in nitrite level in PLTs stored in PL120 Teflon containers. Nitrite was found to leach from CLX containers and this appears to compensate for nitrite consumption in these preparations. Nitrate level did not significantly change during storage. PLTs stored at 20 to 24°C maintain measurable levels of nitrite and nitrate. The nitrite decline in nonleachable Teflon containers in contrast to increases in CLX containers that leach nitrite suggests that it is consumed by PLTs, residual white blood cells, or red blood cells. These results suggest NO-related metabolic changes occur in PLT units during storage.

Validation of a microbial detection system for use with ACD‐A platelets with PAS III platelet additive solution

The BacT/ALERT microbial detection system (BTA) is used for testing leukoreduced apheresis platelets (LR-AP) in plasma. Platelet additive solutions (PASs) such as InterSol (PAS III) may be used to reduce the amount of plasma transfused in LR-AP. This study evaluated the performance of the two-bottle BTA testing scheme in the recovery of seeded microorganisms from LR-AP in InterSol-plasma compared to a reference plate culture method. Hyperconcentrated, double LR-AP were collected from healthy donors; InterSol was added (65% Intersol:35% plasma), equally divided into two containers, and then inoculated with an isolate of 1 of 10 clinically relevant index organisms at two levels. Aerobic (BPA) and anaerobic (BPN) BTA bottles were inoculated with 4 mL each of the inoculated LR-AP, and blood agar plates (BAPs) for aerobic and anaerobic culture (0.5 mL each). Zero false-positives from 103 bottle pairs were observed. All 400 two-bottle BTA tests were positive within 24 hours, except for Propionibacterium acnes (maximum time-to-detection of 86.4 hr) and 13 of 20 pairs of Streptococcus viridans (maximum time-to-detection of 31.7 hr). Thirteen of 400 BAP two-plate tests were negative for starting bacterial concentrations of 10 colony-forming units (CFUs)/mL or less. At 40 CFUs/mL or less, BTA was 100% positive while BAP was 94% positive. Seeded organism recovery was superior in the two-bottle BTA test system compared to the two-plate BAP system using InterSol platelets (PLTs). This performance is comparable to previously published results for PLTs in plasma. The use of InterSol does not appear to have a detrimental effect on the performance of the two-bottle BTA system.

Bacterial growth kinetics in ACD‐A apheresis platelets: comparison of plasma and PAS III storage

Our objective was to determine the growth kinetics of bacteria in leukoreduced apheresis platelets (LR-AP) in a platelet (PLT) additive solution (PAS; InterSol, Fenwal, Inc.) compared to LR-AP stored in plasma. Hyperconcentrated, double-dose LR-AP were collected from healthy donors with a separator (AMICUS, Fenwal, Inc.). LR-AP were evenly divided, InterSol was added to half (65% InterSol:35% plasma [PAS]), and PLTs in autologous plasma were used for a paired control (PL). Bacteria were inoculated into each LR-AP PAS/PL pair (0.5-1.6 colony-forming units [CFUs]/mL), and bacterial growth was followed for up to 7 days. Time to the end of the lag phase, doubling times, maximum concentration (conc-max), and time to maximum concentration (time-max) were estimated. Streptococcus viridans did not grow to detectable levels in either PAS or PL units. The other bacteria had no significant overall difference in the conc-max (p = 0.47) or time-max (p = 0.7) between PL and PAS LR-AP; PL had a 0.14 hours faster doubling rate (p = 0.023); and PAS had a 4.7 hours shorter lag time (p = 0.016). We observed that five index organisms will grow in LR-AP stored in a 35%:65% ratio of plasma to InterSol where initial bacterial concentrations are 0.5 to 1.6 CFUs/mL. The more rapid initiation of log-phase growth for bacteria within a PAS storage environment resulted in a bacterial concentration up to 4 logs higher in the PAS units compared to the plasma units at 24 hours, but with no difference in the conc-max. This may present an early bacterial detection advantage for PAS-stored PLTs.

Preliminary validation of a new standard of efficacy for stored platelets.

Platelet preparation and storage systems, unlike those for RBC, lack an objective, absolute performance criterion to determine acceptability. Recently, a criterion based on paired comparison with the radiolabeled recovery and survival of "fresh" platelets has been proposed, namely, recovery = two-thirds and survival = half of "fresh" platelets. Eleven normal subjects donated a unit of leukoreduced apheresis platelets using a standard, approved system. They received an aliquot radiolabeled with 111In or 51Cr (random selection) 4 to 20 hours after donation and, using the other radioisotope, on Day 5 of storage. The recovery was calculated based on the injectate radioactivity. The survival was determined using the multiple-hit model. The area under the platelet survival curve was calculated using the COST program. Reinfusion of platelets less than 20 hours after collection resulted in a recovery of 74.7 +/- 12.3 percent and a survival time of 7.5 +/- 1.1 days. Reinfusion on Day 5 resulted in a recovery of 58.2 +/- 12.0 percent and a survival time of 6.9 +/- 1.4 days, values that were 77.9 +/- 9.5 percent and 91.8 +/- 16.1 percent of the observation using "fresh" platelets, respectively. The area under the curve using Day 5 platelets was 67.8 +/- 11.5 percent of that using "fresh" platelets. The proposed criterion for objective evaluation of platelet preparation and storage systems appears applicable to a commonly accepted approach, leukoreduced apheresis platelets stored in plasma for 5 days, and merits evaluation using other collection, treatment, and storage systems.

テルモアフェレーシス装置ＡＣ‐５５０（白血球除去フィルター組み込みタイプ）の検討

The newly developed Leukoreductive Apheresis System TERUSYS™ allows leukoreduction from platelet concentrates during the course of platelet collection. Seventy-two bags of leukoreduced apheresis platelets were obtained. Among them, 6 bags were filtered with leukoreduction filter IMUGARD III-PL under bedside filtration conditions after 3 days' storage to confirm that double filtration has no adverse effect on the quality of PC. Samples were taken before and after the filtration process, and daily up to 5 days' storage. Leukocyte counts, platelet count, β-thromboglobulin (β-TG), anaphylatoxins, histamine, fibrinopeptide A (FPA), cytokines and platelet storage properties were measured in all units.No bags showed more 1×105 leukocytes after filtration. Average platelet loss was 6% (n=7). High levels of β-TG and C3a were observed in samples stored for 3 and 5 days, but β-TG, C3a, C5a, histamine, FPA and cytokine values were comparable in pre- and post-filtration samples (n=7). With regard to platelet properties pH, hypotonic shock recovery and aggregation reaction results were acceptable for clinical use (n=10). Double filtration had no adverse effect on the quality of PC (n=6).These results suggest that filtration during the course of platelet collection is effective.