Evaluation of a scoring system for vein suitability in platelet apheresis donors.

INTRODUCTION: Donor vein assessment for the selection of good quality veins is crucial for a successful apheresis procedure. This study intends to find out the effectiveness of a vein assessment scoring tool (VST) used and found to be effective in selecting whole blood donors to reduce the difficulty in identifying good quality veins for the plateletpheresis procedure. MATERIALS AND METHODS: This was a prospective observational study on platelet apheresis donors with the application of a VST consisting of three vein descriptor parameters (vein visibility, vein palpability, and vein size) with 5 Likert-type responses constituting a score of 0-12 for each arm. Two vein assessors independently evaluated the vein in both arms and marked their responses blinded from each other as well from the principal investigator. The scores were then calculated and analyzed at the end of the study for their association with phlebotomy and procedural outcomes. RESULTS: A total of 190 donors were recruited. The mean scores for the arms with successful and failed phlebotomy were 9.1 and 9.4 (SD 2.3), respectively. The intra-class correlation Alpha Cronbach value was 0.834 and 0.837 for total scoring in the left arm and right arm, respectively, between the two assessors. Scores neither showed a correlation with other outcomes like low flow alarms, hematoma formation, number of phlebotomy attempts, and procedure completion. CONCLUSION: The study showed that the vein score tool did not truly predict the phlebotomy outcome in apheresis donors, though there was a good degree of inter-assessor reliability.

Risk factors for T-cell lymphopenia in frequent platelet donors: The BEST collaborative study.

BACKGROUND: Severe T-cell lymphopenia of uncertain clinical significance has been observed in frequent apheresis platelet donors. Two commonly used plateletpheresis instruments are the Trima Accel, which uses a leukoreduction system (LRS) chamber to trap leukocytes and the Fenwal Amicus, which does not use an LRS chamber. STUDY DESIGN AND METHODS: We performed an international, multicenter, observational study comparing T-cell populations in frequent platelet donors collected exclusively using the Trima instrument (n = 131) or the Amicus instrument (n = 77). Age- and sex-matched whole blood donors (n = 126) served as controls. RESULTS: CD4+ T-cell counts <200 cells/µL were found in 9.9% of frequent Trima (LRS+) platelet donors, 4.4% of frequent Amicus (LRS-) platelet donors, and 0 whole blood donors (p < .0001). CD4+ T-cell counts <200 cells/µL were only seen in platelet donors with ≥200 lifetime donations. In multivariable analysis, age, lifetime donations, and instrument (Trima vs. Amicus) were independent risk factors for lymphopenia. In 40 Trima platelet donors, a plasma rinseback procedure was routinely performed following platelet collections. No Trima platelet donors receiving plasma rinseback had a CD4+ T-cell count <200 cells/µL versus 13/91 Trima platelet donors not receiving plasma rinseback (p = .01). DISCUSSION: Recurrent bulk lymphocyte removal appears to contribute to the development of T-cell lymphopenia in frequent, long-term platelet donors. Lymphopenia is more common when an LRS chamber is used during platelet collection but can occur without an LRS chamber. Blood centers using LRS chambers can mitigate donor lymphopenia by performing plasma rinseback.

The effect of thrombocytapheresis on hemogram and biochemistry parameters in patients with essential thrombocytemia.

BACKGROUND: Essential thrombocythemia is one of the chronic myeloproliferative neoplasms characterized by clonal proliferation of myeloid cells with variable morphological maturation and hematopoietic activity.It is characterized by excessive clonal platelet production with a tendency to thrombosis and bleeding. Thrombocytapheresis is the removal of platelets by apheresis techniques. Thrombocytapheresis is generally recommended in patients with essential thrombocythemia with acute, severe thrombotic or hemorrhagic events. METHODS: The study included 39 patients who were diagnosed with essential thrombocythemia, started cytoreductive and aspirin therapy, and underwent thrombocytapheresis due to the development of acute severe thrombotic or hemorrhagic events, diagnosed in the adult hematology clinic of Inönü University Turgut Ozal Medical Center. Hemogram and biochemistry values of the patients were scanned retrospectively. RESULTS: After thrombocytapheresis, a statistically significant difference was found between the first and last measurements of hemoglobin, mean platelet volume, White blood cell, neutrophil, platelet, platelet distribution width, creatine, lactate dehydrogenase, fibronogen and calcium levels of the patients. CONCLUSION: The use of thrombocytapheresis in patients with essential thrombocytosis causes a rapid decrease in platelet values as well as an effect on hemogram and biochemistry parameters. Other hemogram and biochemistry parameters such as platelet value should be monitored in patients.

Comparison of platelet quality and function across apheresis collection platforms.

BACKGROUND: Platelet concentrates (PLT) can be manufactured using a combination of apheresis collection devices and suspension media (plasma or platelet additive solution (PAS)). It is unclear how platelet quality and hemostatic function differ across the current in-use manufacturing methods in the United States. The objective of this study was therefore to compare baseline function of PLT collected using different apheresis collection platforms and storage media. STUDY DESIGN AND METHODS: PLT were collected at two sites with identical protocols (N = 5 per site, N = 10 total per group) on the MCS® + 9000 (Haemonetics; "MCS"), the Trima Accel® 7 (Terumo; "Trima"), and the Amicus Cell Separator (Fresenius Kabi, "Amicus"). MCS PLT were collected into plasma while Trima and Amicus PLT were collected into plasma or PAS (Trima into Isoplate and Amicus into InterSol; yielding groups "TP", "TI" and "AP", "AI", respectively). PLT units were sampled 1 h after collection and assayed to compare cellular counts, biochemistry, and hemostatic function. RESULTS: Differences in biochemistry were most evident between plasma and PAS groups, as anticipated. MCS and TP had the highest clot strength as assessed by viscoelastometry. AI had the lowest thrombin generation capacity. Both TP and TI had the highest responses on platelet aggregometry. AI had the greatest number of microparticles. DISCUSSION: Platelet quality and function differ among collection platforms at baseline. MCS and Trima platelets overall appear to trend toward higher hemostatic function. Future investigations will assess how these differences change throughout storage, and if these in vitro measures are clinically relevant.

The role of sodium citrate during extended cold storage of platelets in platelet additive solutions.

BACKGROUND: Cold-stored platelets are increasingly being used to treat bleeding. Differences in manufacturing processes and storage solutions can affect platelet quality and may influence the shelf life of cold-stored platelets. PAS-E and PAS-F are approved platelet additive solutions (PAS) in Europe and Australia, or the United States respectively. Comparative data are required to facilitate international transferability of laboratory and clinical data. STUDY DESIGN AND METHODS: Single apheresis platelets from matched donors (n = 8) were collected using the Trima apheresis platform and resuspended in either 40% plasma/60% PAS-E or 40% plasma/60% PAS-F. In a secondary study, platelets in PAS-F were supplemented with sodium citrate, to match the concentration in PAS-E. Components were refrigerated (2-6°C) and tested over 21 days. RESULTS: Cold-stored platelets in PAS-F had a lower pH, a greater propensity to form visible (and micro-) aggregates, and higher activation markers compared to PAS-E. These differences were most pronounced during extended storage (14-21 days). While the functional capacity of cold-stored platelets was similar, the PAS-F group displayed minor improvements in ADP-induced aggregation and TEG parameters (R-time, angle). Supplementation of PAS-F with 11 mM sodium citrate improved the platelet content, maintained the pH above specifications and prevented aggregate formation. DISCUSSION: In vitro parameters were similar during short-term cold storage of platelets in PAS-E and PAS-F. Storage in PAS-F beyond 14 days resulted in poorer metabolic and activation parameters. However, the functional capacity was maintained, or even enhanced. The presence of sodium citrate may be an important constituent in PAS for extended cold storage of platelets.

Plateletpheresis donor deferral patterns at a tertiary care hospital in North India: A need for rethink of haemoglobin cutoff.

INTRODUCTION: The donor deferral criteria for blood or apheresis donations are established for two main reasons: (i) to ensure the safety of the blood donor (non-maleficence); (ii) to obtain safe blood of standard quality that has therapeutic benefit for the patient (beneficence). This study was planned to assess the various causes and patterns of plateletpheresis donor deferral in our hospital and to subsequently assess whether any evidence based changes can be done in the current plateletpheresis donor deferral criteria in India to maximize the platelet donor pool without compromising donor safety. MATERIAL AND METHODS: The present study was conducted from May 2021 till June 2022 in the department of transfusion medicine of a tertiary care hospital in North India. The first part of the study was conducted from May 2021 till March 2022 to assess the various causes of donor deferral by analysing the plateletpheresis donor deferral data during the corresponding period. The second part of the study was conducted from April 2022 till June 2022, to assess: (i) average decrease in haemoglobin after plateletpheresis procedure; (ii) red blood cell loss during plateletpheresis procedure; (iii) to determine whether any correlation exists between donor haemoglobin and platelet yield. RESULTS: During the study period, a total of 260 donors were screened for plateletpheresis, out of which 221 (85%) donors were accepted and 39 (15%) donors were deferred for various reasons. Out of the 39 deferred donors, 33 (84.6%) were temporary deferrals, while 6 (15.4%) were permanent deferrals. Low haemoglobin (Hb < 12.5 g/dl) was a cause of deferral in 12.8% (n = 5) of the deferred donors. 192 (73.9%) out of the 260 donors were replacement donors. The calculated mean decrease in haemoglobin as a result of plateletpheresis procedure was 0.4 g/dl. No correlation was seen between donor pre-donation haemoglobin and platelet yield (p = 0.86, r = 0.06, R2 = 0.003). The calculated mean red cell loss as a result of plateletpheresis procedure was 28 ml. CONCLUSION: Low haemoglobin (<12.5 g/dl) is a significant cause of temporary plateletpheresis donor deferral in India. In view of the advancement in plateletpheresis technology, which has resulted in minimal red cell loss with the current generation apheresis devices, haemoglobin cutoff of 12.5 g/dl needs to be reconsidered. Perhaps, after performing a multi-centric trial, a consenscus can be reached for revision of haemoglobin cutoff for plateletpheresis donations.

The safety and performance of the Spectra Optia apheresis system platelet depletion protocol in patients with elevated platelet counts.

BACKGROUND: Thrombocytosis is a presenting and progressive clinical feature found in multiple disease states. It is characterized by high platelet (PLT) counts (>450 × 109 /L) and can lead to thrombohemorrhagic events. Thrombocytapheresis or platelet depletion (PLTD) can be performed in acutely symptomatic patients suffering from thrombocytosis and may reduce or prevent acute serious complications associated with thrombocythemia thereby enabling patients to receive potentially curative high-dose chemotherapy. METHODS: This report details the results from 2 clinical studies, one conducted in the European Union (EU) and one in the People's Republic of China, assessing the PLTD procedure on the Spectra Optia Apheresis System. The primary objective of both studies was to assess the safety and performance of the PLTD procedure in patients with elevated PLT counts. RESULTS: Data were collected from 56 participants completing 64 PLTD procedures. The mean percent change in PLT count and collection efficiency (CE1) was 55.1% and 68.5%, respectively. In the EU study, 6 participants experienced a total of 9 adverse events (AEs) and in the China study, 44 participants reported a total of 212 AEs. In both studies, the majority of AEs reported were Grade 2 or lower and no serious AEs, unanticipated adverse device effects, or AEs leading to death were reported. CONCLUSIONS: The data collected within these studies indicate that the PLTD procedure is well tolerated and effective at reducing circulating PLTs in patients suffering from thrombocytosis as evaluated by a percent decrease in PLT count, CE1, and AE incidence.

COVID-19 vaccine humoral response in frequent platelet donors with plateletpheresis-associated lymphopenia.

BACKGROUND: Plateletpheresis involves platelet separation and collection from whole blood while other blood cells are returned to the donor. Because platelets are replaced faster than red blood cells, as many as 24 donations can be done annually. However, some frequent apheresis platelet donors (>20 donations annually) display severe plateletpheresis-associated lymphopenia; in particular, CD4+ T but not B cell numbers are decreased. COVID-19 vaccination thereby provides a model to assess whether lymphopenic platelet donors present compromised humoral immune responses. STUDY DESIGN AND METHODS: We assessed vaccine responses following 2 doses of COVID-19 vaccination in a cohort of 43 plateletpheresis donors with a range of pre-vaccination CD4+ T cell counts (76-1537 cells/µl). In addition to baseline T cell measurements, antibody binding assays to full-length Spike and the Receptor Binding Domain (RBD) were performed pre- and post-vaccination. Furthermore, pseudo-particle neutralization and antibody-dependent cellular cytotoxicity assays were conducted to measure antibody functionality. RESULTS: Participants were stratified into two groups: <400 CD4/µl (n = 27) and ≥ 400 CD4/µl (n = 16). Following the first dose, 79% seroconverted within the <400 CD4/µl group compared to 87% in the ≥400 CD4/µl group; all donors were seropositive post-second dose with significant increases in antibody levels. Importantly differences in CD4+ T cell levels minimally impacted neutralization, Spike recognition, and IgG Fc-mediated effector functions. DISCUSSION: Overall, our results indicate that lymphopenic plateletpheresis donors do not exhibit significant immune dysfunction; they have retained the T and B cell functionality necessary for potent antibody responses after vaccination.

A method based on plateletpheresis to obtain functional platelet, CD3+ and CD14+ matched populations for research immunological studies.

BACKGROUND: In previous studies with peripheral blood cells, platelet factors were found to be associated with severe allergic phenotypes. A reliable method yielding highly concentrated and pure platelet samples is usually not available for immunological studies. Plateletpheresis is widely used in the clinics for donation purposes. In this study, we designed a protocol based on plateletpheresis to obtain Platelet-Rich Plasma (PRP), Platelet-Poor Plasma (PPP) as well as CD3+ and CD14+ cells matched samples from a waste plateletpheresis product for immunological studies. METHODS: Twenty-seven subjects were voluntarily subjected to plateletpheresis. PRP, PPP and blood cell concentrate contained in a leukocyte reduction system chamber (LRSC) were obtained in this process. CD3+ and CD14+ cells were isolated from the LRSC by density-gradient centrifugation and positive magnetic bead isolation. RNA was isolated from PRP, CD3+ and CD14+ cell samples and used for transcriptomic studies by Affymetrix. PRP and PPP samples were used for platelet protein quantification by multiplex assays. RESULTS: A reliable high yield method to obtain matched samples of PRP, PPP, CD3+ and CD14+ from a single donor for RNA and protein analyses has been designed. The RNA quality indicators (RQI) routinely used for other cell types were not suitable for platelet RNA characterization. Despite this, the platelet RNA was valid for transcriptomic studies by Affymetrix, as platelet transcripts obtained in our previous studies were confirmed in PRP samples. Platelet samples were enriched in platelet factors as determined in protein multiplex analysis. CONCLUSIONS: We have developed a method that yields not only high content and pure platelet samples from a single donor but also CD3+ and CD14+ matched samples that can be used for RNA and protein analyses in immunological studies.

The effect of platelet apheresis collection on some immunological factors in donors using two different apheresis devices.

INTRODUCTION: The aim of this study was to evaluate and compare two different apheresis and changes in some immunological factors in donors. MATERIAL AND METHODS: The cross-sectional study was performed from January 2017 to September 2018. Fifty six male blood donors were randomly divided into two groups. CD4, CD8, and CD25 markers by flow cytometry, and TGFBeta by real-time polymerase chain reaction (RT-PCR) method were done before and 7 days after the apheresis procedure. Independent Sample t-test, Mann-Whitney U Test, Wilcoxon signed ranked test, and Fisher exact test were used. RESULTS: WBC in MCS+ group after donation is significantly higher than before donation (P < 0.05) but no significant difference was seen between MCS+ and Trima groups in these two indicators. But in CD4, CD25, and TGFBeta, there was no significant difference between the two groups. CONCLUSION: There was no significant difference on CD4, CD25, and TGFBeta gene 7 days after donation.

Assessment of serum iron stores in regular plateletpheresis donors.

BACKGROUND: Iron deficiency anaemia is the most common nutritional deficiency disorder in the world. Iron deficiency is a potential complication in repeated apheresis donation. The present study was aimed to evaluate serum iron stores in regular plateletpheresis donors. MATERIALS AND METHODS: A total of 60 donors were included in this study, which included 30 regular plateletpheresis donors as cases and controls were 30 first time donors. The donor samples were collected before donation for complete hemogram, transfusion transmissible infections screening and serum iron, total iron binding capacity, percentage saturation of transferrin and serum ferritin. RESULTS: Out of 60 donors, more than half of the donors (56.6 %) had serum ferritin less than 30 ng/mL. Out of these 34 donors, 25 were from the case group and 9 donors in the control group. The median serum ferritin level in cases and controls was 11.86 ng/mL (Interquartile range 4.18-17.34 ng/mL) and 37.92 ng/mL (Interquartile range 27.87-86.20 ng/mL) respectively (p < 0.001). The mean serum iron in cases and controls was 71.23 ± 31.32 µg/dL and 93.53 ± 33.53 µg/dL respectively (p = 0.016). The mean percentage saturation in cases and controls was 20.09 ± 9.31 % and 26.26 ± 9.03 % respectively (p = 0.012). A significant decline in mean serum ferritin with increase in number of annual donations and decrease in donation interval was observed. DISCUSSION: Regular plateletpheresis donation may lead to depletion of iron stores and subclinical iron deficiency. Donors with high platelet count are more likely to exhibit iron deficiency. Periodic serum ferritin estimation in donors participating in regular plateletpheresis donation is warranted.

Changes in hematological parameters post plateletpheresis: Single center study from North India.

INTRODUCTION: Increasing demand for platelet transfusion implies the need to recruit greater numbers of donors. We planned this study to evaluate donor safety issues with regards to changes in hematological values after plateletpheresis to improve donor safety and satisfaction. MATERIALS & METHODS: The study was conducted on 1000 healthy plateletpheresis donors over a period of 24 months. Pre- and post-apheresis hematological parameters of donors were analyzed. Recovery of platelet was also observed in plateletpheresis donor who returned to after 48 h. RESULT: We observed that the Platelet counts decreased significantly in the plateletpheresis donors (p=<0.001) after each procedure and there was a non-significant decline in Hb (p = 0.34), Hct (p = 0.44) and RBCs (p = 0.08). The hematological changes were within the normal limits with no clinical evidence of anemia or thrombocytopenia. Recovery of platelets in plateletpheresis donors after 48 h was observed in 30 donors (0.03 %). CONCLUSION: A significant immediate post procedure decrease in platelet count was observed in our study but the recovery of platelets was adequate suggesting next platelet collection from the donor can be safely done after a period of 48 h.

Total platelet donation count and donation frequency are determinants of plateletpheresis-associated lymphopenia.

BACKGROUND: Plateletpheresis using a leukocyte reduction system (LRS) traps donor WBCs in the LRS chamber, which may lead to lymphopenia, especially in frequent plateletpheresis donors. It seems plausible that this might cause adverse effects. However, current knowledge about potential confounders and donor health impacts is incomplete. DONORS AND METHODS: Recent platelet donors and donations collected at University Hospital Regensburg from 2016 to 2019 using the Terumo BCT Trima Accel LRS system were retrospectively analyzed and compared with historical platelet donors and donations collected mainly with Fresenius Kabi Amicus non-LRS system from 2010 to 2013. Additionally, recent donors were prospectively surveyed using a health-related topics questionnaire. RESULTS: Analysis of 819 recent donors with 11,254 blood counts and 1464 questionnaires and 1011 historical donors with 12,848 blood counts revealed that increased annual platelet donation frequencies were associated with decreased lymphocyte counts in both groups. Median lymphocyte counts in recent donors with no versus ≥24 previous annual donations declined from 2.0 to 1.2 × 103 /µL (p < 2.2 × 10-16 ), and those in historical donors with no versus ≥24 previous annual donations decreased from 2.0 to 1.5 × 103 /µL (p = 6 × 10-4 ), respectively. The questionnaire results showed that donation frequency and lymphopenia were not associated with upper respiratory tract infection (URTI) incidence or duration, but platelet donors who concomitantly donated granulocytes had significantly shorter URTI durations than those who did not (p = .008). CONCLUSION: This study confirmed that plateletpheresis-associated lymphopenia occurs in LRS and to a lesser degree in non-LRS platelet donors, but revealed no evidence of a negative impact on donor health.

Assessing the performance of a plateletpheresis unit at a tertiary-care academic medical center in Mexico: A 6-year experience.

BACKGROUND: Optimization of platelet (PLT) apheresis collection is a priority to satisfy the increasing demand of hemato-oncology patients. We assessed the performance of a plateletpheresis unit supporting hematology patients. STUDY DESIGN AND METHODS: This descriptive retrospective study included 561 plateletpheresis collections from 2013 to 2018. For data analysis, descriptive statistics and receiver operating characteristic (ROC) curve were used. A 5-item satisfaction questionnaire was analyzed. RESULTS: Ninety percent of the donors were males. The median plateletpheresis time was 89 minutes; its success rate was 92.5%; median donor PLT count was 232 × 109 /L, women median PLT count was 247 × 109 /L vs 231x109 /L in men (P = .017). Seventy-seven percent donors were candidates for a double product and 24.5% were processed; 20.8% of these donors had a weight ≤75 and 79.2% >75 kg, P = .003, and 6.6% were women and 93.4% men, P = .161. Thirty-six of donors had ≥250 × 109 /L and 16.8% was processed as a triple product. ROC analysis showed that with donor PLT counts ≥200 × 109 /L the sensitivity for obtaining double products was 0.981 and specificity 0.714, with an area under the curve (AUC) = 0.877. The adverse effect rate was 4.3%. Of the potential donors, 6.3% were rejected. The cost of processing single or double products was 430 USD. Comfort and time spent during plateletpheresis were areas for improvement. CONCLUSION: Platelet count and donor weight predicted PLT yield and obtaining double products. Women had higher PLT counts, but no significant difference was found between donor gender and processed products. Assessment of the apheresis unit can help to improve its performance.

Apheresis practice patterns in the United States of America: Analysis of a market claims database.

INTRODUCTION: Indications for apheresis procedures are expanding; however, the evidence for many is low quality. A better understanding of apheresis patterns in the United States is needed to better plan prospective research studies. METHODS: Data from January 1, 2013, to September 30, 2015, were analyzed from the IBM MarketScan Research Databases of de-identified health insurance claims data of several million enrollees at all levels of care from large employers and health plans across the United States. Apheresis procedures were identified by International Classification of Diseases, Ninth version (ICD-9) and Current Procedure Terminology (CPT) codes. RESULTS: Combining inpatients and outpatients, 18 706 patients underwent 70 247 procedures. The patients were 52.7% female, 5.1% <18 years, and 55.9% inpatient, while the procedures were 49.5% female, 5.7% <18 years, and 19.8% inpatient. For each apheresis modality, the percent of patients treated and procedures performed, respectively, are plasmapheresis 36.4% and 42.5%, autologous harvest of stem cells 22.8% and 10.7%, plateletpheresis 11.1% and 3.5%, allogeneic harvest of stem cells 8.2% and 2.5%, photopheresis 5.4% and 24.4%, erythrocytapheresis 3.8% and 4.7%, leukopheresis 2.0% and 0.7%, immunoadsorption 1.4% and 0.4%, extracorporeal selective adsorption/filtration and plasma reinfusion 1.0% and 3.6%, and other 21.6% and 6.9%. A wide variety of diagnoses were treated; however, analysis of the diagnoses suggests the procedure codes may not always reflect an apheresis procedure. CONCLUSION: This study describes the landscape of apheresis in the United States, but may overestimate some procedures based on linked diagnosis codes. Direct measures of apheresis procedures are needed to plan future research studies.

Adopting a vein assessment tool improves procedural outcomes in double dose platelet collections - A prospective study.

BACKGROUND: This study aims to determine the phlebotomy and procedural outcomes using a vein assessment tool (VAT) in Double Dose Platelet (DDP) collections by apheresis. METHODS: VAT was based on assessing vein visibility, palpation and size with maximum score of 12 and the least being 0 and the scores were graded as adequate and inadequate. A vein-viewer was used for studying cubital vein patterns (type 1-5). Phlebotomy outcome was defined based on need for re-puncture. Procedural outcomes in terms of target yield attained and RBC reinfusion completed. Chi square test and Mann- Whitney U test were used to assess the vein score and pattern against phlebotomy and procedural outcome. RESULTS: Out of 200 DDP collections, the phlebotomy was successful in 88 % with good procedural outcome in 94 % donations. The cut off in VAT scores for successful phlebotomy was ≥8 (AUC: 70 %). Median vein scores of the arm selected for phlebotomy was 9 and graded adequate in 154 (77 %) donations.Odds for successful phlebotomy was 3.7 times higher when donors had an adequate VAT grades(p = 0.003). Procedural outcomes was favourable when at least one arm had adequate VAT grade when compared to both arms being inadequate (98 % vs 82 %; p < 0.001). Phlebotomy failure was more with first time apheresis donors than repeat apheresis donors (p = 0.014). CONCLUSION: This study indicated that a VAT score with a cut off of ≥8 had better phlebotomy and procedural outcomes in DDP collections and that donor with at least one arm having the VAT score of ≥8 are preferred for DDP collections.

MicroRNA expression profiles analysis of apheresis platelets treated with vitamin B2 and ultraviolet-B during storage.

Whether platelet (PLT) microRNA (miRNA) profiles are affected by pathogen reduction technology (PRT) using vitamin B2 and ultraviolet-B (VB2-PRT) remains unclear. Samples from VB2-PRT-treated (experimental group, E_) and untreated (control group, C_) apheresis PLTs were taken on days 1, 3 and 5 of storage, designated as E_1, E_3, E_5, C_1, C_3 and C_5, respectively. The miRNA expression profiles were assessed by DNA Nano Ball (DNB) sequencing technology, and verified by quantitive real-time fluorescence quantitative PCR (qRT-PCR). Compared with the expression profiles of PLT miRNAs, 3895 miRNAs were identified in the E_ groups while 4106 were in the C_ groups. There were 487 significant differentially expressed miRNAs in E_1 vs C_1 group, including 220 upregulated and 287 downregulated, such as miR-146a-5p and let-7b-5p. There were 908 significant differentially expressed miRNAs in E_3 vs C_3 group, including 297 upregulated and 611 downregulated, such as miR-142-5p and miR-7-5p. There were 229 significant differentially expressed miRNAs in E_5 vs C_5 group, including 80 upregulated and 149 downregulated, such as miR-3529-3p and miR-451a. These differentially expressed miRNAs had been suggested to have functional roles in energy homeostasis, cell communication, proliferation, migration and apoptosis. GO analysis showed a significant enrichmen in relevant biological process categories as receptor activity, signal transduction, cell transport, motility and chemotaxis. The significantly enriched KEGG pathway of predicted target genes was Glycosaminoglycan biosynthesis in E_ vs C_ groups. These new observation could provide insights on the understanding of change of miRNA profiles of PLT treated with VB2-PRT.

HLA class I depletion by citric acid, and irradiation of apheresis platelets for transfusion of refractory patients.

BACKGROUND: Patients can form antibodies to foreign human leukocyte antigen (HLA) Class I antigens after exposure to allogeneic cells. These anti-HLA class I antibodies can bind transfused platelets (PLTs) and mediate their destruction, thus leading to PLT refractoriness. Patients with PLT refractoriness need HLA-matched PLTs, which require expensive HLA typing of donors, antibody analyses of patient sera and/or crossmatching. An alternative approach is to reduce PLT HLA Class I expression using a brief incubation in citric acid on ice at low pH. METHODS AND MATERIALS: Apheresis PLT concentrates were depleted of HLA Class I complexes by 5 minutes incubation in ice-cold citric acid, at pH 3.0. Surface expression of HLA Class I complexes, CD62P, CD63, phosphatidylserine, and complement factor C3c was analyzed by flow cytometry. PLT functionality was tested by thromboelastography (TEG). RESULTS: Acid treatment reduced the expression of HLA Class I complexes by 71% and potential for C3c binding by 11.5-fold compared to untreated PLTs. Acid-treated PLTs were significantly more activated than untreated PLTs, but irrespective of this increase in steady-state activation, CD62P and CD63 were strongly upregulated on both acid-treated and untreated PLTs after stimulation with thrombin receptor agonist peptide. Acid treatment did not induce apoptosis over time. X-ray irradiation did not significantly influence the expression of HLA Class I complexes, CD62P, CD63, and TEG variables on acid treated PLTs. CONCLUSION: The relatively simple acid stripping method can be used with irradiated apheresis PLTs and may prevent transfusion-associated HLA sensitization and overcome PLT refractoriness.

The current state of the platelet supply in the US and proposed options to decrease the risk of critical shortages.

Due to circumstances such as increased demand and an aging donor pool, the likelihood of critical platelet shortages is increasing. The platelet supply could be improved through the expansion of the donor pool, the identification and sustained utilization of high-quality donors, and changes in component processing and storage that result in a longer platelet shelf-life. Refrigerated platelets, stored at 1° to 6°C, have the potential to improve patient safety by decreasing the risk of bacterial contamination while concurrently allowing for a longer storage period (eg, 14 days) and improved hemostatic effectiveness in actively bleeding patients. An approach utilizing remuneration of apheresis platelet donors combined with pathogen reduction of the platelet components could be used as a means to increase the donor pool and identify and sustain safe, reliable, high-quality donors. Remuneration might provide an incentive for underutilized populations (eg, individuals <30 years old) to enter the apheresis platelet donor population resulting in a significant expansion of the platelet donor pool. Over time, approaches such as the use of refrigerated platelets, platelet donor remuneration, and the application of pathogen reduction technology, might serve to attract a large, reliable, and safe donor base that provides platelet collections with high yields, longer shelf-lives and, excellent hemostatic function.

In vitro thrombus formation and in vivo hemostasis mediated by platelets irradiated with bactericidal ultraviolet C from xenon flash under flow conditions.

BACKGROUND: We previously reported a flow path-ultraviolet C (UVC) irradiation system for platelet concentrates (PCs) with platelet additive solution (PAS) to minimize contamination by bacteria. Here, we investigated functionalities of irradiated platelets (PLTs) in in vitro thrombus formation and in vivo hemostasis. STUDY DESIGN AND METHODS: PAS-PCs were irradiated with flash UVC using the flow path system. Their variables (PLT count, mean platelet volume, pH, glucose, lactate, glycoprotein [GP] Ib, and activated integrin αIIbß3) were evaluated. Static adhesion to collagen or fibrinogen was analyzed using fluorescent microscopy. Thrombus formation under flow conditions was assessed using a collagen-coated bead column. Adenosine diphosphate (ADP)-induced Akt phosphorylation was determined by western blot. In vivo hemostasis and circulatory survival of PLTs were assessed with a rabbit bleeding model. RESULTS: All variables, except for GPIb expression, were slightly, but significantly, impaired after flash UVC irradiation throughout the 6-day storage period. No difference was observed in static adhesion to either collagen or fibrinogen between irradiated and nonirradiated PAS-PCs. In vitro thrombus formation of flash UVC-irradiated PAS-PCs was significantly greater than that of nonirradiated PAS-PCs. ADP-induced Akt phosphorylation was enhanced in irradiated PAS-PCs. In vivo hemostatic efficacy was comparable between the groups on Day 1. The efficacy declined in nonirradiated PAS-PCs on Day 5, while it was retained in flash UVC-irradiated PAS-PCs. Circulatory survival of PLTs was lower in irradiated PAS-PCs. CONCLUSIONS: PAS-PCs irradiated with UVC from xenon flash have favorable properties to achieve hemostasis compared with nonirradiated PAS-PCs.