Platelet Units Research Articles

Splitting apheresis platelets as a contingency measure for inventory shortages.

Splitting apheresis platelet (PLT) units increase available inventory during shortages. The impact of prolonged storage in gas-impermeable aliquot bags on PLT quality in vitro and transfusion outcomes in patients remains uncertain. We assessed in vitro PLT quality and thromboelastography (TEG) in PLTs stored for 8 or 24 h in aliquot bags compared with baseline (T0). Retrospective assessment of response (PLT increment and corrected count increment (CCI)) was conducted among adults (≥18 years) transfused with split platelet units from January 2021 to June 2022. No differences were observed in PLT and white blood cell (WBC) counts, mean platelet volume, or TEG parameters during storage, except for an increase in TEG R time (mean ± SD) at 24 h (6.1 ± 0.5 min) compared to T0 (4.4 ± 0.8 min), p = 0.0031 one-way ANOVA. Eighty-one patients were transfused 119 split units with a median [IQR] PLT yield of 2.1 × 1011[1.9 × 1011 to 2.3 × 1011] and storage duration of 1.6[0.7-9.1] h. The overall median PLT count increment was 6.0 × 103/uL and CCI was 5.0 × 103, correlating negatively with split unit storage duration (Spearman rho = -0.218, p = 0.017). Compared with split transfusions of pathogen-reduced (PR) PLTs, non-PR splits were associated with higher median platelet count increments (7.0 × 103/μL vs. 4.0 × 103/μL, p = 0.0263 Mann-Whitney U) and higher CCIs (6.5 × 103 vs. 3.9 × 103, p = 0.0116 Mann-Whitney U) despite no differences in PLT yields (2.1 × 1011/μL vs. 2.1 × 1011/μL). Storing PLTs in aliquot bags for 8 or 24 h does not adversely affect their quality in vitro. Splitting apheresis PLTs are feasible for adult transfusions during shortages. It may be advisable to prioritize non-PR PLTs for splitting given improved patient responses.

Donor Parameters and Platelet Yield during Plateletpheresis: A Cross-sectional Prospective Study

Abstract Background: Platelet transfusion can be life-saving in bleeding patients with thrombocytopenia or reduced platelet function. Single donor platelets (SDP) unit use is preferred due to the various advantages like reduction in transfusion-transmitted diseases and transfusion reactions. The quality of SDP is determined by platelet yield. Therefore, we conducted this study to assess the donor parameters affecting platelet yield during plateletpheresis. Materials and Methods: This cross-sectional prospective study included 160 single-donor platelet apheresis procedures done for 1 year. The pre-donation platelet count of the donor was set to 250 × 109/L to get double-dose platelet. Plateletpheresis was performed using Trima Accel single-needle separator apheresis machine. The demographic and hematologic parameters of donors were correlated with their platelet yield. Data obtained were tabulated using version 20 of the Statistical Package for the Social Sciences (SPSS). A relationship between pre-donation donor variables and platelet yield was studied using the Pearson correlation coefficient (r). P < 0.05 was considered statistically significant. Results: There was a significant positive correlation between platelet yield and body mass index (BMI) (r = 1710 and P = 0.0304), total leukocyte count (TLC) (r = 0.2220 and P = 0.0048), and platelet count (r = 0.8880 and P < 0.0001). The mean platelet volume (MPV) showed a negative correlation with platelet yield (r = −0.1910 and P = 0.0156). Age, hemoglobin, hematocrit, and platelet distribution width showed no significant correlation with the platelet yield. Conclusion: Donor parameters such as pre-donation platelet count, BMI, TLC, and MPV need to be considered while recruiting the donors for the SDP procedure for better yield of platelets.

Bacterial contamination of platelets concentrates in a lower middle-income country: Data from a single tertiary care hospital

BackgroundTransfusion of bacterially contaminated platelets may cause life threatening sepsis in the recipients. Cost of platelet screening is a major challenge for low middle income countries (LMICs). In this study, we evaluated the frequency of bacterial contamination in the platelet units (PUs) and the outcome of transfusing such platelets to the patients in a single institute at Pakistan. Material and methodsDuring 2018–2022, whole blood-derived (WB-PU) and apheresis platelets (AP) were screened by BacT-ALERT® automated system. Single sample from each AP and samples from ≤ 5 WB-PUs were pooled and cultured within 24 h-post collection. An initial positive signal was followed by re-culture, Gram’s staining, pool resolution and bacterial identification. Results were interpreted as ‘confirmed positive’ or ‘indeterminate’ and ‘confirmed negative’ based on differences in initial-reactive and final results. ResultsA total of 84246 PUs (476 AP and 83770 WB-PU) was screened, and 239 (0.28 %) culture bottles were positive on day one. Individual cultures were performed on 1378 PUs (239 bottles) for pool resolution. Seven of 1378 (0.5 %) PUs were ‘confirmed positive’ while 1371 (99.4 %) were ‘indeterminate’. No bacterial growth was observed in 82868 (82392 WB-PU and 476 AP) of 84246 (98.3 %). Overall bacterial contamination rate was low at 1 in 12000 PUs approximately. Seven patients were transfused with contaminated PUs but no transfusion reaction was observed. ConclusionAn insignificant risk of bacterial contamination was observed in this study but remains a concern for patient safety. LMICs need cost effective but efficient techniques to screen platelets for the presence of bacteria.

Determination of Citrate Content of Commonly Transfused Blood Products

Abstract Background Citrate is a calcium-chelating anion used as an anticoagulant in the collection and manufacturing of blood products for transfusion. Overwhelming of normal hepatic catabolism of infused citrate, such as in liver failure or in massive transfusion, may cause citrate toxicity. Resultant hypocalcemia, impaired coagulation, and metabolic alkalosis results in increased patient mortality and morbidity. The citrate load per blood product unit is rarely known to the transfusionist, precluding precise calcium repletion. Manufacturing data of citrate content is available, but it is unreliable and often contradictory. The aim of this project is to directly measure the citrate concentrations of common blood products including packed red blood cells (pRBCs), plasma, and apheresis platelets. Methods Blood products (or samples thereof) were obtained, centrifuged, and assayed using a benchtop enzymatic citrate assay (Sigma-Aldrich). This technique generates a chromogenic product detectable via spectrophotometry at 570nm via conversion of citrate to a pyruvate intermediate. Blood products were serially diluted to the assay’s concentration measurement range based on estimations from the product manufacturing processes. Validation studies were performed to verify no significant interference from native pyruvate or from hemolysis at the dilutions used. All samples were run with a paired reference standard. Product type, storage duration, volume, and anticoagulant/preservative solution were recorded. Results Preliminary testing was performed on eleven pRBC units, twelve apheresis platelet units, and four whole blood(WB)-derived plasma. Measured citrate content of AS-1 and AS-5 units ranged from 43.56 - 114.5 mg while that of AS-3 units ranged from 327.23 – 816.82 mg, compared to manufacturing estimates of 188 mg and 883 mg, respectively. Measured citrate content of apheresis platelets ranged from 822-1533 mg compared to manufacturing estimates of 805 mg. Measured citrate content of WB-derived plasma also exceeded the manufacturing estimate of 1201 mg. Interference from pyruvate and hemolysis were insignificant at the dilutions used for testing. Validation of pRBC segment sampling is ongoing. Conclusion Varying guidelines exist for the correction of hypocalcemia during ongoing trauma resuscitation; however, guidance is limited regarding repletion by specific blood product. Our investigation affirms significant heterogeneity in pRBC citrate concentrations by collection method and identifies lower citrate concentrations than expected. This may be due to citrate metabolism by RBCs during storage. Platelet and FFP products contain significantly greater citrate masses by comparison, with a high degree of variation observed due to inherent product volume variability. Further sampling and testing are ongoing to establish reliable expected citrate loads for commonly transfused blood products.

Platelet transfusion.

Platelet transfusions, used as prophylaxis or treatment for bleeding, are potentially life-saving. In many countries, demand for platelet transfusion is rising. Platelets are a limited and costly resource, and it is vital that they are used appropriately. This study will explore the evidence behind platelet transfusions in different contexts, in particular recent and important research in this area. Recent randomized clinical trials demonstrate the efficacy of platelet transfusions in some contexts but potential detrimental effects in others. Platelet transfusions also carry risk of transfusion reactions, bacterial contamination and platelet transfusion refractoriness. Observational and clinical studies, which highlight approaches to mitigate these risks, will be discussed. There is growing interest in cold-stored or cryopreserved platelet units, which may improve platelet function and availability. Clinical trials also highlight the efficacy of other supportive measures such as tranexamic acid or thrombopoietin receptor agonists in patients with bleeding. Although platelet transfusions are beneficial in many patients, there remain many settings in which the optimal use of platelet transfusions is unclear, and some situations in which they may have detrimental effects. Future clinical trials are needed to determine optimal use of platelet transfusions in different patient populations.

Formation of Single-Species and Multispecies Biofilm by Isolates from Septic Transfusion Reactions in Platelet Bag Model.

During 2018-2021, eight septic transfusion reactions occurred from transfusion of platelet units contaminated with Acinetobacter spp., Staphylococcus saprophyticus, Leclercia adecarboxylata, or a combination of those environmental organisms. Whether biofilm formation contributed to evasion of bacterial risk mitigations, including bacterial culture, point-of-care testing, or pathogen-reduction technology, is unclear. We designed a 12-well plate-based method to evaluate environmental determinants of single-species and multispecies biofilm formation in platelets. We evaluated bacteria isolated from septic transfusion reactions for biofilm formation by using crystal violet staining and enumeration of adherent bacteria. Most combinations of bacteria had enhanced biofilm production compared with single bacteria. Combinations involving L. adecarboxylata had increased crystal violet biofilm production and adherent bacteria. This study demonstrates that transfusion-relevant bacteria can produce biofilms well together. More work is needed to clarify the effect of biofilms on platelet bacterial risk control strategies, but US Food and Drug Administration-recommended strategies remain acceptable.

Use of Eltrombopag to Improve Thrombocytopenia and Tranfusion Requirement in Anti-CD19 CAR-T Cell-Treated Patients.

Background/Objectives: Immune effector cell-associated hematotoxicity (ICAHT) is a frequent adverse event after chimeric antigen receptor (CAR)-T cell therapy. Grade ≥ 3 thrombocytopenia occurs in around one-third of patients, and many of them become platelet transfusion-dependent. Eltrombopag is a thrombopoietin receptor agonist (TPO-RA) able to accelerate megakaryopoiesis, which has been used successfully in patients with bone marrow failure and immune thrombocytopenia (ITP). Its role in managing thrombocytopenia and other cytopenias in CAR-T cell-treated patients has been scarcely addressed. Our aim was to report the safety and efficacy of this approach in patients included in the Spanish Group for Hematopoietic Transplantation and Cellular Therapy (GETH-TC) registry. Methods: This is a retrospective, multicenter, observational study. Patients who developed platelet transfusion dependence subsequently to CAR-T cells and received eltrombopag to improve platelet counts were recruited in 10 Spanish hospitals. Results: Thirty-eight patients were enrolled and followed up for a median (interquartile range [IQR]) of 175 (99, 489) days since CAR-T cell infusion. At the moment eltrombopag was indicated, 18 patients had thrombocytopenia and another severe cytopenia, while 8 patients had severe pancytopenia. After 32 (14, 38) days on eltrombopag, 29 (76.3%) patients recovered platelet transfusion independence. The number of platelet units transfused correlated with the time needed to restore platelet counts higher than 20 × 109/L (Rho = 0.639, p < 0.001). Non-responders to eltrombopag required more platelet units (58 [29, 69] vs. 12 [6, 26] in responders, p = 0.002). Nineteen out of twenty-three (82.6%) patients recovered from severe neutropenia after 22 (11, 31) days on eltrombopag. Twenty-nine out of thirty-five (82.9%) patients recovered red blood cell (RBC) transfusion independence after 29 (17, 44) days. Seven patients recovered all cell lineages while on treatment. No thromboembolic events were reported. Only two transient toxicities (cholestasis, hyperbilirubinemia) were reported during eltrombopag treatment, none of which compelled permanent drug withdrawal. Conclusions: Eltrombopag could be safely used to manage thrombocytopenia and accelerate transfusion independence in CAR-T cell-treated patients.

Use of Low-Dose Platelets in Actively Bleeding Patients: A Retrospective Analysis of a Cardiac Surgery Cohort.

During platelet shortages, many hospitals produce low-dose platelets by splitting a standard platelet unit (>3 × 1011 platelets in the United States) in 2, then providing these low-dose units to patients. While low-dose units were previously found to be effective for prophylactic purposes in patients undergoing chemotherapy in the Prophylactic Platelet Dose (PLADO) trial, their use in actively bleeding patients has not yet been assessed. To assess the use and safety of low-dose platelets in actively bleeding patients. We performed a retrospective review of cardiac surgery cases receiving platelet units for 18 months at 1 hospital. Two cohorts, those receiving only whole-dose platelets (37 cases) and those receiving only low-dose platelets (38 cases), were compared during the intraoperative and the 24-hour perioperative period. Mean number of platelet transfusions, dose of other blood products, estimated blood loss, bleeding complications in index cases, and all-cause mortality within 30 days of discharge were compared. There was no significant difference in mean number of intraoperative platelet transfusions between the cohorts (1.61 versus 1.53, P = .57). There was no significant increase in the transfusion of other blood products, estimated blood loss, bleeding complications in index cases, or all-cause mortality within 30 days of discharge in the low-dose platelet cohort, apart from a small increase in requirement for fresh frozen plasma in the perioperative period. These results suggest that low-dose platelets are tentatively equivalent to whole-dose platelets in cardiac surgery during shortages, with similar transfusion requirements and clinical outcomes between groups. Future multicenter studies are needed to confirm these findings.

COVID-19-related challenges in blood donation in the United Arab Emirates

Background: Blood donation was among the most severely disrupted service during the COVID-19 pandemic, and different measures were taken nationally and internationally to mitigate the impact of the pandemic on donation services. Aim: To compare blood donation before, during and after the pandemic and the effectiveness of efforts to mitigate the effects of COVID-19 on donation services. Methods: This retrospective, observational, population-based study assessed the number and locations of blood donations, number of blood and platelet units issued to hospitals, and characteristics of 82 619 blood donors at the reference blood donation facility in United Arab Emirates in 2019 and 2020. Service recovery was assessed by comparing blood donation in 2021 and 2022 with 2019. The data were analysed using SPSS version 26 and the extent of the effect of COVID-19 on the measured parameters was tested using Pearson’s χ2 test. P ≤ 0.05 was considered statistically significant. Results: COVID-19 significantly affected the number of donors, location of blood donations, and quantities of blood and platelets issued to hospitals. Median annual number of donors was 19 121 males and 1393 females. In 2020, male donors increased by 1.6%, while female donors decreased by 22.3%. The number of donors decrease to 18 977 in 2020 from 19 035 in 2019 and increased to 22 542 in 2021 and 22 065 in 2022. Whole blood collections decreased by 0.3% in 2020 and increased by 18.0% in 2021 and 13.6% in 2022. Conclusion: Proactive measures, good infrastructure, flexibility, emergency planning, community awareness, good communication between stakeholders, and close coordination among national authorities are needed to effectively manage blood donation centres during crisis.

Risk of Transfusion in Isolated Coronary Artery Bypass Graft: Models Developed From The Society of Thoracic Surgeons Database

BackgroundPerioperative blood transfusion is associated with adverse outcomes and higher costs after coronary artery bypass graft (CABG) surgery. We developed risk assessments for patients’ probability of perioperative transfusion and the expected transfusion volume to improve clinical management and resource use. MethodsAmong 1,266,545 consecutive (2008-2016) isolated CABG operations in The Society of Thoracic Surgeons Adult Cardiac Surgery Database, 657,821 (51.9%) received perioperative transfusions of red blood cells (RBC), fresh frozen plasma (FFP), cryoprecipitate, and/or platelets. We developed “full” models to predict perioperative transfusion of any blood product, and of RBC, FFP, or platelets. Using least absolute shrinkage and selection operator model selection, we built a rapid risk score based on 5 variables (age, body surface area, sex, preoperative hematocrit, and use of intra-aortic balloon pump). ResultsC statistics for the full model were 0.785, 0.815, 0.707, and 0.699 for any blood product, RBC, FFP, and platelets, respectively. C statistics for rapid risk assessments were 0.752, 0.785, 0.670, and 0.661 for any blood product, RBC, FFP, and platelets, respectively. The observed vs expected risk plots showed strong calibration for full models and risk assessment tools; absolute differences between observed and expected risks of transfusion were <10.8% in each percentile of expected risk. Risk assessment–predicted probabilities of transfusion were strongly and nonlinearly associated (P < .0001) with total units transfused. ConclusionsThese robust and well-calibrated risk assessment tools for perioperative transfusion in CABG can inform surgeons regarding patients’ risks and the number of RBC, FFP, and platelets units they can expect to need. This can aid in optimizing outcomes and increasing efficient use of blood products.

Primary Posterior Uterine Rupture in Labor: Case Report and Literature Review

Purpose: To report a rare case of primary posterior uterine rupture in a healthy term multigravida. Methods: Case report. Results: We present the case of an otherwise healthy 35-year-old gravida 4 para 3 with no reported medical or surgical history and three prior uncomplicated term vaginal deliveries who presented in labor at 39 weeks gestation. After four hours of oxytocin augmentation, the fetus was noted to have recurrent late decelerations and then became bradycardic with a baseline of 60 bpm. The patient’s cervix was found to be 7 cm dilated, 90% effaced, and -1 station. Standard resuscitative measures were undertaken at which point the patient’s cervix was rechecked and found to be 9 cm dilated, 90% effaced, and -1 station. Attempts at manually reducing the cervix while the patient pushed were unsuccessful. With the fetus still bradycardic with a baseline of 60 bpm, the patient was taken for an emergency Cesarean delivery. Within seven minutes of calling the emergency Cesarean delivery, surgery had started. However, there was difficulty with delivering the fetus, who had flipped to transverse back down. The fetus was rotated to breech before being delivered through a “T” incision made on the uterus to facilitate delivery of the head. Three tight nuchal cords were reduced at time of delivery. Examination of the uterus after delivery of the fetus revealed a full thickness, cruciate-shaped laceration in the posterior lower uterine segment extending ~9 cm in the vertical plane, involving the vagina, and ~5 cm in the transverse plane. The rupture was repaired, and the remainder of the surgery proceeded without further complication. Blood loss was estimated at 2500 mL, and she required transfusion of 4 units of packed red cells, 2 units cryoprecipitate, 1 unit fresh frozen plasma, and 1 unit of platelets. The infant was atonic upon delivery with a weight of 3785g and APGARs of 1/5/7. Umbilical artery blood gas analysis was normal with a pH of 7.19 and a base deficit of 7.9 mmol/L. The infant initially required intubation, but quickly improved and was extubated to room air at 1 hour of life. Imaging and neurological exams indicated possible moderate encephalopathy, and the infant underwent therapeutic hypothermia for four days at which point cooling was discontinued after improvement was noted. The remainder of his NICU stay was unremarkable and he was discharged on day nine of life. The mother required 2 additional units of packed red cells during the remainder of her postpartum course, but otherwise did well and she was discharged on post-op day five. Conclusion(s): Uterine rupture is the complete separation of all three layers of the uterus. It is a life-threatening event for both the fetus and the mother. Most uterine ruptures occur in a previously scarred uterus. Uterine rupture in a previously unscarred uterus (primary uterine rupture) is rare and estimated to occur in ~1:20,000 pregnancies. Over 90% of primary uterine ruptures occur in the anterior lower uterine segment. Although this patient did not have any reported medical or surgical history, her status as a multipara and being of advanced maternal age did pose a higher risk of primary rupture. This patient also underwent 3 ½ hours of oxytocin infusion at the time the Cesarean was called. Although she was not on oxytocin for long, its use is associated with primary uterine rupture more so than secondary rupture. Normal indicators of uterine rupture include non-reassuring fetal heart rate tracing, sudden unexplained abdominal pain, unexplained vaginal bleeding, and loss of fetal station. In this patient, fetal bradycardia was the only sign that her uterus was compromised. Although the uterine arteries were not involved in this patient’s rupture, blood loss was still profound due to the extensive uterine defect. This case highlights that, while rare, uterine rupture can occur in any patient, regardless of uterine surgical history and physicians must be prepared to intervene quickly.

Thromboelastography-Guided versus Standard-of-Care or On-Demand Platelet Transfusion in Patients with Cirrhosis and Thrombocytopenia Undergoing Procedures: A Randomized Controlled Trial

PurposeTo determine the rate of platelet transfusion in patients with cirrhosis and severe thrombocytopenia (platelet counts <50 × 109/L) undergoing high-risk invasive procedures when prescribed by thromboelastography (TEG) compared with empirical and on-demand transfusion strategies. Materials and MethodsThis was a single-center, single-blinded, randomized controlled trial. Patients with cirrhosis and severe thrombocytopenia undergoing high-risk invasive procedures were randomized into 3 groups: TEG group, transfusions based on TEG parameters; standard of care (SOC) group, 3 units of random donor platelets before procedure; and on-demand group, transfusions based on procedural adverse events/clinician’s discretion. The primary outcome was periprocedural platelet transfusion in each arm. ResultsEighty-seven patients were randomized (29 in each group) with no significant differences in demographics/coagulation profile/procedures. The median platelet count was 33 × 109/L (interquartile range, 26–43 × 109/L). Percutaneous liver biopsy was the most common procedure (46, 52.9%). Significantly lower number of patients in the TEG group received platelets (4 cases, 13.8%; 95% CI, 3.9–31.7) compared with SOC group (100%; 95% CI, 88.1–100; P < .001). Four patients in the on-demand group received platelets (13.8%; 95% CI, 3.9–31.7). Minor (World Health Organization [WHO] Grade 2) procedure-related bleeding occurred in 3 (10%; 95% CI, 2.2–27.4) patients in the TEG-guided transfusion group compared with 1 (3.4%; 95% CI, 0.1–17.8) patient each in the SOC and on-demand groups (P = .43), although the study was not powered for comparison of bleeding rates. No bleeding-related mortality was observed in any of the 3 groups. ConclusionsTEG-prescribed transfusion reduced prophylactic transfusions in patients with cirrhosis and severe thrombocytopenia undergoing high-risk invasive procedures. The study was not powered for comparison of bleeding rates.

Living donor liver transplantation for patients with portal vein thrombosis: high-volume single center experience.

End-stage liver disease is commonly associated with portal vein thrombosis (PVT). Lastly, PVT is no longer an absolute contraindication for liver transplantation, and many centers adopt portal vein thrombectomy. PVT imposes special technical difficulties during living donor liver transplantation (LDLT). In this research, the experience with PVT cases during LDLT in a high-volume center is introduced. Between January 2018 and July 2023, 312 patients underwent LDLT. After 88 cases were excluded, 224 cases were included, and their incidence of pre-transplant PVT was 16.5% (37/224). Demographic and clinical features, perioperative variables, and post-transplant outcomes of patients with PVT (PVT group, n=37) were compared to patients who had no PVT (non-PVT group, n=187). According to Yerdel classification, 16, 16, 2, and 3 patients had PVT grade I, II, III, and IV, respectively. Complete venous thrombectomy was accomplished in 34 patients, while for three patients, thrombectomy was not feasible, and graft inflow was established by interposition vascular graft. For portal flow modulation, splenectomy and splenic artery ligation were performed in 7 and 4 patients, respectively, while two patients underwent post-transplant splenic artery embolization. The PVT group had longer operation time (p<0.001), longer warm ischemia time (p=0.031), longer anhepatic phase (p<0.001), and intraoperatively required more than 3 packed RBCs units (p=0.029) and ≥1 platelet unit transfusion (p=0.021) than the non-PVT group. No statistically significant difference was found between groups in terms of re-exploration (p=0.954), post-transplant PVT (p=0.375), biliary (p=0.253) and arterial complications (p=0.593), ICU stay (p=0.633), hospital stay (p=896), and 30-day mortality (p=1.000). Survival analysis showed no statistically significant difference regarding 1-year survival (p=0.176) between both groups. This study showed that patients with different stages of PVT can successfully undergo LDLT in experienced centers and that they do not differ from patients without PVT in terms of post-transplant complications.

Anti-A and anti-B titers in A, B and O whole blood donors: Beyond “dangerous O”

Background and ObjectivesHemolytic transfusion reactions (HTRs) pose significant risks in transfused patients, with anti-A and anti-B antibodies in donor plasma being potential contributing factors. Despite advancements in component preparation, HTRs remain a concern, particularly with apheresis-derived platelets. This study aimed to determine the prevalence of high anti-A and anti-B titers among A, B, and O blood group donors and to explore factors associated with high titers. Materials and MethodsA cross-sectional observational study was conducted over 18 months, enrolling 978 participants from a tertiary care teaching hospital in Western India. Anti-A and anti-B titers were determined using the Conventional Tube Technique (CTT). Statistical analysis assessed correlations between high titers and demographic factors. ResultsThe majority of participants were young males (98.8%). Prevalence of high titers for IgM anti-A was 12.2% and IgG anti-A was 2.5%. For anti-B, IgM titers were 2.3% and IgG titers were 0.2%. The prevalence of dangerous O was found to be 14.1%, while 3.52% and 10.5% of A and B blood group donors were found to have high titers, respectively. Factors associated with high titers included female gender, vegetarian diet, age <30 years, and O blood group. ConclusionThe study sheds additional light and provides supplementary information regarding the prevalence and correlation of high anti-A and anti-B titers among O, A and B blood donors. Understanding these factors is crucial for optimizing transfusion safety protocols, including selective screening of platelet units and tailored transfusion strategies based on donor characteristics.

Isohemagglutinin titration in pooled and apheresis platelets.

Platelet inventory constraints necessitate ABO-incompatible platelet transfusion. Many minimize the hemolytic impact by confirming low titre (LT) donor isohemagglutinins. This process is costly. Pathogen-reduced platelets (PRP) in platelet additive solutions (PAS) will dilute plasma and decrease high-titre isohemagglutinins (HT). We determined the proportion of HT platelets and incompatible transfusions for units suspended in plasma to reassess the need for titres following introduction of PRP/PAS. Our titre method is manual tube (1:50) dilution of platelet supernatant from apheresis or whole blood derived buffy coat pools suspended in plasma, tested with A1/B red cells. Testing included 49,058 pooled and 11,738 apheresis platelets over 4 years. The HT proportion, rate of out-of-group transfusions, and hemolytic reactions were determined. The impact of PAS dilution was estimated. Totally 60,796 platelet units were tested. Group O pooled and group B apheresis platelets had HT in 6.6% and 5.7%, respectively. Group A pooled and apheresis platelets included 2% with HT. Approximately 25% of platelets transfused were ABO-incompatible and no hemolytic reactions were reported. Based on the proportions of PAS-E and plasma for PRP platelets, plasma from each donor comprises 11 mL (6% of total volume) vs 20-257 mL in untreated pools. PAS-E will replace and dilute residual plasma by at least 50%. Rare platelet pools may demonstrate HT. PRP platelets with PAS will reduce titres and may abrogate the need for titration. A strategy of group specific transfusion or transfusion of group A PRP platelet transfusions may be a safe alternative.

PREBOA vs ER-REBOA impact on blood utilization and resuscitation requirements: A pilot analysis.

Partial occlusion of the aorta is a resuscitation technique designed to maximize proximal perfusion while allowing a graduated amount of distal flow to reduce the ischemic sequelae associated with complete aortic occlusion. The pREBOA catheter affords the ability to titrate perfusion as hemodynamics allows, however, the impact of this new technology for REBOA on blood use and other resuscitative requirements is currently unknown. We hypothesize pREBOA's ability to provide partial occlusion, when appropriate, decreases overall resuscitative requirements when compared to ER-REBOA. The entire AAST AORTA Registry was used to compare resuscitation requirements between all ER-REBOA and pREBOA. Unpaired t-tests were used to compare resuscitation strategies including packed red blood cells (PRBCs), fresh frozen plasma (FFP), platelets, cryoprecipitate, crystalloids, and need for pressors. When comparing ER-REBOA (n=800) use to pREBOA (n=155), initial patient presentations were similar except for age (44 vs 40 p=0.026) and rates of blunt injury (78.4% vs 78.7% p<0.010). Zone-1 occlusion was used less often in ER-REBOA (65.8 vs 71.7 p=0.046). Partial occlusion was performed in 85% of pREBOA compared to 11% in ER-REBOA (p<0.050). Vitals at the time of REBOA were worse in ER-REBOA, and received significantly more units of PRBCs, FFP, platelets, and liters of crystalloids than pREBOA (p<0.05). Rates of ARDS and septic shock were lower in pREBOA (p<0.05). When comparing pREBOA to ER-REBOA, there has been a rise in Zone-1 and partial occlusion. In our pilot analysis of the AORTA Registry, there was a reduction in administration of pRBC, FFP, platelets, and crystalloids. Though further prospective studies are required, this is the first to demonstrate an association between pREBOA, partial occlusion, and reduced blood use and resuscitative requirements.

The impact of infused red blood cell volume on major and bidirectional ABO-mismatched bone marrow transplantation

Background aimsABO incompatibility does not hinder bone marrow transplantation (BMT), but it has been associated with worse outcomes and additional adverse events. This study aimed to verify the impact of incompatible red blood cells (iRBCs) in allogeneic BMT and to determine a safe number of iRBCs to be infused. MethodsWe compared ABO-incompatible (iABO) allogeneic BMT (n = 42) with ABO-compatible allogeneic BMT (n = 44) and evaluated the impact of the number of infused iRBCs on outcomes and adverse events. ResultsThe iABO patients demonstrated delayed time to transfusion independence at 30 days and 60 days, increased requirement for red blood cell (RBC) transfusion and greater hemolysis signals and incidence of pure red cell aplasia. Neutrophil/platelet engraftment, length of hospitalization post-transplant, platelet units required, graft-versus-host disease occurrence and overall survival were similar in both groups. Patients in the iABO group received 1.03 × 1010 iRBCs/kg (range, 0.36–3.88). Infusion of iRBCs >1.0 × 1010 /kg was related to graft failure or death before neutrophil engraftment or platelet engraftment or both as well as increased plasma requirement and increased creatinine. Our results also suggest that antibody titers impact the transplantation scenario. ConclusionsThe iABO transplantation showed some unfavorable outcomes. It is important to monitor the value of iRBCs to be infused, considering the recipient antibody titers. We propose using the number of iRBCs (iRBCs/kg) as a dose parameter with regard to infused iRBCs. Further studies are necessary to clarify the maximum safe number of iRBCs in iABO transplants.

Early Cold Stored Platelet Transfusion Following Severe Injury: A Randomized Clinical Trial.

To determine the feasibility, efficacy, and safety of early cold stored platelet transfusion compared with standard care resuscitation in patients with hemorrhagic shock. Data demonstrating the safety and efficacy of early cold stored platelet transfusion are lacking following severe injury. A phase 2, multicenter, randomized, open label, clinical trial was performed at 5 US trauma centers. Injured patients at risk of large volume blood transfusion and the need for hemorrhage control procedures were enrolled and randomized. The intervention was the early transfusion of a single apheresis cold stored platelet unit, stored for up to 14 days versus standard care resuscitation. The primary outcome was feasibility and the principal clinical outcome for efficacy and safety was 24-hour mortality. Mortality at 24 hours was 5.9% in patients who were randomized to early cold stored platelet transfusion compared with 10.2% in the standard care arm (difference, -4.3%; 95% CI, -12.8% to 3.5%; P =0.26). No significant differences were found for any of the prespecified ancillary outcomes. Rates of arterial and/or venous thromboembolism and adverse events did not differ across treatment groups. In severely injured patients, early cold stored platelet transfusion is feasible, safe and did not result in a significant lower rate of 24-hour mortality. Early cold stored platelet transfusion did not result in a higher incidence of arterial and/or venous thrombotic complications or adverse events. The storage age of the cold stored platelet product was not associated with significant outcome differences. ClinicalTrials.gov identifier: NCT04667468.

Is there a need for fresh frozen plasma and platelet transfusion in trauma patients receiving submassive transfusion?

BackgroundBlood transfusions have become a vital intervention in trauma care. There are limited data on the safety and effectiveness of submassive transfusion (SMT), that is defined as receiving less than...

Characterization of a novel mouse platelet transfusion model.

Platelet transfusions are increasing with medical advances. Based on FDA criteria, platelet units are assessed by in vitro measures; however, it is not known how platelet processing and storage duration affect function in vivo. Our study's aim was to develop a novel platelet transfusion model stored in mouse plasma that meets FDA criteria adapted to mice, and transfused fresh and stored platelets are detectable in clots in vivo. Platelet units stored in mouse plasma were prepared using a modified platelet-rich plasma (PRP) collection protocol. Characteristics of fresh and stored units, including pH, cell count, in vitro measures of activity, including activation and aggregation, and post-transfusion recovery (PTR), were determined. Lastly, a tail transection assay was conducted using mice transfused with fresh or stored units, and transfused platelets were identified by confocal imaging. Platelet units had acceptable platelet and white cell counts and were negative for bacterial contamination. Fresh and 1-day stored units had acceptable pH; the platelets were activatable by thrombin and adenosine diphosphate, agreeable with thrombin, had acceptable PTR, and were present in vivo in clots of recipients after tail transection. In contrast, 2-day stored units had clinically unacceptable quality. We developed mouse platelets for transfusion analogous to human platelet units using a modified PRP collection protocol with maximum storage of 1 day for an 'old' unit. This provides a powerful tool to test how process modifications and storage conditions affect transfused platelet function in vivo.