Platelet Transfusion: And Update on Challenges and Outcomes

Safety of local thermal ablation in hepatocellular carcinoma patients with cirrhosis and severe thrombocytopenia

Generally, invasive treatment is contraindication for patients with severe thrombocytopenia, because it may increase risk of bleeding. However, many early hepatocellular carcinoma (HCC) patients with cirrhosis have platelet counts (PC) less than 50 × 109/L due to hypersplenism. These patients are often accompanied by hepatic insufficiency, which makes hepatectomy impossible, and local thermal ablation (LTA) has become a major treatment. The aim of our study is to investigate the correlation between severe thrombocytopenia and bleeding after LTA in HCC patients with cirrhosis, and evaluate risk factors of bleeding. 473 patients with cirrhosis who underwent LTA for HCC from 2016 to 2020 were enrolled, and 709 ablations were performed in total. Based on preoperative PC, cases were divided into three groups, namely, group A (PC > 50 × 109/L), group B (30 × 109/L < PC ≤ 50 × 109/L) and group C (PC ≤ 30 × 109/L). The incidence of bleeding after LTA was compared among the three groups. Logistic regression was used to explore the risk factors for bleeding after ablation. The overall incidence of bleeding complications was 4.4%, and no significant difference was observed between group A, B, and C (3.9% vs. 6.4% vs. 3.3%, P = 0.410). In multivariate analysis, tumor diameter (OR = 2.657 per 1 cm, P < 0.001), and multiple lesions (≥ 3) (OR = 3.723, P = 0.006) were found to be independent predictors of bleeding after LTA. In small HCC patients with cirrhosis and hypersplenism, the PC range 30-50 × 109/L will not increase the risk of bleeding after LTA. Tumor diameter and number of lesions are independent predictors for bleeding after LTA in HCC patients.

HPA1-29w Genotyping and the Foundation for the Platelet Apheresis Registry in Jiangsu Province of China by MassARRAY Spectrometry

Introduction

This study aimed to investigate the allele frequencies of the human platelet antigens (HPA) HPA-1-29w system in Jiangsu (China) and establish the platelet apheresis registry in blood donors.

Methods

HPA genotyping was performed using the MassARRAY iPLEX® platform. Allele and genotype frequencies were estimated by direct counting and tested for Hardy-Weinberg equilibrium. The transfusion mismatch probability was calculated for every HPA specificity.

Results

The HPA allele frequencies in the Jiangsu Han population of HPA-1b, -2b, -3b, -4b, -5b, -6b, -11b, -15b, and -21b were 0.0055, 0.0530, 0.4116, 0.0015, 0.0155, 0.0162, 0.0003, 0.4683, and 0.0070, respectively, in which a heterozygote of HPA-11a/b was first detected in China. Only allele a was detected for HPA-7-10w,-12-14w,-16-20w, and -22-29w quasi-systems. The highest mismatch rate of HPA genes in 1,640 platelet donors was the HPA-15 system, followed by the HPA-3 system with a rate of 37.4% and 36.71%, respectively.

Conclusion

China's largest-scale platelet registry of HPA-1-29w has been explored. The MassARRAY platform may help found the platelet apheresis registry which would be useful to provide matching platelets and lead to a more accurate, effective, and safe transfusion for patients with platelet therapy.

Platelet-Type von Willebrand Disease: Complex Pathophysiology and Insights on Novel Therapeutic and Diagnostic Strategies

von Willebrand disease (VWD) is the most common well-studied genetic bleeding disorder worldwide. Much less is known about platelet-type VWD (PT-VWD), a rare platelet function defect, and a "nonidentical" twin bleeding phenotype to type 2B VWD (2B-VWD). Rather than a defect in the von Willebrand factor (VWF) gene, PT-VWD is caused by a platelet GP1BA mutation leading to a hyperaffinity of the glycoprotein Ibα (GPIbα) platelet surface receptor for VWF, and thus increased platelet clearing and high-molecular-weight VWF multimer elimination. Nine GP1BA gene mutations are known. It is historically believed that this enhanced binding was enabled by the β-switch region of GPIbα adopting an extended β-hairpin form. Recent evidence suggests the pathological conformation that destabilizes the compact triangular form of the R-loop-the GPIbα protein's region for VWF binding. PT-VWD is often misdiagnosed as 2B-VWD, even the though distinction between the two is crucial for proper treatment, as the former requires platelet transfusions, while the latter requires VWF/FVIII concentrate administration. Nevertheless, these PT-VWD treatments remain unsatisfactory, owing to their high cost, low availability, risk of alloimmunity, and the need to carefully balance platelet administration. Antibodies such as 6B4 remain undependable as an alternative therapy due to their questionable efficacy and high costs for this purpose. On the other hand, synthetic peptide therapeutics developed with In-Silico Protein Synthesizer to disrupt the association between GPIbα and VWF show preliminary promise as a therapy based on in vitro experiments. Such peptides could serve as an effective diagnostic technology for discriminating between 2B-VWD and PT-VWD, or potentially all forms of VWD, based on their high specificity. This field is rapidly growing and the current review sheds light on the complex pathology and some novel potential therapeutic and diagnostic strategies.

Analysis of erythrocyte and iron study data among plateletpheresis donors in Hangzhou, China

BACKGROUND

The purpose of this study is to obtain the iron parameters level of blood donors and the population who need to pay attention to iron parameters level in this area.

METHODS

A total of 993 plateletpheresis donors were included in this study, including 798 males and 195 females. The results of erythrocyte and iron parameters of blood donors were compared and analyzed in different groups according to the gender, age and number of blood donations.

RESULT

The proportion of men and women with low serum ferritin (SF) levels was 10.8 % and 27.7 %, respectively. The mean levels of serum iron (SI), SF, transferrin saturation (Tfs), hemoglobin (Hb) and hematocrit (HCT) of male blood donors decreased with the increase of age groups, but there was no significant statistical difference between the results of female blood donors. The level of SI, SF, Tfs, Hb and HCT of male donors decreased with the increase of blood donations in the past year, while TRF and TIBC increased. The level of Hb, HCT and SF of female donors showed no significant downward trend, while the levels of TRF increased with increasing donations in the past year, excluding first-time donors. The SI of female donors trended down, and TIBC trended up with increasing donations.

CONCLUSION

Blood collection institutions need to focus on iron parameters levels in older and frequent male donors, and young fertile female donors.

The Effect of High Intensity Interval Exercise on Platelet Engraftment in Autologous Bone Marrow Transplantation (BMT)

Background: Thrombocytopenia is a frequent complication after hematopoietic stem cell transplantation (HSCT). Although platelet transfusion is the most used treatment for severe thrombocytopenia, it is associated with well-established risks. High-intensity interval exercise (HIIE) results in thrombocytosis. Therefore, this study aimed to reduce thrombocytopenia by increasing platelet count through exercise. Materials and Methods: Twenty lymphoma and multiple myeloma patients were divided into HIIE and control groups. To determine the maximal exercise capacity, patients in the HIIE group performed a graded exercise test. All patients received granulocyte colony-stimulating factor for 5 days, followed by a HIIE trial. After 5 min warm up at 10 to 20% of peak power, patients in the HIIE group performed an HIIE protocol that included 12 intervals of one-minute work at 100% peak power interspersed by one-minute active rest at 20% of peak power. Patients in the control group were seated for the same duration without any physical activity. Two blood samples were taken before and immediately after the trials and were analyzed for measuring complete blood count. Results: Platelet count on the day of platelet engraftment in the HIIE group was significantly higher than in the control group (P=0.02). Single-donor platelet transfusion was significantly lower in the HIIE group than in the control group (P=0.05). Conclusion: Based on the findings of the present study, a short bout of HIIE had a positive effect on platelet engraftment through thrombocytosis and reduced platelet transfusion and its complications, which could be a useful strategy for HSCT patients.

Judicious Transfusion of Platelets Among Neonates: A Systematic Review

In newborns, especially premature babies, there is a high association between thrombocytopenia and bleeding, particularly intraventricular hemorrhage, which may be due to immaturity. It was usual clinical practice that neonates should be transfused with higher platelet counts than older children or adults to reduce their risk of bleeding. However, after keen observations, we noticed that bleeding and mortality were more common in newborns who received more platelet transfusions. The mechanisms underlying the adverse effects of platelet transfusions in neonates may be due to higher antigenicity and immunological factors. We know that neonatal platelets are hyporeactive; this hyporeactivity is balanced by factors in the neonatal blood that promote coagulation, such as increased hematocrit, von Willebrand factor, and fibrinogen, which, on balance, leads to normal primary neonatal hemostasis. Platelets are very similar to adults in number, but functional capabilities were less, and for the reasons mentioned above, particularly bleeding time was short. Theologically, neonatal platelet lifespan was high to compensate for less production. We started this review because we observed that many babies were not having bleeding symptoms in some instances of severe thrombocytopenia. Many well-active babies are receiving unnecessary transfusions, as human blood is precious, and many young neonatologists are going on protocol-based excessive transfusions. This stimulated us to write a review.

Baffled-flow culture system enables the mass production of megakaryocytes from human embryonic stem cells by enhancing mitochondrial function

Human embryonic stem cells (hESCs) have become an ideal cell source for the ex vivo generation of megakaryocyte (MK) and platelet products for clinical applications. However, an ongoing challenge is to establish scalable culture systems to maximize the yield of stem cell-derived MKs that release platelets. We defined a specific dynamic 3D manufacturing system in a baffled-flow manner that could remarkably facilitate megakaryopoiesis and increase the yield of platelet-producing MKs from hESCs within a 12-day induction period. Additionally, an increased number of >16N ploidy MKs, proplatelets, and platelets were generated from induced cells harvested on Day 12 using the specific dynamic culture method. The specific dynamic culture method significantly enhanced endothelium-to-haematopoietic transition and early haematopoiesis. More importantly, MK fate was significantly facilitated in a specific dynamic manner during early haematopoiesis. Mechanistically, this dynamic culture significantly enhanced mitochondrial function via the oxidative phosphorylation pathway and caused differentiation skewing of hESCs toward megakaryopoiesis. This study can aid in the automatic and scalable production of MKs from stem cells using baffled-flow bioreactors and assist in the manufacturing of hESC-derived MK and platelet products.

Platelet Function Testing Using Sonoclot and TEG6s as a Platelet Transfusion Prediction Tool in Open Heart Surgery

Introduction The point-of-care test (POCT) is useful for blood coagulation management during cardiovascular surgery. Although thromboelastography (TEG6s) has been reported to have targeted benefits for blood transfusion in cardiac surgery, Sonoclot analysis has not yet been fully validated. In this study, we evaluated the accuracy of Sonoclot, especially platelet function (PF) as a platelet concentrate (PC) transfusion parameter, compared to TEG6s in cardiovascular surgery. Methods This single-center, prospective, randomised trial was conducted at a university hospital. Forty-two adult patients who underwent elective cardiac surgery requiring cardiopulmonary bypass were included in this study between 2017 and 2021. The participants were randomly assigned to the Sonoclot (S) or Sonoclot and TEG6s (ST) groups. The amount of intraoperative PC was determined according to the POCT parameter values at the time of protamine administration. In addition, we investigated the correlation between PF parameters of POCT and platelet count at the end of surgery. Results There was no statistically significant difference in the intraoperative PC volume between the two groups. The Sonoclot PF parameter, PF, was moderately correlated with platelet count at the end of surgery (r=0.5449, p=0.009), and the TEG6s PF parameter showed a strong correlation with platelet count at the end of surgery (r=0.7744, p<0.001). Conclusion There was no statistically significant difference in platelet transfusion volume between the Sonoclot and TEG6s in this study. The correlation between the PF of the Sonoclot and platelet count was moderate. This study suggests that PF of Sonoclot may be a potentiating indicator of PF.

Multidisciplinary consensus document on the management of massive haemorrhage. First update 2023 (document HEMOMAS-II)

This document is an update of the multidisciplinary document HEMOMAS, published in 2016 with the endorsement of the Spanish Scientific Societies of Anaesthesiology (SEDAR), Intensive Care (SEMICYUC) and Thrombosis and Haemostasis (SETH). The aim of this document was to review and update existing recommendations on the management of massive haemorrhage. The methodology of the update was based on several elements of the ADAPTE method by searching and adapting guidelines published in the specific field of massive bleeding since 2014, plus a literature search performed in PubMed and EMBASE from January 2014 to June 2021. Based on the review of 9 guidelines and 207 selected articles, the 47 recommendations in the original article were reviewed, maintaining, deleting, or modifying each of them and the accompanying grades of recommendation and evidence. Following a consensus process, the final wording of the article and the resulting 41 recommendations were approved by all authors.

Multidisciplinary consensus document on the management of massive haemorrhage. First update 2023 (document HEMOMAS-II)

This document is an update of the multidisciplinary document HEMOMAS, published in 2016 with the endorsement of the Spanish Scientific Societies of Anaesthesiology (SEDAR), Intensive Care (SEMICYUC) and Thrombosis and Haemostasis (SETH). The aim of this document was to review and update existing recommendations on the management of massive haemorrhage. The methodology of the update was based on several elements of the ADAPTE method by searching and adapting guidelines published in the specific field of massive bleeding since 2014, plus a literature search performed in PubMed and EMBASE from January 2014 to June 2021. Based on the review of 9 guidelines and 207 selected articles, the 47 recommendations in the original article were reviewed, maintaining, deleting, or modifying each of them and the accompanying grades of recommendation and evidence. Following a consensus process, the final wording of the article and the resulting 41 recommendations were approved by all authors.

Platelet transfusion in adults: An update

Many patients worldwide receive platelet components (PCs) through the transfusion of diverse types of blood components. PC transfusions are essential for the treatment of central thrombocytopenia of diverse causes, and such treatment is beneficial in patients at risk of severe bleeding. PC transfusions account for almost 10% of all the blood components supplied by blood services, but they are associated with about 3.25 times as many severe reactions (attributable to transfusion) than red blood cell transfusions after stringent in-process leukoreduction to less than 10⁶ residual cells per blood component. PCs are not homogeneous, due to the considerable differences between donors. Furthermore, the modes of PC collection and preparation, the safety precautions taken to limit either the most common (allergic-type reactions and febrile non-hemolytic reactions) or the most severe (bacterial contamination, pulmonary lesions) adverse reactions, and storage and conservation methods can all result in so-called PC "storage lesions". Some storage lesions affect PC quality, with implications for patient outcome. Good transfusion practices should result in higher levels of platelet recovery and efficacy, and lower complication rates. These practices include a matching of tissue ABH antigens whenever possible, and of platelet HLA (and, to a lesser extent, HPA) antigens in immunization situations. This review provides an overview of all the available information relating to platelet transfusion, from donor and donation to bedside transfusion, and considers the impact of the measures applied to increase transfusion efficacy while improving safety and preventing transfusion inefficacy and refractoriness. It also considers alternatives to platelet component (PC) transfusion.

The Involvement of Canonical NFκB Pathway in Megakaryocyte Differentiation Induction by Nanocurcumin

Background: Megakaryopoiesis is characterized by progressive polyploidization and the expression of megakaryocytic markers. Numerous transcription factors and physiological signaling pathways regulate this phenomenon. Megakaryocyte differentiation induction in the K562 cell line and hematopoietic stem cells via nanocurcumin drug has been identified in our previous study. K562 cells are typical Chronic Myelogenous Leukemia (CML) cells that are resistant to apoptosis and express the bcr-abl fusion gene. These cells have the potential to differentiate into erythrocytes and megakaryocytes. Curcumin is well known as a component with strong potential to alter NFκB activity in various cells. NFκB pathway regulates various genes such as apoptotic and immune response genes. The current study attempted to evaluate the possible role of nanocurcumin in NFκB pathway regulation during the megakaryopoiesis process in the K562 cell line. Materials and Methods: Megakaryocyte markers expression and phenotype alteration of nanocurcumin-treated K562 cells have been detected by flow cytometry and microscopy imaging. The nuclear level of the RelA (p65) subunit of NFκB was determined by western blot test in K562 cells during megakaryopoiesis induction via nanocurcumin treatment at different times. The expression of NFκB target genes including c-MYC, BAX, and NQO1 was also analyzed in nanocurcumin-treated K562 cells by quantitative RT-PCR assay at different times. Results: The study has shown that nanocurcumin causes an increase in NFκB activity transiently during megakaryocyte differentiation, followed by a change in the expression of c-MYC, BAX, and NQO1 target genes. Conclusion: The NFκB pathway can be considered a new pathway for inducing megakaryocyte differentiation by nanocurcumin in vitro and in vivo megakaryopoiesis experiments.

Simultaneous genotyping for human platelet antigen systems and HLA-A and HLA-B loci by targeted next-generation sequencing

In order to treat the alloimmunization platelet transfusion refractoriness (PTR), human leukocyte antigen (HLA)-type and/or human platelet antigen (HPA)-type matched platelets between donors and patients are usually used. Therefore, genotyping of HLA-A and HLA-B loci, as well as HPA systems, for donors and patients, is of great significance. However, there is a rare report of genotyping for HLA-A and HLA-B loci as well as HPA systems at the same time. In this study, a high-throughput method for simultaneous genotyping of HLA-A and HLA-B loci, as well as HPA genotyping, was developed. A RNA capture probe panel was designed covering all exon sequences of the GP1BA, GP1BB, ITGA2, CD109, ITGB3, and ITGA2B genes and HLA-A and HLA-B loci. The HLA-A, HLA-B, and 34 HPA systems were genotyped using a targeted next-generation sequencing (NGS) method. The genotypes of the HLA-A and HLA-B loci, as well as the HPA, were assigned based on the nucleotides in the polymorphism sites. Using the NGS method, 204 unrelated blood specimens were successfully genotyped for all 34 HPA systems as well as HLA-A and HLA-B loci. The accuracy of the NGS method was 100%. Only HPA-2, HPA-3, HPA-5, HPA-6w, HPA-15, and HPA-21w showed polymorphism with frequencies of 0.9412, 0.6863, 0.9853, 0.9779, 0.4314, and 0.9951 for a allele, respectively. Thirty-two single nucleotide variants (SNVs) were detected. Of them, 12 SNVs can lead to amino acid change. HLA-A*11:01 and HLA-B*46:01 are the most common alleles for HLA-A and HLA-B loci. A targeted next-generation sequencing method for simultaneously genotyping HPA systems and HLA-A and HLA-B loci was first established, which could be used to create a database of HLA-typed and/or HPA-typed unrelated donors.

Usability of German hospital administrative claims data for healthcare research: General assessment and use case of multiple myeloma in Munich university hospital in 2015–2017

Objectives

To assess the usability of German hospital administrative claims data (GHACD) to determine inpatient management patterns, healthcare resource utilization, and quality-of-care in patients with multiple myeloma (PwMM).

Methods

Based on German tertiary hospital’s claims data (2015–2017), PwMM aged >18 years were included if they had an International Classification of Diseases, Tenth Revision, code of C90.0 or received anti-MM therapy. Subgroup analysis was performed on stem cell transplantation (SCT) patients.

Results

Of 230 PwMM, 59.1% were men; 56.1% were aged ≥65 years. Hypertension and infections were present in 50% and 67.0%, respectively. Seventy percent of PwMM received combination therapy. Innovative drugs such as bortezomib and lenalidomide were given to 36.1% and 10.9% of the patients, respectively. Mean number of admissions and mean hospitalization length/patient were 3.69 (standard deviation (SD) 2.71 (1–16)) and 12.52 (SD 9.55 (1–68.5)) days, respectively. In-hospital mortality was recorded in 12.2%. Seventy-two percent of SCT patients (n = 88) were aged ≤65 years, 22.7% required second transplantation, and 89.8% received platelet transfusion at a mean of 1.42(SD 0.63 (1–3)).

Conclusion

GHACD provided relevant information essential for healthcare studies about PwMM from routine care settings. Data fundamental for quality-of-care assessment were also captured.

Platelet-inspired nanomedicine in hemostasis thrombosis and thromboinflammation

Platelets are anucleate cell-fragments derived predominantly from megakaryocytes in the bone marrow and released in the blood circulation, with a normal count of 150 000-40 000 per μl and a lifespan of approximately 10 days in humans. A primary role of platelets is to aid in vascular injury site-specific clot formation to stanch bleeding, termed hemostasis. Platelets render hemostasis by a complex concert of mechanisms involving platelet adhesion, activation and aggregation, coagulation amplification, and clot retraction. Additionally, platelet secretome can influence coagulation kinetics and clot morphology. Therefore, platelet defects and dysfunctions result in bleeding complications. Current treatment for such complications involve prophylactic or emergency transfusion of platelets. However, platelet transfusion logistics constantly suffer from limited donor availability, challenges in portability and storage, high bacterial contamination risks, and very short shelf life (~5 days). To address these issues, an exciting area of research is focusing on the development of microparticle- and nanoparticle-based platelet surrogate technologies that can mimic various hemostatic mechanisms of platelets. On the other hand, aberrant occurrence of the platelet mechanisms lead to the pathological manifestation of thrombosis and thromboinflammation. The treatments for this are focused on inhibiting the mechanisms or resolving the formed clots. Here, platelet-inspired technologies can provide unique platforms for disease-targeted drug delivery to achieve high therapeutic efficacy while avoiding systemic side-effects. This review will provide brief mechanistic insight into the role of platelets in hemostasis, thrombosis and thromboinflammation, and present the current state-of-art in the design of platelet-inspired nanomedicine for applications in these areas.

Platelet Dysfunction in Blood Donors Detected by Platelet Function Analyzer PFA-100™

Background

Platelet transfusions may be indicated to prevent and treat bleeding in patients with quantitative or qualitative platelet defects. Millions of platelet components are transfused worldwide. It is well known that platelet dysfunction predicts blood loss after surgery. Hence, the quality of the platelet donation and the resulting platelet concentrate are critical for the transfusion. The aim of this study is to assess platelet function in well-qualified blood donors.

Methodology

Blood samples from 275 blood donors were collected in 0.129 M (3.8%) sodium citrate tubes prior to routine blood donation. Platelet function was assessed by measuring the closure time (CT) on the platelet function analyzer (PFA-100™; Siemens Health Diagnostics, Marburg, Germany) using collagen/epinephrine (CEPI) and collagen/ADP (CDP) cartridges.

Results

Using the PFA-100™, 20.4% of donors had an abnormal platelet function test, of whom 9.4% had prolonged CT with two cartridges, 7% had only prolonged CEPI CTs consistent with aspirin-like defect, and 4% had prolonged CADP CTs only. We found no closure (>300 seconds) in 6.54% of donors, including 1.45% with the CEPI cartridge, 2.9% with the CADP cartridge, and 2.18% with CEPI and CADP cartridges. Level of von Willebrand factor ristocetin cofactor (vWF: RCo) activity was 112% (56-168%). Of the factors examined (age, sex, cigarette smoking, blood donation type, ABO, and Rhesus blood group), only blood group O was significantly linked with impaired platelet function test in qualified blood donors (p = 0.023; odds ratio = 1.981; 95% confidence interval (1.091-3.595)).

Conclusions

Some qualified blood donors present abnormal platelet function results. More research is required to provide greater insight into the impact of platelet dysfunction in blood donors on the clinical efficacy of their platelet components. This study has confirmed that the influence of ABO blood group on the CT PFA-100™is not wholly dependent on vWF.

Impact of Platelet Transfusion Thresholds on Outcomes of Patients With Sepsis: Analysis of the MIMIC-IV Database

BACKGROUND

The benefits of platelet thresholds for transfusion remain unclear. This study assessed the effect of two transfusion thresholds on the survival outcomes of patients with sepsis and thrombocytopenia.

METHODS

In this retrospective cohort study, data of patients with sepsis admitted to an intensive care unit (ICU) and who had received platelet transfusion were extracted from the Medical Information Mart for Intensive Care IV database. Patients were classified into the lower-threshold group (below 20,000/μL) and higher-threshold group (20,000-50,000/μL), based on thresholds calculated from their pretransfusion platelet count. The endpoints included 28- and 90-day mortality, red blood cell (RBC) transfusion, ICU-free days, and hospital-free days.

RESULTS

There were 76 and 217 patients in the lower-threshold and higher-threshold groups, respectively. The higher-threshold group had a higher rate of surgical ICU admission (35.0% vs. 9.2%) and lower quick Sequential Organ Failure Assessment (qSOFA) score than the lower-threshold group. In the higher-threshold group, 94 (43.3%) and 132 (60.8%) patients died within 28 and 90 days, compared to 51 (67.1%) and 63 (82.9%) patients in the lower-threshold group (adjusted odds ratio, 1.96; 95% confidence interval, 1.16 to 3.03; P = 0.012; adjusted odds ratio, 2.04; 95% confidence interval, 1.16 to 3.57; P = 0.012, respectively). After stratification by mortality risk, the subgroup analysis showed a consistent trend favoring higher-threshold transfusion but reached statistical significance only in the low-risk group. There were no differences in red blood cell transfusion, ICU-free days, and hospital-free days between the groups. The E-value analysis suggested robustness to unmeasured confounding.

CONCLUSIONS

In patients with sepsis and thrombocytopenia, platelet transfusion at a higher threshold was associated with a greater reduction in the 28- and 90-day mortalities than that at a lower threshold.

Transparency on Platelet Transfusion in Routine Cancer Care: The Key for Optimal Blood Usage?

INTRODUCTION

In Germany, up to 75% of platelet concentrates (PC) are administered to haematological and oncological patients. Only limited transparency exists on the characteristics of haematological/oncological patients receiving PC transfusions, treatment patterns and guideline adherence in daily clinical routine care. This information would be key for managing platelet supply and optimal platelet usage strategies. This study aimed to analyse data from clinical routine transfusions to fill the aforementioned information gaps and to create an inventory as a blueprint for electronic data capturing systems that allow simplified, recurring analyses.

METHODS

Prospective open-label, single-centre, observational study in a German tertiary teaching haematological/oncological setting. All in-patients who received any transfusion of PCs in routine use over a period of 3 months (03.2015-05.2015) were consecutively included. Except for age (≥18 years), no exclusion criteria were applied. For guideline adherence, the Cross-Sectional Guidelines for Therapy with Blood Components and Plasma Derivatives - amended edition 2020 were used. An inventory blueprint was created through a narrative literature review and the data collected in this study.

RESULTS

Ninety-four patients received 942 PCs. The mean (± SD) age was 54.6 (± 13.9) years, 68% were male and 86% were diagnosed with a haematological disease. Thirteen patients received 42% of all transfused PCs. The mean ± SD number of transfused PC per patient was 10.81 ±9.24. Five (0.5% per transfusion) minor adverse events were documented. Approximately 19% of PCs were not administered according to existing guidelines. The mean transfusion interval was 1.71 ±1.1 days, and the mean increment was 12.62 ±14.7 G/l. The inventory showed which platelet transfusion-specific data should be documented for answering questions in terms of quality, effectiveness and management of PC transfusions.

CONCLUSIONS

Platelet transfusions in a haematological/oncology setting are highly individual in terms of the total number of transfusions and transfusion intervals. The majority of all PC transfusions was given to only a small group of patients. Continuous, structured real-world data collection/evaluation and benchmarking with data from more centres seems essential in determining specific needs in this vulnerable patient group, assessing quality of transfusion practices, determining effectiveness and anticipating future demand for platelets and a sustainable blood supply. So far, not all relevant data are collected routinely. The advancing digitisation of health systems offers opportunities to collect and link data and thus make them more accessible and evaluable.

Platelet Transfusion in Patients With Sepsis and Thrombocytopenia: A Propensity Score-Matched Analysis Using a Large ICU Database

Purpose

Sepsis with thrombocytopenia is highly prevalent in critically ill intensive care unit (ICU) patients and is associated with adverse outcomes. Platelet transfusion is the primary treatment of choice. However, evidence for the beneficial effects of platelet transfusion in patients with sepsis and thrombocytopenia is scarce and low in quality. This study aimed to evaluate the association between platelet transfusion and mortality among ICU patients with sepsis and thrombocytopenia.

Patients and Methods

Using the Medical Information Mart for Intensive Care III database (v. 1.4), the outcomes of sepsis patients with platelet counts of ≤ 150,000/μL were compared between those who did and did not receive platelet transfusion. The primary outcomes were 28- and 90-day all-cause mortalities. The secondary outcomes were red blood cell (RBC) transfusion, ICU-free days, and hospital-free days. Propensity score matching was employed to assemble a cohort of patients with similar baseline characteristics.

Results

Among 7,765 eligible patients, 677 received platelet transfusion and were matched with 677 patients who did not receive platelet transfusion according to propensity scores. Platelet transfusion, as compared with no platelet transfusion, was associated with an increased risk of 28-day all-cause mortality [36.9 vs. 30.4%, odds ratio (OR), 1.21; 95% confidence interval (CI), 1.01–1.46; p = 0.039], increased risk of 90-day all-cause mortality (50.8 vs. 44.6%, OR, 1.13; 95% CI, 1.00–1.31; p = 0.048), fewer mean (standard deviation) 28-day ICU-free days (15.88 ± 8.97 vs. 18.64 ± 8.33 days, p < 0.001), and fewer hospital-free days (10.29 ± 8.49 vs. 11.43 ± 8.85 days, p = 0.017). The rate of RBC transfusion was not significantly different between the platelet transfusion and non-transfusion groups (p = 0.149). The results were maintained across several subgroup and sensitivity analyses.

Conclusion

In this study, platelet transfusion was associated with higher 28- and 90-day all-cause mortalities. These results suggest the potential hazards of platelet transfusion in ICU patients with sepsis and thrombocytopenia.

Reduction of Platelet Outdating and Shortage by Forecasting Demand With Statistical Learning and Deep Neural Networks: Modeling Study

BACKGROUND

Platelets are a valuable and perishable blood product. Managing platelet inventory is a demanding task because of short shelf lives and high variation in daily platelet use patterns. Predicting platelet demand is a promising step toward avoiding obsolescence and shortages and ensuring optimal care.

OBJECTIVE

The aim of this study is to forecast platelet demand for a given hospital using both a statistical model and a deep neural network. In addition, we aim to calculate the possible reduction in waste and shortage of platelets using said predictions in a retrospective simulation of the platelet inventory.

METHODS

Predictions of daily platelet demand were made by a least absolute shrinkage and selection operator (LASSO) model and a recurrent neural network (RNN) with long short-term memory (LSTM). Both models used the same set of 81 clinical features. Predictions were passed to a simulation of the blood inventory to calculate the possible reduction in waste and shortage as compared with historical data.

RESULTS

From January 1, 2008, to December 31, 2018, the waste and shortage rates for platelets were 10.1% and 6.5%, respectively. In simulations of platelet inventory, waste could be lowered to 4.9% with the LASSO and 5% with the RNN, whereas shortages were 2.1% and 1.7% with the LASSO and RNN, respectively. Daily predictions of platelet demand for the next 2 days had mean absolute percent errors of 25.5% (95% CI 24.6%-26.6%) with the LASSO and 26.3% (95% CI 25.3%-27.4%) with the LSTM (P=.01). Predictions for the next 4 days had mean absolute percent errors of 18.1% (95% CI 17.6%-18.6%) with the LASSO and 19.2% (95% CI 18.6%-19.8%) with the LSTM (P<.001).

CONCLUSIONS

Both models allow for predictions of platelet demand with similar and sufficient accuracy to significantly reduce waste and shortage in a retrospective simulation study. The possible improvements in platelet inventory management are roughly equivalent to US $250,000 per year.

Effect of avatrombopag in the management of severe and refractory chemotherapy-induced thrombocytopenia (CIT) in patients with solid tumors

Chemotherapy-induced thrombocytopenia (CIT) is a common complication in cancer patients, especially after multiple cycles of chemotherapy, which leads to the delayed treatment or reduced dosage. The treatment of CIT is limited for refractory and severe cases. Herein we reported a single-center study of avatrombopag, a type of thrombopoietin receptor agonist (TPO-RA), for the treatment of severe and refractory (S/R) CIT who failed from multi-line treatments. A total of 13 cancer patients with S/R CIT were enrolled at the First Affiliated Hospital of Zhejiang Chinese Medical University from September 2020 to February 2021. All the patients were administered oral avatrombopag at an initial dose of 60 mg/day, which could be decreased as needed, over a period of 8 weeks. Eight (8/13, 61.5%) patients responded to avatrombopag (with a platelet count ≥50 × 10⁹/L and transfusion independent), with a median response time of 27.5 (11-50) days, and the median cumulative day of platelet response was 79 (20-167). Ten of 13 patients (76.9%) no longer required platelet transfusion at the study endpoint. The predictor of response was the level of hemoglobin (HB) at study entry, patients with an HB over 90 g/L achieved a response rate of 88.9%. In addition, platelet count showed 87.5% sensitivity and 100% specificity to predict the treatment response at a cutoff value of 25.5× 10⁹/L at the end of the third week management. No drug-related side effects were noticed during administration. Our study showed that avatrombopag could be a novel and effective drug for the treatment of severe and refractory CIT, especially for those with hemoglobin above 90 g/L. This study was registered at chictr.org.cn as # ChiCTR2100050646.

Bioinspired artificial platelets: past, present and future

Platelets are anucleate blood cells produced from megakaryocytes predominantly in the bone marrow and released into blood circulation at a healthy count of 150,000-400,00 per μL and circulation lifespan of 7-9 days. Platelets are the first responders at the site of vascular injury and bleeding, and participate in clot formation via injury site-specific primary mechanisms of adhesion, activation and aggregation to form a platelet plug, as well as secondary mechanisms of augmenting coagulation via thrombin amplification and fibrin generation. Platelets also secrete various granule contents that enhance these mechanisms for clot growth and stability. The resultant clot seals the injury site to stanch bleeding, a process termed as hemostasis. Due to this critical role, a reduction in platelet count or dysregulation in platelet function is associated with bleeding risks and hemorrhagic complications. These scenarios are often treated by prophylactic or emergency transfusion of platelets. However, platelet transfusions face significant challenges due to limited donor availability, difficult portability and storage, high bacterial contamination risks, and very short shelf life (~5-7 days). These are currently being addressed by a robust volume of research involving reduced temperature storage and pathogen reduction processes on donor platelets to improve shelf-life and reduce contamination, as well as bioreactor-based approaches to generate donor-independent platelets from stem cells in vitro. In parallel, a complementary research field has emerged that involves the design of artificial platelets utilizing biosynthetic particle constructs that functionally emulate various hemostatic mechanisms of platelets. Here, we provide a comprehensive review of the history and the current state-of-the-art artificial platelet approaches, along with discussing the translational opportunities and challenges.

The Role of Funduscopy in Severe Thrombocytopenia: A Prospective Study

PURPOSE

Platelet transfusions for patients suffering from severe thrombocytopenia are regulated by clinical bleedings and platelet counts. The aim of this study was to assess the prevalence of retinal hemorrhage in patients with hematologic and oncologic malignancies and severe thrombocytopenia, and to determine the benefit of systematic funduscopic examination in this setting.

MATERIALS AND METHODS

Hospitalized patients with hematologic and oncologic malignancies having a platelet count less than 25,000 per µL underwent indirect ophthalmoscopy. The prevalence of retinal hemorrhage and its correlation with different patients' characteristics were determined. The decision to transfuse platelets or not following bedside indirect ophthalmoscopy was left at the discretion of the treating physician.

RESULTS

A total of 34 severe thrombocytopenic patients were included in the study. The prevalence of retinal hemorrhage was detected in 10 patients (29.4%). No significant correlation was found between the occurrence of retinal hemorrhage and age, platelet count or thrombocytopenia etiology (P >0.05). No significant difference was found concerning the rate of transfusion between those with and without retinal hemorrhage.

CONCLUSION

According to our statistical results, retinal hemorrhage is a frequent finding in severely thrombocytopenic patients. Early detection may lead to an increase in the platelet transfusion threshold from to 30,000 per µL offering additional protection against spontaneous bleedings. Funduscopy is a safe and easy exam to perform systematically in patients with severe thrombocytopenia.

High titers of anti-A1 and anti-B antibodies among Peruvian group O platelet donors

Critical antibody titers have been described as factors associated with hemolysis in ABO plasma-incompatible platelet (PLT) transfusions. This study was carried out to describe the frequency of high-titers anti-A and antiB IgM and IgG antibodies in group O apheresis platelet donors, and to explore differences according to the donor characteristics. A cross-sectional study was carried out at the Blood Bank of a National Hospital in Peru from January to March 2019. IgM and IgG antibodies against A1 and B antigens were quantified in 339 platelet donors using the direct hemagglutination technique and the solid-phase adherence technique, respectively. For analysis purposes, two cut-off points; ≥128 and ≥64, were used to define a critical titer for IgM due to a lack of consensus. An IgG titer of ≥256 was also defined as critical. Of the donors, 22.1 % had critical IgM titers when the cut-off point was defined as ≥128. However, when the IgM cut-off was ≥64, the frequency of platelet donors with critical titers increased to 54.0 %. The frequency of donors with critical IgG titers was 23.5 %. Higher IgG titers were associated with female donors while higher IgM titers were negative associated with age. One in two or three platelet donors, depending on the cutoff point used to define a critical IgM titer, had at least one critical titer of anti-A or anti-B antibodies. Early identification of platelet donors with critical antibody titers could prevent passive transfusion of ABO antibodies to non-isogroup recipients.

Platelet transfusion practice and related transfusion reactions in a large teaching hospital

BACKGROUND

Platelet transfusion practice varies widely since many aspects of platelet concentrate (PC) use have not been definitively determined. The objectives of this retrospective study were to present platelet transfusion practice and evaluate PC and patient characteristics, as well as their association with transfusion reaction (TR) rate.

MATERIAL AND METHODS

Platelet transfusions over a 5-year period were analysed regarding PC characteristics (the ABO and RhD compatibility, product type, and storage duration), patient characteristics (most responsible diagnosis, age, and gender), and TR type.

RESULTS

A total of 46,351 PCs were transfused: 76.4% whole blood-derived (WBD) and 23.6% single donor apheresis (SDA). Three thousand seven hundred seventy-six patients received platelet transfusions: 24.7% paediatric and 75.3% adult patients, 79.6% outpatients and 20.4% inpatients. As much as 63.1% of all transfused PCs were fresh (stored for≤3 days), 98.0% ABO-identical, and 87.3% of all PCs given to RhD- patients were RhD-. PCs were mainly transfused to haemato-oncology (76.8%) and cardiovascular surgery patients (6.5%). Overall, 84 (0.18%) TRs were reported, with allergic TRs (ATRs) being the most common. Although PC ABO compatibility and storage duration, as well as patient age and gender, showed differences in TR rate, only the use of PCs in platelet additive solution (PAS) showed a statistically significant reduction of TRs (P<0.001).

CONCLUSION

Transfusion practice at the University Hospital Centre Zagreb resulted in almost all patients receiving ABO and RhD identical PCs, and most of them were fresh PCs. The most important factor affecting the incidence of TRs was platelet storage solution. The use of PAS effectively reduced the rate of TRs, particularly allergic TRs.

Biomarkers of complement and platelet activation are not correlated with the one or twenty-four hours corrected count increments in prophylactically platelet transfused hematological patients: a prospective cohort study

Platelet transfusion refractoriness is a serious clinical concern that complicates the management of thrombocytopenic patients. Previous studies have suggested a potential role for both complement and platelet activation based on in vitro analyses of platelet concentrates. In this study, the post-transfusion platelet response, as indicated by the corrected count increment at 1 and 24 h after prophylactic platelet transfusions, respectively, was correlated with the 1 h post-transfusion Δconcentration (1 h post-transfusion - pretransfusion) of complement and platelet activation biomarkers. The study was registered as a clinical trial at ClinicalTrials.gov (identifier: NCT02601131) and patients were recruited during inpatient care in the hematological department. Soluble terminal complement complexes, soluble P-selectin and soluble CD40 ligand were analyzed. Confirmed alloimmunized patients were excluded. Included subjects were either given platelet transfusions (n = 43) and categorized into four clinical study groups or included in a non-transfused control group (n = 10). In total, 54 transfusions were included. No transfusion-mediated complement activation was observed. The transfusions were associated with a significant increase in the concentration of soluble P-selectin (p < .001), primarily corresponding to the passive infusion of soluble P-selectin-containing plasma residuals. The Δconcentration of soluble P-selectin was, however, not significantly correlated with the corrected count increments. Thus, significant correlations between biomarkers of complement and platelet activation and the post-transfusion platelet response could not be demonstrated in this study.

Human leukocyte antigen (HLA)-incompatible mean fluorescence intensity-selected platelet products have corrected count increments similar to HLA antigen-matched platelets

BACKGROUND

Donor specific antibody sum mean fluorescence intensity (MFI) values have been successfully used in transplant medicine to assess risk for organ rejection. However, little is known regarding whether MFI values could be similarly used to aid in platelet product selection. We have developed a novel protocol where MFI values are used to offer human leukocyte antigen (HLA)-incompatible platelet products when HLA antigen-matched products are not available. We aimed to evaluate the efficacy of this protocol.

METHODS

We performed a 4-year retrospective chart review for all patients who received at least one MFI-selected platelet product. A corrected count increment (CCI) was calculated for each transfusion event. A mixed effects model was used to investigate the association between CCIs for MFI-selected, HLA antigen matched, and random donor platelet transfusions. A random effects expectation-maximization regression tree was used to define the extent to which other patient variables, such as age, sex, and diagnosis impacted the CCI for each platelet transfusion.

RESULTS

Twenty highly HLA alloimmunized patients received a total of 591 platelets. MFI-selected platelet (low MFI) transfusions had a significantly higher median CCI 0-6 hour post-transfusion (13,559, interquartile range [IQR]: 8275-18,736) compared to random donor platelets (2121, IQR: 0-10,368, p < 0.0001). There was no significant difference in median CCI between HLA antigen matched and MFI selected platelet transfusions (p = 0.2). Mixed effects and regression modeling revealed that MFI-selected platelet products had a significantly higher CCI than non-matched platelets, even when accounting for other significant patient variables.

CONCLUSION

MFI-selected HLA-incompatible platelet products could provide a comparable alternative to traditional HLA antigen-matched platelet products.

Platelet production using adipose-derived mesenchymal stem cells: Mechanistic studies and clinical application

Megakaryocytes (MKs) are platelet progenitor stem cells found in the bone marrow. Platelets obtained from blood draws can be used for therapeutic applications, especially platelet transfusion. The needs for platelet transfusions for clinical situation is increasing, due in part to the growing number of patients undergoing chemotherapy. Platelets obtained from donors, however, have the disadvantages of a limited storage lifespan and the risk of donor-related infection. Extensive effort has therefore been directed at manufacturing platelets ex vivo. Here, we review ex vivo technologies for MK development, focusing on human adipose tissue-derived mesenchymal stem/stromal cell line (ASCL)-based strategies and their potential clinical application. Bone marrow and adipose tissues contain mesenchymal stem/stromal cells that have an ability to differentiate into MKs, which release platelets. Taking advantage of this mechanism, we developed a donor-independent system for manufacturing platelets for clinical application using ASCL established from adipose-derived mesenchymal stem/stromal cells (ASCs). Culture of ASCs with endogenous thrombopoietin and its receptor c-MPL, and endogenous genes such as p45NF-E2 leads to MK differentiation and subsequent platelet production. ASCs compose heterogeneous cells, however, and are not suitable for clinical application. Thus, we established ASCLs, which expand into a more homogeneous population, and fulfill the criteria for mesenchymal stem cells set by the International Society for Cellular Therapy. Using our ASCL culture system with MK lineage induction medium without recombinant thrombopoietin led to peak production of platelets within 12 days, which may be sufficient for clinical application.

How do I see the production of engineered blood cells available for transfusion?

The in vitro production of red blood cells and platelets is a groundbreaking technology that can-when optimized-surrogate for donated blood cells, in total or in part. Here we discuss questions that may arise when the technology is available, relative to safety issues (comprising both quantitative and qualitative parameters) and to ethics, an item often forgotten in the debates so far.

Overview of Plasma and Platelet Transfusions in Critically Ill Children

Critically ill children are a unique population who frequently receive plasma and platelet transfusions for both active bleeding and mitigation of bleeding risk. While these products are frequently administered, transfusion indications in this population remain unclear, and practice varies across institutions and providers. In this manuscript, we will outline the current evidence regarding plasma and platelet transfusions for hemostasis in the pediatric intensive care setting. For both products, we will describe the product composition, epidemiology, and product indications and discuss the potential risks and benefits involved with the transfusion. We will also discuss knowledge gaps and future areas of research.