Impacts of ABO-incompatible platelet transfusions on platelet recovery and outcomes after intracerebral hemorrhage

Rethinking Platelet and Plasma Transfusion Strategies for Neonates: Evidence, Guidelines, and Unanswered Questions

The transfusion of platelets and fresh frozen plasma (FFP) to critically ill neonates in neonatal intensive care units (NICUs) is a common intervention, yet it is still widely performed without adhering to international guidelines. The guidance itself on the therapeutic management of neonatal coagulation disorders is generally limited due to the absence of strong indications for treatment and is mainly aimed at the prevention of major hemorrhagic events such as intraventricular hemorrhage (IVH) in premature neonates. Historically, the underrepresentation of neonates in clinical studies related to transfusion medicine had led to significant gaps in our knowledge regarding the best transfusion practices in this vulnerable group and to a wide variability in policies among different neonatal units, often based on local experience or guidance designed for older children or adults, and possibly increasing the risk of inappropriate or ineffective interventions. Platelet transfusion and, particularly, FFP administration have been linked to potentially fatal complications in neonates and thus any decision needs to be carefully balanced and requires a thorough consideration of multiple factors in the neonatal population. Despite recent advances toward more restrictive practices, platelet and FFP transfusions are still subject to wide variability in practices.This review examines the existing literature on platelet and FFP transfusions and on the management of massive hemorrhage in neonates, provides a summary of evidence-based guidelines on these topics, and highlights current developments and areas for ongoing and future research with the aim of improving clinical practices.

The latest therapeutic advances with spontaneous intracerebral hemorrhage

INTRODUCTION

Intracerebral hemorrhage (ICH) accounts for 10% of strokes; however, compared with ischemic stroke, progress leading to novel treatments and improved patient outcomes has been lacking. Recently, there have been several promising developments and renewed research interest within the field. Positive results from randomized controlled trials have now been reported in multiple domains of care for patients with ICH. Anticoagulation-associated ICH is increasingly frequent, and clinicians deciding on reversal and timing of re-initiation of oral anticoagulation now have more therapeutic agents available and evidence to guide them. Minimally invasive techniques are also added to the neurosurgical arsenal, leading to improvements in functional outcomes. Acute treatment at presentation is best served by bundled care approaches, which ensure goal-directed management of blood pressure, glucose and temperature.

AREAS COVERED

This narrative review summarizes the recent developments in this area, as well as the current recommendations of key international guidelines. Literature search was carried out using PubMed database with priority given to publications since 2020.

EXPERT OPINION

There is renewed optimism for innovation in ICH. The standard of care for this condition now leads to improvements in mortality and long-term functional ability. Efforts to improve the patient selection and surgical techniques for operative management are ongoing.

Admission Viscoelastic Hemostatic Assay Parameters Predict Poor Long-Term Intracerebral Hemorrhage Outcomes

BACKGROUND

Viscoelastic hemostatic assays (VHAs) provide more comprehensive assessments of coagulation compared with conventional coagulation assays. Although VHAs have enabled guided hemorrhage control therapies, improving clinical outcomes in life-threatening hemorrhage, the role of VHAs in intracerebral hemorrhage (ICH) is unclear. If VHAs can identify coagulation abnormalities relevant for ICH outcomes, this would support the need to investigate the role of VHAs in ICH treatment paradigms. Thus, we investigated whether VHA assessments of coagulation relate to long-term ICH outcomes.

METHODS

Patients with spontaneous ICH enrolled into a single-center cohort study receiving admission Rotational Thromboelastometry (ROTEM) VHA testing between 2013 and 2020 were assessed. Patients with previous anticoagulant use or coagulopathy on conventional coagulation assays were excluded. Primary ROTEM exposure variables were coagulation kinetics and clot strength assessments. Poor long-term outcome was defined as modified Rankin Scale ≥ 4 at 6 months. Logistic regression analyses assessed associations of ROTEM parameters with clinical outcomes after adjusting for ICH severity and hemoglobin concentration.

RESULTS

Of 44 patients analyzed, the mean age was 64 years, 57% were female, and the median ICH volume was 23 mL. Poor 6-month outcome was seen in 64% of patients. In our multivariable regression models, slower, prolonged coagulation kinetics (adjusted odds ratio for every second increase in clot formation time 1.04, 95% confidence interval 1.00-1.09, p = 0.04) and weaker clot strength (adjusted odds ratio for every millimeter increase of maximum clot firmness 0.84, 95% confidence interval 0.71-0.99, p = 0.03) were separately associated with poor long-term outcomes.

CONCLUSIONS

Slower, prolonged coagulation kinetics and weaker clot strength on admission VHA ROTEM testing, not attributable to anticoagulant use, were associated with poor long-term outcomes after ICH. Further work is needed to clarify the generalizability and the underlying mechanisms of these VHA findings to assess whether VHA-guided treatments should be incorporated into ICH care.

The Effects of High Particulate Matter Levels on Platelet Recovery in Patients Receiving Prophylactic Platelet Transfusion

Aim

Exposure to fine particulate matter, particularly PM2.5, has been associated with increased platelet activation and cardiovascular risks. However, its effect on platelet recovery after transfusion remains unclear.

Purpose

This study aims to assess the influence of PM2.5 exposure on platelet recovery in patients with hematologic malignancies receiving prophylactic platelet transfusions.

Patients and Methods

We conducted a cross-sectional study involving 66 patients with hematologic malignancies who developed chemotherapy-induced thrombocytopenia and received prophylactic platelet transfusions between January and December 2021. A total of 191 transfusion events were analyzed. Platelet increment and corrected count increment (CCI) were measured one hour post-transfusion. Transfusions were categorized based on mean PM2.5 levels one day prior to platelet collection: the control group (< 37.5 μg/m³) and the case group (≥ 37.5 μg/m³). Multivariate analyses were used to adjust for potential confounders.

Results

No significant differences were observed in platelet increment (p = 0.128) or CCI (p = 0.828) between the PM2.5 exposure groups. Correlation analyses showed no significant association between PM2.5 levels and platelet increment (r = 0.0565, p = 0.437) or CCI (r = 0.0370, p = 0.614). These findings suggest that exposure to elevated PM2.5 levels one day before donation does not significantly impair platelet recovery.

Conclusion

Short-term exposure to elevated PM2.5 levels does not significantly affect platelet recovery in patients receiving prophylactic platelet transfusions. These results provide important reassurance regarding the immediate effects of air pollution on transfusion outcomes, while highlighting the need for further research into potential long-term impacts.

ABO-identical versus incompatible platelet transfusion in patients with intracranial hemorrhage

BACKGROUND

Patients with spontaneous and traumatic intracranial hemorrhage (ICH) are frequently transfused platelets to treat thrombocytopenia, platelet function defects, and reverse antiplatelet drugs. ABO-identical platelet transfusion has been suggested to lead to higher post-transfusion platelet increments compared to major-ABO incompatible transfusion. We hypothesized that patients who received ABO-identical transfusion would have higher post-transfusion platelet increments and superior neurologic outcomes.

METHODS

Adults with traumatic or non-traumatic ICH from January 1st 2018 to December 31st 2022 were identified using electronic medical records and international classification of disease (ICD)-10 codes. Patients were excluded if they lacked a platelet count within 24 hours before and within 24 hours after transfusion or if they received multiple platelet transfusions before their platelet count was remeasured. After stratification by ABO-identical, ABO-major incompatible, and ABO-minor incompatible transfusion, post transfusion increments were compared, as were clinical outcomes.

RESULTS

Among 167 patients who received platelet transfusion, 76 (45.5%) received ABO-identical transfusion, 54 (32.3%) received ABO-major incompatible transfusion, and 37 (22.2%) received ABO-minor incompatible transfusion. There were no significant differences in absolute platelet increment between groups. The median increment was 7x109/L for ABO-identical platelets, 10x109/L for ABO-major incompatible platelets, and 11x109/L for ABO-minor incompatible platelets, p = .87. There was no significant difference in the percentage of patients discharged alive with modified Rankin score of 1 or 2 or cerebral performance category 1 or 2 between groups (p = .56 and .39 respectively). After adjusting for confounders in a general linear model there remained no associations between ABO compatibility and platelet increment after transfusion.

CONCLUSIONS

Our data support similar efficacy for ABO-identical and ABO-incompatible platelet transfusion in patients with ICH.

Do Babesia microti Hosts Share a Blood Group System Gene Ortholog, Which Could Generate an Erythrocyte Antigen That Is Essential for Parasite Invasion?

The United States of America (US) has the highest annual number of human babesiosis cases caused by Babesia microti (Bm). Babesia, like malaria-causing Plasmodium, are protozoan parasites that live within red blood cells (RBCs). Both infectious diseases can be associated with hemolysis and organ damage, which can be fatal. Since babesiosis was made a nationally notifiable condition by the Centers for Disease Control and Prevention (CDC) in January 2011, human cases have increased, and drug-resistant strains have been identified. Both the Bm ligand(s) and RBC receptor(s) needed for invasion are unknown, partly because of the difficulty of developing a continuous in vitro culture system. Invasion pathways are relevant for therapies (e.g., RBC exchange) and vaccines. We hypothesize that there is at least one RBC surface antigen that is essential for Bm invasion and that all Bm hosts express this. Because most RBC surface antigens that impact Plasmodium invasion are in human blood group (hBG) systems, which are generated by 51 genes, they were the focus of this study. More than 600 animals with at least one hBG system gene ortholog were identified using the National Center for Biotechnology Information (NCBI) command-line tools. Google Scholar searches were performed to determine which of these animals are susceptible to Bm infection. The literature review revealed 28 Bm non-human hosts (NHH). For 5/51 (9.8%) hBG system genes (e.g., RhD), no NHH had orthologs. This means that RhD is unlikely to be an essential receptor for invasion. For 24/51 (47.1%) hBG system genes, NHH had 4-27 orthologs. For the ABO gene, 15/28 NHH had an ortholog, meaning that this gene is also unlikely to generate an RBC antigen, which is essential for Bm invasion. Our prior research showed that persons with blood type A, B, AB, O, RhD+, and RhD- can all be infected with Bm, supporting our current study's predictions. For 22/51 (43.1%) hBG system genes, orthologs were found in all 28 NHH. Nineteen (37.3%) of these genes encode RBC surface proteins, meaning they are good candidates for generating a receptor needed for Bm invasion. In vitro cultures of Bm, experimental Bm infection of transgenic mice (e.g., a CD44 KO strain), and analyses of Bm patients can reveal further clues as to which RBC antigens may be essential for invasion.

ABO blood groups and galectins: Implications in transfusion medicine and innate immunity

ABO blood group antigens, which are complex carbohydrate moieties, and the first human polymorphisms identified, are critical in transfusion medicine and transplantation. Despite their discovery over a century ago, significant questions remain about the development of anti-ABO antibodies and the structural features of ABO antigens that cause hemolytic transfusion reactions. Anti-ABO antibodies develop naturally during the first few months of life, in contrast to other red blood cell (RBC) alloantibodies which form after allogeneic RBC exposure. Anti-ABO antibodies are the most common immune barrier to transfusion and transplantation, but the factors driving their formation are incompletely understood. Some studies suggest that microbes that express glycans similar in structure to the blood group antigens could play a role in anti-blood group antibody formation. While the role of these microbes in clinically relevant anti-blood group antibody formation remains to be defined, the presence of these microbes raises questions about how blood group-positive individuals protect themselves against blood group molecular mimicry. Recent studies suggest that galectins can bind and kill microbes that mimic blood group antigens, suggesting a unique host defense mechanism against microbial molecular mimicry. However, new models are needed to fully define the impact of microbes, galectins, or other factors on the development of clinically relevant naturally occurring anti-blood group antibodies.

Impact of dose and storage duration of platelet concentrates on platelet recovery between ABO identical and ABO non-identical random donor platelet transfusions in hemato-oncology patients

INTRODUCTION AND OBJECTIVES

It is challenging to adopt a policy of ABO identical platelet transfusion in hemato-oncological patients because of the high demand. Moreover, there are no global standards for the management of ABO non-identical platelet transfusions due to limited evidence. The current study compared the impact of dose and storage duration of platelets on percent platelet recovery (PPR) at 1 h and 24 h between ABO identical and ABO non-identical platelet transfusions in hemato-oncological conditions. The other objectives were to assess the clinical efficacy and compare adverse reactions between the two groups.

METHODS

A total of 130 random donor platelet transfusion episodes (81 ABO identical and 49 ABO non-identical) were evaluated in 60 eligible patients with different malignant, as well as non-malignant, hematological conditions. All analysis was performed using two-sided tests, and p-values <0.05 were considered significant.

RESULTS

The PPR at 1 h and 24 h was significantly higher in ABO identical platelet transfusion. Platelet recovery and survival were not affected by the gender, dose or storage duration of platelet concentrate. Aplastic anemia and myelodysplastic syndrome (MDS) disease conditions were observed to be independent risk predictors for 1-h post-transfusion refractoriness.

CONCLUSION

ABO identical platelets have higher platelet recovery and survival. Both ABO identical and ABO non-identical platelet transfusions have similar efficacy in controlling bleeding episodes up to World Health Organization (WHO) grade two. Assessment of other factors, such as platelet functional properties in the donor, anti-HLA and anti-HPA antibodies, may be needed to better understand the platelet efficacy of platelet transfusions.

Admission viscoelastic hemostatic assay parameters predict poor long-term intracerebral hemorrhage outcomes

Background

Viscoelastic hemostatic assays (VHA) provide more comprehensive assessments of coagulation compared to conventional coagulation assays. While VHAs have enabled guided hemorrhage control therapies, improving clinical outcomes in life-threatening hemorrhage, the role of VHAs in intracerebral hemorrhage (ICH) is unclear. If VHAs can identify coagulation abnormalities relevant for ICH outcomes, this would support the need to investigate the role of VHAs in ICH treatment paradigms. Thus, we investigated whether VHA assessments of coagulation relate to long-term ICH outcomes.

Methods

Spontaneous ICH patients enrolled into a single-center cohort study receiving admission Rotational Thromboelastometry (ROTEM) VHA testing between 2013 and 2020 were assessed. Patients with prior anticoagulant use or coagulopathy on conventional coagulation assays were excluded. Primary ROTEM exposure variables were coagulation kinetics and clot strength assessments. Poor long-term outcome was defined as modified Rankin Scale ≥ 4 at 6 months. Logistic regression analyses assessed associations of ROTEM parameters with clinical outcomes after adjusting for ICH severity and hemoglobin concentration.

Results

Of 44 patients analyzed, mean age was 64, 57% were female, and the median ICH volume was 23 mL. Poor 6-month outcome was seen in 64%. In our multivariable regression models, slower, prolonged coagulation kinetics (adjusted OR for every second increase in clot formation time: 1.04, 95% CI: 1.00-1.09, p = 0.04) and weaker clot strength (adjusted OR for every millimeter increase of maximum clot firmness: 0.84, 95% CI: 0.71-0.99, p = 0.03) were separately associated with poor long-term outcomes.

Conclusions

Slower, prolonged coagulation kinetics and weaker clot strength on admission VHA ROTEM testing, not attributable to anticoagulant use, were associated with poor long-term outcomes after ICH. Further work is needed to clarify the generalizability and the underlying mechanisms of these VHA findings to assess whether VHA guided treatments should be incorporated into ICH care.

[Correction of the effect of vitamin K antagonists and antiplatelet agents in hemorrhagic stroke]

BACKGROUND

Hemorrhagic stroke (HS) is associated with high risk of mortality or disability. To date, up to 25% of HSs are associated with anticoagulants and antiplatelet agents. Early hemostatic therapy and correction of effect of antithrombotic drugs in patients with HS significantly reduce the risk of adverse outcomes. The latest international guidelines on this issue were presented almost 10 years ago.

MATERIAL AND METHODS

In accordance with the PRISMA recommendations, we reviewed the PubMed, eLibrary and UpToDate databases and identified 137 articles. Of these, 52 were enrolled as the most relevant.

RESULTS AND DISCUSSION

Regarding correction of the effect of indirect anticoagulants, various researchers discuss the possibility of either individual dosing or injection of a fixed dose of 4- or 3-factor prothrombin complex (1000-2000 IU regardless of body weight and international normalized ratio). To correct the effect of antiplatelet agents, platelet transfusion and desmopressin are proposed. There is currently no evidence of safety and effectiveness of both methods in patients with HS.

CONCLUSION

The optimal drug for correction of the effect of indirect anticoagulants is 4- or 3-factor prothrombin complex. In the last case, it is necessary to administer factor VIIa or fresh frozen plasma, as well as parenteral form of phytomenadione (vitamin K1) in all cases. The issue of correction of the effects of antiplatelet agents remains open. Regular analysis of available data with updating the guidelines for correction of the effect of anticoagulants and antiplatelet agents in HS is necessary.

Associations between ABO non-identical platelet transfusions and patient outcomes-A multicenter retrospective analysis

BACKGROUND

Due to platelet availability limitations, platelet units ABO mismatched to recipients are often transfused. However, since platelets express ABO antigens and are collected in plasma which may contain ABO isohemagglutinins, it remains controversial as to whether ABO non-identical platelet transfusions could potentially pose harm and/or have reduced efficacy.

STUDY DESIGN AND METHODS

The large 4-year publicly available Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) database was used to investigate patient outcomes associated with ABO non-identical platelet transfusions. Outcomes included mortality, sepsis, and subsequent platelet transfusion requirements.

RESULTS

Following adjustment for possible confounding factors, no statistically significant association between ABO non-identical platelet transfusion and increased risk of mortality was observed in the overall cohort of 21,176 recipients. However, when analyzed by diagnostic category and recipient ABO group, associations with increased mortality for major mismatched transfusions were noted in two of eight subpopulations. Hematology/Oncology blood group A and B recipients (but not group O) showed a Hazard Ratio (HR) of 1.29 (95%CI: 1.03-1.62) and intracerebral hemorrhage group O recipients (but not groups A and B) showed a HR of 1.75 (95%CI: 1.10-2.80). Major mismatched transfusions were associated with increased odds of receiving additional platelet transfusion each post-transfusion day (through day 5) regardless of the recipient blood group.

DISCUSSION

We suggest that prospective studies are needed to determine if specific patient populations would benefit from receiving ABO identical platelet units. Our findings indicate that ABO-identical platelet products minimize patient exposure to additional platelet doses.

Effect of antiplatelet therapy on the incidence, prognosis, and rebleeding of intracerebral hemorrhage

OBJECTIVE

Antiplatelet medications are increasingly being used for primary and secondary prevention of ischemic attacks owing to the increasing prevalence of ischemic stroke occurrences. Currently, many patients receive antiplatelet therapy (APT) to prevent thromboembolic events. However, long-term use of APT might also lead to an increased occurrence of intracerebral hemorrhage (ICH) and affect the prognosis of patients with ICH. Furthermore, some research suggest that restarting APT for patients who have previously experienced ICH may result in rebleeding events. The precise relationship between APT and ICH remains unknown.

METHODS

We searched PubMed for the most recent related literature and summarized the findings from various studies. The search terms included "antiplatelet," "intracerebral hemorrhage," "cerebral microbleeds," "hematoma expansion," "recurrent," and "reinitiate." Clinical studies involving human subjects were ultimately included and interpreted in this review, and animal studies were not discussed.

RESULTS

When individuals are administered APT, the risk of thrombotic events should be weighted against the risk of bleeding. In general, for some patients' concomitant with risk factors of thrombotic events, the advantages of antiplatelet medication may outweigh the inherent risk of rebleeding. However, the use of antiplatelet medications for other patients with a higher risk of bleeding should be carefully evaluated and closely monitored. In the future, a quantifiable system for assessing thrombotic risk and bleeding risk will be necessary. After evaluation, the appropriate time to restart APT for ICH patients should be determined to prevent underlying ischemic stroke events. According to the present study results and expert experience, most patients now restart APT at around 1 week following the onset of ICH. Nevertheless, the precise time to restart APT should be chosen on a case-by-case basis as per the patient's risk of embolic events and recurrent bleeding. More compelling evidence-based medicine evidence is needed in the future.

CONCLUSION

This review thoroughly discusses the relationship between APT and the development of ICH, the impact of APT on the course and prognosis of ICH patients, and the factors influencing the decision to restart APT after ICH. However, different studies' conclusions are inconsistent due to the differences in quality control. To support future clinical decisions, more large-scale randomized controlled trials are required.

Reduction of anti-A and anti-B isoagglutinin titers of group O whole blood units employing an ABO antibody immune adsorption column

BACKGROUND

Massive hemorrhage is a leading cause of death from trauma. There is growing interest in group O whole blood transfusions to mitigate coagulopathy and hemorrhagic shock. Insufficient availability of low-titer group O whole blood is a barrier to routine use. We tested the efficacy of the Glycosorb® ABO immunoadsorption column to reduce anti-A/B titers in group O whole blood.

METHODS

Six group O whole blood units were collected from healthy volunteers, and centrifuged to separate platelet poor plasma. Platelet-poor plasma was filtered through a Glycosorb® ABO antibody immunoabsorption column, then reconstituted to prepare post-filtration whole blood. Anti-A/B titers, CBC, free hemoglobin, and thromboelastography (TEG) assays were performed on pre-and post-filtration whole blood.

RESULTS

Mean( ± SEM) anti-A (224 ± 65 pre vs 13 ± 4 post) and anti-B (138 ± 38 pre vs 11 ± 4 post) titers were significantly reduced (p = 0.004) in post-filtration whole blood. No significant changes were detected in CBC, free hemoglobin, and TEG parameters on day 0. Free hemoglobin increased throughout storage (48 mg/dl ± 24 Day 0 vs 73 ± 35 Day 7 vs 96 ± 44 Day 14; p = 0.14).

CONCLUSIONS

The Glycosorb® ABO column can significantly reduce anti-A/B isoagglutinin titers of group O whole blood units. Glycosorb® ABO could be employed to provide whole blood with lower risk of hemolysis and other consequences of infusing ABO incompatible plasma. Preparation of group O whole blood with substantially reduced anti-A/B would also increase the supply of low-titer group O whole blood for transfusion.

How do we forecast tomorrow's transfusion? - Next generation transfusion practices to improve recipient safety

Recipient safety measures play a key role in overall transfusion efficacy. The key advances in safety over the first century of transfusion medicine have been the development of techniques to prevent hemolytic transfusion reactions, hemolytic disease of the newborn and transmission of viral pathogens. While these risks remain important, they affect many fewer patients than previously. We propose that some of the most important current safety issues relate to toxicities broadly encompassed by the immunomodulatory effects of allogeneic transfusion. These include (1) universal leukoreduction to mitigate nosocomial infections, inflammation and organ injury, (2) removal of stored supernatant and its attendant toxic contents that cause dysfunctional immunity and organ injury, (3) avoiding infusing ABO incompatible antigen and antibody that can lead to bleeding, platelet refractoriness and inflammation, (3) minimizing prophylactic transfusions (particularly of plasma and platelets) except where benefit is proven, and (4) avoiding use of normal saline which is linked to renal failure and possibly hemolysis. Accompanying these safety measures will be the continued growth of one of the most important safety measures, patient blood management, which has as one benefit the avoidance of unnecessary and harmful transfusions. Reducing the toxicity of transfusions will enhance the improved clinical outcomes seen with patient blood management.

How I use platelet transfusions

Platelet transfusions are commonly administered for the prevention or treatment of bleeding in patients with acquired thrombocytopenia across a range of clinical contexts. Recent data, including randomized trials, have highlighted uncertainties in the risk-benefit balance of this therapy, which is the subject of this review. Hemovigilance systems report that platelets are the most frequently implicated component in transfusion reactions. There is considerable variation in platelet count increment after platelet transfusion, and limited evidence of efficacy for clinical outcomes, including prevention of bleeding. Bleeding events commonly occur despite the different policies for platelet transfusion prophylaxis. The underlying mechanisms of harm reported in randomized trials may be related to the role of platelets beyond hemostasis, including mediating inflammation. Research supports the implementation of a restrictive platelet transfusion policy. Research is needed to better understand the impact of platelet donation characteristics on outcomes, and to determine the optimal thresholds for platelet transfusion before invasive procedures or major surgery (eg, laparotomy). Platelet transfusion policies should move toward a risk-adapted approach that does not focus solely on platelet count.

A Prospective Observational Study To Compare Transfusion Outcomes In Abo Identical Versus Abo Non-Identical Single Donor Platelet Concentrates: An Experience From A Tertiary Healthcare Center In India

ABO incompatible single donor platelet concentrates (SDPC) have a concern about unsatisfactory increments as well as possibility of hemolytic transfusion reaction. But from Indian population no study has commented on the clinical and laboratory outcome of ABO mismatched platelet transfusion. The aim of study was to compare transfusion outcomes in ABO identical versus ABO non-identical single donor platelet concentrates. In this prospective observational study, 400 SDPC transfusions among different patients were included. In group A (n = 200), ABO identical SDPC transfusions and in group B (n = 200) ABO non-identical SDPC transfusions were added. Corrective count increment (CCI), absolute count increment (ACI), percent platelet recovery (PPR) were calculated and incidents of hemolytic transfusion reactions were noted. In group A mean ± SD of ACI, CCI and PPR were as 30.78 ± 12.51, 15.10 ± 6.677, 39948.9 ± 20099.392. In group B, mean ± SD of ACI, CCI and PPR were - 25.4 ± 15.65, 12.509 ± 5.906, 33559.2 ± 22150.304. And when CCI, ACI, PPR were compared with group A and group B, statistically significant differences were noted (p <0.05). There was statistically significant difference in CCI, ACI and PPR in oncology patients and other prophylactic recipients except patients with dengue and other infectious disease. But there was no hemolytic transfusion reaction noted in any group. Our study clearly establish the potential benefits of ABO-identical PLT transfusion. It also points out that in emergency conditions or when there is a paucity in inventory, ABO non-identical SDPC transfusion may be lifesaving and clinically significant.

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P): A research program striving to improve blood donor safety and optimize transfusion outcomes across the lifespan

BACKGROUND

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) is a new iteration of prior National Heart, Lung, and Blood Institute (NHLBI) REDS programs that focus on improving transfusion recipient outcomes across the lifespan as well as the safety and availability of the blood supply.

STUDY DESIGN AND METHODS

The US program includes blood centers and hospitals (22 including 6 free-standing Children's hospitals) in four geographic regions. The Brazilian program has 5 participating hemocenters. A Center for Transfusion Laboratory Studies (CTLS) and a Data Coordinating Center (DCC) support synergistic studies and activities over the 7-year REDS-IV-P program.

RESULTS

The US is building a centralized, vein-to-vein (V2V) database, linking information collected from blood donors, their donations, the resulting manufactured components, and data extracts from hospital electronic medical records of transfused and non-transfused patients. Simultaneously, the Brazilian program is building a donor, donation, and component database. The databases will serve as the backbone for retrospective and prospective observational studies in transfusion epidemiology, transfusion recipient outcomes, blood component quality, and emerging blood safety issues. Special focus will be on preterm infants, patients with sickle cell disease, thalassemia or cancer, and the effect of donor biologic variability and component manufacturing on recipient outcomes. A rapid response capability to emerging safety threats has resulted in timely studies related to Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2).

CONCLUSIONS

The REDS-IV-P program endeavors to improve donor-recipient-linked research with a focus on children and special populations while also maintaining the flexibility to address emerging blood safety issues.

There and Back Again: The Once and Current Developments in Donor-Derived Platelet Products for Products for Hemostatic Therapy

Over 100 years ago, Duke transfused whole blood to a thrombocytopenic patient to raise the platelet count and prevent bleeding. Since then, platelet transfusions have undergone numerous modifications from whole blood-derived platelet-rich plasma to apheresis-derived platelet concentrates. Similarly, the storage time and temperature have changed. The mandate to store platelets for a maximum of 5-7 days at room temperature has been challenged by recent clinical trial data, ongoing difficulties with transfusion-transmitted infections, and recurring periods of shortages, further exacerbated by the COVID-19 pandemic. Alternative platelet storage approaches are as old as the first platelet transfusions. Cold-stored platelets may offer increased storage times (days) and improved hemostatic potential at the expense of reduced circulation time. Frozen (cryopreserved) platelets extend the storage time to years but require storage at -80 °C and thawing before transfusion. Lyophilized platelets can be powder-stored for years at room temperature and reconstituted within minutes in sterile water but are probably the least explored alternative platelet product to date. Finally, whole blood offers the hemostatic spectrum of all blood components but has challenges, such as ABO incompatibility. While we know more than ever before about the in vitro properties of these products, clinical trial data on these products are accumulating. The purpose of this review is to summarize the findings of recent preclinical and clinical studies on alternative, donor-derived platelet products.

Cerebral Hemorrhage: Pathophysiology, Treatment, and Future Directions

Intracerebral hemorrhage (ICH) is a devastating form of stroke with high morbidity and mortality. This review article focuses on the epidemiology, cause, mechanisms of injury, current treatment strategies, and future research directions of ICH. Incidence of hemorrhagic stroke has increased worldwide over the past 40 years, with shifts in the cause over time as hypertension management has improved and anticoagulant use has increased. Preclinical and clinical trials have elucidated the underlying ICH cause and mechanisms of injury from ICH including the complex interaction between edema, inflammation, iron-induced injury, and oxidative stress. Several trials have investigated optimal medical and surgical management of ICH without clear improvement in survival and functional outcomes. Ongoing research into novel approaches for ICH management provide hope for reducing the devastating effect of this disease in the future. Areas of promise in ICH therapy include prognostic biomarkers and primary prevention based on disease pathobiology, ultra-early hemostatic therapy, minimally invasive surgery, and perihematomal protection against inflammatory brain injury.

Neonatal platelet transfusions: New evidence and the challenges of translating evidence-based recommendations into clinical practice

Platelet transfusions are a common intervention for thrombocytopenia. Although the main reason for transfusing platelets is to improve hemostasis, platelets have many additional physiological roles, including interactions with immune pathways. Much of the evidence base for safe and effective transfusions has been informed by randomized trials in adult patients with hematological malignancies. Only three randomized trials have been conducted in sick neonates. These trials have indicated evidence of harm, including a significantly higher rate of death or major bleeding within 28 days after randomization for the largest trial, which enrolled 660 infants. The overall research indicates limited effectiveness of platelet transfusions to reduce bleeding risk. It is important that the results of trials are implemented into practice, but uptake of research findings into neonatal medicine remains inconsistent, as for many areas of health care. There is a need to establish which potential implementation strategies (cost-) efficiently enact change, such as audit and feedback, automated reminder systems for ordering transfusions, and use of opinion leaders. Research is exploring potential mechanisms underlying the lack of effectiveness of platelet transfusions and the increased bleeding and mortality observed in neonatal randomized trials. One potential mechanism concerns the roles of platelets to promote excessive angiogenic signals during a vulnerable period of brain development. A further hypothesis explores the effects of transfusing "adult" platelets into "neonatal" thrombocytopenic blood on primary hemostasis and immune responses.

Essential Role of Rho-Associated Kinase in ABO Immune Complex-Mediated Endothelial Barrier Disruption

ABO immune complexes (ABO-IC) formed by ABO-incompatible antigen-antibody interaction are associated with hemolysis and platelet destruction in patients transfused with ABO-nonidentical blood products. However, the effects of ABO-IC on endothelial cells (EC) are unclear. ABO-IC were formed in vitro from normal donor-derived plasma and serum. Human pulmonary artery EC (HPAEC) were cultured and treated with media, ABO-identical and –non-identical plasma, and ABO-IC. EC barrier integrity was evaluated using transendothelial electrical resistance (TEER), scanning electron microscopy (SEM), vascular endothelial (VE)-cadherin and phalloidin staining, and Rho-associated Kinase (ROCK) inhibitor treatment. TEER revealed significant/irreversible barrier disruption within 1–2 h of exposure to ABO non-identical plasma and ABO-IC; this occurred independently of EC ABO type. Treatment with ABO-IC resulted in decreased VE-cadherin staining and increased phalloidin staining in a time-dependent manner, suggesting that the resultant increased EC barrier permeability is secondary to actin stress fiber formation and loss of cell surface VE-cadherin. Inhibition of ROCK was effective in protecting against IC-induced barrier disruption even two hours after ABO-IC exposure. ABO-IC causes increased EC barrier permeability by decreasing cell surface VE-cadherin and promoting stress fiber formation, which is preventable by inhibiting ROCK activation to protect against EC contraction and gap formation.

Prediction of Hematoma Expansion in Patients With Intracerebral Hemorrhage Using Thromboelastography With Platelet Mapping: A Prospective Observational Study

Background and Purpose: The purpose of the study was to evaluate the usefulness of thromboelastography with platelet mapping (TEG-PM) for predicting hematoma expansion (HE) and poor functional outcome in patients with intracerebral hemorrhage (ICH).

Methods: Patients with primary ICH who underwent baseline computed tomography (CT) and TEG-PM within 6 h after symptom onset were enrolled in the observational cohort study. We performed univariate and multivariate logistic regression models to assess the association of admission platelet function with HE and functional outcome. In addition, a receiver operating characteristic (ROC) curve analysis investigated the accuracy of platelet function in predicting HE. A mediation analysis was undertaken to determine causal associations among platelet function, HE, and outcome.

Results: Of 142 patients, 37 (26.1%) suffered HE. Multivariate logistic regression identified arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition as significant independent predictors of HE. The area under the ROC curves was 0.727 for AA inhibition and 0.721 for ADP inhibition. Optimal threshold for AA inhibition was 41.75% (75.7% sensitivity; 67.6% specificity) and ADP inhibition was 65.8% (73.0% sensitivity; 66.7% specificity). AA and ADP inhibition were also associated with worse 3-month outcomes after adjusting for age, admission Glasgow Coma Scale score, intraventricular hemorrhage, baseline hematoma volume, and hemoglobin. The mediation analysis showed that the effect of higher platelet inhibition with poor outcomes was mediated through HE.

Conclusions: These findings suggest that the reduced platelet response to ADP and AA independently predict HE and poor outcome in patients with ICH. Platelet function may represent a modifiable target of ICH treatment.

The Effect of Preoperative Antiplatelet Therapy on Early Postoperative Rehemorrhage and Outcomes in Patients With Spontaneous Intracranial Hematoma

Background and Purpose

The effect of antiplatelet therapy (APT) on early postoperative rehemorrhage and outcomes of patients with spontaneous intracerebral hemorrhage (ICH) is still unclear. This study is to evaluate the effect of preoperative APT on early postoperative rehemorrhage and outcomes in ICH patients.

Methods

This was a multicenter cohort study. ICH patients undergoing surgery were divided into APT group and no antiplatelet therapy (nAPT) group according to whether patients received APT or not. Chi-square test, t-test, and Mann–Whitney U test were used to compare the differences in variables, postoperative rehematoma, and outcomes between groups. Multivariate logistics regression analysis was used to correct for confounding variables, which were different in group comparison.

Results

One hundred fifty ICH patients undergoing surgical treatment were consecutively included in this study. Thirty five (23.33%) people were included in the APT group, while 115 (76.67%) people were included in the nAPT group. The incidence of early postoperative rehemorrhage in the APT group was significantly higher than that in the nAPT group (25.7% VS 10.4%, p = 0.047 < 0.05). After adjustment for age, ischemic stroke history, and ventricular hematoma, preoperative APT had no significant effect on early postoperative rehemorrhage (p = 0.067). There was no statistical difference between the two groups in early poorer outcomes (p = 0.222) at 14 days after surgery. After adjustment for age, ischemic stroke history, and ventricular hematoma, preoperative APT also had no significant effect on early poorer modified Rankin Scale (mRS) (p = 0.072).

Conclusion

In conclusion, preoperative APT appears to be safe and have no significant effect on early postoperative rehematoma and outcomes in ICH patients.