Platelet Transfusion Research Articles

Sequence analysis and identification of a novel HLA-DPB1*02:01:69 allele by third-generation sequencing

To analyze the sequence of a novel HLA-DPB1 allele in an individual. A individual identified from the database of blood donors for matched platelet transfusion at the Blood Center of Zhejiang Province in May 2022 was selected as the study subject. HLA genotype of the individual was determined by next-generation sequencing (NGS) on an Ion Torrent S5 platform. The sequence of the HLA-DPB1 locus was also determined by NGS on an Illumina Miseq platform and third-generation sequencing using Oxford Nanopore MinION. This study was approved by the Blood Center of Zhejiang Province (Ethics No. 2021-001). A novel HLA-DPB1*02 allele was identified in the specimen, for which the closest genotype was HLA-DPB1*02:new,17:01:01G, with the variant located in exon 3. Meanwhile, the NGS also revealed a novel HLA-DPB1*17 allele, with the closest genotype being HLA-DPB1*02:01,17:new. Both the HLA-DPB1*17:01:01:01 and HLA-DPB1*02 alleles were identified by third-generation sequencing. Compared with the HLA-DPB1*02:01:02:01 allele, the novel allele had a G>A variation at position 369 in the exon 3, which however did not result in amino acid change. A novel HLA-DPB1 allele has been identified and validated by both NGS and TGS, which has been named as HLA-DPB1*02:01:69 by the World Health Organization Committee on Nomenclature of Factors of the HLA System.

Fetomaternal Outcome in Pregnancy with Gestational Thrombocytopenia

Introduction: Gestational thrombocytopenia, a common hematological disorder in pregnancy, poses risks to both maternal and neonatal health. This study aims to evaluate the fetomaternal outcomes in pregnancies complicated by gestational thrombocytopenia compared to those with normal platelet counts. Methods: This prospective cohort study was conducted over 12 months at Jalalabad Ragib-Rabeya Medical college hospital sylhet Bangladesh. It included 100 pregnant women diagnosed with gestational thrombocytopenia (platelet count <150,000/µL after 20 weeks of gestation) and 100 matched controls with normal platelet counts. Maternal data included demographic information, obstetric and medical history, mode of delivery, incidence of pre-eclampsia, postpartum hemorrhage, and need for platelet transfusions. Fetal outcomes assessed were birth weight, Apgar scores, preterm birth rates, NICU admissions, and neonatal thrombocytopenia. Data were analyzed using t-tests for continuous variables and chi-square tests for categorical variables, with multivariate logistic regression to identify predictors of adverse outcomes. Result: The gestational thrombocytopenia group showed higher, though not statistically significant, rates of cesarean delivery (30% vs. 25%, p=0.453), pre-eclampsia (15% vs. 12%, p=0.540), and postpartum hemorrhage (18% vs. 10%, p=0.110). Platelet transfusions were required more frequently in the gestational thrombocytopenia group (8% vs. 2%, p=0.052). Fetal outcomes revealed lower mean birth weight (2950g vs. 3050g, p=0.145), higher preterm birth rates (14% vs. 10%, p=0.371), and more NICU admissions (20% vs. 12%, p=0.132) in the gestational thrombocytopenia group. Notably, neonatal thrombocytopenia was significantly more prevalent in the gestational thrombocytopenia group (10% vs. 2%, p=0.017). Conclusion: Gestational thrombocytopenia is associated with increased risks of certain maternal and neonatal complications. Vigilant monitoring and management are essential to improve outcomes in affected pregnancies. Further research is needed to develop targeted interventions and improve antenatal care practices.

Comparative outcomes of cardioplegic arrest versus beating heart in pediatric undergoing extracardiac total cavopulmonary connection

BackgroundTotal cavopulmonary connection (TCPC) is a definitive palliative procedure for functionally univentricular congenital heart disease. The study aims to compare the impact of on-pump cardioplegic arrest and on-pump beating heart cardiopulmonary bypass (CPB) on the prognosis of pediatric patients undergoing extracardiac TCPC.MethodsThe medical data of patients (< 18 years) who underwent extracardiac TCPC with CPB between January 2008 and December 2020 in the cardiac surgery center were retrospectively analyzed. Depending on CPB strategies, the patients were assigned to the beating-heart (BH) and cardioplegic arrest (CA) groups. Data including baseline characteristics, intra/postoperative variables, and clinical outcomes were collected for analysis with 1:1 propensity score matching and multivariable stepwise logistic regressions.ResultsFifty-seven matched patient pairs were obtained. No significant difference existed between the two groups in the in-hospital mortality (3.5% vs. 1.8%, P = 1) and one-year survival rate (100% vs. 96.4%, P = 0.484). The BH group had significantly less intraoperative platelet transfusion (10 mL vs. 150 mL, P = 0.019) and blood loss (100 mL vs. 150 mL, P = 0.033) than the CA group. The CA group had significantly higher vasoactive-inotropic scores (P < 0.05) and longer postoperative ICU stays (2.0 d vs. 3.7 d, P = 0.017). No significant difference existed between the two groups in the incidence of postoperative adverse events.ConclusionAlthough both CPB strategies are safe and feasible for extracardiac TCPC, the BH technique would cause less intraoperative platelet transfusion and blood loss, and achieve faster early-term postoperative recovery.

Introduction of 7-day amotosalen/ultraviolet A light pathogen-reduced platelets in Honduras: Impact on platelet availability in a lower middle-income country.

Honduras became the first lower middle-income country (LMIC) to adopt amotosalen/UVA pathogen-reduced (PR) platelet concentrates (PCs) as a national platelet safety measure in 2018. The Honduran Red Cross (HRC) produces ~70% of the national platelet supply using the platelet-rich plasma (PRP) method. Between 2015 and 2018, PCs were screened with bacterial culture and issued as individual, non-pooled PRP units with weight-based dosing and 5-day shelf-life. PR PCs were produced in six-PRP pools with a standardized dose (≥3.0 × 1011), no bacterial screening and 7-day shelf-life. Gamma irradiation and leukoreduction were not used. PC production and distribution data were retrospectively analysed in two periods. Period 1 (P1) included 3 years of PRP PCs and a transition year (2015-18). Period 2 (P2) included 5 years of PR PCs (2019-23). PC doses were standardized to an equivalent adult dose for both periods. Descriptive statistics were calculated. HRC produced 10% more PC doses per year on average in P2 compared to P1. Mean annual waste at HRC declined from 23.9% in P1 to 1.1% in P2. Two urban regions consumed 96% of PC doses in P1 and 88.3% in P2. PC distributions increased in 14/18 regions. Standardized dosage, PR and 7-day shelf-life increased PC availability, reduced waste, eliminated bacterial screening and avoided additional costs for arboviral testing, leukoreduction and irradiation. Access to PC transfusion remains limited in Honduras; however, the conversion to pooled PR PCs illustrates the potential to sustainably expand PC distribution in an LMIC.

Shrimp allergy leading to severe transfusion reaction: A case report

AbstractBackgroundTransfusion reactions occur at an estimated incidence of 2 per 1.000 transfused products. Anaphylactic transfusion reactions are rarer, and seen in 1 per 10.000 transfusions, and are mostly related to platelet transfusions. Here, we describe a rare cause of a transfusion reaction.Case presentationA 19‐year‐old man underwent an allogeneic haematopoietic stem cell transplantation for sickle cell disease and developed an anaphylactic shock following a platelet transfusion, after excluding all common causes. The patient reported a shrimp allergy, and one of the blood/platelet donors had consumed shrimp the day before donation. Elevated levels of specific immunoglobulin E (IgE) against shrimp and tropomyosin were found in the patient. Subsequent transfusions were performed with apheresis platelets from selected donors who were instructed to avoid shrimp consumption, and these transfusions were uneventfully.ConclusionWhen a severe transfusion reaction occurs in a patient with a known food allergy, an IgE‐mediated (food‐related) transfusion reaction should be considered after excluding other causes.

Commonalities of platelet dysfunction in heart failure with preserved ejection fraction and underlying comorbidities.

Heart failure with preserved ejection fraction (HFpEF) is characterized by a lack of a specific targeted treatment and a complex, partially unexplored pathophysiology. Common comorbidities associated with HFpEF are hypertension, atrial fibrillation, obesity and diabetes. These comorbidities, combined with advanced age, play a crucial role in the initiation and development of the disease through the promotion of systemic inflammation and consequent changes in cardiac phenotype. In this context, we suggest platelets as important players due to their emerging role in vascular inflammation. This review provides an overview of the role of platelets in HFpEF and its associated comorbidities, including hypertension, atrial fibrillation, obesity and diabetes mellitus, as well as the impact of age and sex on platelet function. These major HFpEF-associated comorbidities present alterations in platelet behaviour and in features linked to platelet size, content and reactivity. The resulting dysfunctional platelets can contribute to further increase inflammation, oxidative stress and endothelial dysfunction, suggesting an active role of these cells in the initiation and progression of HFpEF. Recent evidence shows that reduced platelet count and elevated mean platelet volume are associated with worsening heart failure in HFpEF patients. However, the specific mechanisms by which platelets contribute to HFpEF development and progression are still largely unexplored, with only a few studies investigating platelet function in HFpEF. We discuss the limited yet significant body of research investigating platelet function in HFpEF, emphasizing the need for more comprehensive studies. Additionally, we explore the potential mechanisms through which platelets may influence HFpEF, such as their interactions with the vascular endothelium and the secretion of bioactive molecules like cytokines, chemokines and RNA molecules. These interactions and secretions may play a role in modulating vascular inflammation and contributing to the pathophysiological landscape of HFpEF. The review underscores the necessity for future research to elucidate the precise contributions of platelets to HFpEF, aiming to potentially identify novel therapeutic targets and improve patient outcomes. The evidence presented herein supports the hypothesis that platelets are not merely passive bystanders but active participants in the pathophysiology of HFpEF and its comorbidities.

Analysis of bleeding outcomes in patients with hypoproliferative thrombocytopenia in the A-TREAT clinical trial.

Despite prophylactic platelet transfusions, hypoproliferative thrombocytopenia is associated with bleeding; historical risk factors include hematocrit (HCT) 25%, activated partial thromboplastin time 30 s, international normalized ratio 1.2, and platelets 5000/μL. We performed a post hoc analysis of bleeding outcomes and risk factors in participants with hematologic malignancy and hypoproliferative thrombocytopenia enrolled in the American Trial to Evaluate Tranexamic Acid Therapy in Thrombocytopenia (A-TREAT) and randomized to receive either tranexamic acid (TXA) or placebo. World Health Organization (WHO) grade 2+ bleeding occurred in 46% of 330 participants, with no difference between the TXA (44%) and placebo (47%) groups (p = 0.66). Overall, the most common sites of bleeding were oronasal (18%), skin (17%), gastrointestinal (11%), and genitourinary (11%). Among participants of childbearing potential, 28% experienced vaginal bleeding. Platelets ≤5000/μL and HCT < 21% (after adjusting for severe thrombocytopenia) were independently associated with increased bleeding risk (HR 3.78, 95% CI 2.16-6.61; HR 2.67, 95% CI 1.35-5.27, respectively). Allogeneic stem cell transplant was associated with nonsignificant increased risk of bleeding versus chemotherapy alone (HR 1.34, 95% CI 0.94-1.91). The overall rate of WHO grade 2+ bleeding was similar to previous reports, albeit with lower rates of gastrointestinal bleeding. Vaginal bleeding was common in participants of childbearing potential. Platelets ≤5000/μL remained a risk factor for bleeding. Regardless of platelet count, bleeding risk increased with HCT < 21%, suggesting a red blood cell transfusion threshold above 21% should be considered to mitigate bleeding. More investigation is needed on strategies to reduce bleeding in this population.

A novel approach to simultaneous genotyping of human platelet antigen systems and human leucocyte antigen class I loci using PacBio long-read sequencing.

Accurate human leucocyte antigen (HLA) and human platelet antigen (HPA) typing is essential for establishing a blood platelet donor bank to deal with refractoriness in patients undergoing multiple platelet transfusions. Current methods, such as Sanger and next-generation sequencing, encounter difficulties in haplotyping. Herein, the aim of this study was to establish a method for HLA and HPA typing based on the long read sequencing. The HPA and HLA class I genotypes of 268 platelet donors from the Taiyuan Blood Center, China were identified using long-read sequencing on the PacBio platform. Allele frequencies for HPA systems and HLA class I genes were calculated, and genetic variability within HPA system genes was analysed. Polymorphisms were identified in 8 of the 35 HPA systems (HPA-1 to HPA-6w, HPA-15 and HPA-21w), with the frequencies of the 'b' allele at 0.0187, 0.0709, 0.4086, 0.0075, 0.0149, 0.0317, 0.4310 and 0.0019, respectively. The alleles with the highest frequencies at the HLA-A, HLA-B and HLA-C loci are HLA-A02:01, B51:01, B46:01 and C06:02, respectively. Additionally, several genetic patterns in HPA systems were identified, including the c.166-1029C>T variant, which was found exclusively in samples carrying the HPA-1b allele. This study developed a targeted long-read sequencing method characterized by high throughput and simultaneity, capable of resolving allele ambiguities for effective HLA class I genotyping in establishing a platelet donor bank.

Applications of Platelet Concentrates (PCs) in Regenerative Onco-Urology: A Systematic Review of Literature

Objective: To assess the effectiveness of Platelet Concentrates (PCs) in the contest of Hemorrhagic, Actinic, and Radiation Cystitis, plus Urethral Obstruction or Stenosis. Eligibility criteria: Open article in English or Italian regarding in situ applications of PCs for the selected pathologies. Information sources: MEDLINE, Cochrane Library, and ELSEVIER. Risk of bias: High (and discussed). Methods for synthesis of results: Selection of relevant contents, resumed by digital tools, checked by authors and used throughout the manuscript. Included studies: 13 screened articles + 7 personal sources + 37 “extra” articles. Synthesis of results: Pre-clinical and clinical studies demonstrated substantial symptom relief, mucosal restoration, and improved growth factor levels, reducing recurrence rates and complications. However, preparation protocols and results varied among studies. Limitations of evidence: Frequent low-quality studies with mall sample size, plus heterogeneous experimental setups and nomenclature/preparations. Interpretation: PCs demonstrate promise due to their bioactive components, enhancing tissue repair and reducing inflammation with no significant adverse events. Despite positive outcomes in pre-clinical and clinical studies, variability in preparation protocols and small sample sizes, together with inconsistent results, highlight the need for high-quality research to validate PCs’ clinical efficacy and cost-effectiveness.

Hypoalbuminemia is a predictor of mortality in patients with cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation.

Hypoalbuminemia is predictive of mortality in critically ill patients, especially those with cardiac etiologies of illness. The objective of this study was to determine the association of albumin level pre-cannulation for veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) and important clinical hospital outcomes. This was a retrospective, observational cohort study of albumin levels in patients with cardiogenic shock requiring V-A ECMO between December 2015 and August 2021 in a single, high-volume ECMO center. The primary outcome was in-hospital mortality. Of 434 patients assessed, 318 were included. The overall mean pre-ECMO albumin was 3 ± 0.8g/dL and mean albumin at 72 hours post-cannulation was 2.7 ± 0.5g/dL. For patients with pre-ECMO albumin ≤3g/dL vs. >3g/dL, in-hospital mortality was 44.9% vs. 27.5%, respectively (p = .002). In multivariable logistic regression analysis, higher albumin (per 1g/dL increase) at time of V-A ECMO initiation was associated with decreased odds of in-hospital mortality (OR, 0.68; 95% CI, 0.48-0.96; p = .03). Patients with a pre-ECMO albumin ≤3g/dL required significantly more platelet transfusions and had higher incidence of gastrointestinal bleeding during V-A ECMO support (both p < .05). Hypoalbuminemia at time of cannulation is significantly associated with in-hospital mortality and ECMO-related complications including platelet transfusion and gastrointestinal bleeding. Albumin levels at the time of consideration of V-A ECMO may serve as a key prognostic indicator and may assist in effective decision-making regarding this invasive and costly resource.

Postoperative bleeding after dentoalveolar surgery in patients with thrombocytopenia—are prophylactic platelet transfusions necessary?

PurposeBenefits of prophylactic platelet (PLT) transfusion before dentoalveolar surgery are unclear. This study investigated the effect of prophylactic PLT transfusions on the incidence of postoperative bleeding (POB) in patients with thrombocytopenia and a PLT count ≤ 75*109/L.MethodsThe cohort in this retrospective study comprised 83 patients with thrombocytopenia ≤ 75*109/L who had undergone dentoalveolar surgery. Exclusion criteria were other coagulation deficiencies or medications that would affect hemostasis. In all, 144 teeth had been removed. POB events were extracted and compared between the group that had received prophylactic PLT transfusion before dentoalveolar surgery and the group that had not.ResultsPOB events were observed in 5 of 83 patients (6.0%) who had a median PLT count of 35*109/L before any transfusion. The group with no postoperative bleeding (NPOB) had a median PLT count of 34*109/L. Two (4.2%) of the 48 patients who had received prophylactic PLT transfusions before dentoalveolar surgery developed POB. Three (8.6%) of the 35 patients who had not received a transfusion experienced POB. The difference between these two groups was not significant (p = 0.646). When two or more teeth were removed in the same session, a significantly higher incidence of POB was observed (p = 0.042).ConclusionsOur data indicate that prophylactic PLT transfusions in thrombocytopenic patients with PLT counts ≤ 75*109/L do not reduce the incidence of POB after dentoalveolar surgery. However, caution is warranted when extracting multiple teeth in the same surgical session since we found this to be significantly associated with an increased risk of POB.

A phase 2/3 study of romiplostim N01 in chemotherapy-induced thrombocytopenia (CIT).

217 Background: CIT causes dose reduction or delay of chemotherapy (chemo), bleeding, and platelet (PLT) transfusion. This phase 2/3 study aimed to assess the efficacy and safety of romiplostim N01 in CIT. Methods: This trial comprising Part A (open-label) and B (randomized double-blinded) recruited patients (pts) with solid tumors or lymphoma and with CIT. In Part A, pts with a PLT count ≤200×10 9 /L before the day of chemo were included. Romiplostim N01 was injected subcutaneously per week (QW) for a 3-week chemo cycle at 1 μg/kg (group 1) or 2 μg/kg (group 2) for pts with a PLT count 100~200×10 9 /L, and at 2 μg/kg (group 3) for pts with a PLT count &lt;100×10 9 /L. Primary endpoint was proportion of responders on the last day of chemo cycle, defined as pts who had an increase in PLT count of ≥30×10 9 /L from baseline for pts with a PLT count 100~200×10 9 /L, and an increase in PLT count of ≥30×10 9 /L or a PLT count ≥100×10 9 /L for pts with a PLT count &lt;100×10 9 /L. In Part B, pts with a PLT count 75~150×10 9 /L were included and randomized 2:1 to receive romiplostim N01 or placebo QW at 2 μg/kg on day 1, and at 1 μg/kg on day 8 and 15 for two chemo cycles. Primary endpoint was proportion of responders, defined as pts resuming two consecutive chemo cycles without thrombocytopenia-induced dose modification (dose reduction by ≥15% or delay by ≥4 days or discontinuation) and without a rescue therapy. Results: In Part A, 50 pts were included between Mar 12, 2021 and Jul 29, 2021. The proportions of responders were 66.7% (10/15) in group 1, 53.3% (8/15) in group 2, and 90.0% (18/20) in group 3. Between Nov 8, 2022 and Jan 15, 2024, 63 pts were randomized in Part B. The proportion of responders in the romiplostim N01 group was significantly higher than that in placebo group (68.3% vs 40.9%). The adjusted rate difference was 27.6% (95% confidence interval [CI]: 2.1%, 50.2%). Treatment-related adverse events (TRAEs) occurred in 17 (41.5%) and 12 (54.5%) pts in the romiplostim N01 and placebo groups, of whom 1 (2.4%) and 0 were ≥grade 3. The most frequent TRAEs were nausea (12.2% vs 0), vomiting (12.2% vs 0), and increased aspartate aminotransferase (9.8% vs 4.5%). No treatment-related hemorrhage or death occurred. In pool analysis, the proportion of responders was 73.3% and 40.9% in pts treated with romiplostim N01 and placebo, respectively. The rate difference was 32.4% (95% CI: 9.2%, 52.9%). Conclusions: Romiplostim N01 showed promising efficacy and manageable safety in patients with CIT. Clinical trial information: PartA:NCT05851027 ; PartB:NCT05554913 . Pool analysis of Part A (pts with PLT count ≥75×10 9 /L) and Part B (all pts). Romiplostim N01 Placebo Rate Difference Part A+B (n=75) Part B (n=22) Romiplostim N01 (Part A+B) vs Placebo Lowest PLT count in Cycle 1, ×10 9 /L 85±41 59±32 / Highest PLT count in Cycle 1, ×10 9 /L 226±101 132±45 / Proportion of responders who completed the first chemo cycle without rescue therapy and without thrombocytopenia-induced dose modification of the second chemo cycle 55 (73.3%) 9 (40.9%) 32.4% 95% CI 61.9~82.9% 20.7~63.6% 9.2~52.9%

The impact of delayed versus early administration of granulocyte colony-stimulating factor following autologous hematopoietic stem cell transplantation on transplantation outcome.

Granulocyte colony-stimulating factor (G-CSF) is routinely administered after autologous hematopoietic stem cell transplantation (auto-HSCT) to decrease the duration of neutropenia and diminish the incidence of febrile neutropenia. Nevertheless, the most advantageous timeframe for administering G-CSF in the transplantation setting remains elusive. We conducted a cross-sectional study of 200 patients diagnosed with hematological malignancies who underwent auto-HSCT between July 2017 and January 2022. Patients were divided into two groups of 100 individuals based on the timing of G-CSF administration after auto-HSCT. In the first group, G-CSF was administered on post-transplantation day +1, while in the second group, G-CSF was administered on post-transplantation day +5. Patient demographics and clinical outcomes, including time to neutrophil engraftment, time to platelet engraftment, length of hospital stay, duration of fever, and incidence of bacterial and fungal bloodstream infections, were compared between the two groups. We identified a significantly shorter platelet engraftment time in the day +5 group than in the day +1 group (P<0.001), though the groups were similar regarding neutrophil engraftment time. The total number of G-CSF injections differed significantly according to the administration schedule. The number of red blood cells and length of hospital stay was greater in the day +1 group (all P<0.001). The incidence of bacterial and fungal bloodstream infections and duration of fever did not differ between the groups. Delayed administration of G-CSF on day +5 is as effective as early administration and can positively influence platelet engraftment, transfusion support, and hospitalization time.

Refractory Thrombocytopenia is the Earliest Diagnostic Criterion for Sinusoidal Obstruction Syndrome in Children.

Sinusoidal obstruction syndrome (SOS) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT), whose diagnostic criteria changed over time to achieve a timelier diagnosis. Recently, pediatric-specific criteria presented by the European Society for Blood and Marrow Transplantation (pEBMT) incorporated transfusion-refractory thrombocytopenia (RT) as an early indicator of SOS in children. However, a comparison of all individual diagnostic parameters belonging to pEBMT and former SOS diagnostic criteria has never been performed. This retrospective study conducted at a pediatric tertiary care hospital analyzed all pediatric HSCT cases diagnosed with SOS among 170 children transplanted from 2009 to 2023. Eleven patients developed SOS during this period (incidence: 11/170, 6.5%). pEBMT, Seattle, and Baltimore criteria were retrospectively applied to the 11 cases and compared, showing that RT was the earliest fulfilled parameter (median onset: 6d post-HSCT). pEBMT and Seattle criteria identified 11/11 SOS cases, with pEBMT leading to an earlier diagnosis. RT typically manifested before diagnosis, with significantly higher platelet transfusion requirements before diagnosis than after. RT is the earliest satisfied criterion in pediatric SOS and typically occurs in the initial stages of the disease before diagnosis. Further research is needed to identify additional early indicators of pediatric SOS.

Establishment and Application of a Multiplex PCR NGS Method for the Genotyping of HLA-Class I and HPA.

Selecting compatible HLA-Class I and/or HPA platelets based on genotyping could alleviate immune platelet transfusion refractoriness (PTR). A fast and reliable method of HLA-Class I and HPA genotyping is necessary to construct a platelet donor bank with known HLA-Class I and HPA genotypes. Ten pairs of specific primers for HLA-A, HLA-B, HLA-C, HPA-1 through HPA-6w, HPA-15 and HPA-21w were designed. The appropriate fragments were optimised for amplification in a single multiplex reaction. After a cleanup step using paramagnetic beads, the amplicon library was prepared and sequenced. To validate the accuracy of the developed method, commercial NGS kits for the genotyping of HLA-A, HLA-B and HLA-C and the TaqMan real-time PCR method in-house for the genotyping of HPA-1 through HPA-6w, HPA-15 and HPA-21w were used to detect all the specimens in parallel. A total of 386 specimens were detected and the results of genotyping HLA-A, HLA-B, HLA-C and HPA-1 through HPA-6w, HPA-15 and HPA-21w were obtained simultaneously, which is 100% consistent between the two methods. Four new HLA alleles, HLA-A*11:451, HLA-A*30:01:26, HLA-B*39:201 and HLA-B*40:538, were also reconfirmed. Two novel SNVs, c.2671C > T and c.2681T > G, in the coding region of ITGA2B were detected, all of which are heterozygous in individuals. A novel NGS method based on multiplex PCR was established to detect HLA-Class I and HPA simultaneously, which is high-throughput, rapid and accurate and could be applied to build a platelet donor bank.

Comprehensive secondary analysis of thrombotic events in pediatric patients receiving extracorporeal membrane oxygenation: A prospective cohort study.

This study aims to describe laboratory and clinical factors associated with thrombotic events during prolonged pediatric extracorporeal membrane oxygenation. A secondary analysis of a multi-center prospective study performed between 2012 and 2014. Patients under the age of 19years that received extracorporeal membrane oxygenation for at least 4days of therapy were included (n = 385). Univariable analysis and binomial regression were performed to evaluate predictive factors of single and multiple thrombotic events. A posteriori scoring tool was created to categorize thrombotic event severity. Over 39% of children receiving prolonged ECMO experienced a thrombotic event (TE). Binomial regression demonstrated an association between higher transfused platelet volume (mL/kg) (OR 1.04, CI: 95% 1.01-1.06, p = 0.003), Anti-Xa (OR 5.38, CI: 95% 1.22-23.8, p = 0.026) and aPTT (OR 1.01, CI: 95% 1.00-1.02, p = 0.032) the day prior to TE. Patients experiencing multiple TEs were associated with higher platelet transfusion volume (mL/kg) (OR 1.08, CI: 95% 1.05-1.12, p =< 0.001), antithrombin III (OR 1.03, CI: 95% 1.01-1.04, p = 0.001) and aPTT (OR 1.02, CI: 95% 1.01-1.03, p = 0.009). Patients experiencing multiple thrombotic events had a higher risk of 28-day mortality based on a cumulative clot severity score >4 (OR 2.37 (CI: 95% 1.32-4.24). Current lab tests show limited sensitivity to predict these events the day prior in a vulnerable patient group, leading to potential ECMO circuit failures. Patients with multiple thrombotic events during ECMO therapy face increased mortality risks, highlighting the need for dynamic reporting tools like clot severity scores and detailed documentation of interventions to enhance understanding and improve outcomes.

Reduced platelet activation in triple-negative essential thrombocythemia compared with JAK2V617F-mutated essential thrombocythemia.

Triple-negative (TN) essential thrombocytopenia (ET) is characterized by the absence of driver mutations while retaining histological and phenotypic characteristics sufficient for an ET diagnosis. Our understanding of TN-ET and its platelet activation remains incomplete. We carried out a large-scale multi-center clinical analysis to analyze the clinical and molecular characteristics, thrombotic complications of TN-ET. We also related the above characteristics to platelet activation to further explore the thrombosis mechanism of TN-ET. A retrospective multicenter study was conducted on 138 TN-ET and 759 ET patients with driver mutations from 1 March 2012 to 1 December 2021. The clinical and molecular characteristics of the TN-ET were summarized. Additionally, platelet activation, apoptosis, and reactive oxygen species (ROS) levels were analyzed in 73 TN-ET patients from this cohort and compared to 41 age- and sex-matched healthy donors. Compared to patients with the JAK2V617F mutation, those with triple-negative mutation were younger (P < 0.001) and exhibited fewer thrombotic events before diagnosis (P < 0.001) and during follow-up (P = 0.039). Patients with triple-negative mutation also presented with significantly reduced CD62P expression in platelets (P = 0.031), slightly reduced calcium concentration in platelets (P = 0.063), increased mitochondrial membrane potential (P = 0.011), reduced phosphatidylserine exposure (P = 0.015), reduced levels of ROS (P = 0.043) and MitoSOX in platelets (P = 0.047). In comparison to JAK2V617F-mutated ET, TN-ET is associated with lower platelet ROS levels, which leads to reduced platelet activation and consequently a lower risk of thrombosis.

Impact of platelet transfusion refractoriness in the first 30 days post-hematopoietic stem cell transplantation on outcomes of patients with myelodysplastic syndrome.

Currently, no study has determined whether platelet transfusion refractoriness (PTR) post-hematopoietic stem cell transplantation (HSCT) before engraftment in patients with myelodysplastic syndrome (MDS) would impacts clinical outcomes. We performed a MDS-specific retrospective analysis to determine whether PTR in one-month post-HSCT in patients with MDS could influence outcomes. Among the 315 patients enrolled, 110 (34.9 %) had PTR from stem cell infusion to one-month post-HSCT. Baseline characteristics of the PTR and non-PTR groups were similar. We found that patients with PTR had a slower and lower rate of platelet engraftment by day 28, as well as a slower recovery of neutrophils. The median days of neutrophil and platelet engraftment were 14 days (9-23) and 17 days (8-28) in the PTR groups versus 13 days (9-23) and 15 days (7-28) in the non-PTR group (P<0.001). By day 28, 84 of 110 patients (76.4%) with PTR achieved platelet engraftment compared with 181 of 205 patients (88.3%) without PTR achieving platelet engraftment (P=0.007). In addition, patients in the PTR group received significantly more red blood cell (median, 17 units vs. 10 units, P<0.001) and platelet transfusions (median, 13 units vs. 7 units, P<0.001). However, the overall survival was similar between the two groups. PTR in one-month post-HSCT, haploidentical donor, and ferritin level>1041ng/ml (median level) were independent adverse factors of platelet engraftment.

Retinopathy of Prematurity in Eight Portuguese Neonatal Intensive Care Units: Incidence, Risk Factors, and Progression-A Prospective Multicenter Study.

Retinopathy of prematurity (ROP) is a retinal neovascular disease affecting preterm infants. Identifying risk factors for its development and progression is critical for effective screening and prevention. This study aimed to analyze the incidence of ROP and identify key risk factors for its development and progression. We conducted a prospective, observational cohort study on 455 neonates (gestational age [GA] < 32 weeks or birth weight < 1500 g) across eight Portuguese NICUs. ROP incidence was 37.8%, with 4.6% requiring treatment. Multivariate analysis identified low GA and the number of red blood cell (RBC) transfusions as significant factors for ROP development and progression. After adjusting for these variables, platelet transfusions, high maximum fraction of inspired oxygen (FiO2) in the second week, and surfactant use remained significantly associated with ROP development, while early and late sepsis, maternal chronic hypertension, and delayed enteral nutrition were associated with progression to ROP requiring treatment. These findings underscore the importance of addressing low GAs and adult RBC transfusions in ROP risk management and suggest that maximum FiO2, platelet transfusions, and sepsis also play crucial roles. Larger studies are needed to validate these results and explore preventive interventions, particularly regarding the impact of multiple adult RBC transfusions on fetal hemoglobin percentages.

Storage properties of platelet concentrates from umbilical cord blood prepared using three different methods.

Thrombocytopenia, common in preterm newborns, may increase bleeding risk and is often treated with transfusions. Recent studies reveal that transfusing platelets at a high threshold worsens outcomes, possibly due to a "developmental mismatch" between adult-derived platelets and neonatal hemostatic system. Cord blood-derived platelet concentrates (CBPCs) could be an alternative for newborns. Our study aims to produce and evaluate the quality parameters of CBPCs during storage. Cord blood was collected from placentas after near-term and full-term pregnancies. Several production methods were attempted to obtain CBPCs, varying centrifugation settings, filtration, and dilution procedures. Adult-derived platelet concentrates (PCs) processed with the same methods, and standard PCs from five buffy-coats were used as controls. Storage tests were performed on days 2, 4-5, 7 from the collection. CBPCs parameters were compared with adult-derived PCs, and no significant differences were found for mean platelet volume (MPV), swirling, morphology, glucose, lactate, pCO2, and pO2. pH and bicarbonate were lower in CBPCs. Some significant differences between methods in CD62P expression and JC-1 ratio were observed. Compared with standard PCs, CBPCs showed lower platelet concentration, pH, and JC-1. Additionally, both in CBPCs as well as in control PCs, the apoptosis marker phosphatidylserine was elevated. CBPCs were of comparable quality to control PCs during storage. However, apoptosis markers in both groups were elevated, suggesting processing and storage of low volumes of PCs require further optimization. Also, filtration of low volumes leads to significant platelet loss, an issue that requires remedy.