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Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare but severe complication following COVID-19 vaccination, marked by thrombocytopenia and thrombosis. Analogous to heparin-induced thrombocytopenia (HIT), VITT shares similarities in anti-platelet factor 4 (PF4) IgG-mediated platelet activation via the FcγRIIa. To investigate the involvement of platelet-antibodies in VITT, we analyzed the presence of platelet-antibodies directed against glycoproteins (GP)IIb/IIIa, GPV and GPIb/IX in the serum of 232 clinically suspected VITT patients determined based on (suspicion of) occurrence of thrombocytopenia and/or thrombosis in relation to COVID-19 vaccination. We found that 19% of clinically suspected VITT patients tested positive for anti-platelet GPs: 39%, 32% and 86% patients tested positive for GPIIb/IIIa, GPV and GPIb/IX, respectively. No HIT-like VITT patients (with thrombocytopenia and thrombosis) tested positive for platelet-antibodies. Therefore, it seems unlikely that platelet-antibodies play a role in HIT-like anti-PF4-mediated VITT. Platelet-antibodies were predominantly associated with the occurrence of thrombocytopenia. We found no association between the type of vaccination (adenoviral vector vaccine versus mRNA vaccine) or different vaccines (ChAdOx1 nCoV-19, Ad26.COV2.S, mRNA-1273, BTN162b2) and the development of platelet-antibodies. It is essential to conduct more research on the pathophysiology of VITT, to improve diagnostic approaches and identify preventive and therapeutic strategies. [ABSTRACT FROM AUTHOR]

Background and Objectives: Donor characteristics have been implicated in transfusion‐related adverse events. Uncertainty remains about whether sex, and specifically pregnancy history of the blood donor, could affect patient outcomes. Whether storage duration of the blood product could be important for patient outcomes has also been investigated, and a small detrimental effect of fresh products remains a possibility. Here, we hypothesize that fresh red blood cell products donated by ever‐pregnant donors are associated with mortality in male patients. Materials and Methods: We used data from a cohort study of adult patients receiving a first transfusion between 2005 and 2015 in the Netherlands. The risk of death after receiving a transfusion from one of five exposure categories (female never‐pregnant stored ≤10 days, female never‐pregnant stored >10 days, female ever‐pregnant stored ≤10 days, female ever‐pregnant stored >10 days and male stored for ≤10 days), compared to receiving a unit donated by a male donor, which was stored for >10 days (reference), was calculated using a Cox proportional hazards model. Results: The study included 42,456 patients who contributed 88,538 person‐years in total, of whom 13,948 died during the follow‐up of the study (33%). Fresh units (stored for ≤10 days) from ever‐pregnant donors were associated with mortality in male patients, but the association was not statistically significant (hazard ratio 1.39, 95% confidence interval 0.97–1.99). Sensitivity analyses did not corroborate this finding. Conclusion: These findings do not consistently support the notion that the observed association between ever‐pregnant donor units and mortality is mediated by blood product storage. [ABSTRACT FROM AUTHOR]

Introduction: Coagulopathy may be the result of hyperfibrinolysis and could exacerbate bleeding following childbirth. Timely recognition of hyperfibrinolysis during the earliest stages of postpartum hemorrhage could identify women at risk of more severe blood loss who may benefit from targeted anti-fibrinolytic therapy. Rotational thromboelastometry (ROTEM® ) is a point-of-care test that could detect hyperfibrinolysis. The aim of this study was to evaluate whether early assessment of hyperfibrinolysis by ROTEM during postpartum hemorrhage could predict progression to severe postpartum hemorrhage.Material and Methods: During a prospective cohort study in the Netherlands among women with postpartum hemorrhage (total blood loss at least 1000 ml within 24 h after childbirth) ROTEM measurements were performed following 800-1500 ml of blood loss. Hyperfibrinolysis was defined as an enzymatic fibrinolysis index (ROTEM EXTEM maximum clot lysis [ML] minus the ROTEM APTEM ML) above 15%. Severe postpartum hemorrhage was defined as a composite end point of total blood loss greater than 2000 ml, transfusion of four or more units of packed cells, and/or need for an invasive intervention. The predictive value of hyperfibrinolysis for progression to severe postpartum hemorrhage was assessed by area under the receiver operating curve (AUC) and positive and negative predictive values.Trial Registration: ClinicalTrials.gov (NCT02149472).Results: Of 390 women included, 82 (21%) had severe postpartum hemorrhage. Four (1%) women had thromboelastometric evidence of hyperfibrinolysis, of whom two developed severe postpartum hemorrhage. The AUC for enzymatic fibrinolysis index more than 15% for progression to severe postpartum hemorrhage was 0.47 (95% CI 0.40-0.54). Positive and negative predictive values for this index were 50.0% (95% CI 6.8-93.2) and 79.3% (95% CI 74.9-83.2), respectively.Conclusions: Thromboelastometric evidence of hyperfibrinolysis was rare in women with postpartum hemorrhage when assessed between 800 and 1500 ml of blood loss. The clinical predictive value of viscoelastometric point-of-care testing for hyperfibrinolysis for progression to severe postpartum hemorrhage during early postpartum hemorrhage is limited. [ABSTRACT FROM AUTHOR]

Background: Intracranial hemorrhage is seen more frequently in acute leukemia patients compared to the general population. Besides leukemia‐related risk factors, also risk factors that are present in the general population might contribute to hemorrhagic complications in leukemia patients. Of those, cardiovascular risk factors leading to chronic vascular damage could modulate the occurrence of intracranial hemorrhage in these patients, as during their disease and treatment acute endothelial damage occurs due to factors like thrombocytopenia and inflammation. Objectives: Our aim was to explore if cardiovascular risk factors can predict intracranial hemorrhage in acute leukemia patients. Methods: In a case‐control study nested in a cohort of acute leukemia patients, including 17 cases with intracranial hemorrhage and 55 matched control patients without intracranial hemorrhage, data on cardiovascular risk factors were collected for all patients. Analyses were performed via conditional logistic regression. Results: Pre‐existing hypertension and ischemic heart disease in the medical history were associated with intracranial hemorrhage, with an incidence rate ratio of 12.9 (95% confidence interval [CI] 1.5 to 109.2) and 12.1 (95% CI 1.3 to110.7), respectively. Conclusion: Both pre‐existing hypertension and ischemic heart disease seem to be strong predictors of an increased risk for intracranial hemorrhage in leukemia patients. [ABSTRACT FROM AUTHOR]

Background and Objectives Materials and Methods Results Conclusion Routine coagulation screens at birth are still standard in some European neonatal intensive care units (NICUs), although interpretation of these results is complex in preterm infants. It is unclear to what extent local coagulation assay results agree with published reference ranges when using different analysers and reagents. We aimed to assess coagulation assay results on day 1 of life in very preterm infants admitted to the NICU.We included all preterm infants born below 32 weeks gestational age (GA) admitted to the Leiden University Medical Center between 2004 and 2020 in whom coagulation assays (prothrombin time [PT] and activated partial thromboplastin time [APTT]) were obtained during the first 24 h of life. Infants either diagnosed with major intraventricular haemorrhage or who received plasma transfusion before coagulation assay were excluded. We assessed coagulation assay results and compared the results between <28 weeks (extremely preterm) and 28–32 weeks (very preterm) GA groups.Coagulation assays were obtained at birth in 144 infants (144/2577; 5.5%) of whom 104 fulfilled the inclusion criteria. We found similar median PT and APTT values for extremely and very preterm infants (PT: 18.1 vs. 18.7 s [p‐value = 0.400]; APTT: 44.2 vs. 47.7 s [p‐value = 0.252], respectively).We found similar coagulation assay results at birth for extremely and very preterm infants; however, results deviated considerably from some of the published reference ranges. This may be due to differences between analysers and reagents, underlining the need for reference ranges calibrated to the equipment used per NICU. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to compare the outcomes of women who were initially managed by intrauterine balloon tamponade or uterine artery embolization because of persistent postpartum hemorrhage demanding an immediate intervention to control bleeding.Material and Methods: Propensity score-matched cohort study including women who had intrauterine balloon tamponade or uterine artery embolization as initial management strategy to control persistent postpartum hemorrhage, that is, refractory to first-line therapy combined with at least one uterotonic agent. The primary outcome measure was a composite of peripartum hysterectomy and/or maternal mortality. Secondary outcomes measures were total volume of blood loss and total number of packed red blood cells transfused.Results: Our 1:1 propensity score-matched cohort comprised of 50 women who had intrauterine balloon tamponade and 50 women who underwent uterine artery embolization at a blood loss between 1000 and 7000 mL. There was no statistically significant difference in the hysterectomy risk between the two groups (n = 6 in each group, odds ratio [OR] 1.00, 95% confidence interval [CI] .30-3.34), in total volume of blood loss (median 4500 mL, interquartile range [IQR] 3600-5400) for balloon vs 4000 mL (IQR 3250-5000) for embolization, P = 0.382) or in total units of packed red blood cells transfused (median 7 (IQR 5-10) for balloon vs 6 [IQR 4-9] for embolization, P = 0.319). Fifteen women (30%) who were initially managed by an intrauterine balloon still underwent uterine artery embolization, of whom one had an embolization-related thrombo-embolic event. Maternal mortality occurred in neither of the intervention groups.Conclusions: No difference in the risk of peripartum hysterectomy and/or maternal death was observed between women who had intrauterine balloon tamponade and women who underwent uterine artery embolization as an initial management for persistent postpartum hemorrhage. Although this study was underpowered to demonstrate equivalence, our study design provides a framework for future research in which intrauterine balloon tamponade may prove to be a suitable intervention of first choice in the management of persistent postpartum hemorrhage. [ABSTRACT FROM AUTHOR]