Association of human leucocyte antigen loci with vaccine-induced immune thrombotic thrombocytopenia: Potential role of the interaction between platelet factor 4-derived peptides and MHC-II.

No risk factors have been identified for vaccine-induced immune thrombotic thrombocytopenia (VITT) so far. The aim of this study was to identify human leucocyte antigen (HLA) alleles potentially associated with VITT susceptibility. Specific HLA class II alleles were detected with significantly higher frequency in VITT patients compared with Italian controls: DPB1*17:01, DQA1*05:01, and DRB1*11:04.

Circulating Activated Platelets in Children With Long Covid: A Case-Controlled Preliminary Observation.

We investigated if children with Long Covid (n=14) have activated platelets compared with healthy controls (n=14). Platelet activation and secretion markers were investigated by flow cytometry using MoAbs directed against P-selectin, CD63, and PAC-1 in quiescent platelets and in platelets stimulated with 10-µM adenosine diphosphate and 25-µM protease activated receptor 1-activating peptide. Circulating platelets of patients with Long Covid had significantly increased expression of the activation marker cytometry using MoAbs directed against P-selectin (P = 0.

Safety and effectiveness of oral anticoagulants in patients with atrial fibrillation and stage 4 chronic kidney disease: a real-world experience.

It is still uncertain whether direct oral anticoagulants (DOACs) perform better than vitamin K antagonists (VKAs) in subjects with non-valvular atrial fibrillation (NVAF) and advanced chronic kidney disease (CKD). The aim of the study was to compare safety and effectiveness of DOACs and VKAs in patients with NVAF and stage 4 CKD (creatinine clearance 15-29 mL/min). We searched the hospital databases of two academic centers to retrospectively identify patients with stage 4 CKD who were on treatment with DOACs or VKAs for NVAF.

Platelets and Neurodegenerative Diseases: Current Knowledge and Future Perspectives.

Platelets have a fundamental role in mediating hemostasis and thrombosis. However, more recently, a new idea is making headway, highlighting the importance of platelets as significant actors in modulating immune and inflammatory responses. In particular, platelets have an important role in the development of vascular amyloid-b-peptide(ab) deposits, known to play a relevant role in Alzheimer's disease (AD) through accumulation and deposition within the frontal cortex and hippocampus in the brain.

More early bleeds associated with high baseline direct oral anticoagulant levels in atrial fibrillation: the MAS study.

Treatment with direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) is effective and safe. However, bleeding complications still occur. Whether DOAC level measurement may further improve treatment efficacy and safety is still an open issue.

Thrombotic events associated with low baseline direct oral anticoagulant levels in atrial fibrillation: the MAS study.

Although effective and safe, treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) is still associated with thrombotic complications. Whether the measurement of DOAC levels may improve treatment efficacy is an open issue. We carried out the observational, prospective, multicenter Measure and See (MAS) study.

Association of laboratory test results with the bleeding history in patients with inherited platelet function disorders (the Bleeding Assesment Tool - LABoratory tests substudy): communication from the Platelet Physiology ISTH-SSC.

Background: In hemophilia and von Willebrand disease, the degree of alteration of laboratory assays correlates with bleeding manifestations. Few studies have assessed the predictive value for bleeding of laboratory assays in patients with inherited platelet function disorders (IPFDs).

Objectives: To assess whether there is an association between platelet function assay results and bleeding history, as evaluated by the International Society on Thrombosis and Haemostasis (ISTH) bleeding assessment tool (BAT).

Cell Surface Platelet Tissue Factor Expression: Regulation by P2Y and Link to Residual Platelet Reactivity.

Background: ADP-induced platelet activation leads to cell surface expression of several proteins, including TF (tissue factor). The role of ADP receptors in platelet TF modulation is still unknown. We aimed to assess the (1) involvement of P2Y and P2Y receptors in ADP-induced TF exposure; (2) modulation of TF-platelets in anti-P2Y-treated patients with coronary artery disease.

Extended coagulation profile of children with Long Covid: a prospective study.

Emerging data suggests that endotheliopathy changes can be associated with post covid condition (PCC) in adults. Research on the matter in children is lacking. We analyzed an extended coagulation profile including biomarkers of endothelial damage in children with PCC and compared it with a control group of children that fully recovered post- SARS-CoV-2 infection.

Evaluation of Novel Guanidino-Containing Isonipecotamide Inhibitors of Blood Coagulation Factors against SARS-CoV-2 Virus Infection.

Coagulation factor Xa (fXa) and thrombin (thr) are widely expressed in pulmonary tissues, where they may catalyze, together with the transmembrane serine protease 2 (TMPRSS2), the coronaviruses spike protein (SP) cleavage and activation, thus enhancing the SP binding to ACE2 and cell infection. In this study, we evaluate in vitro the ability of approved (i.e.

Autoimmune disorders of platelet function: systematic review of cases of acquired Glanzmann thrombasthenia and acquired delta storage pool disease.

Acquired platelet function disorders (PFD) are rare bleeding diseases that should be suspected in all patients with unexplained mucocutaneous bleedings of recent onset, with no previous history of haemorrhages, and with normal coagulation test and platelet count. Drug-induced platelet function bleeding disorders are the most frequent PFDs and can easily be identified on the basis of recent administration of platelet-inhibiting drugs. Apart from these, the most challenging acquired PFDs are those caused by autoimmune mechanisms.

Does chronic oral anticoagulation reduce in-hospital mortality among COVID-19 older patients?

Background: Patients hospitalized with COVID-19 experienced an increased risk of venous thromboembolism.

Aims: To evaluate the effect of chronic oral anticoagulation (OAC) therapy, both with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs), on prognosis of COVID-19 older patients.

Methods: Single-center prospective study conducted in the Emergency Department (ED) of a teaching hospital, referral center for COVID-19 in central Italy.

Direct oral anticoagulants and therapeutic adherence: do not let your guard down.

Background: Direct oral anticoagulants (DOAC) and vitamin K antagonist drugs (VKA) are recommended for stroke prevention in atrial fibrillation and for treatment of venous thromboembolism. Undoubtedly, DOAC have contributed to improve quality of life of these patients, but unfortunately, available 'real world' data show a very high variable compliance to DOAC.

Aims And Objectives: to evaluate predictors that adversely affect therapeutic adherence in patients naive to DOAC.

The ISTH bleeding assessment tool as predictor of bleeding events in inherited platelet disorders: Communication from the ISTH SSC Subcommittee on Platelet Physiology.

Background: The ISTH Bleeding Assessment Tool (ISTH-BAT) has been validated for clinical screening of suspected von Willebrand disease (VWD) and for bleeding prediction. Recently it has been validated for subjects with inherited platelet disorders (IPD) (BAT-VAL study).

Objectives: To determine whether the ISTH-BAT bleeding score (BS) predicts subsequent bleeding events requiring treatment in IPD patients.

Heparin induced thrombocytopenia: position paper from the Italian Society on Thrombosis and Haemostasis (SISET).

Heparin induced thrombocytopenia (HIT) is a rare immune mediated adverse drug reaction occurring after exposure to heparin. It is a serious and potentially fatal condition, which may be associated with the development of arterial or venous thrombotic events. Although known for many years, HIT is still often misdiagnosed.

Nonalcoholic fatty liver disease (NAFLD) severity is associated to a nonhemostatic contribution and proinflammatory phenotype of platelets.

Nonalcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease and ranges from simple steatosis to nonalcoholic steatohepatitis. Recently, a platelet role in NAFLD pathogenesis and progression has been reported in mouse models and in patients. We investigated whether platelets are involved in liver and systemic inflammation processes in NAFLD.

Noncanonical type 2B von Willebrand disease associated with mutations in the VWF D'D3 and D4 domains.

We observed a 55-year-old Italian man who presented with mucosal and cutaneous bleeding. Results of his blood analysis showed low levels of von Willebrand factor (VWF) antigen and VWF activity (both VWF ristocetin cofactor and VWF collagen binding), mild thrombocytopenia, increased ristocetin-induced platelet aggregation, and a deficiency of high-molecular-weight multimers, all typical phenotypic hallmarks of type 2B von Willebrand disease (VWD). The analysis of the VWF gene sequence revealed heterozygous in cis mutations: (1) c.

Novel manifestations of immune dysregulation and granule defects in gray platelet syndrome.

Gray platelet syndrome (GPS) is a rare recessive disorder caused by biallelic variants in NBEAL2 and characterized by bleeding symptoms, the absence of platelet α-granules, splenomegaly, and bone marrow (BM) fibrosis. Due to the rarity of GPS, it has been difficult to fully understand the pathogenic processes that lead to these clinical sequelae. To discern the spectrum of pathologic features, we performed a detailed clinical genotypic and phenotypic study of 47 patients with GPS and identified 32 new etiologic variants in NBEAL2.

Hemophilia A and von Willebrand deficiency: therapeutic implications.

: Hemophilia A is an X-linked bleeding disorder caused by a deficiency of factor VIII. Depending on the factor VIII activity in patient's plasma, we can have three different forms of hemophilia A: mild (5-40 IU/dl), moderate (1-5 IU/dl) and severe (<1 IU/dl). The most common symptoms include recurrent bleeding episodes of soft tissues and joints.

Data on the application of early coagulation support protocol in the management of major trauma patients.

This article provides additional data on the application of early coagulation support protocol in the management of major trauma patients. Data come from a retrospective analysis reported in the article "Early coagulation support protocol: a valid approach in real-life management of major trauma patients. Results from two Italian centres" [1].