Detection of anti-cardiolipin and anti-β2glycoprotein I antibodies differs between platforms without influence on association with clinical symptoms

Background: The anti-phospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy morbidity with persistent presence of anti-phospholipid antibodies (aPL). Laboratory criteria include aPL detection by coagulation tests for lupus anticoagulant (LAC) or solid phase assays measuring anti-beta 2 glycoprotein I (a beta 2GPI) or anticardiolipin (aCL) immunoglobulin (Ig) G/IgM antibodies. External quality control programs illustrate that commercially available aPL assays produce variable results. Objective: We aimed to investigate the agreement and diagnostic accuracy of solid phase assays. Materials and Methods: In thismulti-centre study, 1,168 patient samples were tested on one site for aCL and a beta 2GPI IgG/IgM antibodies by four solid phase test systems. Samples included APS patients, controls and monoclonal antibodies (MoAB) against different epitopes of beta 2GPI. LAC was determined by the local centre. Results: aCL IgM assays resulted in the most discrepancies (60%), while aCL IgG and a beta 2GPI IgM assays resulted in lower discrepancies (36%), suggesting better agreement. Discrepant samples displayed lower median aPL titers. Dependent on the solid phase test system, odds ratios (ORs) for thrombosis and pregnancy morbidity ranged from 1.98 to 2.56 and 3.42 to 4.78, respectively. Three platforms showed lower sensitivity for MoAB directed against the glycine (Gly) 40-arginine (Arg) 43 epitope of domain I of beta 2GPI. Conclusion: Poor agreement was observed between different commercially available aCL and a beta 2GPI IgG/IgM assays, hampering uniformity in the identification of aPL-positive patients. Clinical association was globally concordant between solid phase test systems considering results of the four aPL together. An assay sensitive in detecting the MoAB against Gly40-Arg43 of domain I of beta 2GPI reached the highest OR for thrombosis

Bleeding phenotype and diagnostic characterization of patients with congenital platelet defects

Phenotypic characterization of congenital platelet defects (CPDs) could help physicians recognize CPD subtypes and can inform on prognostic implications. We report the analyses of the bleeding phenotype and diagnostic characteristics of a large cohort of adult patients with a confirmed CPD. A total of 96 patients were analyzed and they were classified as Glanzmann thrombasthenia, Bernard-Soulier syndrome, dense granule deficiency, defects in the ADP or thromboxane A2 (TxA2) pathway, isolated thrombocytopenia or complex abnormalities. The median ISTH-BAT bleeding score was nine (IQR 5-13). Heavy menstrual bleeding (HMB) (80%), post-partum hemorrhage (74%), post-operative bleeds (64%) and post-dental extraction bleeds (57%) occurred most frequently. Rare bleeding symptoms were bleeds from the urinary tract (4%) and central nervous system (CNS) bleeds (2%). Domains with a large proportion of severe bleeds were CNS bleeding, HMB and post-dental extraction bleeding. Glanzmann thrombasthenia and female sex were associated with a more severe bleeding phenotype

Congenital platelet disorders and health status-related quality of life

Background: Patients with congenital blood platelet disorders (CPDs) demonstrate a predominantly mucocutaneous bleeding tendency. Repeated bleeds throughout life can have a significant impact on health status-related quality of life (HR-QoL), but few studies have investigated HR-QoL in patients with CPDs. Objectives: To determine HR-QoL in patients with suspected or confirmed CPDs as compared with the general Dutch population and to assess the association between bleeding phenotype and HR-QoL. Methods: Data were derived from the Thrombocytopathy in the Netherlands (TiN) study, a cross-sectional study of individuals suspected for a congenital platelet defect. TiN patients with an increased ISTH Bleeding Assessment Tool (ISTH-BAT) score (>3 in men and > 5 in women) were included for analysis. HR-QoL was assessed with the Short Form (SF)-36 survey. Bleeding symptoms were evaluated with the ISTH-BAT, resulting in a bleeding score. Results: One hundred fifty-six patients were analyzed, of whom 126 (81%) were women. Sixty-two patients (40%) had a confirmed CPD. Compared to the general Dutch population, patients with a suspected or confirmed CPD reported decreased physical functioning, limitations in daily activities due to physical health problems, limitations in social activities, decreased energy levels and fatigue, pain, and lower general health status. HR-QoL was not correlated with the ISTH-BAT score and was similar in patients with a confirmed CPD and those in whom a CPD could not be diagnosed. Conclusion: A bleeding tendency in patients with a suspected or confirmed CPD significantly impacts HR-QoL, independent of a confirmed explanatory diagnosis

DosEmi study protocol: a phase IV, multicentre, open-label, crossover study to evaluate non-inferiority of pharmacokinetic-guided reduced dosing compared with conventional dosing of emicizumab in people with haemophilia A

INTRODUCTION: Emicizumab effectively prevents bleeding in people with haemophilia A (PwHA), but is a burden for national healthcare budgets and consequently may limit access. According to the drug label, dosing of emicizumab is based on body weight with fixed intervals of 7, 14 or 28 days, which leads to mean plasma concentrations of 55 µg/mL (SD 15 µg/mL). However, a moderate variability of concentrations and a minimal effective concentration of 30 µg/mL have been suggested in studies. Therefore, a dose of emicizumab that targets a trough concentration of 30 µg/mL is hypothesised to be equally effective as conventional dosing in the prevention of bleeding. METHODS AND ANALYSIS: We designed a phase IV, multicentre, open-label, crossover study to evaluate non-inferiority of bleed control of ≥6 months on conventional dosing in comparison to ≥6 months on dose intervention. This dose intervention consists of reducing the dose of emicizumab to target a trough concentrations of 30 µg/mL using individual pharmacokinetic (PK) parameters. Ninety-five PwHA aged >1 years who received conventional dosing of emicizumab for ≥12 months with good bleeding control during the last 6 months will be recruited from all Dutch haemophilia treatment centres. The study is powered to detect a clinically relevant decrease (risk difference) of 15% in the proportion of patients without treated bleeds during follow-up. Secondary endpoints are spontaneous joint or muscle bleeds, and annualised treated bleeding rates (using negative binomial regression). Cost-effectivity between conventional dosing and individualised PK-guided dosing of emicizumab will be compared. ETHICS AND DISSEMINATION: The DosEmi study was approved by the Medical Ethics Review Committee NedMec of the University Medical Center of Utrecht, The Netherlands. Study results will be communicated through publications in international scientific journals and presentations at (inter)national conferences. TRIAL REGISTRATION NUMBER: EUCTR2021-004039-10-NL at https://trialsearch.who.int. PROTOCOL VERSION: V.4.1 on 28 October 2022 (DosEmi protocol_V4.1; NL81112.041.22)

Особенности фразеологического варианта в английском, немецком и шведском языках

Объект исследования – фразеология английского, немецкого и шведского языков, предмет изучения – характер вариантности ФЕ, цель исследования – выявление изоморфизма структурной организации германской фразеологии и вариантности посредством выполнения задач сопоставительного анализа, позволяющего выделить различные типы вариантов ФЕ в каждом из рассматриваемых германских языков

The limitation of genetic testing in diagnosing patients suspected for congenital platelet defects

Thrombosis and Hemostasi

Flow cytometric mepacrine fluorescence can be used for the exclusion of platelet dense granule deficiency

Background: δ-storage pool disease (δ-SPD) is a bleeding disorder characterized by a reduced number of platelet-dense granules. The diagnosis of δ-SPD depends on the measurement of platelet ADP content, but this test is time consuming and requires a relatively large blood volume. Flow cytometric analysis of platelet mepacrine uptake is a potential alternative, but this approach lacks validation, which precludes its use in a diagnostic setting. Objectives: To evaluate the performance of platelet mepacrine uptake as a diagnostic test for δ-SPD. Patients/Methods: Mepacrine fluorescence was determined with flow cytometry before and after platelet activation in 156 patients with a suspected platelet function disorder and compared with platelet ADP content as a reference test. Performance was analyzed with a receiver operating characteristic (ROC) curve. Results: Eleven of 156 patients had δ-SPD based on platelet ADP content. Mepacrine fluorescence was inferior to platelet ADP content in identifying patients with δ-SPD, but both mepacrine uptake (area under the ROC curve [AUC] 0.87) and mepacrine release after platelet activation (AUC 0.80) had good discriminative ability. In our tertiary reference center, mepacrine uptake showed high negative predicitive value (97%) with low positive predictive value (35%). Combined with a negative likelihood ratio of 0.1, these data indicate that mepacrine uptake can be used to exclude δ-SPD in patients with a bleeding tendency. Conclusion: Mepacrine fluorescence can be used as a screening tool to exclude δ-SPD in a large number of patients with a suspected platelet function disorder

Quantification of emicizumab by mass spectrometry in plasma of people with hemophilia A: A method validation study

Background: Emicizumab is a new treatment option for people with hemophilia A. Emicizumab was approved with a body-weight-based dosage regimen, without laboratory monitoring requirements. Guidelines, however, recommend measuring emicizumab concentrations when the presence of antidrug antibodies is suspected. Furthermore, drug monitoring can be useful in clinical decision making, in adherence checking, and for research purposes. Therefore, we developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for quantifying emicizumab. We performed a validation study on this LC-MS/MS method quantifying emicizumab in the plasma of people with hemophilia A. Methods: Sample preparation for LC-MS/MS analysis included ammonium sulfate protein precipitation and trypsin digestion. A signature peptide of emicizumab and a matching stable isotope-labeled internal standard were used to quantify emicizumab by LC-MS/MS analysis. Validation was performed in accordance with the “Guideline on Bioanalytical Method Validation” of the European Medicines Agency (EMA). The LC-MS/MS method was cross validated against a modified and calibrated (r2 Diagnostics) one-stage clotting assay (OSA). Conclusions: The LC-MS/MS method demonstrated linearity over a wide range of emicizumab concentrations, far exceeding the concentrations observed in people with hemophilia A. Precision and accuracy were excellent, and all other validation parameters were also within the acceptance EMA criteria. Cross validation showed that the LC-MS/MS method and the OSA-based method can be used interchangeably for drug monitoring of emicizumab without the application of a correction factor

SYMPHONY consortium:Orchestrating personalized treatment for patients with bleeding disorders

Background Treatment choices for individual patients with an inborn bleeding disorder are increasingly challenging due to increasing options and rising costs for society. We have initiated an integrated interdisciplinary national research program. Objectives The SYMPHONY consortium strives to orchestrate personalized treatment in patients with an inborn bleeding disorder, by unraveling the mechanisms behind interindividual variations of bleeding phenotype. Patients The SYMPHONY consortium will investigate patients with an inborn bleeding disorder, both diagnosed and not yet diagnosed. Results Research questions are categorized under the themes: (1) diagnosis, (2) treatment, and (3) fundamental research, and consist of work packages addressing specific domains. Importantly, collaborations between patients and talented researchers from different areas of expertise promise to augment the impact of the SYMPHONY consortium, leading to unique interactions and intellectual property. Conclusions SYMPHONY will perform research on all aspects of care, treatment individualization in patients with inborn bleeding disorders, as well as diagnostic innovations and results of molecular genetics and cellular model technology with regard to the hemostatic process. We believe that these research investments will lead to health-care innovations with long-term clinical and societal impact. This consortium has been made possible by a governmental, competitive grant from the Netherlands Organization for Scientific Research (NWO) within the framework of the NWA-ORC Call grant agreement NWA.1160.18.038