Five new F10 variants in hereditary factor x deficiency detected by high-throughput sequencing.

INTRODUCTION: Factor X deficiency is a rare inherited bleeding disorder. To date, 181 variants are reported in the recently updated F10-gene variant database. AIM: This study aimed to describe new F10 variants. METHOD: The F10 gene was analysed in 16 consecutive families with FX deficiency by a targeted high-throughput sequencing approach, including F10, F9, F8 genes, and 78 genes dedicated to haematological malignancies. RESULTS: We identified 19 variants (17 missense, one nonsense and one frameshift) and two copy number variations. Two patients presenting a combined FVII-FX deficiency showed a loss of one F10 gene copy (del13q34) associated with a missense variant on the remaining allele, leading to a FX:C significantly lower than the FVII:C level and explaining their unusual bleeding history. We reported five novel variants. Three missense variants (p.Glu22Val affecting the signal peptide cleavage site, p.Cys342Tyr removing the disulphide bond between the FX heavy and light chains, and p.Val385Met located in FX peptidase S1 domain) were detected at compound heterozygosis status in three patients with severe bleeding symptoms and FX:C level below 10 IU/dL. Two truncating variants p.Tyr279* and p.Thr434Aspfs*13 leading to an altered FX protein were found at heterozygous state in two patients with mild bleeding history. CONCLUSION: This study showed the feasibility and the interest of high-throughput sequencing approach for rare bleeding disorders, enabling the report of F10 gene screening in a 3-weeks delay, suitable for clinical use. The description of five new variants may contribute to a better understanding of the phenotype-genotype correlation in FX deficiency.

Identifying high-risk profile in primary antiphospholipid syndrome through cluster analysis: French multicentric cohort study.

INTRODUCTION: Antiphospholipid syndrome (APS) is an autoimmune disease characterised by thrombosis (arterial, venous or small vessel) or obstetrical events and persistent antiphospholipid antibodies (aPL), according to the Sydney classification criteria. Many studies have performed cluster analyses among patients with primary APS and associated autoimmune disease, but none has focused solely on primary APS. We aimed to perform a cluster analysis among patients with primary APS and asymptomatic aPL carriers without any autoimmune disease, to assess prognostic value. METHODS: In this multicentre French cohort study, we included all patients with persistent APS antibodies (Sydney criteria) measured between January 2012 and January 2019. We excluded all patients with systemic lupus erythematosus or other systemic autoimmune diseases. We performed hierarchical cluster analysis on the factor analysis of mixed data coordinates results with baseline patient characteristics to generate clusters. RESULTS: We identified four clusters: cluster 1, comprising 'asymptomatic aPL carriers', with low risk of events during follow-up; cluster 2, the 'male thrombotic phenotype', with older patients and more venous thromboembolic events; cluster 3, the 'female obstetrical phenotype', with obstetrical and thrombotic events; and cluster 4, 'high-risk APS', which included younger patients with more frequent triple positivity, antinuclear antibodies, non-criteria manifestations and arterial events. Regarding survival analyses, asymptomatic aPL carriers relapsed less frequently than the others, but no other differences in terms of relapse rates or deaths were found between clusters. CONCLUSIONS: We identified four clusters among patients with primary APS, one of which was 'high-risk APS'. Clustering-based treatment strategies should be explored in future prospective studies.

A review of latest clinical practice guidelines for the management of cancer-associated thrombosis.

The management of cancer-associated thrombosis (CAT) poses unique challenges to healthcare professionals. While low-molecular weight heparins (LMWHs) have long been the gold standard for both the primary and secondary prevention of CAT, results from large randomized controlled trials assessing the benefit of direct oral anticoagulants (DOACs) in both settings have resulted in some paradigm shifts. Herein, we review and compare recommendations from the latest authoritative clinical practice guidelines (CPGs) for the management of CAT and summarize the most recent evidence on available treatment options. A rigorous methodology was used to select high quality CPGs and compare the recommendations across CPGs. Only CPGs focusing on the management of CAT developed by a multidisciplinary international working group and issued or endorsed by national or international scientific societies, or government organizations were eligible for inclusion. The quality of selected CPGs was assessed using the Appraisal of Guidelines, Research, and Evaluation II (AGREE II) tool. Four CPGs met the inclusion criteria, including the International Initiative on Thrombosis and Cancer (ITAC), the American Society of Clinical Oncology (ASCO), the American Society of Hematology (ASH), and the National Comprehensive Cancer Network (NCCN).

The Ottawa Score Performs Poorly to Identify Cancer Patients at High Risk of Recurrent Venous Thromboembolism: Insights from the TROPIQUE Study and Updated Meta-Analysis.

The Ottawa score (OS) for predicting the risk of recurrent venous thromboembolism (VTE) in cancer patients with VTE may help to guide anticoagulant treatment decisions that will optimize benefit-risk ratios. However, data on its reliability are conflicting. We applied the OS to all cancer patients with VTE enrolled in the prospective multicenter TROPIQUE study who received low-molecular-weight heparin over a 6-month period. Of 409 patients, 171 (41.8%) had a high-risk OS. The 6-month cumulative incidence of recurrent VTE was 7.8% (95%CI 4.2-14.8) in the high-risk OS group versus 4.8% (95%CI 2.6-8.9) in the low-risk OS group (SHR 1.47; 95%CI 0.24-8.55). The Area Under the Receiver Operating Characteristic curve (AUROC) of the OS in identifying patients who developed recurrent VTE was 0.53 (95%CI 0.38-0.65), and its accuracy was 57.9%. Among individual variables included in the OS, only prior VTE was significantly associated with the 6-month risk of recurrent VTE (SHR 4.39; 95% CI 1.13-17.04). When pooling data from all studies evaluating this score for predicting VTE recurrence in cancer patients (7 studies, 3413 patients), the OS estimated pooled AUROC was 0.59 (95%CI 0.56-0.62), and its accuracy was 55.7%. The present findings do not support the use of the OS to assess the risk of recurrent VTE in cancer patients.