Genetic analysis of a pedigree with hereditary coagulation factor XI deficiency To identify potential mutations of F11 gene in a family with hereditary coagulation factor XI (FXI) deficiency and explore the molecular pathogenesis. The FXI activity and FXI antigen were tested with clotting assay and ELISA, respectively. The FXI gene was amplified by PCR with direct sequencing. Three bioinformatics softwares were used to study the conservatism and harm of the mutation. The proband had a prolonged activated partial thromboplastin time (84.2 s), whose FXI activity and FXI antigen were 3.0 and 8.6%. Gene sequencing revealed that the propositus carried a heterozygous nonsense mutation c.738G>A in exon 7 resulting in a p.Trp228stop and deletions mutation c.1325delT in exon 12 resulting in a p.Leu424Cys. Two bioinformatics softwares all were indicated the mutation had affected the function of the protein. The c.738G>A heterozygous nonsense variation and the c.1325delT heterozygous deletion variation are associated with decreased FXI levels in this family, which is the first reported in the world. Correspondence to Lihong Yang, Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325015, China. Tel: +86 57788069594; e-mail: YLH91@163.com Received 10 April, 2019 Revised 31 July, 2019 Accepted 21 August, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Argatroban to achieve therapeutic anticoagulation in two patients with acute thrombosis and heparin resistance We present two cases where argatroban was successfully used in patients with acute thrombosis requiring anticoagulant treatment where heparin resistance with unfractionated heparin had been encountered. The first case was a woman with abdominal arterial thrombosis, of unknown cause, treated with therapeutic low molecular weight heparin that developed pulmonary embolism despite therapeutic anticoagulation (and had evidence of heparin resistance on anti-Xa monitoring). The second patient had provoked abdominal arterial thrombosis from sepsis and could not attain therapeutic anticoagulation with intravenous unfractionated heparin. In both cases therapeutic anticoagulation was achieved with the use of argatroban, as a temporizing measure to treat the acute thrombotic event. Conventionally, argatroban has been described for use in heparin-induced thrombocytopenia. The use of argatroban is briefly discussed, especially in the context of heparin resistance where anticoagulation can be challenging. Further research using argatroban in heparin resistant patients could be justified. Correspondence to Will Thomas, Department of Haematology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK Tel: +44 01223 257 039; fax: +44 01223 216 891; e-mail: w.thomas1@nhs.net Received 4 June, 2019 Revised 3 September, 2019 Accepted 5 September, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Rare bleeding disorders and advances in gene therapy Rare bleeding disorders usually begin in childhood and manifest as varying degrees of bleeding, which can be life-threatening in severe cases. With the development of gene editing technology, it is expected that hereditary coagulation factor disorders will someday be fundamentally cured by gene therapy. On account of their rarity, comprehension of these diseases is essential for the application of new treatment strategies. We have compiled the features of some newly discovered mutations of prothrombin, factor VII, and factor X in recent years. In addition, this review introduces the advances and obstacles in gene therapy. Correspondence to Zhigang Yang, Department of Hematology and Rheumatology, Affiliated Zhanjiang Central People's Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China. Tel: +86 759-3152128; e-mail: yangzg@gdmu.edu.cn Received 24 June, 2019 Revised 8 August, 2019 Accepted 21 August, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Hemophilia A in Afghanistan, the first report Hemophilia A is the most severe congenital bleeding disorder with estimated incidence of 1 per 5000 live male birth. Afghanistan located within south Asia and central Asia have a considerable number of patients with bleeding disorders that is accompanied by low government resources and limited diagnostic facilities. This study aimed to evaluate different aspects of hemophilia A in Afghanistan for the first time. This study was conducted on 167 patients with hemophilia A who were referred to hemophilia center of Kabul city. The diagnosis of the disease was performed based on standard questionnaire, evaluation of clinical manifestations and family history as well as laboratory assays. Diagnose of hemophilia A was confirmed by coagulation factor VIII (C: FVIII) assay. The mean age and mean age at diagnosis were 13.7 ± 2.4 and 1.4 ± 0.7 years, respectively. The mean FVIII level was 0.7 IU/dl. The most common clinical manifestation was hemarthrosis, which was detected in 80% of patients. According to geographical distribution, 42% of patients are residents of Kabul Province. About 41% of patients were Tajik, whereas 37% were Pashtun. In Afghanistan, as a country with low number of diagnosed patients with hemophilia A because of limited diagnostic and treatment facilities, high amount of investments are required in order to improve the quality and quantity of hemophilic patients. Correspondence to Akbar Dorgalaleh, Department of Hematology and Blood Transfusion, School of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran. E-mail: dorgalaleha@gmail.com Received 10 September, 2018 Revised 10 July, 2019 Accepted 21 August, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

A bacterial metabolite, trimethylamine N-oxide, disrupts the hemostasis balance in human primary endothelial cells but no coagulopathy in mice The gut microbial metabolite, trimethylamine N-oxide (TMAO), was previously reported to induce platelet hypersensitivity, which leads to thrombotic risk. However, the molecular mechanism underlying the effects of TMAO on endothelial cells (EC), which is the primary vessel wall contact with the lumen, remains unclear. Here, we investigated the impact of TMAO on procoagulant activity (PCA) in EC and mice, for a possible link between microbiota and coagulation. To test the PCA of TMAO in EC, we performed one-stage clotting assays and converted into PCA. Antitissue factor (TF) antibody was used to test the TF role in PCA. Quantitative PCR was performed to measure the TF, thrombomodulin, IL-6, TF pathway inhibitor and IL-1b expressions at mRNA levels. To test the PCA and thrombotic risk by TMAO in mice, we challenged the mice with TMAO (8 mg/kg; 3 h) and measured the thrombin-anti-thrombin complex (TAT) and D-dimer levels as well as ferric chloride (FeCl3)-induced carotid artery thrombosis model. TMAO-induced TF expression in EC at mRNA and protein levels, dose-dependently. TF blocking experiment confirmed that the increased PCA by TMAO is TF-dependent. Also, mitogen-activated protein kinase pathway inhibitors abolished TMAO-induced TF expression. However, TMAO challenged mice failed to develop systemic activation of coagulation (TAT and D-dimer), as well as a FeCl3-induced carotid arterial thrombosis model. Our results indicated that TMAO triggered TF-dependent PCA via activation of nuclear factor-κB and downregulated thrombomodulin expression in human EC, but failed to develop systemic activation of coagulation in mice. Correspondence to Dr Saravanan Subramaniam, PhD, Blood Research Institute, BloodCenter of Wisconsin: Part of Versiti, Milwaukee, Wisconsin, USA. E-mail: SSubramaniam1@versiti.org Received 8 March, 2019 Revised 3 July, 2019 Accepted 9 July, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Plasma phenotypes of protein S Lys196Glu and protein C Lys193del variants prevalent among young Japanese women Protein S Tokushima (p.Lys196Glu) and two protein C gene variants (p.Arg189Trp, p.Lys193del) are hereditary thrombophilia in Japanese and Chinese populations, respectively; however, their diagnosis by plasma analyses is difficult because of the type II deficiency phenotype. Three gene variant genotypes were examined in young Japanese women (n = 231). Plasma total protein S activity and total protein S antigen levels were measured using a total protein S assay system, protein C and protein S activities by clot-based methods, and protein C and free protein S antigen levels by latex agglutination methods. protein S Tokushima (p.Lys196Glu) and protein C p.Lys193del variants were prevalent among participants with allele frequencies of 1.08 and 0.86%, respectively, whereas any carrier of protein C p.Arg189Trp variant was not identified. The plasma phenotype of the type II deficiency of protein S Tokushima heterozygotes was demonstrated by decreased total protein S activity with a normal total protein S antigen level; however, the protein C activities of protein C p.Lys193del heterozygotes were within reference intervals, whereas their protein C antigen levels were elevated. We compared the diagnostic accuracy of the total protein S activity/total protein S antigen ratio for identifying protein S Tokushima heterozygotes with that of the clot-based protein S activity/free protein S antigen ratio and found that sensitivity and specificity of 100% each was only achieved by the former. Protein S Tokushima and protein C p.Lys193del are prevalent among young Japanese women, and a plasma analysis using the total protein S assay system is more accurate than the clot-based protein S activity/free protein S antigen ratio for diagnosing protein S Tokushima carriers. Correspondence to Hiroko Tsuda, MD, PhD, Graduate School of Health and Nutrition Sciences, Nakamura Gakuen University, 5-7-1, Befu, Johnan-ku, Fukuoka 814-0198, Japan E-mail: tsuda@nakamura-u.ac.jp Received 26 April, 2019 Revised 5 August, 2019 Accepted 21 August, 2019 This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Severe acquired platelet dysfunction because of primary myelofibrosis with full functional and morphological recovery after allogeneic hematopoietic cell transplantation Primary myelofibrosis (PMF) is a clonal hematopoietic stem cell disorder characterized by fibrosis of the marrow cavity, marked megakaryocyte atypia and progressive cytopenias. Although thrombosis predominates, bleeding is the primary manifestation in up to 20% of patients and may be life-threatening. In this report, we document restoration of megakaryocyte and platelet structure and function in PMF after allogeneic hematopoietic cell transplantation (HCT). A 59-year-old man presented with recurrent episodes of postoperative bleeding preceding a diagnosis of primary myelofibrosis (PMF). Platelet aggregation and secretion studies showed abnormal responses to all agonists tested (epinephrine, ADP, arachidonic acid, U46619, collagen, ristocetin) despite the presence of thrombocytosis. After an allogeneic HCT, platelet morphology and function studies were all normal. The pathophysiology of platelet dysfunction in myeloid neoplasia is not well understood but, as highlighted in our report, restoration of platelet function by HCT supports a clonal process involving an early hematopoietic progenitor cell. Correspondence to Yevgeniy A. Linnik, MD, Department of Pathology & Laboratory Medicine, Dartmouth Hitchcock Medical Center and Norris Cotton Cancer Center, One Medical Center Drive, Lebanon, NH 03756, USA Tel: +1 603 650 8523; fax: +1 603 650 7214; e-mail: Yevgeniy.Linnik@vumc.org Received 25 March, 2019 Accepted 14 August, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Dabigatran for catastrophic antiphospholipid syndrome Vitamin K antagonists (VKA) remain the treatment of choice for catastrophic antiphosphilipid syndrome (CAPS). However, when VKAs do not work for a specific patient, direct oral anticoagulants (DOAC) may be a valid therapeutic alternative. We present a patient with a psychiatric disorder and CAPS who was noncompliant to VKA and low-molecular-weight heparin. He was started on dabigatran and has remained thrombosis-free for 8 years. Due to CAPS he has developed progressive renal failure but dabigatran levels were within the expected range. In conclusion, this case report provides anecdotic evidence that dabigatran may be of use in patients with high-risk APS in whom VKA are not an option. Correspondence to Marc Sorigue, MD, Hematology Laboratory-Division of Thrombosis and Hemostasis, ICO-Badalona, Hospital Germans Trias i Pujol, Institut de Recerca Josep Carreras, Universitat Autònoma de Barcelona, Badalona, Ctra. Canyet s/n 08916 Badalona, Spain Tel: +34 93 487 88 68; fax: +34 93 497 87 94; e-mail: msorigue@iconcologia.net Received 25 July, 2018 Revised 6 June, 2019 Accepted 9 July, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

When age is truly only a number: late diagnosis of von Willebrand disease type 2B in a 61-year-old woman von Willebrand disease (VWD) type 2B is a rare bleeding disorder, presenting with moderate-to-severe lifelong bleeding. We present the case of a 61-year-old woman who was misdiagnosed as immune thrombocytopenic purpura during her three pregnancies resulting in a delayed diagnosis of VWD type 2B. This genetically confirmed diagnosis resulted in testing and the establishment of the diagnosis in her otherwise asymptomatic adult son as well. VWD may not be diagnosed till beyond mid adulthood in women with thrombocytopenia previously attributed to pregnancy and should be considered as a differential in female patients developing thrombocytopenia less than 100 × 103/μl with an increased bleeding assessment tool score. Correspondence to Peter A. Kouides, MD, Mary M. Gooley Hemophilia Treatment Center, 1415 Portland Ave, Suite 500, Rochester NY 14621, USA Tel: +1 585 922 4020; fax: +1 585 563 1832; e-mail: peter.kouides@rochesterregional.org Received 10 June, 2019 Revised 5 August, 2019 Accepted 6 August, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.

Evaluation of nonneutralizing antibodies against factor VIII in severe haemophilia A patients from India Haemophilia A is treated by replacement therapy with factor VIII (FVIII) concentrate. This strategy of treatment is ineffective in some patients due to the development of neutralizing antibodies (NNAs) against FVIII. The inhibitors have been identified to act against the functional domains of FVIII. The presence of NNAs against FVIII has also been identified. There is limited data on the prevalence and significance of NNA in haemophilia. To identify the presence of NNA in severe haemophilia A in our population, patients who were recruited from community-based camps were evaluated for FVIII activity. The patient's samples were further analysed for inhibitor activity with Nijmegen-Bethesda Assay and for NNAs using an in-house ELISA. 312 severe haemophilia patients were analysed for inhibitors and NNA. In-house ELISA picked up antibodies in 56 patients (17.9%). Of these 42 (13.7%) had inhibitory antibodies and in 14 patients (4.5%) there was no evidence of FVIII inhibitory activity. A substantial number of patients with severe haemophilia A have NNA. Continuous long-term follow-up is required in this cohort to evaluate the significance of this observation. Correspondence to Sukesh C. Nair, Department of Transfusion Medicine and Immunohaematology, Christian Medical College, Vellore 632004, Tamil Nadu, India. Tel: +91 416 2283431; e-mail: scnair@cmcvellore.ac.in Received 12 March, 2019 Revised 3 June, 2019 Accepted 9 July, 2019 Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.