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Makoto Saito,1 Minoru Kanaya,1 Koh Izumiyama,1 Akio Mori,1 Tatsuro Irie,1 Masanori Tanaka,1 Masanobu Morioka,1 Masahiro Ieko2 1Department of Internal Medicine and Hematology, Aiiku Hospital, Japan; 2Department of Internal Medicine, Health Sciences University of Hokkaido, Japan Abstract: Recombinant activated factor VII (rFVIIa) is the bypassing agent used in the first-line hemostatic therapy for acquired hemophilia A (AHA); however, the occurrence of thrombotic complications in rFVIIa-treated AHA patients was recently reported to be 2.9–6.5%. Therefore, the investigation of the proper administration of rFVIIa for AHA is needed. In the present study, we retrospectively investigated the clinical features of AHA with regards to the use of rFVIIa (presence or absence of use and total amount) in 7 AHA patients encountered in our department for 7 years between January 2008 and December 2014. Ages were 63–89 years old (median: 79 years old), and there were 5 male and 2 female patients. The coexistence of cardiovascular risk factors and arteriosclerotic diseases, such as hypertension, diabetes mellitus, and cerebral infarction were present in 6 patients. Anemia progressed to less than 7 g/dL of hemoglobin and required red blood cell transfusion in 5 patients, showing “severe” hemorrhage. Factor VIII inhibitors were removed by immunological treatments in 6 patients. As a hemostatic therapy, rFVIIa was used in 4 patients. rFVIIa was not administered or was administered at a very low dose (20 mg) to 3 and 1 patient, respectively, and bleeding stopped as inhibitor titers decreased and disappeared in these patients. Inhibitors did not disappear in 1 patient and the control of hemostasis became poor and was accompanied by intestinal hemorrhage. Although a large amount of rFVIIa (265 mg in total) was administered, the patient bled to death. Therefore, bleeding may be stopped without the administration of rFVIIa in some AHA cases, while the dose of rFVIIa is not necessarily related to hemostatic effects in other cases. Since the main aim of AHA treatments is the removal of inhibitors, caution is needed to ensure that more than the necessary amount of rFVIIa is not administered. Keywords: acquired hemophilia A, recombinant activated factor VII, thrombotic complications

Introduction: Cardiovascular diseases (CVD) that require long-term anticoagulant and antiplatelet therapy presents a problem in people with haemophilia (PWH) who receive factor replacement therapy to reduce bleeding risk. Currently, there are no Japanese guidelines for the management of PWH with CVD., Aim: To develop expert guidance on managing CVD in PWH in Japan., Methods: A steering committee of four experts (two haemophilia specialists, one thrombosis specialist, one cardiologist) identified 44 statements related to five key themes. An online questionnaire was produced comprising a mix of 4-point Likert scale and multiple-choice questions that was sent to specialists in the management of PWH with CVD in Japan. Consensus was defined as high or very high if a respective ≥75% or ≥90% of respondents agreed with a statement., Results: Of 16 potential respondents, responses were received from 15 specialists. Of the Likert scale questions, 71% (29/41) achieved ≥90% agreement (very strong agreement), 17% (7/41) achieved 75%-89% agreement (strong agreement) and 15% (6/41) did not achieve consensus agreement. The three multiple-choice questions failed to identify a strong preference. Agreement on specific target trough clotting factor levels for managing certain clinical situations, such as when in the presence of non-valvular atrial fibrillation or myocardial infarction, was also achieved., Conclusion: The results of this consensus study provide a framework for cardiologists and haematologists to manage PWH who are at risk of, or who have, CVD. Implementation of the recommendations provided herein may improve outcomes for PWH with CVD., (© 2024 John Wiley & Sons Ltd.)

Age is a significant risk factor for ischemic stroke. However, the influence of aging on coagulation parameters in non-valvular atrial fibrillation (NVAF) patients treated with direct oral anticoagulants (DOACs) remains unclear. A total of 775 samples were collected from 224 NVAF patients receiving apixaban, edoxaban or rivaroxaban. The samples were categorized into three age groups: (i) ≤ 64 years, (ii) 65-74 years, and (iii) ≥ 75 years (apixaban: N = 48, 108, 119; edoxaban: N = 63, 68, 126; rivaroxaban: N = 115, 90, 38, respectively). Coagulation parameters including fibrinogen (Fbg), factor II, factor V, factor VII, factor X, and D-dimer, were compared between the three age groups for each drug. The slopes in the correlation between drug concentrations and modified diluted prothrombin time (mdPT) were also assessed. Fbg and factor V increased with age, while factor II and factor X decreased. Factor VII and D-dimer showed no significant differences across age categories. The slope in response to drug concentrations was similar between the age groups. In NVAF patients treated with apixaban, edoxaban and rivaroxaban, some coagulation parameters exhibited age-related variation. However, the response of mdPT to drug concentration was consistent across age categories., (© 2024. Japanese Society of Hematology.)

Objective: Heparin resistance is often encountered during cardiopulmonary bypass. Heparin dose and activated clotting time target values for the initiation of cardiopulmonary bypass are not yet universally standardized; further no consensus exists on the management of heparin resistance. This study aimed to investigate the current real-world practice on heparin management and anticoagulant treatment for heparin resistance in Japan., Methods: A questionnaire survey was conducted at medical institutions nationwide with which The Japanese Society of Extra-Corporeal Technology in Medicine members are affiliated, targeting surgical cases with cardiopulmonary bypass performed from January 2019 through December 2019., Results: Among 69% (230/332) of the participating institutions, the criterion for heparin resistance was defined as "the target activated clotting time value not reached even with an additional dose of heparin administration". Cases of heparin resistance were reported in 89.8% (202/225) of the responded institutions. Of note, 75% (106/141) of the responded institutions reported heparin resistance associated with antithrombin activity ≥ 80%. Antithrombin concentrate was used in 38.4% (238/619 responses) or third dose of heparin in 37.8% (234/619 responses) for advanced heparin resistance treatment. Antithrombin concentrate was found to be effective in resolving heparin resistance in patients having normal, as well as lower antithrombin activity., Conclusion: Heparin resistance has occurred in many cardiovascular centers, even among patients with normal antithrombin activities. Interestingly, the administration of antithrombin concentrate resolved heparin resistance, regardless of the baseline antithrombin activity value., (© 2023. The Author(s).)

Introduction: A single assay to assess the effect of the direct FXa inhibitor is needed clinically because prothrombin (PT) assay is not yet sensitive enough for accurate evaluation. We developed modified diluted prothrombin time (mdPT) assay showing a high reactivity to direct FXa inhibitors based on prothrombin time (PT) reagent. The purpose of this study was to evaluate the reactivity of mdPT to direct FXa inhibitors comparing to that of commercial PT reagents and diluted prothrombin time (dPT)., Methods: The correlation and slopes of mdPT against the drug concentrations by anti-Xa assay were compared to those of the four commercial reagents of PT or dPT in 275, 257, and 243 clinical samples collected from non-valvular atrial fibrillation (NVAF) patients who are prescribed apixaban, edoxaban or rivaroxaban for stroke prevention, respectively., Results: The correlation coefficient (95% confidence interval) of mdPT against apixaban, edoxaban, and rivaroxaban was 0.818 (0.775-0.854), 0.914 (0.892-0.932), and 0.814 (0.766-0.852), respectively. The slope (95% confidence interval) of mdPT for apixaban, edoxaban, and rivaroxaban was 0.0068 (0.0063-0.0075), 0.0076 (0.0072-0.0080), and 0.0072 (0.0065-0.0078), respectively, which were higher than that of four commercial PT and dPT reagents, ranging within 0.0006-0.0023, 0.0017-0.0038, and 0.0016-0.0057 (all, p < 0.001), respectively., Conclusion: Compared with other PT and dPT reagents, mdPT reagent showed sharper slope to all direct FXa inhibitors, and higher correlation to apixaban and comparable correlation to edoxaban and rivaroxaban. This new reagent is expected to be a coagulation screening assay having a consistently high response to any types of direct FXa inhibitors., (© 2022 John Wiley & Sons Ltd.)

A woman in her 70s who was undergoing treatment for an overlap syndrome of autoimmune hepatitis and primary biliary cirrhosis developed persistent genital bleeding. Coagulation tests revealed a longer activated partial thromboplastin time, a 7% decrease in coagulation factor IX activity (FIX:C) and a FIX inhibitor (of 3 BU/ml). Lupus anticoagulant (LA), anticardiolipin antibody, and anti-β2 glycoprotein I antibody were positive, and the activated partial thromboplastin time cross-mixing test suggested the presence of LA. Additionally, all intrinsic coagulation factors decreased, but activity of all factors except FIX showed dilution linearity, which suggested a false decrease in activity due to LA. Although definitive diagnosis was difficult due to concurrent LA, this case was strongly suspected to be autoimmune coagulation FIX deficiency complicated by LA. Bypass therapy was not performed because the patient had no anemia and was positive for LA, and immunosuppressive therapy with prednisolone was initiated immediately. Eleven weeks after diagnosis, FIX:C was 41% and zFIX inhibitor was less than 1 BU/ml, leading to remission.

Background: The best thromboprophylaxis for pregnant women with congenital antithrombin deficiency (CAD) is controversial., Objective: To clarify the effectiveness of a protocol for venous thromboembolism (VTE) prevention in pregnant women with CAD., Methods: Women at high risk of VTE were administered antithrombin concentrate and heparin after conception, whereas those at low risk of VTE were administered heparin alone until delivery. All women received antithrombin concentrate at delivery except for one who was diagnosed with CAD., Results: Ten women had CAD, including one in the high-risk group and nine in the low-risk group. No women had VTE at delivery as per the protocol for VTE prevention. Almost all women had increased antithrombin activity before delivery followed by maintenance at ≥ 70% due to antithrombin concentrate administration. VTE prophylaxis during and after delivery was successful in all women with CAD. However, one woman in the low-risk group did not receive heparin and developed VTE induced by severe hyperemesis at 9 gestational weeks, before the diagnosis of CAD. Women in the high-risk group received antithrombin concentrate after delivery but had increased D-dimer levels at postpartum., Conclusions: Our protocol to prevent VTE in pregnant women with CAD is safe and effective., (© 2022. Japanese Society of Hematology.)

Background: Anticardiolipin antibodies (aCL) and anti-β 2 -glycoprotein I antibodies (aβ 2 GPI) are essential in diagnosing antiphospholipid syndrome (APS) according to the international APS guideline. Five commercial assays for aCL and aβ 2 GPI are available in Japan, but their test results are quite discordant. For harmonization of diagnosing APS, upper reference limit (URL) and diagnostic accuracy of each assay were evaluated and compared by testing common sets of specimens across all assays., Methods: We evaluated two manual and three automated assays for aCL and aβ 2 GPI of IgG- and IgM classes. 99%URL (the upper limit of reference interval: as per guideline) together with 97.5%URL were determined by testing sera from 198 to 400 well-defined healthy subjects. Both URLs were compared with the cutoff values, which were determined based on ROC analysis by testing 50 each of plasma specimens from patients with/without APS. Diagnostic accuracy was evaluated as area under curve (AUC) of the ROC curve., Results: A variable degree of discrepancy between URLs and the cutoff values was observed, which was partly attributable to between-year assay variability. 97.5%URLs were set lower and closer to the cutoff values than 99%URLs. For all assays, diagnostic accuracies of both aβ 2 GPI-IgG and aCL-IgG were generally high (AUC: 0.84-0.93); whereas those for IgM-class assays were low (AUC: 0.57-0.67), implicating its utility is limited to rare IgG negative APS cases., Conclusion: To ensure harmonized APS diagnosis, the diagnostic thresholds of the five assays were evaluated by common procedures. Contrary to the guideline, 97.5%URL is rather recommended for diagnosing APS, which showed a closer match to the cutoff value., (© 2022 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Purpose: The use of direct oral Xa inhibitors (DXaIs) to prevent venothrombotic events is increasing. However, gastrointestinal bleeding, including that related to endoscopic resection, is a concern. In this study, we evaluated bleeding and coagulation times during the perioperative period of gastric endoscopic submucosal dissection (ESD)., Materials and Methods: Patients who consecutively underwent gastric ESD from August 2016 to December 2018 were analyzed. Bleeding rates were compared among the 3 groups (antiplatelet, DXaIs, and control). DXaI administration was discontinued on the day of the procedure. Prothrombin time (PT), activated partial thromboplastin time, and the ratio of inhibited thrombin generation (RITG), which was based on dilute PT, were determined before and after ESD., Results: During the study period, 265 gastric ESDs were performed in 239 patients, where 23 and 50 patients received DXaIs and antiplatelets, respectively. Delayed bleeding occurred in 17 patients (7.4%) and 21 lesions (7.1%). The bleeding rate in the DXaI group was significantly higher than that in the other groups (30.4%, P<0.01), and the adjusted odds ratio of bleeding was 5.7 (95% confidence interval, 1.4-23.7; P=0.016). In patients using DXaIs, there was a significant (P=0.046) difference in the median RITG between bleeding cases (18.6%) and non-bleeding cases (3.8%)., Conclusions: A one-day cessation of DXaIs was related to a high incidence of bleeding after gastric ESD, and monitoring of residual coagulation activity at trough levels might enable the predicted risk of delayed bleeding in patients using DXaIs., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2022. Korean Gastric Cancer Association.)

Coagulation factor inhibitors (CFIs) sometimes cause fatal bleeding conditions. Determination of an inhibitor titer (INH-titer) using the Bethesda method is essential for diagnosing diseases associated with CFIs and examining the effects of immunosuppressive therapy. We reviewed 17 cases with CFIs (acquired hemophilia A, n = 11; FV inhibitor, n = 6) to examine the usefulness of determining quantities of an autoantibody to a coagulation factor (CF-IgG) by ELISA for diagnosis and therapeutic efficacy, as compared with INH-titer. One patient with an INH-titer and no evidence of CF-IgG was lupus anticoagulant (LA)-positive, and thus the positive INH-titer may have been a false positive caused by LA. Although INH-titer alone was insufficient to correctly identify patients with CFI, determination of CF-IgG appeared to be useful. In addition, even after INH-titer disappearance, hemorrhagic conditions recurred when CF-IgG was detected. These findings suggest that the presence of a clearance antibody against the coagulation factor might reduce the activity of that coagulation factor even after disappearance of the corresponding neutralizing antibody. Although the diagnosis and therapeutic efficacy can also be determined by INH-titer disappearance and improvement of corresponding coagulation factor activity, determination of CF-IgG by ELISA can improve the accuracy of these assessments., (© 2021. Japanese Society of Hematology.)

Before a new method is used for clinical testing, it is essential that it is evaluated for suitability for its intended purpose. This document gives guidance for the performance, verification and implementation processes required by regulatory and accreditation bodies. It covers the planning and verification of specialist haemostatic tests, including factor assays, D-dimers, direct anticoagulants and thrombophilia testing., (© 2021 John Wiley & Sons Ltd.)

Introduction: Fibrin/fibrinogen degradation products (FDP) values reflect coagulation and fibrinolysis status, and FDP levels are helpful for diagnosis and classification of disseminated intravascular coagulation (DIC). FDP measurement has always played a key role in diagnosing DIC, a phenomenon that has recently gained renewed attention because of its occurrence in coronavirus disease 2019 (COVID-19) patients. Although the evaluation of FDP is crucial for the management of critical care, the variability among FDP reagents is unclear. In this study, we aimed to compare LIASAUTO P-FDP with three FDP reagents and investigate their characteristics., Methods: In total, 172 plasmas samples were used in the correlation. The sample data were divided into three groups including negative, no and positive discrepancy based on the discrepancy percentages calculated from each correlation between LIASAUTO P-FDP and other three reagents. D-dimer, plasmin-α 2 plasmin inhibitor complex (PIC), fibrin monomer complex (FMC), fibrinogen (Fbg) and Plasmin-α 2 Plasmin Inhibitor (α 2 PI) were measured and included in data analysis., Results: The positive discrepancy groups showed higher D-dimer, PIC and FMC values than the negative discrepancy groups. The data indicated that LIASAUTO P-FDP had higher reactivity to D-dimer than other reagents and the values were elevated in the fibrinolysis-enhanced samples with various FDP fragments., Conclusion: LIASAUTO P-FDP displayed the reactivity towards various fibrin/fibrinogen degradation products, and it might be useful for DIC diagnosis because the fibrinolytic status differed in the DIC types and stages., (© 2020 John Wiley & Sons Ltd.)

Before a new method is used for clinical testing, it is essential that it is evaluated for suitability for its intended purpose. This document gives guidance for the performance of verification, validation and implementation processes required by regulatory and accreditation bodies. It covers the planning and execution of an evaluation of the commonly performed screening tests (prothrombin time, activated partial thromboplastin time, thrombin time and fibrinogen assay), and instrument-specific issues. Advice on selecting an appropriate haemostasis analyser, planning the evaluation, and assessing the reference, interval, precision, accuracy, and comparability of a haemostasis test system are also given. A second companion document will cover specialist haemostasis testing., (© 2020 John Wiley & Sons Ltd.)

Patients with congenital protein S (PS) deficiency show a hereditary predisposition for thrombosis, and PS deficiency is prevalent among Japanese populations. Diagnosis is based on symptoms of thrombosis and reduced PS activity. Three reagents that use different measurement principles for determining PS activity are available in Japan. This study aimed to confirm the possibility of harmonization of these three reagents to establish a universal standard for PS activity in Japanese populations. Commercial normal plasma and plasma samples obtained from healthy individuals and healthy pregnant women were tested at three facilities using three reagents for measuring PS: STA-Staclot Protein S (STA-PS), HemosIL Protein S (Clotting) (IL-PS), and a total PS assay (SNT-PS). The within-run precision of each reagent was good, as each had a coefficient of variation of ≤ 3.8%. The dilution linearity for each reagent was also good. The correlation coefficient was 0.94 for STA-PS vs. IL-PS, 0.93 for SNT-PS vs. STA-PS, and 0.90 for SNT-PS vs. IL-PS, indicating a good correlation. Although the three reagents available in Japan for measuring PS activity use different measurement methods, each showed good performance, and large differences were not observed between the obtained values. Harmonization among them appears possible.

Background: Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is characterized by bleeding and thrombosis in patients with autoimmune diseases or infections. Paediatric LAHPS exhibits various degrees of bleeding, ranging from mild to severe; however, adrenal haemorrhage due to LAHPS and its long-term clinical course have not been sufficiently described., Case Presentation: A 9-year-old boy presented with prolonged abdominal pain and abnormal coagulation screening tests. The laboratory tests showed prolonged activated partial thromboplastin time and subsequently revealed the presence of lupus anticoagulant, anti-nuclear antibodies, and hypoprothrombinemia, leading to diagnosis of LAHPS. An enhanced computed tomogram demonstrated nodular lesions in the adrenal glands bilaterally, suggestive of adrenal haemorrhage. Laboratory and clinical manifestations exhibited life-threatening adrenal insufficiency that required hydrocortisone administration. The patient developed systemic lupus erythematosus, diagnosed 12 months later., Conclusions: This patient with LAHPS developed rare adrenal failure due to adrenal haemorrhage, a life-threatening event that should be recognized and treated early. In our case, renal dysfunction was also observed when systemic lupus erythematosus was diagnosed 1 year after LAHPS. Our case emphasizes that early recognition of adrenal failure and careful long-term observation is required in patients with autoantibodies.

Background: Hereditary angioedema (HAE) is a rare but life-threatening condition. HAE types I and II (HAE-1/2) result from C1-inhibitor (C1-INH) deficiency. However, recent genetic analysis has established a new type of HAE with normal C1-INH (HAEnC1-INH). The mutations of factor XII, plasminogen, angiopoietin 1, and kininogen 1 genes may be the cause of HAEnC1-INH. Nevertheless, other causative molecules (HAE-unknown) may be involved. The Japanese therapeutic environment for HAE has been improving owing to the self-subcutaneous injection of icatibant, which was approved for the treatment of acute attack and enables early therapy. Erythema marginatum (EM) is a visible prodromal symptom which occasionally occurs prior to an angioedema attack; hence, recognizing the risk of an acute attack is important for early treatment. However, the detailed characteristics of EM remain unclear. In this study, we first investigated the clinical manifestations of EM in Japanese patients with HAE., Methods: A 20-point survey was developed and distributed to 40 physicians to gather clinical data on EM from patients with HAE., Results: Data on 68 patients with HAE (58 patients with HAE-1/2 and 10 patients with HAE-unknown) were collected. Of the patients with HAE-1/2, 53.4% experienced EM, whereas 43.1% did not. The forearm was the most frequent area of EM (64.5%), followed by the abdomen (29.0%) and upper arm and precordium (19.3%). Of the HAE-1/2 patients with EM, 41.9% always had angioedema following EM, while 29.0% always had colocalization of EM with angioedema. Moreover, 3.2% showed a correlation between the awareness of EM and severity of an angioedema attack. In 60.9% of HAE-1/2 patients with EM, the interval between the awareness of EM and appearance of angioedema was <3 h. Of the patients with HAE-unknown, 30.0% also experienced EM., Conclusion: We confirmed that more than one-half of Japanese patients with HAE-1/2 and one-third of those with HAE-unknown develop EM as the prodromal symptom of an angioedema attack. Physicians should communicate the significance of EM to patients with HAE to prepare them for possible imminent attacks., Competing Interests: The authors report no conflicts of interest., (© 2021 The Authors.)

Antiphospholipid syndrome (APS) is an acquired thrombophilia associated with autoimmunity and is a syndrome that should always be considered when examining patients with thrombosis and pregnancy complications. As per the Sydney criteria, a diagnosis can be established with at least one clinical finding, such as arteriovenous thrombosis and the presence of at least one of the antiphospholipid antibodies (aPL), such as anticardiolipin antibodies (aCL). Moreover, phosphatidylserine-dependent anti-prothrombin antibody and anti-b2GPI-domain 1 antibody are correlated with APS manifestations and enable APS diagnosis. In addition to the inhibition of physiological coagulation inhibitors, such as protein C, the activation of vascular endothelial cells and complement activation by aPL is presumed to be the thrombus mechanism of APS. The mainstay of treatment is anticoagulant therapy with warfarin. For treating APS that has developed by arterial thrombosis, antiplatelet agent alone or in combination with warfarin is considered. In the triple positive aPL (aCL, anti-b2GPI antibodies, and lupus anticoagulant are detected at the same time) cases, sufficient anticoagulant therapy is required. Direct oral anticoagulants are not recommended in cases of triple positive aPL or arterial thrombosis. For patients with catastrophic APS, heparin therapy, plasmapheresis, and steroid pulse therapy are recommended.

Background: Direct oral anticoagulants targeting factor Xa (DXaIs) are administered as prophylaxis for various venothrombotic diseases without routine monitoring required. However, assessment of their anticoagulant effects is necessary to prevent severe events, including major bleeding and/or refractory thrombosis., Objectives: We examined the correlation of ratio of inhibited thrombin generation (RITG), determined using a novel assay based on dilute prothrombin time (dPT), with coagulant markers and laboratory test results to show drug effects. In addition, RITG usefulness as a confirmation test for DXaI therapy was investigated., Methods: Citrated plasma samples were obtained from patients treated with rivaroxaban (n = 882), apixaban (n = 1214), or edoxaban (n = 820) at 4 different institutions in Japan. Laboratory tests, including prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer, and plasma concentrations of DXaIs, were conducted, with drug concentrations divided into peak and trough groups, within and after 5 h of administration., Results: In each DXaI group, RITG was positively correlated with PT, APTT, and drug concentration, and negatively with D-dimer. RITG fluctuation during the peak and trough periods reflected the anticoagulant activity characteristic of each DXaI, which was different from blood concentration fluctuations. RITG showed a significant decrease in cases with thrombosis, while that was increased in those with hemorrhage., Conclusion: We developed RITG, a novel measurement method based on dPT. RITG represents residual coagulation ability in plasma samples, and is useful for assessment of bleeding and thrombotic tendencies in DXaI patients. RITG can be utilized to confirm the effectiveness of oral anticoagulation therapy with DXaI agents., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Accurate clotting time assay results are vital, as the test is employed to indicate the amount of oral anticoagulant to be prescribed, while it is also used for screening the hemorrhagic and thrombotic diseases. The procedure chosen for preparation of a patient blood sample including centrifugation can contribute to significant differences in the results obtained. Thus, for the purpose of proposing a standardized method to appropriately prepare blood samples prior to assay, the Japanese Society of Laboratory Hematology organized the Working Group for Standardization of Sample Preparation for Clotting Time Assays (WG). Following reviews of previously announced guidelines and original experimental results, consensus was obtained by the WG, with the main findings as follows. (1) The recommended anticoagulant in the blood collection tube is sodium citrate solution at 0.105-0.109 M (3.13-3.2%). (2) Whole blood samples should be stored at room temperature (18-25 ˚C) within 1 h of collection from the patient. (3) For plasma preparation, centrifugation at 1500 × g should be performed for at least 15 min or at 2000 × g for at least 10 min at room temperature. (4) After the plasma sample is prepared, it should be stored at room temperature and assayed within 4 h.

Glucose uptake in adipocytes is crucial for regulating systemic metabolism. Long noncoding RNAs (lncRNAs), defined as being transcripts with lengths exceeding 200 nucleotides that are not translated, are recently identified regulators of cellular functions. Previously, we have shown that an lncRNA, "down-regulated expression by hepatitis B virus X" (dreh), is involved in glucose transport in skeletal muscle cells. Here, we aimed to examine the involvement of dreh in glucose transport in 3T3-L1 adipocytes. Expression analysis showed that dreh was expressed in 3T3-L1 fibroblasts and adipocytes. Knockdown of dreh expression using its specific siRNAs lowered the glucose concentration of the medium and facilitated [ 3 H]-2-deoxyglucose transport in adipocytes. Additionally, dreh silencing enhanced the protein expression of glucose transporter (GLUT4) in the plasma membrane of adipocytes. Treatment with siRNA against vimentin attenuated the glucose-lowering effect of dreh depletion. These results suggest that the repression of dreh facilitates glucose transport via increased GLUT4 expression in the plasma membrane through the involvement of vimentin in 3T3-L1 adipocytes. In conclusion, dreh is the first observed lncRNA that regulates glucose transport in adipocytes and could serve as a novel therapeutic target for diabetes by modulating adipocyte function. Considering the new function of dreh, we propose that dreh be renamed "down-regulated expression-related hexose/glucose transport enhancer.", Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Acquired hemophilia A (AHA) is a rare, life-threatening bleeding disorder caused by autoantibodies against coagulation factor VIII (FVIII). Immunosuppressive therapy for AHA aims to arrest bleeding by eliminating FVIII inhibitors. Factor VIII activity overshoot after complete remission (CR) has been reported anecdotally, but details remain unclear. We retrospectively analyzed data from 17 patients with AHA who achieved CR under immunosuppressive therapy between 2009 and 2019 at Gunma University Hospital. FVIII activity overshoot was defined as ≥ 150%. All 17 patients had low FVIII activity (median 2.1%; range < 1.0-8.9%) due to FVIII inhibition (median 14.7 BU/mL; range 2.0-234.0) and all achieved CR within a median of 39 (range 19-173) days. Overshoot occurred in 11 (64.7%) patients and maximal FVIII activity reached > 200% in six of them. The median duration from CR to overshoot was 13 (range 0-154) days. The FVIII overshoot was transient (72.7%) or persistent (27.3%). Venous thromboembolism developed as a complication of overshoot in one patient due to iliac vein compression by a massive hematoma. Overshoot of FVIII activity after CR occurs more frequently than previously expected in patients with AHA.

Introduction: Detection of lupus anticoagulant (LA), an antiphospholipid (aPL) antibody, in a clotting time test is an important finding for diagnosis of antiphospholipid syndrome (APS). However, confirmation of LA requires several different testing procedures, some of which can be difficult and require time. We report here a simple and highly specific method for detecting LA., Materials and Methods: We examined 66 plasma samples obtained from LA-positive (LA) and 75 from LA-negative (non-LA) subjects, which included patients with acquired hemophilia and coagulation disorders, as well as from 43 healthy volunteer samples as normal controls. Activated partial thromboplastin time (APTT) was determined by adding 20 mmol of CaCl 2 (Ca-APTT) or 25 mmol of a mixture of Mg and Ca (Mg-APTT). The ratio of Mg-APTT/Ca-APTT was then calculated and used as the Mg/Ca Index., Results: The Mg/Ca Index value for the LA group was significantly lower than that for the non-LA and normal control groups (P < .0001). When the cutoff value of the Mg/Ca Index was less than 1.00, the sensitivity of LA determination using the Mg-APTT assay was 80.3%, while specificity was 100%., Conclusion: Our findings indicate that the present Mg-APTT assay is a simple yet highly specific method for LA detection., (© 2019 John Wiley & Sons Ltd.)

We investigated the relationships between circulating procoagulants and trauma severity, including cellular destruction, and the effects of thrombin generation on procoagulants in a rat blunt trauma model. The rats were subjected to tumbling blunt trauma, where they were tumbled for 0, 250, 500, or 1000 revolutions. Creatine kinase, nucleosome, and microparticle plasma levels increased gradually with trauma severity. Strong interrelationships were observed among creatine kinase, nucleosome, and microparticle levels. Time to initiation of thrombin generation shortened with increasing trauma severity. In accordance with trauma severity, prothrombin activity decreased, but the thrombin generation ratio increased. Time to initiation of thrombin generation and the thrombin generation ratio correlated with creatine kinase levels. In an in vitro study, a homogenized muscle solution, which included massive nucleosomes and microparticles, showed accelerated thrombin generation of plasma from healthy subjects. Procoagulants, such as microparticles and nucleosomes, are released from destroyed parenchymal cells immediately after external traumatic force, activating the coagulation cascade. The procoagulants shorten the time to initiation of thrombin generation. Furthermore, although coagulation factors are consumed, the thrombin generation ratio increases.

Aims: The anti-hyperglycemic action of metformin on skeletal muscles is presently unclear. Long noncoding RNAs (lncRNAs) are implicated in multiple cellular functions. This study aims to explore the role of lncRNAs in the glucometabolic action of metformin on skeletal muscle cells., Main Methods: Metformin accumulation was assessed using [ 14 C]-metformin. A lncRNA array was used to investigate metformin-regulated lncRNAs in C2C12 skeletal muscle cells. Knockdown studies were applied to evaluate the function of lncRNA Dreh. A colorimetric assay was used for the measurement of medium glucose concentration; glucose transport was assessed using [ 3 H]-2-deoxyglucose; real-time PCR was used for RNA expression analysis, and western blotting was used to assess protein expression in myotubes. A Dreh overexpression plasmid was transfected into the cells., Key Findings: Metformin accumulated in C2C12 myotubes. Metformin reduced medium glucose concentration and repressed lncRNA Dreh expression in the myotubes. Knockdown of Dreh in the myotubes resulted in reduced glucose concentration in the culture medium, increased glucose transport, and increased levels of GLUT4 protein in the plasma membrane. Overexpression of Dreh attenuated the glucose-lowering effect of metformin in myotubes., Significance: The glucoregulatory actions of metformin are mediated in part by a lncRNA, Dreh, in the skeletal muscle cells. Dreh is a novel regulator for glucose transport and could be a therapeutic target for diabetes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Patients with lupus anticoagulant (LA), a thrombotic risk factor, along with decreased prothrombin (FII) activity are classified as lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) and occasionally show bleeding symptoms, although this is not essential for diagnosis. We treated 20 cases of LAHPS over a 3-year period. Median FII activity was 20.9% and the anti-prothrombin antibody (anti-II Ab), shown by ELISA findings, was detected in 55%. Bleeding symptoms were observed in 20%, although that finding was not correlated with FII activity or anti-FII Ab quantity. We also observed 21 LA cases with decreased activity of coagulation factors other than FII, which we have designated LAHPS-like syndrome (LLS). Among LLS patients, anti-FII Ab and bleeding symptoms were seen in 47.6% and 14.3%, respectively. Our findings suggest that bleeding in LAHPS and LLS cannot be explained only by FII activity decreased by anti-FII Ab. Low FVIII activity and the anti-FVIII antibody (anti-FVIII Ab) were detected in some LAHPS and LLS patients, making it difficult to distinguish those from acquired hemophilia A cases. Detection of anti-FVIII Ab quantity by ELISA may be useful for accurate determination, as that was not performed in our LAHPS or LLS patients.

A 72-year-old man was hospitalized because of thrombocytopenia (0.5×10 4 /µl) and anemia. The bone marrow test result revealed excessive numbers of megakaryocytes and no platelet adhesion. Furthermore, platelet-associated immunoglobulin G levels were high, and he was tested positive for Helicobacter pylori antibody. On the basis of these findings, immune thrombocytopenia was diagnosed. The patient was initially treated with eradication therapy; prednisolone, 20 mg/day (0.5 mg/kg) and a thrombopoietin receptor agonist 12.5 mg/day. During the course of treatment, the anemia worsened. Detailed examination revealed marked prolongation of activated partial thromboplastin time and inhibition of factor VIII activity. Therefore, he was diagnosed with acquired hemophilia A. Although extensive muscle hemorrhage had occurred, hemostatic therapy comprising intensification of the immunosuppressive therapy and administration of recombinant activated factor VII resulted in successful hemostasis. As the treatment progressed, inhibition of factor VIII recurred temporarily; however, immunosuppressive therapy was continued. No recurrence was observed even after 1 year of the onset of both diseases.

A 74-years-old male who was a smoker and received treatment for hypertension, dyslipidemia, peripheral arterial disease and idiopathic interstitial pneumonia complained of subcutaneous hemorrhage of the right lower thigh. Marked anemia (hemoglobin 5.5 g/dL) and prolonged activated partial thromboplastin time (≥130 seconds) were noted. The factor VIII activity level was reduced to 1.2%, and the factor VIII inhibitor titer was 285.3 BU/mL, a diagnosis of acquired hemophilia A (AHA) was made. Then, hematomas of 5 intra-muscles were recurred. Hemostasis became difficult despite frequent and high-dose administration of recombinant human coagulation factor VIIa (total: 18 days, 305 mg). Hemostasis was achieved by switching to activated prothrombin complex concentrate (for 3 days, 18,000 units), however, cerebral infarction occurred after 36 days. After the frequent administration of bypass hemostatic agents on elderly AHA patients with several risk factors for ischemic stroke, the risk of subsequent thrombotic events may persist for 1 month.

Background: Laboratory determination of fibrin/fibrinogen degradation products (FDP) levels, along with that of the D-dimer, is important for assessing the fibrinolytic situation. Recently, we developed a new FDP reagent "Lias Auto P-FDP", which can detect various FDP fragments. The purpose of this study was to evaluate the basic performance of the newly developed Lias Auto P-FDP and compare it with Lias Auto D-Dimer Neo assay., Methods: The within-run precision of Lias Auto P-FDP and Lias Auto D-Dimer was determined 20 times in low and high value controls. The between-day precision was evaluated five times a day for five days. The linearity study was performed by diluting high value samples for 2 - 10-fold and 2 - 8-fold. The comparative study was performed using 172 patient samples with elevated FDP values. For the discrepancy analysis, the samples were divided into three groups by the discrepancy percentage between the FDP and D-dimer values. The groups were defined as follows: lower discrepancy group, less than -20%; no discrepancy group, -20% to 20%; upper discrepancy group, more than 20%., Results: The coefficient of variation % (CV%) in within-run and between-day precision were within 3.8% for both FDP and the D-dimer. The correlation coefficients were more than 0.999 and the linearity was high. In the comparative study, the values of FDP were higher than that of the D-dimer in all samples. The median FDP and D-dimer values of lower discrepancy, no discrepancy, and upper discrepancy groups were 11.8, 20.3, and 51.4, and 8.0, 11.3, and 13.1, respectively. FDP showed an increasing tendency but D-Dimer showed constant values. Thus, the possible cause of discrepancy between FDP and D-dimer values were the elevated FDP values. In addition, the values of plasmin-α2 plasmin inhibitor complex (PIC) in the upper discrepancy group were higher than that of the lower and no discrepancy groups, indicating progression of fibrinolysis., Conclusions: In this study, we evaluated the newly developed Lias Auto P-FDP reagent and confirmed that the basic performance was acceptable. FDP was elevated in samples with high PIC values, which indicated progression of fibrinolysis. Determination of fibrinolysis conditions by FDP measurement is important.

Sarcolipin is a transmembrane protein expressed in the sarco/endoplasmic reticulum of skeletal and atrial muscles in large animals. Sarcolipin plays crucial roles in heat production through modifying the function of sarco/endoplasmic reticulum Ca 2+ ATPase, thereby being involved in thermogenesis and systemic metabolism. In skeletal muscle, endoplasmic reticulum (ER) stress has been implicated in several conditions, such as insulin resistance, muscle diseases, and hypo/hyper-contraction. Here, we investigated the effect of ER stress on sarcolipin expression in skeletal muscle cells, C2C12 myotubes. First, gene expression of sarcolipin was confirmed in the cells during myogenesis. Then, ER stress was induced in C2C12 myotubes by treatment with tunicamycin or thapsigargin. Sarcolipin messenger RNA (mRNA) and protein expression were significantly reduced by ER stress induction. The reduction was independent of inositol-requiring element 1 (IRE1), which is activated by ER stress and has potent endonuclease activity, when evaluated by treatment with an IRE1 inhibitor, 4μ8C. On the other hand, sarcolipin mRNA stability was reduced under the ER stress when evaluated by treatment with actinomycin D. In conclusion, these results show that ER stress represses sarcolipin expression due to changes in mRNA stability in C2C12 myotubes.

Acquired hemophilia A (AHA), which is caused by autoantibodies against coagulation factor VIII (FVIII) is a rare, life-threatening bleeding disorder, the incidence of which appears to be increasing in Japan as the population ages. However, the clinical characteristics, treatment, and outcomes of AHA remain difficult to establish due to the rarity of this disease. We retrospectively analyzed data from 25 patients (median age 73 years; range 24-92 years; male n = 15) diagnosed with AHA between 1999 and 2015 at Gunma University Hospital. We identified autoimmune diseases and malignancy as underlying conditions in four and three patients, respectively. Factor VIII activity was significantly decreased in all patients (median 2.0%; range <1.0-8.0) by FVIII inhibitor (median 47.0 BU/mL; range 2.0-1010). Among 71 bleeding events, subcutaneous or intramuscular hemorrhage was the most prevalent. Seventeen patients required bypassing agents. Twenty-two (91.7%) of 24 patients treated with immunosuppressive agents achieved complete response (CR) during a median of 57.5 days (range 19-714 days). Although three patients (12%) relapsed and seven (28%) died of infection, none of the deaths were related to bleeding. Although most of our patients achieved CR after immunosuppressive therapy, the rate of infection-related mortality was unsatisfactorily high.

Antiphospholipid antibodies (aPLs) can vary both immunologically and functionally, thus it is important to effectively and correctly identify their presence when diagnosing antiphospholipid syndrome. Furthermore, since many immunological/functional tests are necessary to measure aPLs, complete examinations are often not performed in many cases due to significant burden on the testing departments. To address this issue, we measured aPLs defined according to the classification criteria (anticardiolipin antibody: aCL) IgG/IgM and anti-β 2 glycoprotein I antibody (aβ 2 GPI) (IgG/IgM) as well as non-criteria antibodies (aCL IgA, aβ 2 GPI IgA and aβ 2 GPI domain I), in a cohort of 211 patients (61 APS, 140 disease controls and 10 healthy individuals). APLs were measured using a fully automated chemiluminescent immunoassay instrument (BIO-FLASH®/ACL AcuStar®) and with conventional ELISA tests. We demonstrated that both sensitivity and accuracy of diagnosis of aCL IgG and aβ 2 GPI IgG were high, in agreement with the past reports. When multiple aPLs were examined, the accuracy of diagnosis increased. The proportion of APS patients that were positive for 2 or more types of aPLs (47/61, 77%) was higher than that of patients with systemic lupus erythematosus (SLE)(3/37, 9%), those with non-SLE connective tissues diseases (1/53,2%), those with other diseases or healthy volunteers. Based on these findings, it was concluded that the fully automated chemiluminescent immunoassay instrument, which allows the simultaneous evaluation of many types of aPLs, offers clear advantages for a more complete, more rapid and less labor-intensive alternative to running multiple ELISA and could help in better diagnosis for suspected APS patients., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Lupus anticoagulant (LA) is an antibody that interferes with in vitro coagulation reactions. The mixing test is considered useful for LA diagnosis and is also recommended to differentiate between acquired hemophilia A (AHA) and factor deficiency. However, there has been little study to differentiate between LA and AHA. Our aims are to investigate whether we can differentiate LA and AHA by the mixing test and to establish new formulas for the mixing test to differentiate these samples clearly., Materials and Methods: We examined 27 LA-positive, 29 coagulation factor deficient, 24 unfractionated heparin and 48 AHA samples. Index of circulating anticoagulant (ICA) values, calculated from the clotting times without incubation and after 2h incubation, were defined as ICA immediate (ICAi) and ICA delayed (ICAd) respectively. ICAd/ICAi and ICAd-ICAi were also calculated to compare the sensitivity and specificity., Results: ICAd/ICAi and ICAd-ICAi for AHA samples were significantly higher than those of the other sample groups. The sensitivities to AHA in ICAi, ICAd, ICAd/ICAi and ICAd-ICAi were 66.7%, 81.3%, 93.8% and 91.7% respectively, while the specificities for AHA were 45.0%, 66.3%, 85.0% and 98.8% respectively. ICAd/ICAi and ICAd-ICAi showed high sensitivity and specificity., Conclusions: ICAd/ICAi and ICAd-ICAi were useful for LA and AHA diagnosis, because these could differentiate between LA and AHA samples. These new formulas can contribute to the rapid diagnosis and treatment of LA and AHA., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Lupus anticoagulant-hypothrombinemia syndrome (LAHS) is a rare disease involving hemorrhagic diathe- sis due to hypothrombinemia with lupus anticoagulant. We report a 28-week-pregnant woman at twenty years of age, who had been hospitalized with jaundice. In laboratory data, AST, ALT, and bilirubin were elevated and the prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged. Although the liver failure was improved after she delivered a baby by Caesarean section, postoperative intraperitoneal bleeding persisted. The diagnosis by liver biopsy was autoimmune hepatitis. Although the bleeding was stopped on the seventh postoperative day, the prolongation of PT and APTT remained. LA was positive in the diluted Russell's viper venom time. Anti-cardiolipin and anti-beta-2-glycoprotein anti- bodies were also positive. The prothrombin activity was reduced. A high titer of phosphatidylserine- dependent antiprothrombin antibody (aPS/PT), which causes bleeding, was observed. Based on these data, she was diagnosed with LAHS. The liver dysfunction and prolongation of PT and APTT were normalized following the administration of corticosteroids. In this case, aPS/PT may have contributed to the pathological physiology of LAHS. [Case Report].

Acquired hemophilia A (AHA) is a rare coagulation disorder caused by autoantibodies against coagulation factor VIII (FVIII). We report herein a very rare case of AHA complicated by immune thrombocytopenia (ITP). A 30-year-old woman was hospitalized with severe thrombocytopenia. Her platelet count was 5,000/μl on admission, at which time APTT was normal. ITP was diagnosed and she was treated with γ-globulin, platelet transfusion, and prednisolone at 1 mg/kg/day. She was discharged after platelet count normalization and prednisolone was tapered to 5 mg/day. During the prednisolone tapering, purpura appeared on both thighs and in the left inguinal region, and APTT was found to be prolonged. She was referred to our hospital for examination of APTT prolongation. FVIII activity was markedly decreased to 7.7% and the FVIII inhibitor was positive (1.5 BU/ml), based on which AHA was diagnosed. We carefully followed this patient without intensification of immunosuppressive therapy for 7 weeks, but her platelet count decreased from 150,000/μl to 70,000/μl and the FVIII inhibitor increased to 4 BU/ml. We therefore increased prednisolone to 30 mg/day, after which her platelet count increased and complete remission of AHA was achieved by day 42. In addition, we examined the relationship of the FVIII inhibitor and FVIII binding antibody in this case.

Although acquired hemophilia A (AHA) often develops in patients with neoplasms, there are few reports on the efficacy of radiation therapy during the bleeding phase of AHA in the prior literature. We herein present a case of AHA experiencing remission soon after radiation therapy for esophageal cancer. A man in his seventies, who had a history of radical nephrectomy for left renal cell carcinoma, received a diagnosis of esophageal cancer. Three months later, he noticed a right thigh hematoma, and was transferred to our hospital. Laboratory data revealed a marked reduction of coagulation factor VIII (FVIII) activity at 0.9% and the inhibitor to FVIII was detected in his serum at 21.8 BU/ml. Under a diagnosis of AHA, the patient received high-dose oral prednisolone, which failed to achieve disease remission. He then underwent radiation therapy to eradicate the underlying esophageal cancer. Despite tapering of the prednisolone dosage, FVIII inhibitor declined to undetectable levels. In this case, radiation therapy for the underlying cancer was associated with achieving complete remission of AHA.

The availability of direct oral anticoagulants (DOACs) has caused a paradigm shift in thrombosis management. DOAC profiles do not differ greatly, though they are quite different from that of warfarin, whereas their dosage and dose regimens are not consistent. The direct thrombin inhibitor dabigatran seems to obstruct tenase by inhibiting thrombin generated in the initial phase and feedback to the amplification phase of cell-based coagulation reactions. Factor Xa inhibitors (rivaroxaban, apixaban, edoxaban) mainly inhibit factor Xa activity of the prothrombinase complex in the propagation phase. The dose regimens of these inhibitors can be classified into once (rivaroxaban, edoxaban) and twice (dabigatran, apixaban) daily. On the other hand, their plasma elimination half-life times are similar, which can be explained by differences in the type of aimed anticoagulation, such as persistent (e.g., warfarin) and intermittent (e.g., low-molecular-weight heparin). Because of the differences among DOACs, an indicator is necessary to compare them. We investigated relative potency to compare dosage and intensity by calculation of conversion using a profile comprised of molecular weight, bioavailability, protein-binding rate, inhibitory constant, and dosage. We found that the relative potencies were different, with that of apixaban higher than edoxaban (60 mg) and nearly twice that of rivaroxaban. However, dabigatran could not be evaluated with this profile, likely due to its different mode of action. These results suggest that rivaroxaban and apixaban differ in regard to anticoagulation type, as the former shows persistent and the latter intermittent anticoagulation.