Search

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

Antiphospholipid antibodies (aPL) are associated with an increased risk of thrombosis; however, the mechanism remains unknown. Recent studies have focused on the impediment of protein C anticoagulant activity by anti-β2-glycoprotein I (β2GPI) antibodies (aβ2GPI Ab). We purified IgG fractions containing a high concentration of aβ2GPI Ab from patients with antiphospholipid syndrome (APS) and then investigated the effect of purified aβ2GPI Ab on the activity of activated protein C (APC). Using a three-step chromatography method (DEAE-sepharose column, phosphatidylserine polyacrylamide gel column dependent on the presence of β2GPI, and protein G column chromatography), we successfully isolated anti-β2GPI IgG from nine patients with APS. Seven of nine samples inhibited APC activity in a concentration-dependent manner only in the presence of β2GPI, as observed by a chromogenic assay that was able to determine thrombin activity even in the presence of APC. The extent of APC inhibition by these fractions appeared to be related to aβ2GPI Ab titers of the purified IgG. However, the inhibitory effect of IgG from patients was not detected in the absence of β2GPI. IgG purified from three normal subjects did not affect APC activity. Herein, we show a useful method for the isolation of IgG containing a high concentration of aβ2GPI Ab. Moreover, the present findings indicate that inhibition by aβ2GPI Ab on APC anticoagulant activity could explain one of the mechanisms for the thrombotic state in APS. [ABSTRACT FROM AUTHOR]

Background To establish an available, economical technique for the large-scale purification of CD34 + cells we used a nylon-fiber syringe (NF-S) for depletion of adherent cells and then selected CD 34 + cells from peripheral blood mobilized by G-CSF, using MAb and magnetic heads. Methods PBSC were mobilized and collected from adult, healthy volunteers. With the effect of concentration of anti-CD34 MAb (9C5) on the purification of CD34 + cells from 1 × 10 8 NF-S treated cells (NF cells), the recovery and the purity of CD34 + cells was identical for 5, 10, 20, 40 µg of 9C5. In this study, therefore, the concentration of 9C5 was maintained at >5 µg/10 8 NF cells, with a cellhead ratio of 1:10. Results When half to one-third of leukapheresis product containing 121.5 ± 26.0 × 10 8 mononuclear cells (mean ± SD; n = 6) was processed for CD34 + cell purification, 5.26 ± 3.01 × 10 7 total purified cells were obtained with a purity of CD34 + cells at 94.9 ± 8.5%. The numbers of CD34 + cells and total progenitor cells recovered in this process were 4.71 ± 2.33 × 10 7 cells and 145.9 + 121.8 × 10 5 cells, respectively. The total recovery of CD34 + cells was 37.0 ± 21.0%. The depletion of monocyte by NF-S reduced the 9C5 anti-human CD34 MAb needed for purification of CD34 + cells to one-third. Two patients were grafted with peripheral blood CD34 + cells selected by this procedure and achieved a rapid and consistent hematopoiesis. Discussion Our clinical data show that these cells are capable of rapid reconstitution of hematopoiesis after high-dose chemotherapy. The procedure contains an additional step; however, consistent high purity of CD34 + cells in the purified population and cost reduction were achieved, both critical issues in the better purging of malignant cells and for a wide clinical application. [ABSTRACT FROM AUTHOR]

Comments on a study on whether multiple thrombosis in major arteries in a patient with antiphospholipid syndrome (APS) is associated with excess of a large multimer of von Willebrand factor. Results of laboratory investigations of antiphospholipid antibodies; Details on the study; Characteristics of catastrophic APS.

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.)