Basement membrane extract potentiates the endochondral ossification phenotype of bone marrow-derived mesenchymal stem cell-based cartilage organoids

Endochondral ossification is a developmental process in the skeletal system and bone marrow of vertebrates. During endochondral ossification, primitive cartilaginous anlages derived from mesenchymal stem cells (MSCs) undergo vascular invasion and ossification. In vitro regeneration of endochondral ossification is beneficial for research on the skeletal system and bone marrow development as well as their clinical aspects. However, to achieve the regeneration of endochondral ossification, a stem cell-based artificial cartilage (cartilage organoid, Cart-Org) that possesses an endochondral ossification phenotype is required. Here, we modified a conventional 3D culture method to create stem cell-based Cart-Org by mixing it with a basement membrane extract (BME) and further characterized its chondrogenic and ossification properties. BME enlarged and matured the bone marrow MSC-based Cart-Orgs without any shape abnormalities. Histological analysis using Alcian blue staining showed that the production of cartilaginous extracellular matrices was enhanced in Cart-Org treated with BME. Transcriptome analysis using RNA sequencing revealed that BME altered the gene expression pattern of Cart-Org to a dominant chondrogenic state. BME triggered the activation of the SMAD pathway and inhibition of the NK-κB pathway, which resulted in the upregulation of SOX9, COL2A1, and ACAN in Cart-Org. BME also facilitated the upregulation of genes associated with hypertrophic chondrocytes (IHH, PTH1R, and COL10A1) and ossification (SP7, ALPL, and MMP13). Our findings indicate that BME promotes cartilaginous maturation and further ossification of bone marrow MSC-based Cart-Org, suggesting that Cart-Org treated with BME possesses the phenotype of endochondral ossification.

Fitusiran prophylaxis in people with hemophilia A or B who switched from prior BPA/CFC prophylaxis (ATLAS-PPX)

Fitusiran, a subcutaneous (SC) investigational siRNA therapeutic, targets antithrombin to rebalance hemostasis in people with hemophilia A or B (PwHA/B), irrespective of inhibitor status. This Phase 3, open-label study (NCT03549871) evaluated the efficacy and safety of fitusiran prophylaxis in males aged ≥ 12 years with hemophilia A or B, with or without inhibitors, who received prior bypassing agent (BPA)/clotting factor concentrate (CFC) prophylaxis. Participants continued their prior BPA/CFC prophylaxis for 6 months before switching to once-monthly 80 mg fitusiran prophylaxis for 7 months (onset and efficacy periods). Primary endpoint was annualized bleeding rate (ABR) in the BPA/CFC prophylaxis and fitusiran efficacy period. Secondary endpoints included spontaneous ABR (AsBR) and joint ABR (AjBR). Safety and tolerability were assessed. Of 80 enrolled participants, 65 (inhibitor/non-inhibitor, n = 19/46) were eligible for ABR analyses. Observed median (IQR) ABRs were 6.5 (2.2, 19.6)/4.4 (2.2, 8.7) with BPA/CFC prophylaxis versus 0.0 (0.0, 0.0)/0.0 (0.0, 2.7) in the corresponding fitusiran efficacy period. Estimated mean ABRs were substantially reduced with fitusiran by 79.7% (P = 0.0021) and 46.4% (P = 0.0598) versus BPA/CFC prophylaxis, respectively. Forty-one participants (63.1%) experienced zero treated bleeds with fitusiran versus 11 (16.9%) with BPAs/CFCs. Median AsBR and AjBR were both 2.2 with BPA/CFC prophylaxis and 0.0 in the fitusiran efficacy period. Two participants (3.0%) experienced suspected or confirmed thromboembolic events with fitusiran. Once-monthly fitusiran prophylaxis significantly reduced bleeding events versus BPA/CFC prophylaxis in PwHA/B, with or without inhibitors and reported adverse events were generally consistent with previously identified risks of fitusiran.

Variability in combinations of APTT reagent and substrate plasma for a one-stage clotting assay to measure factor VIII products

INTRODUCTION

An investigation of the suitability of reagents for measuring FVIII products in a one-stage clotting assay (OSA) showed variations in their FVIII activity (FVIII:C). Most studies have focused on the activated partial thromboplastin time (APTT) reagent rather than FVIII-deficient plasma (F8DP), even though the APTT-based OSA is comprised of APTT reagents and factor-deficient plasma.

AIM

A single-centre study was conducted to clarify variations in measurements of FVIII products in an OSA using a total of 12 reagent combinations, including four APTT reagents and three types of F8DP.

METHODS

FVIII:C in nine types of FVIII product-spiked plasma was measured using an OSA with four different APTT reagents and three types of F8DP.

RESULTS

F8DP-dependent variations were found in addition to differences derived from APTT reagents. Variations in target recovery (TR) were observed for NovoEight®, Eloctate®, and Jivi®. Reduced TR for Jivi was found only for Pathromtin SL in combination with congenital F8DP (F8DP-3). This lower TR was not observed with alternative manufacturing lots of F8DP-3. The reduced TR for Jivi might be related to impaired contact activation due to lower factor XI activity in F8DP-3.

CONCLUSION

In addition to APTT reagents, variations in F8DPs used for OSAs can also affect FVIII:C results. F8DPs as well as the APTT reagent used for OSA should be chosen with caution, and laboratories should evaluate reagents for F8DPs as they currently do for APTT reagents, especially when lot changes occur.

Interim analyses of the multinational real-world prospective cohort HEM-POWR study evaluating the effectiveness and safety of damoctocog alfa pegol in patients with hemophilia A

OBJECTIVES

To assess effectiveness and safety of damoctocog alfa pegol in interim analyses of the ongoing real-world hemophilia A HEM-POWR study.

METHODS

HEM-POWR (NCT03932201) is a multinational Phase 4 prospective observational study. The primary objective was annualized bleeding rate (ABR) in previously treated patients (PTPs) with hemophilia A. Secondary objectives included adverse events and number of affected joints.

RESULTS

At data cut-off (August 17, 2022), the safety analysis set included 268 patients and the full analysis set (FAS) included 161 patients. The most common dosing regimen during observation period was prophylaxis (FAS = 158/161, 98.1%) every 3-4 days (twice weekly; FAS = 78/158, 49.4%) and a median (min, max) infusion dose of 37.5 (10, 72) IU/kg. PTPs receiving prophylactic damoctocog alfa pegol have fewer infusions compared with prior treatment. Median total ABR (Q1, Q3) was 0.0 (0.0, 1.8) and mean total ABR (SD) was 2.4 (8.2). The proportion of patients with no affected joints increased between initial visit and follow-up. No FVIII inhibitors, treatment-related adverse events, or deaths were reported.

CONCLUSIONS

Damoctocog alfa pegol shows effectiveness and acceptable safety, as well as consistent utilization, in real-world PTPs with hemophilia A, including in patients with non-severe hemophilia and those with a history of inhibitors. Please see video for a summary of this study.

Haemophilia and cardiovascular disease in Japan: Low incidence rates from ADVANCE Japan baseline data

INTRODUCTION

With the increasing life expectancy of people with haemophilia, the risk of cardiovascular disease (CVD) and thrombotic events has become a growing concern. Longitudinal studies on the incidence and risk factors of CVD in this population are limited, and optimal prevention and treatment strategies are yet to be established.

AIM

This study aimed to present the baseline data of a prospective longitudinal study focusing on a subset of Japanese patients with haemophilia, specifically investigated the incidence, risk factors and treatment modalities for CVD and thrombotic diseases in people aged 40 years in Japan over 10 years through the ADVANCE Japan study.

METHODS

The ADVANCE Japan study is a prospective multicentre cohort study involving 600 adult individuals with haemophilia A/B aged 40 years in Japan. The primary endpoint was the incidence of CVD, with secondary endpoints encompassing anticoagulant use, mortality rates, and comparison with the general population.

RESULTS

Baseline data from the 600 participants revealed that thrombotic events occurred in 13 individuals (2.2%), mostly in those with haemophilia A. Atrial fibrillation was observed in 11 participants (1.8%). Hypertension and dyslipidaemia were identified as the prevalent risk factors. Various prophylactic treatments were employed, and no severe bleeding events were observed during the study period.

CONCLUSION

This study provides vital baseline data for a 10-year prospective investigation of CVD and thrombotic disease risk in people with haemophilia. These findings will contribute to refining prevention and treatment approaches and improving patients' quality of life.

The immunogenicity, safety, and efficacy of N8-GP in previously untreated patients with severe hemophilia A: pathfinder6 end-of-trial results

BACKGROUND

The pathfinder6 (NCT02137850) international phase 3 trial examined immunogenicity, safety, and efficacy of the extended half-life factor VIII (FVIII) replacement product N8-GP (turoctocog alfa pegol; Esperoct) in previously untreated patients (PUPs) with hemophilia A.

OBJECTIVES

We present end-of trial results for extended PUP N8-GP treatment for up to a median (range) 2.5 (0.0; 7.4) years.

PATIENTS/METHODS

Longer-term N8-GP treatment in PUPs with hemophilia A was examined. The prophylaxis regimen was ∼60 IU/kg N8-GP i.v. twice weekly, or every 3 or 7 days. The primary endpoint was the incidence of FVIII inhibitors.

RESULTS

Overall, 81 patients received N8-GP and were included in this analysis. The inhibitor incidence was 30.0% (15.7% high-titer [>5 BU]) for the extension phase. Patients had a median (range) 2.9 (0.1; 7.2) years of prophylaxis following the pre-prophylaxis period. During prophylaxis, the median annualized bleeding rate (ABR) (interquartile range) was 1.4 (0.6; 3.5), 13% of patients experienced no bleeding episodes, and 55.1% of patients experienced no spontaneous bleeds. The proportion of patients without any spontaneous bleeding episodes increased after the first year of prophylaxis. The hemostatic success rate in the treatment of bleeding episodes was 87.6%. No additional safety concerns were observed in patients with previously reported observation of temporarily decreased incremental recovery (IR).

CONCLUSION

Long-term end-of-trial PUP N8-GP prophylaxis data indicate that PUPs respond well to long-term N8-GP treatment. The inhibitor incidence was consistent with previous results. Median ABR during prophylaxis was 1.4. There were no lasting clinical impacts or safety concerns for patients with an observation of temporarily decreased IR.

Cases of less-than-expected FVIII activity in previously treated patients during post-marketing surveillance of N8-GP

INTRODUCTION

Turoctocog alfa pegol (N8-GP) is a glycoPEGylated, extended half-life (EHL), human recombinant factor VIII (FVIII) approved for the treatment and prevention of bleeding episodes in patients with haemophilia A. Since its launch in August 2019, > 800 patients have been treated worldwide.

AIM

To present data from identified post-marketing cases of less-than-expected FVIII activity in previously treated patients (PTPs) without inhibitors after switching to N8-GP.

METHODS

The post-marketing safety database was searched using keywords such as 'coagulation FVIII level decreased'. Identified cases reported prior to 13 October 2021 were included in this report. Cases in which patients had FVIII inhibitors were excluded.

RESULTS

Here we report 14 cases of less-than-expected FVIII activity. Details varied greatly amongst the cases. At presentation, FVIII activity ranged from 1% (15 min post-dose) to 51% (2 days post-dose). Seven patients experienced bleeding episodes after switching to N8-GP with heterogeneity in bleeding presentations. Six out of seven patients who were tested for anti-PEG IgG and/or IgM antibodies were positive. In all known cases, FVIII activity returned to the expected range when switched to an alternative FVIII replacement product.

CONCLUSION

In conclusion, the 14 reported cases of less-than-expected FVIII activity, without presence of detectable FVIII inhibitors, presented with heterogenous characteristics, and wide variations in FVIII activity and anti-PEG antibody titre. FVIII activity returned to the expected range after switching to alternative FVIII products. In line with WFH guidelines, monitoring of FVIII activity can ensure FVIII activity in the expected range. The safety surveillance of N8-GP continues.

Clinical course and prognosis of patients with hepatocellular carcinoma and haemophilia

INTRODUCTION

Although patients with haemophilia are known to develop hepatocellular carcinoma (HCC) at a lower age than patients without, there are few reports on the clinical course and prognosis of HCC.

AIM

We aimed to investigate the clinical course and prognosis of patients with HCC and haemophilia.

METHODS

Twenty-two patients with haemophilia, who were initially diagnosed with HCC between 2003 and 2021, were included. Their clinical courses and prognoses were retrospectively analysed. The results were compared with those of the 24th Nationwide Follow-up Survey of Primary Liver Cancer.

RESULTS

All 22 patients were male; of these, 20 patients had haemophilia A, and 2 had haemophilia B. The mean age of diagnosis was 63 years (range 45-78 years) which is lower than the mean of 72 years reported in the Nationwide Survey. The mean diameter of the largest tumour was 30 mm (range 11-70 mm), and 18 tumours (82%) were solitary at the initial diagnosis. Standard treatments for HCC were performed in all patients. Sixty-one transarterial chemoembolisation, 28 RFA, 10 hepatectomies, and 2 radiation treatments were performed, and molecular-targeted agents were administered to 5 patients during their clinical courses. No deaths were associated with complications of HCC treatments. The median survival time after initial treatment was 6.4 years (range 0.9-18.7 years) which did not differ much from the median survival time of 5.8 years in the Nationwide Survey.

CONCLUSION

Standard treatment for HCC could improve the prognosis of patients with HCC and haemophilia.

Phase 3 Trial of Concizumab in Hemophilia with Inhibitors

BACKGROUND

Concizumab is an anti-tissue factor pathway inhibitor monoclonal antibody designed to achieve hemostasis in all hemophilia types, with subcutaneous administration. A previous trial of concizumab (explorer4) established proof of concept in patients with hemophilia A or B with inhibitors.

METHODS

We conducted the explorer7 trial to assess the safety and efficacy of concizumab in patients with hemophilia A or B with inhibitors. Patients were randomly assigned in a 1:2 ratio to receive no prophylaxis for at least 24 weeks (group 1) or concizumab prophylaxis for at least 32 weeks (group 2) or were nonrandomly assigned to receive concizumab prophylaxis for at least 24 weeks (groups 3 and 4). After a treatment pause due to nonfatal thromboembolic events in three patients receiving concizumab, including one from the explorer7 trial, concizumab therapy was restarted with a loading dose of 1.0 mg per kilogram of body weight, followed by 0.2 mg per kilogram daily (potentially adjusted on the basis of concizumab plasma concentration as measured at week 4). The primary end-point analysis compared treated spontaneous and traumatic bleeding episodes in group 1 and group 2. Safety, patient-reported outcomes, and pharmacokinetics and pharmacodynamics were also assessed.

RESULTS

Of 133 enrolled patients, 19 were randomly assigned to group 1 and 33 to group 2; the remaining 81 were assigned to groups 3 and 4. The estimated mean annualized bleeding rate in group 1 was 11.8 episodes (95% confidence interval [CI], 7.0 to 19.9), as compared with 1.7 episodes (95% CI, 1.0 to 2.9) in group 2 (rate ratio, 0.14 [95% CI, 0.07 to 0.29]; P<0.001). The overall median annualized bleeding rate for patients receiving concizumab (groups 2, 3, and 4) was 0 episodes. No thromboembolic events were reported after concizumab therapy was restarted. The plasma concentrations of concizumab remained stable over time.

CONCLUSIONS

Among patients with hemophilia A or B with inhibitors, the annualized bleeding rate was lower with concizumab prophylaxis than with no prophylaxis. (Funded by Novo Nordisk; explorer7 ClinicalTrials.gov number, NCT04083781.).

Investigation of removal and inactivation efficiencies of human sapovirus in drinking water treatment processes by applying an in vitro cell-culture system

Here, we examined the efficiencies of drinking water treatment processes for the removal and inactivation of human sapovirus (HuSaV). We applied a recently developed in vitro cell-culture system to produce purified solutions of HuSaV containing virus concentrations high enough to conduct virus-spiking experiments, to develop an integrated cell culture-polymerase chain reaction (ICC-PCR) assay to quantify the infectivity of HuSaV, and to conduct virus-spiking experiments. In virus-spiking coagulation-sedimentation-rapid sand filtration (CS-RSF) and coagulation-microfiltration (C-MF) experiments, HuSaV removals of 1.6-3.7-log₁₀ and 1.2->4.3-log₁₀, respectively, were observed. The removal ratios observed with CS-RSF were comparable and correlated with those of murine norovirus (MNV, a widely used surrogate for human noroviruses) and pepper mild mottle virus (PMMoV, a potential surrogate for human enteric viruses in physical and physicochemical drinking water treatment processes), and those observed with C-MF were higher than but still correlated with those of MNV and PMMoV, indicating that MNV and PMMoV are both potential surrogates for HuSaV in CS-RSF and C-MF. For astrovirus (AstV, a representative human enteric virus), removal ratios of 1.8-3.3-log₁₀ and 1.1->4.0-log₁₀ were observed with CS-RSF and C-MF, respectively. The removal ratios of AstV observed with CS-RSF were comparable and correlated with those of PMMoV, and those observed with C-MF were higher than but still correlated with those of PMMoV, indicating that PMMoV is a potential surrogate for AstV in CS-RSF and C-MF. When the efficacy of chlorine treatment was examined by using the developed ICC-PCR assay, 3.8-4.0-log₁₀ inactivation of HuSaV was observed at a CT value (free-chlorine concentration [C] multiplied by contact time [T]) of 0.02 mg-Cl₂·min/L. The infectivity reduction ratios of HuSaV were comparable with those of MNV. For AstV, 1.3-1.7-log₁₀ and >3.4-log₁₀ inactivation, as evaluated by ICC-PCR, was observed at CT values of 0.02 and 0.09 mg-Cl₂·min/L, respectively. These results indicate that HuSaV and AstV are both highly sensitive to chlorine treatment and more sensitive than a chlorine-resistant virus, coxsackievirus B5 (1.3-log₁₀ inactivation at a CT value of 0.4 mg-Cl₂·min/L, as evaluated by the ICC-PCR assay).

The usefulness of tranexamic acid for bleeding symptoms of chronic consumptive coagulopathy complicated by aortic disease: a single-institute, retrospective study of 14 patients

BACKGROUND

Tranexamic acid (TXA) is an antifibrinolytic drug that blocks lysine-binding sites on the profibrinolytic enzyme plasminogen. Aortic diseases with chronic consumption coagulopathy may lead to disseminated intravascular coagulation (DIC) and cause fatal bleeding. Although the use of antifibrinolytic agents in DIC is generally not recommended due to enhanced fibrin deposition risking thrombotic symptoms, the efficacy of TXA has been reported in several cases of DIC with aortic diseases. However, the efficacy and safety of TXA for bleeding symptoms of chronic consumption coagulopathy with aortic diseases have not been studied in detail.

METHODS

We evaluated the efficacy of TXA in 14 patients with chronic consumptive coagulopathy due to aortic disease complicated by bleeding symptoms. Changes in coagulation and fibrinolysis parameters from baseline were analyzed with Wilcoxon matched-pairs signed-rank tests, excluding missing values. Kaplan-Meier curves were used to analyze overall survival.

RESULTS

Median age was 78.5 years (range, 66-89 years) and median observation period was 448 days (range, 0-2282 days). Twelve patients had chronic renal failure and 1 patient had chronic liver failure. Before starting treatment, median Japanese Ministry of Health and Welfare DIC diagnostic criteria score was 8 (range, 4-11) and median platelet count was 64 × 10⁹/L (range, 25-97 × 10⁹/L). Twelve patients underwent evaluation of bleeding symptoms after introduction of TXA, and 10 of those 12 patients showed improved bleeding tendencies within 30 days (median, 5.0 days). One patient with chronic liver failure showed worsening of bleeding symptoms. Although only one patient was initiated TXA in combination with anticoagulants, no significant worsening of thrombotic events was observed within 30 days.

CONCLUSIONS

TXA therapy appears effective against chronic consumptive coagulopathy with bleeding due to aortic disease, with few side effects.

The efficacy and safety of caplacizumab in Japanese patients with immune-mediated thrombotic thrombocytopenic purpura: an open-label phase 2/3 study

Caplacizumab is an anti-von Willebrand factor humanized single-variable-domain immunoglobulin fragment whose efficacy and safety in immune-mediated thrombotic thrombocytopenia purpura (iTTP) have been demonstrated in international studies. This prospective, open-label phase 2/3 study evaluated caplacizumab 10 mg administered daily during plasma exchange and for 30 days afterward, in combination with immunosuppressive treatment, in Japanese adults with a clinical diagnosis of iTTP (new or recurrent). The primary endpoint was prevention of iTTP recurrence; key secondary endpoints included time to platelet count response, time to organ damage normalization, and safety. Among 21 treated patients, 1 of 15 (6.7%) evaluable patients developed iTTP recurrence. Median time to normalization was 2.79 days for platelet count and 2.65 days for organ damage markers (n = 15). Treatment-emergent adverse events (TEAEs) were mostly mild to moderate in severity; the most frequently reported caplacizumab-related TEAEs were increased alanine aminotransferase, epistaxis, and gastrointestinal hemorrhage (all in 9.5% of patients). At least one bleeding event was reported in 7 of 21 patients (33%). Caplacizumab was effective in Japanese patients with iTTP, with a low rate of iTTP recurrence, rapid normalization of platelet counts and organ damage markers, and no unexpected TEAEs. Trial registration: ClinicalTrials.gov identifier, NCT04074187.

The seroprevalence of neutralizing antibodies against the adeno-associated virus capsids in Japanese hemophiliacs

Adeno-associated virus (AAV) vectors are promising modalities of gene therapy to address unmet medical needs. However, anti-AAV neutralizing antibodies (NAbs) hamper the vector-mediated therapeutic effect. Therefore, NAb prevalence in the target population is vital in designing clinical trials with AAV vectors. Hence, updating the seroprevalence of anti-AAV NAbs, herein we analyzed sera from 100 healthy individuals and 216 hemophiliacs in Japan. In both groups, the overall seroprevalence against various AAV serotypes was 20%–30%, and the ratio of the NAb-positive population increased with age. The seroprevalence did not differ between healthy participants and hemophiliacs and was not biased by the concomitant blood-borne viral infections. The high neutralizing activity, which strongly inhibits the transduction with all serotypes in vitro, was mostly found in people in their 60s or of older age. The multivariate analysis suggested that “60s or older age” was the only independent factor related to the high titer of NAbs. Conversely, a large proportion of younger hemophiliacs was seronegative, rendering them eligible for AAV-mediated gene therapy in Japan. Compared with our previous study, the peak of seroprevalences has shifted to older populations, indicating that natural AAV exposure in the elderly occurred in their youth but not during the last decade.

VWF-Gly2752Ser, a novel non-cysteine substitution variant in the CK domain, exhibits severe secretory impairment by hampering C-terminal dimer formation

BACKGROUND

Von Willebrand factor (VWF) is a multimeric glycoprotein that plays important roles in hemostasis and thrombosis. C-terminal interchain-disulfide bonds in the cystine knot (CK) domain are essential for VWF dimerization. Previous studies have reported that missense variants of cysteine in the CK domain disrupt the intrachain-disulfide bond and cause type 3 von Willebrand disease (VWD). However, type 3 VWD-associated noncysteine substitution variants in the CK domain have not been reported.

OBJECTIVE

To investigate the molecular mechanism of a novel non-cysteine variant in the CK domain, VWF c.8254 G>A (p.Gly2752Ser), which was identified in a patient with type 3 VWD as homozygous.

METHODS

Genetic analysis was performed by whole exome sequencing and Sanger sequencing. VWF multimer analysis was performed using SDS-agarose electrophoresis. VWF production and subcellular localization were analyzed using ex vivo endothelial colony forming cells (ECFCs) and an in vitro recombinant VWF (rVWF) expression system.

RESULTS

The patient was homozygous for VWF-Gly2752Ser. Plasma VWF enzyme-linked immunosorbent assay showed that the VWF antigen level of the patient was 1.2% compared with healthy subjects. A tiny amount of VWF was identified in the patient's ECFC. Multimer analysis revealed that the circulating VWF-Gly2752Ser presented only low molecular weight multimers. Subcellular localization analysis of VWF-Gly2752Ser-transfected cell lines showed that rVWF-Gly2752Ser was severely impaired in its ER-to-Golgi trafficking.

CONCLUSION

VWF-Gly2752Ser causes severe secretory impairment because of its dimerization failure. This is the first report of a VWF variant with a noncysteine substitution in the CK domain that causes type 3 VWD.

Elucidation of peripheral nerve myelination by bimodal waveform analysis

PURPOSE

As the myelin sheath of the peripheral nerves is immaturely developed in children, a bimodal waveform may be evoked when sensory nerve conduction studies are performed in them. However, there has been no study regarding the relationship between age and the frequency of appearance of the bimodal waveform or the inter-peak latency. Herein, we examined how the bimodal waveform changes with age.

METHODS

A total of 218 sensory nerves (109 median and 109 ulnar nerves) in 86 children (0 to 15 years old) were analyzed. The frequency of the bimodal waveform and the distance-corrected inter-peak latency were examined with antidromic sensory nerve conduction studies of the upper limbs on proximal stimulation.

RESULTS

The frequency of bimodal waveforms and distance-corrected inter-peak latency decreased with age. Analysis of the slope line of the scatter plot demonstrated that the bimodal waveform was present until the age of 15-16 years.

CONCLUSION

The bimodal waveform of sensory nerves faded with growth. Given that development-associated temporal dispersion is considered to be the cause of the differences in the bimodal waveform, our findings suggest that the underlying cause of the bimodal waveform is an immature myelin sheath, which may not be fully developed until the age of 15-16 years.

Clinical conditions and risk factors for inhibitor-development in patients with haemophilia: A decade-long prospective cohort study in Japan, J-HIS2 (Japan Hemophilia Inhibitor Study 2)

BACKGROUND

Inhibitor-development is a serious complication in patients with haemophilia (PwH). Previous studies reported that therapeutic and genetic factors could be associated with these alloantibodies. Relevant clinical features such as genetic-background and different treatment regimens in Japan remain unclear, however.

AIMS

To analyse a nation-wide Japanese registry for PwH, and to examine risk factors for inhibitor-development.

METHODS AND RESULTS

Newly diagnosed patients with haemophilia A (PwHA) or haemophilia B (PwHB) without inhibitors after 2007, and with treatment records traceable from 0 to 75 exposure days (ED), were enrolled in the Japan Hemophilia Inhibitor Study 2 (J-HIS2) initiated in 2008. Of 417 patients (340 PwHA, 77 PwHB) from 46 facilities, 83 (76 PwHA, 7 PwHB) were recorded with inhibitors by July 2020. Inhibitors were observed in 31.0% of severe PwHA, 8.0% moderate and 1.6% mild and in 17.1% of severe PwHB. The majority of inhibitors (89.7% in severe PwHA and 71.4% in severe PwHB) were detected on or before 25ED (median 12ED in PwHA and 19ED in PwHB). Genotyping in these severe patients identified an association between inhibitor-development and null variants of F8 (P < .01) or F9 (P < .05). A lower incidence of inhibitors was recorded in severe PwHA treated with prophylaxis than in those treated on-demand (P < .01). A past-history of intracranial-haemorrhage appeared to be associated with inhibitor-development, while FVIII-concentrates infusion and routine vaccination on the same day was not related to inhibitor-development.

CONCLUSION

The J-HIS2 study has identified significant clinical variables associated with inhibitor-development in Japanese PwH, consistent with other global studies.

OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION

Background

Genome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.

Objectives

The study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.

Methods

A total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.

Results

We identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.

Conclusion

Our study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.

References

[1]F. C. Arnett et al. Ann Rheum Dis, 2010.

[2]T. R. Radstake et al. Nat Genet, 2010.

[3]Y. Allanore et al. PLoS Genet, 2011.

[4]O. Gorlova et al. PLoS Genet, 2011.

[5]C. Terao et al. Ann Rheum Dis, 2017.

[6]E. López-Isac et al. Nat Commun, 2019.

[7]W. Pu et al. J Invest Dermatol, 2021.

Disclosure of Interests

None declared

Evaluation of reduction efficiencies of pepper mild mottle virus and human enteric viruses in full-scale drinking water treatment plants employing coagulation-sedimentation-rapid sand filtration or coagulation-microfiltration

Here, we evaluated the reduction efficiencies of indigenous pepper mild mottle virus (PMMoV, a potential surrogate for human enteric viruses to assess virus removal by coagulation-sedimentation-rapid sand filtration [CS-RSF] and coagulation-microfiltration [C-MF]) and representative human enteric viruses in four full-scale drinking water treatment plants that use CS-RSF (Plants A and B) or C-MF (Plants C and D). First, we developed a virus concentration method by using an electropositive filter and a tangential-flow ultrafiltration membrane to effectively concentrate and recover PMMoV from large volumes of water: the recovery rates of PMMoV were 100% when 100-L samples of PMMoV-spiked dechlorinated tap water were concentrated to 20 mL; even when spiked water volume was 2000 L, recovery rates of >30% were maintained. The concentrations of indigenous PMMoV in raw and treated water samples determined by using this method were always above the quantification limit of the real-time polymerase chain reaction assay. We therefore were able to determine its reduction ratios: 0.9-2.7-log10 in full-scale CS-RSF and 0.7-2.9-log10 in full-scale C-MF. The PMMoV reduction ratios in C-MF at Plant C (1.0 ± 0.3-log10) were lower than those in CS-RSF at Plants A (1.7 ± 0.5-log10) and B (1.4 ± 0.7-log10), despite the higher ability of MF for particle separation in comparison with RSF owing to the small pore size in MF. Lab-scale virus-spiking C-MF experiments that mimicked full-scale C-MF revealed that a low dosage of coagulant (polyaluminum chloride [PACl]) applied in C-MF, which is determined mainly from the viewpoint of preventing membrane fouling, probably led to the low reduction ratios of PMMoV in C-MF. This implies that high virus reduction ratios (>4-log10) achieved in previous lab-scale virus-spiking C-MF studies are not necessarily achieved in full-scale C-MF. The PMMoV reduction ratios in C-MF at Plant D (2.2 ± 0.6-log10) were higher than those at Plant C, despite similar coagulant dosages. In lab-scale C-MF, the PMMoV reduction ratios increased from 1-log10 (with PACl [basicity 1.5], as at Plant C) to 2-4-log10 (with high-basicity PACl [basicity 2.1], as at Plant D), suggesting that the use of high-basicity PACl probably resulted in higher reduction ratios of PMMoV at Plant D than at Plant C. Finally, we compared the reduction ratios of indigenous PMMoV and representative human enteric viruses in full-scale CS-RSF and C-MF. At Plant D, the concentrations of human norovirus genogroup II (HuNoV GII) in raw water were sometimes above the quantification limit; however, whether its reduction ratios in C-MF were higher than those of PMMoV could not be judged since reduction ratios were >1.4-log10 for HuNoV GII and 2.3-2.9-log10 for PMMoV. At Plant B, the concentrations of enteroviruses (EVs) and HuNoV GII in raw water were above the quantification limit on one occasion, and the reduction ratios of EVs (>1.2-log10) and HuNoV GII (>1.5-log10) in CS-RSF were higher than that of PMMoV (0.9-log10). This finding supports the usefulness of PMMoV as a potential surrogate for human enteric viruses to assess virus removal by CS-RSF.

International consensus recommendations on the management of people with haemophilia B

Haemophilia B is a rare X-linked genetic deficiency of coagulation factor IX (FIX) that, if untreated, can cause recurrent and disabling bleeding, potentially leading to severe arthropathy and/or life-threatening haemorrhage. Recent decades have brought significant improvements in haemophilia B management, including the advent of recombinant FIX and extended half-life FIX. This therapeutic landscape continues to evolve with several non-factor replacement therapies and gene therapies under investigation. Given the rarity of haemophilia B, the evidence base and clinical experience on which to establish clinical guidelines are relatively sparse and are further challenged by features that are distinct from haemophilia A, precluding extrapolation of existing haemophilia A guidelines. Due to the paucity of formal haemophilia B-specific clinical guidance, an international Author Group was convened to develop a clinical practice framework. The group comprised 15 haematology specialists from Europe, Australia, Japan, Latin America and North America, covering adult and paediatric haematology, laboratory medicine and biomedical science. A hybrid approach combining a systematic review of haemophilia B literature with discussion of clinical experience utilized a modified Delphi format to develop a comprehensive set of clinical recommendations. This approach resulted in 29 recommendations for the clinical management of haemophilia B across five topics, including product treatment choice, therapeutic agent laboratory monitoring, pharmacokinetics considerations, inhibitor management and preparing for gene therapy. It is anticipated that this clinical practice framework will complement existing guidelines in the management of people with haemophilia B in routine clinical practice and could be adapted and applied across different regions and countries.

The influence of hepatitis C virus eradication on hepatocarcinogenesis in patients with hemophilia

INTRODUCTION AND OBJECTIVES

Hepatitis C virus (HCV) infections in patients with hemophilia lead to the development of hepatocellular carcinoma (HCC) at a relatively younger age than that in patients without hemophilia. Although recent progress in direct-acting-antivirals has facilitated a high rate of sustained virological response (SVR), the clinical influence of HCV eradication in hemophilia patients remains unclear. This study aimed to compare the clinical outcomes of SVR against HCV in patients with and without hemophilia.

PATIENTS AND METHODS

The study enrolled 699 patients who achieved SVR after HCV antiviral treatment. Patients were divided into two groups: 78 patients with hemophilia (H group) and 621 patients without hemophilia (NH group). We evaluated patient characteristics, clinical outcomes, and the cumulative incidence of HCC after SVR.

RESULTS

Compared with the NH group, patients in the H-group were significantly younger and had a lower hepatic fibrosis score. No difference was found in the incidence of liver-related disease or overall death between the two groups over a mean follow-up period of 7 years. Four patients in the H group and 36 patients in the NH group were diagnosed with HCC after SVR. Multivariate analysis showed that male sex, age, and cirrhosis were significant risk factors for HCC incidence. There was no significant difference in the cumulative incidence of HCC after propensity-score matching adjusting for the risk factors of HCC between the two groups.

CONCLUSION

Hemophilia is not a significant risk factor for hepatocarcinogenesis after SVR against HCV.

AKATSUKI study: a prospective, multicentre, phase IV study evaluating the safety of emicizumab under and immediately after immune tolerance induction therapy in persons with congenital haemophilia A with factor VIII inhibitors

INTRODUCTION

For persons with haemophilia A with factor (F) VIII inhibitors (PwHAwI), immune tolerance induction (ITI) therapy is indicated for inhibitor eradication; however, since PwHAwI on ITI were excluded from the emicizumab clinical development programme, there are limited safety data for emicizumab treatment under/immediately after ITI in PwHAwI. Accordingly, there is a need to collect safety and efficacy data on this concomitant treatment strategy. The AKATSUKI study aims to evaluate the safety of emicizumab under/immediately after ITI in PwHAwI; here we report details of the study protocol.

METHODS AND ANALYSIS

AKATSUKI is an open-label, non-randomised, interventional, multicentre study. Twenty participants with congenital HA with FVIII inhibitors will be enrolled from 17 sites across Japan. Emicizumab will be administered subcutaneously, with an initial loading dose of 3 mg/kg once per week (QW) for the first 4 weeks, followed by a maintenance dose of 1.5 mg/kg QW, 3 mg/kg once every 2 weeks or 6 mg/kg once every 4 weeks. For ITI therapy, 50 IU/kg FVIII will be administered three times per week. For extended half-life FVIII, a dosing frequency of twice per week will be permitted. The primary endpoint is a comprehensive safety evaluation of adverse events (mainly thromboembolic events) and abnormal laboratory values over time. Secondary endpoints are the number of bleeds requiring coagulation factor treatment, the number of participants achieving a partially successful ITI response, FVIII inhibitor titres under/immediately after ITI, quality of life and time to achieve a negative FVIII inhibitor result (<0.6 BU/mL) and partial success in PwHAwI starting ITI after study enrolment.

CONCLUSIONS

AKATSUKI will evaluate the safety of emicizumab administered under/immediately after ITI, providing reference data to inform treatment strategies in PwHAwI.

ETHICS AND DISSEMINATION

The results of this study will be published in a peer-reviewed international journal and presented at national and/or international medical scientific conferences; the major findings of this study will be published on the jRCT registry website (https://jrct.niph.go.jp).

TRIAL REGISTRATION NUMBER

jRCTs041200037.

International Society of Blood Transfusion survey of experiences of blood banks and transfusion services during the COVID-19 pandemic

BACKGROUND AND OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic has impacted blood systems worldwide. Challenges included maintaining blood supplies and initiating the collection and use of COVID-19 convalescent plasma (CCP). Sharing information on the challenges can help improve blood collection and utilization.

MATERIALS AND METHODS

A survey questionnaire was distributed to International Society of Blood Transfusion members in 95 countries. We recorded respondents' demographic information, impacts on the blood supply, CCP collection and use, transfusion demands and operational challenges.

RESULTS

Eighty-two responses from 42 countries, including 24 low- and middle-income countries, were analysed. Participants worked in national (26.8%) and regional (26.8%) blood establishments and hospital-based (42.7%) institutions. CCP collection and transfusion were reported by 63% and 36.6% of respondents, respectively. Decreases in blood donations occurred in 70.6% of collecting facilities. Despite safety measures and recruitment strategies, donor fear and refusal of institutions to host blood drives were major contributing factors. Almost half of respondents working at transfusion medicine services were from large hospitals with over 10,000 red cell transfusions per year, and 76.8% of those hospitals experienced blood shortages. Practices varied in accepting donors for blood or CCP donations after a history of COVID-19 infection, CCP transfusion, or vaccination. Operational challenges included loss of staff, increased workloads and delays in reagent supplies. Almost half of the institutions modified their disaster plans during the pandemic.

CONCLUSION

The challenges faced by blood systems during the COVID-19 pandemic highlight the need for guidance, harmonization, and strengthening of the preparedness and the capacity of blood systems against future infectious threats.

Assessment of global coagulation function under treatment with emicizumab concomitantly with bypassing agents in haemophilia A with inhibitor (UNEBI Study): multicentre open-label non-randomised clinical trial

INTRODUCTION

Subcutaneous emicizumab prophylaxis substantially reduces bleeding episodes in patients with haemophilia A (PwHA) and factor VIII inhibitor. However, thrombotic events occurred in some PwHA with inhibitor who had received high cumulative doses of activated prothrombin complex concentrates at their breakthrough bleeds, when they were also given prophylactic emicizumab. After that, although the recommended guidance was proposed for bypassing agents (BPAs) therapy under emicizumab prophylaxis for haemostatic management, detailed investigation(s) is(are) required to elucidate the safe and appropriate dose of BPAs to use concomitantly with emicizumab prophylaxis.

METHODS AND ANALYSIS

In the UNEBI Study, 60 PwHA with inhibitor will be enrolled for a maximum duration of 3 years, and samples of 20 events following concomitant use of BPAs with emicizumab will be collected. An 'event' is defined as obtaining blood samples before and after administration of BPA when a breakthrough bleed or a surgical procedure occurs. The coagulation potential in the obtained samples will be measured by global coagulation assays. The primary endpoint is the degree of improvement in the maximum coagulation rate by clot waveform analysis (CWA) before and after administration of fixed-dose BPAs. This parameter obtained from CWA, which is triggered with an optimally diluted mixture of prothrombin time/activated partial thromboplastin time-reagents, is reported to be an excellent marker for assessing the degree of improvement in coagulation potential in emicizumab-treated plasma.

ETHICS AND DISSEMINATION

The UNEBI Study was approved by the Japan Certified Review Board of Nara Medical University. The results of the study will be communicated through publication in international scientific journals and presentations at (inter)national conferences.

TRIAL REGISTRATION NUMBER

jRCTs051190119.

Feasibility of the automated column agglutination technique for titration of anti-A/B antibodies in ABO-incompatible living kidney transplantation

INTRODUCTION

Quantitative measurement of anti-A/-B antibody titers is important during ABO-incompatible living kidney transplantation (ABOi-LKT).

METHODS

We conducted a multi-institutional study to measure the antibody titers using the automated column agglutination technique (auto-CAT) and tube test (TT) method in ABOi-LKT recipients. Statistical analysis was performed to evaluate the two methods.

RESULTS

We examined 111 samples from 35 ABOi-LKT recipients at four institutions. The correlation coefficient of the two methods was >0.9; the concordance rate and clinically acceptable concordance rate for the IgG titers were 60.4% and 88.3%, respectively. Perioperative status did not influence the statistical significance. Parallel changes were observed in the IgG antibody titers measured using the auto-CAT or TT technique by desensitizing therapy in time-course monitoring.

CONCLUSION

Auto-CAT is comparable with the TT technique and is feasible for IgG anti-A/B antibody titration in ABOi-LKT recipients.

Design of the HEM-POWR study: a prospective, observational study of real-world treatment with damoctocog alfa pegol in patients with haemophilia A

INTRODUCTION

Haemophilia A is a rare bleeding disorder caused by defects in coagulation factor VIII (FVIII). Damoctocog alfa pegol (BAY 94-9027, Jivi, Bayer, Germany) is a site-specifically PEGylated, extended-half-life, recombinant FVIII, approved for use in previously treated patients (PTPs) aged ≥12 years with haemophilia A. However, a real-world evidence regarding routine clinical use of damoctocog alfa pegol is limited.

METHODS AND ANALYSIS

HEM-POWR is a multinational, multicentre, non-interventional, prospective, postmarketing cohort study evaluating the effectiveness and safety of real-world treatment with damoctocog alfa pegol. Estimated enrolment is ≥200 PTPs with haemophilia A, receiving damoctocog alfa pegol (on-demand, prophylaxis or intermittent prophylaxis (as per local label)), observed for 36 months. Primary outcomes are total bleeding events and annualised bleeding rate; secondary outcomes include long-term safety, joint health, pharmacokinetics, patient-reported outcomes (PROs) from validated questionnaires and perioperative haemostasis. Where applicable, reasons for switching to damoctocog alfa pegol, choice of treatment regimen and dose will also be captured. Exploratory and descriptive statistical analyses will be performed, and will be stratified by parameters including, but not limited to, prophylaxis regimen and haemophilia severity. Patients can record bleeds and consumption in electronic (e) Diaries, ePROs, and can access non-promotional study information (videos explaining study procedures) via an online patient portal. Optionally, patients can enrol in the LIFE-ACTIVE substudy designed to investigate the relationship between activity (measured by the ActiGraph CP Insight watch) and effectiveness parameters collected from HEM-POWR.

ETHICS AND DISSEMINATION

Study approval was obtained by local independent ethics committees and authorities in participating study centres across Europe, the Americas and Asia. Informed consent from patients or their legal representative is a requirement for participation. The study results will be submitted for publication in a peer-reviewed scientific journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBERS

NCT03932201, EUPAS26416.

PROTOCOL VERSION AND DATE

V.1.2, 27 September 2019.

Concomitant use of bypassing agents with emicizumab for people with haemophilia A and inhibitors undergoing surgery

INTRODUCTION

Surgery in people with haemophilia and factor VIII inhibitors is typically managed with perioperative administration of haemostatic agents to prevent or control the occurrence of bleeding events. Practical experience of surgery in patients with inhibitors who are receiving treatment with emicizumab is growing; however, the novelty of the situation means that standardised guidelines are lacking with regard to the concomitant administration of haemostatic agents, including dose and laboratory monitoring.

AIM

To review approaches to haemostatic management during major and minor invasive procedures in patients with haemophilia A and inhibitors, and to provide recommendations for controlling bleeding events.

METHODS

A search was conducted, limited to the past 4 years (January 2016-April 2020), pertaining to published evidence of surgery for patients receiving emicizumab. Publications identified from the search were manually reviewed to determine studies and case reports relevant for inclusion.

RESULTS

Identified literature and practical experience of the authors were used to build a consensus of practical recommendations for the concomitant administration of haemostatic agents during the perioperative period for elective surgery in patients with inhibitors who are receiving emicizumab.

CONCLUSIONS

The current evidence base indicates that surgery can be successfully performed in patients with inhibitors who are receiving emicizumab and that bypassing agents can be used concomitantly. Data from prospective studies are required to further support recommendations for haemostatic management of surgery in patients receiving emicizumab.

[The management strategy for von Willebrand disease]

The von Willebrand factor (VWF), one of the largest plasma proteins in mammals, is an essential factor in primary hemostasis. It forms a bridge between platelet membrane glycoprotein Ib and extracellular matrix constituents, thereby playing a critical role in platelet adhesion to vascular injury sites. Its deficiency, known as von Willebrand disease is the most common inherited bleeding disorder. VWF is also a carrier protein for blood clotting factor VIII, an interaction required for normal factor VIII survival in circulation. As its symptoms are less severe than those of hemophilia and due to its wide variety, a large number of cases may not have actually been diagnosed. In the selection of therapeutic measures and patient management for bleeding symptoms, introduction of recombinant VWF concentrates is expected to expand the range of therapeutic options.

Anemia in older adults as a geriatric syndrome: A review

Anemia, a frequently occurring condition in older patients, has no standard definition; however, in most studies, it is defined as hemoglobin level <12 and <13 g/dL in women and men, respectively. Approximately 10% of older adults living in the community have anemia. The prevalence of anemia is significantly correlated with advanced age and male sex. Anemia is associated with falls, frailty and other negative outcomes, including early mortality. However, there remains little consensus regarding whether anemia treatment favorably affects these adverse outcomes. Therefore, this article reviews the prevalence of anemia, and provides updates on its common causes and treatments in older adults. While excluding well-established hematopoietic diseases, the etiology of anemia in older adults has been grouped into four categories: (i) nutritional deficiency; (ii) inflammation; (iii) clonal hematopoiesis; and (iv) "unexplained anemia," when there is no clear mechanism to account for the anemia. Recently, clonal leukocytes were detected in a considerable number of older individuals. The number of somatic mutations in blood leukocytes increases with age; however, single mutations of DNMT3A, TET2 and ASXL1 are not correlated with the presence of unexplained anemia in older adults. With an increased understanding of anemia etiology and the availability of innovative anti-anemic drugs, future studies that evaluate the causes and benefits of treatment are required. Geriatr Gerontol Int 2021; 21: 549-554.

Tolerability of Molecular-targeted Agents for Hepatocellular Carcinoma Treatment in Haemophiliacs

BACKGROUND

Hepatocellular carcinoma (HCC) is considered a leading cause of death in patients with haemophilia. Recent advances in the treatment of unresectable HCC with molecular-targeted agents (MTAs) have led to better clinical outcomes. However, the tolerability of MTAs by haemophilic patients with HCC remains unclear.

AIM

This study aimed to compare the tolerability of MTAs in such patients.

PATIENTS AND METHODS

From January 2011 to October 2020, five haemophilic patients with HCC were treated with MTAs. Adverse events were assessed in comparison with 265 non-haemophilic patients with HCC.

RESULTS

The prevalence of hand-foot skin reaction was not higher in the haemophiliacs than in the non-haemophiliacs, whereas the rate of haemorrhagic events was higher in the haemophiliacs (6.0% versus 40.0%, p=0.037).

CONCLUSION

Haemophiliacs tolerate long-term MTA use, without the occurrence of life-threatening complications. However, careful observation and prevention are needed for MTA-related gastrointestinal bleeding in haemophiliacs.

Essential role of a carboxyl-terminal α-helix motif in the secretion of coagulation factor XI

BACKGROUND

Coagulation factor XI (FXI) is a plasma serine protease zymogen that contributes to hemostasis. However, the mechanism of its secretion remains unclear.

OBJECTIVE

To determine the molecular mechanism of FXI secretion by characterizing a novel FXI mutant identified in a FXI-deficient Japanese patient.

PATIENT/METHODS

The FXI gene (F11) was analyzed by direct sequencing. Mutant recombinant FXI (rFXI) was overexpressed in HEK293 or COS-7 cells. Western blotting and enzyme-linked immunosorbent assay were performed to examine the FXI extracellular secretion profile. Immunofluorescence microscopy was used to investigate the subcellular localization of the rFXI mutant.

RESULTS

We identified a novel homozygous frameshift mutation in F11 [c.1788dupC (p.E597Rfs*65)], resulting in a unique and extended carboxyl-terminal (C-terminal) structure in FXI. Although rFXI-E597Rfs*65 was intracellularly synthesized, its extracellular secretion was markedly reduced. Subcellular localization analysis revealed that rFXI-E597Rfs*65 was abnormally retained in the endoplasmic reticulum (ER). We generated a series of C-terminal-truncated rFXI mutants to further investigate the role of the C-terminal region in FXI secretion. Serial rFXI experiments revealed that a threonine at position 622, the fourth residue from the C-terminus, was essential for secretion. Notably, Thr622 engages in the formation of an α-helix motif, indicating the importance of the C-terminal α-helix in FXI intracellular behavior and secretion.

CONCLUSION

FXI E597Rfs*65 results in the pathogenesis of a severe secretory defect resulting from aberrant ER-to-Golgi trafficking caused by the lack of a C-terminal α-helix motif. This study demonstrates the impact of the C-terminal structure, especially the α-helix motif, on FXI secretion.

[The diagnosis and management of von Willebrand disease]

Von Willebrand disease (VWD) is a congenital bleeding disorder caused by quantitative and qualitative abnormalities in von Willebrand factor (VWF). VWD was first reported in 1926 by Dr. Erik von Willebrand, a Swedish physician, who reported a bleeding disorder in a family. VWD manifests as bleeding from the skin and mucous membranes (abnormal primary hemostasis). The symptoms are less severe than those of hemophilia and may be undiagnosed in many cases. Evidence-based guidelines are required for selection and patient management. Since ristocetin cofactor activity (vWF:RCo) and VWF antigen levels (vWF:Ag) are not routinely measured in clinical laboratories, the actual diagnosis is often determined by a mild prolongation of the activated partial thromboplastic time (APTT) associated with a relative decrease in factor VIII activity. Particularly, it is desirable to provide standard treatment measures on how to introduce the recently proposed bleeding score (BS; clinically scored for various bleeding symptoms of VWD) and how to deal with gynecological symptoms, such as excessive menstruation and irregular vaginal bleeding. In terms of treatment options, recombinant vWF concentrates were introduced in 2020, which has led to the expansion in the range of treatment options for patients.

Phase I clinical trial of intra-bone marrow cotransplantation of mesenchymal stem cells in cord blood transplantation

Mesenchymal stem cells (MSCs) have immunomodulatory properties and support hematopoiesis in the bone marrow (BM). To develop a new strategy to not only prevent graft‐vs‐host disease (GVHD) but also to enhance engraftment, a phase I trial of cord blood transplantation (CBT) combined with intra‐BM injection of MSCs (MSC‐CBT) was designed. Third‐party BM‐derived MSCs were injected intra‐BM on the day of CBT. The conditioning regimen varied according to patient characteristics. GVHD prophylaxis was tacrolimus and methotrexate. The primary endpoint was toxicity related to intra‐BM injection of MSCs. Clinical outcomes were compared with those of six controls who received CBT alone. Five adult patients received MSC‐CBT, and no adverse events related to intra‐BM injection of MSCs were observed. All patients achieved neutrophil, reticulocyte, and platelet recoveries, with median times to recoveries of 21, 35, and 38 days, respectively, comparable with controls. Grade II‐IV acute GVHD developed in three controls but not in MSC‐CBT patients. No patients developed chronic GVHD in both groups. At 1 year after transplantation, all MSC‐CBT patients survived without relapse. This study shows the safety of MSC‐CBT, and the findings also suggest that cotransplantation of MSCs may prevent GVHD with no inhibition of engraftment. This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry as number 000024291.

Safety and efficacy of percutaneous radiofrequency ablation for hepatocellular carcinoma patients with haemophilia

Haemophilia is an X-linked inherited bleeding disorder caused by coagulation factor deficiency. Hepatocellular carcinoma (HCC) is a major complication associated with the disease. No study thus far has investigated the safety and efficacy of percutaneous radiofrequency ablation (RFA) for HCC in patients with haemophilia.

AIM

This study aimed to evaluate the safety and efficacy of RFA for HCC in haemophilia patients.

METHODS

From July 2008 to June 2019, 217 patients with HCC underwent 300 RFA sessions. Of these, 18 sessions were performed in ten haemophilia patients (H group) and 282 in 207 non-haemophilia patients (NH group). The patients' characteristics, incidence of haemorrhagic complications and rates of local tumour recurrence were compared between the groups.

RESULTS

A majority of the haemophilia patients received clotting factor concentrate replacement therapy before and after RFA treatment, with the aim of reaching a plasma clotting factor level of higher than 60%-80%. Twelve haemorrhagic complications were observed in the NH group (4.2%; 12/282). Major bleeding requiring control procedures was observed in two patients and minor bleeding with careful observation was noted in ten patients. No bleeding complications were observed in the H group (0/18). There were no significant differences in the 5-year local tumour recurrence rates after RFA treatment between the groups (35.0% in the H group and 32.1% in the NH group).

CONCLUSION

RFA could be an effective and a safe method for HCC treatment in patients with haemophilia.

Long-term safety and efficacy of emicizumab for up to 5.8 years and patients' perceptions of symptoms and daily life: A phase 1/2 study in patients with severe haemophilia A

Introduction

Safety and efficacy results of the phase 1 study and phase 1/2 extension study of the bispecific antibody emicizumab in patients with severe haemophilia A with or without factor VIII inhibitors for up to 2.8 years were reported previously.

Aim

To evaluate further longer‐term data including patients’ perceptions at study completion.

Methods

Emicizumab was administered subcutaneously once weekly at maintenance doses of 0.3, 1 or 3 mg/kg with potential up‐titration. All patients were later switched to the approved maintenance dose of 1.5 mg/kg.

Results

Eighteen patients received emicizumab for up to 5.8 years. Most adverse events were mild and unrelated to emicizumab. Annualized bleeding rates (ABRs) for bleeds treated with coagulation factors decreased from pre‐emicizumab rates or remained zero in all patients. The median ABRs were low at 1.25, 0.83 and 0.22 during the 0.3, 1 and 3 mg/kg dosing periods, respectively. Of 8 patients who decreased their doses from 3 to 1.5 mg/kg, ABRs decreased in 4, remained at zero in 2, and increased in 2. Total time spent with symptoms associated with treated bleeds decreased in all patients except 2. All patients answered ‘improved’ for bleeding severity and time until bleeding stops, except 1 answering ‘slightly improved’. Most patients answered ‘improved’ or ‘slightly improved’’ for daily life and feelings; in particular, all patients except 1 answered ‘improved’ or ‘slightly improved’ for anxiety.

Conclusions

Long‐term emicizumab prophylaxis for up to 5.8 years was safe and efficacious, and may improve patients’ daily lives and feelings, regardless of inhibitor status.

Vascular endothelial growth factor (VEGF)-A and VEGF-A165b are associated with time to remission of granulomatosis with polyangiitis in a nationwide Japanese prospective cohort study

BACKGROUND

Effective prognostic markers are needed for antineutrophil cytoplasmic antibody-associated vasculitis (AAV). This study evaluated the clinical associations of serum vascular endothelial growth factor-A (sVEGF-A) and sVEGF-A₁₆₅b (an antiangiogenic isoform of VEGF-A) concentrations with time to remission of AAV in a nationwide Japanese prospective follow-up cohort.

METHODS

We collected samples from patients with AAV who were enrolled in the nationwide Japanese cohort study (RemIT-JAV-RPGN). We measured sVEGF-A and sVEGF-A₁₆₅b concentrations using enzyme-linked immunosorbent assays in 57 serum samples collected 6 months before and after initiation of AAV treatment. Patients were classified based on AAV disease subtypes: microscopic polyangiitis, granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis (EGPA).

RESULTS

Results revealed significant reductions in sVEGF-A and sVEGF-A₁₆₅b concentrations in patients with microscopic polyangiitis and EGPA, respectively. However, despite the comparable concentrations of sVEGF-A and sVEGF-A₁₆₅b during the 6 months of treatment in granulomatosis with polyangiitis patients, correlation analysis revealed that the differences in log₂-transformed concentrations of sVEGF-A and sVEGF-A₁₆₅b were inversely correlated with time to remission in granulomatosis with polyangiitis patients.

CONCLUSION

These results suggest that sVEGF-A and -A₁₆₅b can serve as potential markers of time to remission in patients with granulomatosis with polyangiitis.

Suitability of pepper mild mottle virus as a human enteric virus surrogate for assessing the efficacy of thermal or free-chlorine disinfection processes by using infectivity assays and enhanced viability PCR

Evaluating the efficacy of disinfection processes to inactivate human enteric viruses is important for the prevention and control of waterborne diseases caused by exposure to those viruses via drinking water. Here, we evaluated the inactivation of two representative human enteric viruses (adenovirus type 40 [AdV] and coxsackievirus B5 [CV]) by thermal or free-chlorine disinfection. In addition, we compared the infectivity reduction ratio of a plant virus (pepper mild mottle virus [PMMoV], a recently proposed novel surrogate for human enteric viruses for the assessment of virus removal by coagulation‒rapid sand filtration and membrane filtration) with that of the two human enteric viruses to assess the suitability of PMMoV as a human enteric virus surrogate for use in thermal and free-chlorine disinfection processes. Finally, we examined whether conventional or enhanced viability polymerase chain reaction (PCR) analysis using propidium monoazide (PMA) or improved PMA (PMAxx) with or without an enhancer could be used as alternatives to infectivity assays (i.e., plaque-forming unit method for AdV and CV; local lesion count assay for PMMoV) for evaluating virus inactivation by disinfection processes. We found that PMMoV was more resistant to heat treatment than AdV and CV, suggesting that PMMoV is a potential surrogate for these two enteric viruses with regard to thermal disinfection processes. However, PMMoV was much more resistant to chlorine treatment compared with AdV and CV (which is chlorine-resistant) (CT value for 4-log₁₀ inactivation: PMMoV, 84.5 mg-Cl₂·min/L; CV, 1.15-1.19 mg-Cl₂·min/L), suggesting that PMMoV is not useful as a surrogate for these enteric viruses with regard to free-chlorine disinfection processes. For thermal disinfection, the magnitude of the signal reduction observed with PMAxx-Enhancer-PCR was comparable with the magnitude of reduction in infectivity, indicating that PMAxx-Enhancer-PCR is a potential alternative to infectivity assay. However, for free-chlorine disinfection, the magnitude of the signal reduction observed with PMAxx-Enhancer-PCR was smaller than the magnitude of the reduction in infectivity, indicating that PMAxx-Enhancer-PCR underestimated the efficacy of virus inactivation (i.e., overestimated the infectious virus concentration) by chlorine treatment. Nevertheless, among the PCR approaches examined in the present study (PCR alone, PMA-PCR or PMAxx-PCR either with or without enhancer), PMAxx-Enhancer-PCR provided the most accurate assessment of the efficacy of virus inactivation by thermal or free chlorine disinfection processes.

Impact of variation in reagent combinations for one-stage clotting assay on assay discrepancy in nonsevere haemophilia A

INTRODUCTION

Factor VIII activity (FVIII:C) is measured by one-stage clotting assay (OSA) or chromogenic substrate assay (CSA). Significant differences in FVIII:C between OSA (FVIII:C_1st ) and CSA (FVIII:C_Chr ) are described as assay discrepancy in nonsevere haemophilia A (HA). A large number of reagent combinations (APTT reagent and FVIII-deficient plasma) are used for OSA, but the impact of variations in reagent combinations on assay discrepancy has not been fully characterized.

AIM

To clarify the variations in FVIII:C_1st /FVIII:C_Chr ratios according to OSA reagent combination in HA subjects with/without assay discrepancy.

METHODS

Thirty-nine patients previously diagnosed with nonsevere HA were enrolled, and their FVIII genes were investigated and FVIII:C levels were assessed by a single CSA reagent and 11 OSA reagent combinations. Receiver operating characteristic (ROC) curve analysis was used to predict possible cut-off values of the FVIII:C_1st /FVIII:C_Chr ratio to define FVIII assay discrepancy for each reagent combination.

RESULTS

Patients were categorized into nondiscrepant (n = 25), discrepant (n = 5) and unclassified (n = 9) groups according to their genotypes and information in the database. The FVIII:C_1st /FVIII:C_Chr ratio in nondiscrepant HA varied widely, depending on the APTT reagents and FVIII-deficient plasma used. The ratio in discrepant HA patients differed with respect to their genotype and the reagent combination used. ROC curve analyses revealed that cut-off values to distinguish the assay discrepancy differed depending on the reagents used, but revealed two novel genotype variants, p.Cys573Gly and p.Gly582Arg, associated with FVIII assay discrepancy.

CONCLUSION

Our findings showed that the FVIII:C_1st /FVIII:C_Chr ratio is dependent on the reagent combination used for OSA.

An overview of the pathfinder clinical trials program: Long-term efficacy and safety of N8-GP in patients with hemophilia A

N8-GP (turoctocog alfa pegol, Esperoct® ; Novo Nordisk A/S, Bagsvaerd, Denmark) is a state-of-the-art, extended half-life factor VIII (FVIII) molecule used for prophylactic and on-demand treatment of patients with hemophilia A. The pathfinder clinical trial program, which began with the pathfinder1 trial in 2010, was developed to assess the long-term efficacy and safety of N8-GP in children, adolescents, and adults. The pivotal pathfinder2 (adolescents and adults) and pathfinder5 (children) trials were completed in late 2018, and comprehensive analyses of the end-of-trial results are published together with this article as part of an N8-GP Supplement. Furthermore, results from the pathfinder3 trial, which was designed to evaluate the safety and efficacy of N8-GP during major surgery, have also recently been finalized. Here, we provide an overview of the pathfinder clinical development program and summarize key data from the completed pathfinder trials. We also provide perspectives on the future of extended half-life FVIII molecules in the treatment of patients with hemophilia A and describe currently ongoing pathfinder trials.

Periodic Elastic Motion in a Self-Assembled Monolayer under Spontaneous Oscillations of Surface Tension: Molecules in a Scrum Push Back a Marangoni Flow

Regularly recurring phenomena are a common and important part of life. Such rhythmic behaviors are often seen in nonliving systems under far-from-equilibrium conditions. The study of simple nonliving systems provides clues for improving our understanding of the origin of biological rhythms. Here, we focus on the spontaneous oscillation of surface tension associated with an intermittent Marangoni convective flow generated by two types of surfactants, those that are partially soluble (long chain alcohols) and insoluble (lipids) in water. In this system, we find that the collective motions of two surfactants interact with each other in a systematic manner to control a stable periodic motion: the alcohol molecules (donor) produce a Marangoni flow, and the lipid molecules (acceptor) in a monolayer push the flow back. The shape of the surface tension oscillation can be explained by the viscoelastic properties of the acceptor surfactant, whereas the period of the surface tension oscillation has been explained by the physical properties of the donor surfactant. A recently developed time-resolved X-ray surface scattering technique enables the dynamic structure of the water surface under flow to be determined. We have repeatedly observed that lipid molecules at the air-water interface become regularly oriented normal to the surface at every onset of the Marangoni convective flow.

Aberrant X chromosomal rearrangement through multi-step template switching during sister chromatid formation in a patient with severe hemophilia A

Background

Hemophilia A (HA) is an X‐linked recessive bleeding disorder caused by pathogenic variants of the coagulation factor VIII gene (F8). Half of the patients with severe HA have a recurrent inversion in the X chromosome, that is, F8 intron 22 or intron 1 inversion. Here, we characterized an abnormal F8 due to atypical complex X chromosome rearrangements in a Japanese patient with severe HA.

Methods

Recurrent F8 inversions were tested with inverse shifting‐PCR. The genomic structure was investigated using PCR‐based direct sequencing or quantitative PCR.

Results

The proband's X chromosome had a 119.5 kb insertion, a reverse duplex of an extragenic sequence on the F8 telomere region into the F8 intron 1 with two breakpoints. The telomeric breakpoint was a joining from the F8 intron 1 to the inverted FUNDC2 via a two‐base microhomology, and the centromeric breakpoint was a recombination between F8 intron 1 homologous sequences. The rearrangement mechanism was suggested as a multi‐step rearrangement with template switching such as fork stalling and template switching (FoSTeS)/microhomology‐mediated break‐induced replication (MMBIR) and/or homologous sequence‐associated recombination during a sister chromatid formation.

Conclusion

We identified the aberrant X chromosome with a split F8 due to a multi‐step rearrangement in a patient with severe HA.