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Factor VIII (FVIII) functions as a cofactor of FIXa for FX activation in the intrinsic tenase complex. The 1811-1818 region in the FVIII A3 domain was observed to contribute to FIXa binding, and the K1813A/K1818A mutant increased the binding affinity for FIXa. The current study aims to identify mutated FVIII protein(s) that increase FVIIIa cofactor activity in the 1811-1818 region. FVIII mutants with K1813A, K1818A, and K1813A/K1818A were expressed in baby hamster kidney cells and were followed by assessments using purified and global coagulation assays for mouse models with hemophilia A (HA). A surface plasmon resonance–based assay revealed that the Kd value of FVIII-K1813A for FIXa interaction was lower than that of the wild-type (WT) (3.9±0.7/6.3±0.3 nM). However, the Km value of FVIII-K1813A for FIXa on tenase activity was comparable with that of the WT, whereas the kcat of this mutant was significantly greater than that of the WT. Thrombin-catalyzed FVIII-K1813A activation was ∼1.3-fold more enhanced than that of the WT, and the spontaneous decay of activated FVIII-K1813A was ∼2.5-fold slower than that of WT. The heat stability assay revealed that the decay rate of FVIII-K1813A was ∼2.5-fold slower than that of WT. Thrombin generation assay and rotational thromboelastometry using blood samples from patients with HA demonstrated that the addition of FVIII-K1813A (0.5 nM) exhibited a coagulation potential compatible with that of WT (1 nM). In the tail clip assay of HA mice, FVIII-K1813A showed a two- to fourfold higher hemostatic potential than that of the WT. FVIII-K1813A, with higher a FIXa binding affinity, enhances the global coagulation potential because of the stability of FVIII/FVIIIa molecules.

Elevated factor VIII activity (FVIII:C) is often observed in patients with acquired hemophilia A (PwAHA) in remission. However, comprehensive coagulation potentials in this patient group remain to be investigated.To evaluate comprehensive coagulation potentials in PwAHA.We investigated coagulation function in eleven PwAHA with high FVIII:C ( 150 IU/dL) using thrombin generation assay (TGA) and/or rotational thromboelastometry (ROTEM), and compared findings with results obtained from contrived samples generated by spiking recombinant FVIII.The median FVIII:C and FVIII inhibitor titers during remission in enrolled PwAHA were 206 IU/dL and 0.44 BU/mL, respectively. In all patients, lag time and time to peak were either prolonged or normal compared to contrived samples corresponding to their FVIII:C. However, higher values of peak thrombin and endogenous thrombin potentials compared to contrived samples were observed in two patients. ROTEM parameters were within normal ranges in all cases. One patient (FVIII:C 171 IU/dL) developed venous thrombosis and pulmonary embolism, but TGA parameters showed low or normal coagulation potential compared to contrived samples corresponding to his FVIII:C.PwAHA with high FVIII:C could exhibit lower coagulation potentials than those corresponding to their FVIII:C.

Congenital cytomegalovirus (cCMV) infection is the most common congenital viral infection and is the leading non-genetic cause of sensorineural hearing loss and an important cause of neurodevelopmental disabilities. Auto auditory brainstem response (AABR) is a simple hearing test and used for the purpose of neonatal hearing screening, but can use it for early detection hard of hearing within the study age of the model. We experienced two case of asymptomatic CMV infection in which congenital and late-onset hearing loss were diagnosed early with AABR, and hearing loss improved with valganciclovir.

Background; Factor (F)V plays pivotal roles in both procoagulant and anticoagulant mechanisms. Genetic mutations, FV-W1920R (FVNara) and FV-A2086D (FVBesançon), in the C1 and C2 domains of FV light chain, respectively, appear to be associated with deep vein thrombosis. The detailed mechanism(s) between these mutations and thrombophilia remains to be fully explored, however. Aim; To clarify thrombotic mechanism(s) in the presence of these FV abnormalities. Methods and Results; Full-length wild-type (WT) and mutated FV were prepared using stable, human cell lines (HEK293T) with the piggyBac transposon system. The susceptibility of FVa-A2086D to activated protein C (APC) was reduced, resulting in significant inhibition of APC-catalyzed inactivation with little cleavage at Arg306 and delayed cleavage at Arg506. Furthermore, APC cofactor activity of FV-A2086D in APC-catalyzed inactivation of FVIIIa through cleavage at Arg336 was impaired. Surface plasmon resonance-based assays demonstrated that FV-A2086D bound to Glu-Gly-Arg-chloromethylketone active site-blocked APC and PS with similar affinities to FV-WT. However, deteriorated interaction between FVa-A2086D to phospholipid membranes was evident, by the prothrombinase assay. Moreover, the addition of FVa-A2086D to plasma failed to inhibit tissue factor (TF)-induced thrombin generation and prothrombin times. This inhibitory effect was independent from protein (P)C, PS, and antithrombin. The coagulant and anticoagulant characteristics of FV(a)-W1920R were similar to those of FV(a)-A2086D. Conclusions; FV-A2086D presented defects in the APC mechanisms associated with FVa inactivation and FV cofactor activity, similar to FV-W1920R. Moreover, both FV proteins that were mutated in the light chain impaired inhibition of TF-induced coagulation reactions. These defects were consistent with congenital thrombophilia.

Global coagulation potential was assessed in 59 patients with acquired hemophilia A (PwAHA) by clot waveform analysis (CWA) and/or thrombin and plasmin generation assay. Relationships between factor VIII activity (FVIII:C) and the parameters from CWA and T/P-GA in patients with congenital HA were compared by grading coagulation potential related to FVIII:C: T1 (FVIII:C < 1 IU/dL), T2 (1 ≤ , ≤ 5 IU/dL), T3 (5 < , 12 ≤ IU/dL), and T4 (12 < , ≤ 50 IU/dL). The median FVIII:C and inhibitor titers in PwAHA on admission were 3.3 IU/dL and 63.0 BU/mL, respectively, but global coagulation parameters corresponded to T1 or less. Median FVIII:C levels during follow-up in PwAHA were 1.7-9.6-6.7-40.0-21.7 IU/dL on days 0-14-28-56-93, respectively. CWA-based data corresponded to less than T2 until day 28, but more closely reflected FVIII:C after day 56. Peak thrombin was severely low (near T1) until day 28 and improved modestly after day 56 but remained less than T2. Peak plasmin was lower than T1 until day 56, and returned to T4 on day 93. In conclusion, global coagulation function in PwAHA was impaired to a greater extent than could be anticipated from assays of FVIII:C, until approximately 1 month after immunosuppression and treatment with FVIII-bypassing agents.

Emicizumab reduces bleeding episodes in patients with severe hemophilia A (PwHA). Little information is available on hemostatic management of severe traumatic hemorrhages in emicizumab-treated pediatric PwHA. We assessed therapeutic efficacy and global coagulation potentials in two pediatric cases of emicizumab-treated pediatric PwHA with intracranial or retroperitoneal/iliopsoas hemorrhage. A modified clot waveform analysis (CWA) triggered by mixtures of tissue factor and ellagic acid was used to assess coagulant potentials, and maximum coagulant velocity (Ad|min1|) was calculated. One patient with intracranial hemorrhage was treated with continuous infusions of recombinant factor VIII (rFVIII) at a dose of 4-4.6 IU/kg/hr for 9 days, followed by bolus infusion at 66 IU/kg/day for 2 days and 33 IU/kg/day for an additional 2 days. The Ad|min1| was increased from 5.5 (at baseline) to 7.0-8.1 under concomitant treatment and maintained within or near normal range (IQR; 6.9-7.7). The other patient with retroperitoneal/iliopsoas hemorrhage received bolus infusions of rFVIII at 50 IU/kg/day for 20 days and every-other-day infusion of rFVIII for 8 days. The Ad|min1| was increased from 5.2 (at baseline) to 5.8-6.8 under concomitant treatment and maintained within the normal range. We successfully managed a treatment plan for severe traumatic bleeding in emicizumab-treated pediatric PwHA using modified CWA.

Disturbances in the balance between coagulation, anticoagulation and fibrinolysis may lead to thrombosis or haemorrhage. Simultaneous assessments of thrombin and plasmin facilitate overall understandings of pathological haemostasis, especially for thrombophilia. Here, we characterized coagulation-fibrinolysis potentials in plasmas with thrombophilia using anticoagulants-mediated thrombin-plasmin generation assay (T/P-GA). T/P-GA was initiated by adding tissue factor, tissue-type plasminogen activator and anticoagulants [recombinant-thrombomodulin (rTM), activated protein (P)C (APC) and antithrombin (AT)], followed by simultaneous thrombin generation and plasma generation monitoring. Patients' plasmas with PC-deficiency (PC-def), PS-deficiency (PS-def), AT-deficiency (AT-def), factor VLeiden (FVL) and antiphospholipid syndrome (APS) were evaluated. A ratio of peak-thrombin (or peak-plasmin) with and without anticoagulants was calculated as anticoagulants (+)/anticoagulants (-). First, TG, in rTM-mediated, PC-def, PS-def and FVL showed higher peak-thrombin ratios than the controls, whereas AT-def and APS exhibited no differences from the controls. In APC-mediated, PC-def, PS-def and AT-def showed low peak-thrombin ratios, similar to the controls, but immune-depleted PS-def (1%) showed the higher ratio than the controls. FVL and APS showed higher peak-thrombin ratios than the controls. In AT-mediated, peak-thrombin ratios in PS-def, PC-def and APS were lower than in controls, but those in AT-def and FVL was not significantly different from the controls. Second, PG, in rTM-mediated, all thrombophilia plasmas showed low peak-plasmin ratios (∼0.5), but no significant difference was observed, relative to the controls. In APC and AT-mediated, peak-plasmin ratios in thrombophilia-related plasmas were similar to the controls (∼1.0). Anticoagulants-mediated T/P-GA may classify thrombin generation characteristics in thrombophilia-related plasmas upon adding anticoagulants.

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder. Various autoimmune diseases, including AHA, have been reported to occur after the administration of mRNA COVID-19 vaccines. However, the characteristics of these AHA cases remain unclear. We report a case in which AHA arose in a young patient after the administration of an mRNA COVID-19 vaccine, but improved rapidly. The patient's factor VIII (FVIII) inhibitor titer spontaneously decreased to less than half of that seen at diagnosis. One week after the initial immunosuppressive therapy, the FVIII inhibitor had disappeared. Our case suggests that AHA that arises in young patients after COVID-19 vaccination may resolve spontaneously, and the levels of FVIII inhibitors may decrease more rapidly in such cases than in idiopathic AHA. Unlike for immune thrombocytopenic purpura (ITP), no acute type of AHA has been recognized. This case suggests that just as there is an acute type of ITP that develops in children/after vaccination, there may be an acute type of AHA that arises in young patients that receive mRNA COVID-19 vaccines.

Introduction Emicizumab prophylaxis improves coagulation function in congenital hemophilia A, regardless of inhibitor presence. We recently reported that emicizumab enhanced the coagulant potentials, ex vivo, in plasmas from patients with acquired hemophilia A (PwAHAs) at diagnosis. However, coagulant effects of emicizumab in PwAHAs during the clinical course remain unclear. Aim To assess ex vivo coagulant effects of emicizumab in PwAHAs during the clinical course. Methods/Results Blood samples were obtained from 14 PwAHAs on (median) days 0 and 6 during a severe-bleeding phase, and days 27 and 59 during a reduced-bleeding phase with elevated endogenous factor VIII (FVIII) and decreased inhibitor titers. If administered a single dose of 3 or 6 mg/kg, or two doses at 6 mg/kg followed by 3 mg/kg, estimated plasma emicizumab concentrations (10/5/2.5, 20/10/5, and 30/15/7.5 µg/mL on days 0–7/30/60, respectively) could be used to represent potential changes, based on the half-life (T 1/2: ∼30 days). Emicizumab concentrations that covered maximum plasma concentrations of each dosage were used for spiking on day 0. Ex vivo addition of estimated emicizumab to PwAHA's plasma containing endogenous FVIII and/or inhibitor, without and with recombinant (r)FVIIa administration during immunosuppressive therapy, increased the calculated Ad|min1| values, assessed by clot waveform analysis, and their coagulant potentials were below normal levels. Rotational thromboelastometry revealed that ex vivo emicizumab addition resulted in the further improvement of coagulant potentials in whole bloods when combined with rFVIIa administration. Conclusion Based on ex vivo and in vitro data, emicizumab has the potential to be effective in clinical situations for PwAHAs.

Background: It is important to analyze the types of vaccines in travel clinics to determine the focus points in future practice. Methods We retrospectively reviewed the electronic medical records of all patients who visited the travel clinic of Nara Medical University between June 2013 and December 2019 to determine their background and the vaccines administered. The information regarding adverse events of the unapproved vaccines in Japan (Havrix®, Verorab®, Boostrix®, Priorix®, Typhim Vi®, and Mencevax®) was also collected. Results Of 645 patients, 58.6% were men and the median age was 31 years. Business was the most common travel purpose (34.9%), and Southeast Asia was the most common destination (40.2%). More than 80% of travelers to low- and middle-income countries were vaccinated against hepatitis A, while the rabies vaccination rate was approximately 50%. Typhoid vaccination coverage among travelers to South Asia was approximately 50%. The incidence of adverse events requiring medical consultation, telephonic consultation, or prolonged stay in the examination room was less than 5% for all unapproved vaccines in Japan. Conclusion More patient education is needed to increase the vaccination rate of rabies and typhoid vaccines. Adverse events to unapproved vaccines in Japan were not high and were well-tolerated.

The precise measurement of very low levels of factor IX activity (FIX:C 1 IU/dL) is essential for understanding clinical severity and risk of inhibitor development in patients with severe hemophilia B (Pw-SHB). However, such measurement sensitivity has not yet been achieved. We aimed to establish a measurement method using clot waveform analysis (CWA). Residual FIX:C by adding anti-FIX monoclonal antibody, FIX:C by adding recombinant (r)FIX to the commercial Pw-SHB plasmas, and FIX:C in our Pw-SHB were determined by CS-2000i

Emicizumab prophylaxis reduces bleeding in hemophilia A (HA) patients. However, there are few data on emicizumab treatment in neonates with HA (neonate-HA), and the procoagulant effects of emicizumab in these patients are unknown.To investigate the coagulation activity of emicizumab in vitro in a plasma model of neonate-HA.Plasmas from 84 neonates with non-HA were enrolled. However, due to the limited plasma volumes in some cases, 50 plasmas were assigned to two different assay groups. To prepare the neonate-HA model, plasma was first preincubated with an antifactor (F) VIII A2 monoclonal antibody (mAb). After further incubation with emicizumab, global coagulation activity was measured: adjusted maximum coagulation velocity (Ad|min1|) in clot waveform analysis (CWA) and peak thrombin in thrombin generation assay (TGA).Because the addition of anti-FVIII mAb to 22 of 43 samples showed little decrease in Ad|min1|, the remaining 21 samples were analyzed by CWA. The addition of emicizumab increased Ad|min1| in 18 of the 19 cases (effective group) but not in the remaining 3 cases (noneffective group). Similarly, TGA found that emicizumab (effective group) improved peak thrombin in seven of the nine samples tested, but two cases did not respond (noneffective group). Although the effective group had lower levels of FX, there was no significant difference between the effective and noneffective groups in terms of FIX, protein S, protein C, antithrombin, and fibrinogen.The in vitro coagulant potentials of emicizumab in the neonate-HA model were more heterogeneous than those recorded in the adult-HA model.

Absolute or relative protein (P)C pathway abnormalities (PC deficiency, PS deficiency, antiphospholipid syndrome (APS), factor (F)V-abnormality, and high FVIII level) cause thrombophilia. Although screening assays for these thrombophilias are available, one utilizing clot waveform analysis (CWA) remains unknown. We aimed to establish a CWA-based screening assay to distinguish PC pathway abnormality-related thrombophilia.Samples were reacted with tissue factor (TF)/phospholipids and recombinant thrombomodulin (rTM; optimal 20 nM), followed by CWA measurement. The peak ratio (with/without rTM) of the first derivative curve of clot waveform was calculated.The peak ratio in healthy plasmas (n = 35) was 0.36 ± 0.13; hence, the cutoff value was set to 0.49. The peak ratios in plasmas with PC deficiency, PS deficiency, high-FVIII (spiked 300 IU/dl), and APS were higher than the cutoff values (0.79/0.97/0.50/0.93, respectively). PC-deficient plasma or PS-deficient plasma mixed with normal plasma (25%/50%/75%/100% PC or PS level) showed dose-dependent decreases in the peak ratios (PC deficient: 0.85/0.64/0.44/0.28; PS deficient: 0.69/0.53/0.40/0.25), suggesting that the peak ratio at ≤50% of PC or PS level exceeded the cutoff value. The peak ratio in FV deficiency with FV ≤25% was higher than the cutoff value. FV-deficient plasma spiked with 40 IU/dl rFV-R506Q (FVrTM-mediated TF-triggered CWA might be useful for screening PC pathway abnormality-related thrombophilia.

A combined product of plasma-derived factor (F)VIIa and FX (pd-FVIIa/FX; Byclot®) is currently available for the hemostatic treatment of hemophilia A and B patients with inhibitors in Japan. Limited information is available, however, on its coagulant effect in acquired hemophilia A (AHA). In the present study, we assessed the coagulant effect of pd-FVIIa/FX on impairment of coagulation potentials in AHA. The bypassing agents, pd-FVIIa/FX, recombinant FVIIa (rFVIIa), and activated prothrombin complex concentrates (aPCC) were spiked with normal plasma preincubated with anti-FVIII monoclonal antibody (AHA-model plasma), and added to plasmas from AHA patients. Clot waveform analysis (CWA) triggered by the mixture of tissue factor and ellagic acid was subsequently performed. In the AHA-model, pd-FVIIa/FX improved all of the CWA parameters in a dose-dependent manner, irrespective of epitope specificity, with significant improvements relative to rFVIIa and aPCC. The coagulant effect of pd-FVIIa/FX at 1.6 µg/mL (corresponding to 120 µg/kg infusion) at the maximum therapeutic dose was outside the normal range. Moreover, the addition of pd-FVIIa/FX led to a greater improvement in the coagulant potentials in AHA plasmas than those of rFVIIa and/or aPCC. These data suggest that pd-FVIIa/FX significantly improves the impaired coagulant potentials in AHA and is potentially therapeutic.

Coagulation and fibrinolytic mechanisms are enhanced in patients with coronavirus (COVID-19), but disturbances in the balance of both functions in COVID-19 patients remain unclear. We assessed global coagulation and fibrinolysis in plasma from 167 COVID-19 patients (mild/moderate/severe: 62/88/17, respectively) on admission using clot-fibrinolysis waveform analysis (CFWA). Maximum coagulation velocity (|min1|) and maximum fibrinolysis velocity (|FL-min1|) were expressed as ratios relative to normal plasma. Ten patients (6.0%) developed thrombosis, 5 (3.0%) had bleeding tendency, and 13 (7.8%) died during admission. FDP levels increased with severity of COVID-19 symptoms (mild/moderate/severe; median 2.7/4.9/9.9 μg/mL, respectively). The |min1| ratios were elevated in all categories (1.27/1.61/1.58) in keeping with enhanced coagulation potential, with significant differences between mild cases and moderate to severe cases. The |FL-min1| ratios were also elevated in all groups (1.19/1.39/1.40), reflecting enhanced fibrinolytic potential. These data identified coagulation dominance in moderate to severe cases, but balanced coagulation and fibrinolysis in mild cases. There were significant differences in FDP and TAT, but no significant differences in |min1| or |FL-min1| ratios, between patients with and without thrombosis. CFWA monitoring of coagulation and fibrinolysis dynamics could provide valuable data for understanding hemostatic changes and disease status in COVID-19 patients.

Emicizumab reduces bleeding events in patients with severe hemophilia A (HA). The coagulation potential of emicizumab at a clinical dose appears to correspond to about 15 IU/dL of factor VIII activity (FVIII:C), the equivalent of converting from a severe to mild phenotype. However, the clinical and laboratory characteristics of HA patients receiving emicizumab (Emi-PwHA) compared with patients with mild HA (PwMHA) remain to be determined. We reviewed clinical data from Emi-PwHA (n = 63) and PwMHA (n = 15) and evaluated comprehensive coagulation function using Ca

Type 2N von Willebrand disease (VWD) is characterized by impaired factor VIII (FVIII) binding to von Willebrand factor (VWF). Type 2N VWD patients generally exhibit mild bleeding tendency, but some exhibit a more severe hemorrhagic pattern. An assay for assessing hemostatic potential and predict clinical severity could significantly improve clinical management in these patients. We examined the relationship between bleeding score (BS) and the potential for thrombus formation in whole blood from type 2N VWD patients with various BS using rotational thromboelastometry (ROTEM) and microchip flow-chamber system (T-TAS®). Collagen-coated PL-chips, or thromboplastin- and collagen-coated AR-chips, were utilized in the T-TAS to assess platelet thrombus formation at high shear flow, or fibrin-rich platelet thrombus formation at low shear flow, respectively. Neither ROTEM nor the T-TAS using PL-chips reflected the BS. The AR-chip parameters in the T-TAS, however, were highly sensitive to different BS levels among these patients, despite similar FVIII/VWF-related measurements including FVIII/VWF binding. Additionally, the results with AR-chip assay were restored to normal after infusions of FVIII/VWF concentrates in the most severe patients. The data indicate that T-TAS using AR-chips may be a useful assay for predicting clinical severity and assessing therapeutic efficiency in type 2N VWD patients.

Emicizumab is a bispecific antibody to factor (F) IX/IXa and FX/FXa, which mimics FVIIIa cofactor function. Emicizumab prophylaxis significantly decreases bleeding events for patients with hemophilia A (PwHA). However, global hemostatic monitoring in emicizumab-treated PwHA remains poorly investigated. Using rotational thromboelastometry (ROTEM), we evaluated coagulation potentials of whole blood samples from seven emicizumab-treated PwHA who participated in ACE001JP/ACE002JP studies. Dose-dependent coagulation-enhancing effects of emicizumab to whole blood from PwHA mixed with an anti-FVIII C2 antibody in vitro were evident by non-activated ROTEM analysis (NATEM). The relationship between FVIII levels and NATEM parameters in PwHA not participating in the clinical trials demonstrated that CT + CFT inversely correlated with FVIII levels. These parameters were defined as NATEM-based grading of coagulation potential; ‘T1’ (FVIII

Soft tissue infections with Mycobacterium mageritense are uncommon. We report the case of a 5-year-old girl who developed a subcutaneous abscess in her right ankle caused by M. mageritense. She had a history of acute encephalopathy and adrenal insufficiency and was hospitalized for acute pancreatitis. During hospitalization, the patient developed fever and tachycardia. Blood culture was positive for gram-positive bacilli. Although initial testing with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) reported a different organism, a repeat test identified M. mageritense. One month after the positive blood culture, she developed redness and swelling in the right ankle. The pus from the subcutaneous abscess after drainage grew M. mageritense, which was further confirmed by the sequencing of housekeeping genes. Based on sensitivity testing, the patient was treated with tosufloxacin and linezolid. The local inflammatory signs gradually improved on starting the treatment. The antibiotics were administered for 6 months, and she experienced no relapse during the 8 months of follow-up after the completion of therapy. This is the first case report of a pediatric M. mageritense infection, which also highlights an important potential pitfall of MALDI-TOF MS. Further, we observe that the choice of antimicrobials for the treatment of M. mageritense is more limited in children than in adults.

The plummeting acceptance rate of the HPV vaccine in Japan is one of the most disappointing vaccine-related events in recent times. Since 2013, the national HPV vaccine coverage rate fell from more than 70% to less than 1%. This survey investigated parental HPV vaccine acceptance and the factors that influence it.A multi-center survey was conducted in eight hospitals in Nara prefecture, Japan, from July 2019 to March 2020. Parents were asked to answer a series of questions in a survey that included information on the HPV vaccine.Among the 1884 parents who answered the questionnaire, 21.8% indicated that they had accepted the HPV vaccine even before reading the information provided in the questionnaire. The overall acceptance rate after everyone had read the information increased to 50.2% (p 0.001). Among those who still did not accept the vaccine after reading the information (N = 925), 26.7% indicated that they might change their mind if more vaccine safety reports were to appear in the mass media; other potentially influencing factors were direct communication from health care providers (35.1%), a recommendation by government (19.5%), and peer behavior (16.8%).The study showed that providing appropriate medical information significantly improves HPV vaccine acceptance. To reverse the loss of HPV vaccine acceptance in Japan, a multi-discipline approach that includes the mass media, health care providers, the government and the general population will be needed.

The human papillomavirus (HPV) vaccine is safe and effective for preventing HPV-related diseases. However, HPV vaccination rates in Japan are low because the "Ministry of Health, Labour and Welfare" had stopped recommending vaccination. We assessed healthcare workers' (HCWs) current recommendations regarding the HPV vaccine and how the provision of information about HPV vaccination affected their recommendations.A survey was conducted among nurses and physicians in Nara prefecture from March 2021 to July 2021. The questionnaire asked about their understanding, recommendations, and opinions regarding HPV vaccination. Before answering the last two questions (optional), the HCWs read evidence-based information quantifying the risks and benefits of HPV vaccination.A total of 441 HCWs completed the questionnaire. Only 19% of HCWs always recommended HPV vaccination for girls aged 12-16 years. The evidence-based information significantly improved the percentage of HCWs who would "always recommend" vaccination.This study showed that the proportion of HCWs who recommend HPV vaccination to adolescent girls remains low in Japan. However, we found that evidence-based information describing the causal relationship between adverse events and vaccination, quantifying the risks and benefits, noting the importance of HCW communications with families, and reporting the recommendations of national societies, might increase HCWs' recommendations for HPV vaccination.

Few studies have analyzed the characteristics of patients who develop physical disorders after overseas travel. We retrospectively reviewed the medical records of 183 patients who visited Nara Medical University Hospital from 2008 to 2016 because of physical problems after traveling abroad. The main travel destinations were Southeast Asia (n = 100), Africa (n = 27), and South Asia (n = 23). The main reasons for the travel were leisure (n = 96), business (n = 51), and volunteer work (n = 19). The most common final diagnosis was gastrointestinal disease (n = 72), followed by febrile disease (n = 59) and respiratory disease (n = 19). There were eight malaria cases, including one patient who was infected after14 days of overseas travel. Additionally, 61 of 71 cases of travelers' diarrhea and 15 of 21 cases of dengue fever occurred after14 days travel. 26 cases of vaccine preventable diseases, such as hepatitis A, typhoid fever, and influenza, were observed. Consequently, healthcare providers should notify Japanese overseas travelers that there is a non-negligible health risk inherent to short-term travel, while stressing on the importance of pre-travel medical consultation.

Bypassing therapy is essential for the haemostatic management of patients with haemophilia A with inhibitor (PWHA-inh), but the therapeutic effects are inconsistent. We previously reported that activated prothrombin complex concentrates (aPCC) activated factor (F)VIIIin vitro, and was mediated mainly by the activated FVII (FVIIa) contained in aPCC. We have extended those studies to assess global coagulation in whole blood from 18 PWHA-inh in the co-presence of aPCC and FVIII using Ca2+ -triggered rotational thromboelastometry. The clot times (CTs) in the presence of both aPCC (0·05 iu/ml) and recombinant (r)FVIII (1 iu/ml) ex vivo were shortened compared to the aPCC alone (P

Continuous infusions (CI) of factor (F)VIII are preferable to the conventional bolus injections for the maintenance of consistent FVIII levels during surgery in patients with severe hemophilia A. A third generation, B domain-truncated recombinant FVIII (turoctocog alfa, Novo Nordisk, NovoEight®), was approved for clinical use in 2014. The hemostatic efficacy and safety of bolus injections of turoctocog alfa in patients undergoing surgery have been reported, but no reports on CI therapy have been published. We describe a 43-year-old patient with severe hemophilia A who required arthroscopic synovectomy of the right elbow and arthrodesis of the right ankle. He was treated with a bolus injection of turoctocog alfa (36 IU/kg) immediately before operation, followed by CI (infusion rate; 2.9 IU/kg/h) to maintain FVIII activity > 80 IU/dl throughout the perioperative period. Surgery was completed successfully with uncomplicated hemostatic control. CIs were continued until post-operative day (POD) 4. Further bolus injections were given from POD5. No anti-FVIII inhibitor has been detected post-operation. This case provides important information on CI therapy using turoctocog alfa during surgery for patients with severe hemophilia A.

A combined product of plasma-derived factor (F)VIIa and FX (pd-FVIIa/FX; Byclot

Introduction Acquired hemophilia A (AHA) is caused by autoantibodies against factor (F)VIII, and is characterized by severe, spontaneous bleeding, which can be life-threatening. Emicizumab, an anti-FIXa/FX bispecific antibody, significantly reduces bleeding events in congenital hemophilia A (HA) with and without inhibitors. The known pathophysiological mechanisms and current preclinical data in HA suggest that emicizumab could provide effective treatment for AHA, but the coagulation activities of emicizumab in these patients remain unknown. Aim To evaluate the coagulant effects of emicizumab in plasma from AHA patients. Methods and results Tissue factor-triggered thrombin generation assays using normal plasma preincubated with anti-FVIII monoclonal antibodies recognizing different epitopes demonstrated that 20 µg/mL emicizumab recovered the depressed peak levels of thrombin generation to 46% to 72%. Further studies were devised, therefore, to simulate the clinical course in AHA patients, including during the acute phase for severe bleeding requiring FVIII-bypassing therapy, and during the subacute/chronic phase with less bleeding. Various concentrations of emicizumab were used to represent the potential changes in plasma levels based on the half-life of the antibody (~30 days). The ex vivo addition of emicizumab to plasma samples from AHA patients (n = 16) increased peak thrombin in all cases, irrespective of the inhibitor epitope specificity. Thrombin generation at 20 and 100 µg/mL emicizumab was restored to (median) 43.9% and 92.2%, respectively. Differences were evident in some cases, however, and recovery rates appeared likely to be greater in patients with type 2 inhibitor than those with type 1. Conclusion Emicizumab improved ex vivo coagulation potential in plasma from AHA patients.

Background: Infantile pertussis is a major concern and causes a significant health burden worldwide. Maternal adult tetanus, diphtheria, and acellular pertussis (Tdap) vaccination is very effective way of preventing infantile pertussis. However, Tdap has not been approved by the Japanese government or been included in Japan’s national immunization program (NIP). We carried out a questionnaire survey to investigate whether Japanese women would accept the Tdap vaccination if they were provided with appropriate information. Methods: The questionnaire survey was administered to pregnant women who visited the Obstetrics and Gynecology Department and mothers who visited the Pediatrics Department of Nara Medical University, Kashihara City, Japan, between October 2018 and May 2019. The questionnaire included information about pertussis infection and maternal vaccination, followed by seven questions. Results: A total of 943 participants answered the questionnaire (481 pregnant women and 462 mothers). Before reading the information, just 4.6% of participants knew that infantile pertussis can be prevented by maternal vaccination. After reading the information, 93.0% and 92.6% of participants thought that the maternal Tdap vaccine should be approved by the Japanese government and be included in the NIP, respectively. Although only 67.6% of participants wished to have the maternal Tdap vaccine without government financial support after reading the information, 92.5% said they would have the vaccine with government support (P

The link between factor (F)VIII and FX is essential for optimum activity of the tenase complex. The interactive site(s) in FVIII for FX remains to be completely clarified, however. We investigated the FVIII A2 domain-FX association that was speculated from inhibitory mechanism(s) by an anti-A2 autoantibody. SDS-PAGE demonstrated that the purified inhibitor IgG recognizing residues 373–562 blocked FXa cleavage at Arg372 in FVIII, and surface-plasmon resonance (SPR)-based assays showed that intact A2 subunit directly bound to FX (K d; 63 nM). The FVIII structure model indicated possible FX-binding site(s) in residues 400–429 in A2. One peptide corresponding to residues 400–409 competitively inhibited both the A2–FX binding and FVIIIa/FIXa-dependent FXa generation. Covalent cross-linking was observed between this peptide and FX following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) using SDS-PAGE. K408 and S409 were not evident in N-terminal sequence analysis of the cross-linked product, suggesting that two residues participated in cross-link formation. SPR-based assays using recombinant FVIII mutants with one or both residues substituted to alanine demonstrated that K408A and K408A/S409A had approximately fourfold high K d values of wild-type (WT-)FVIII. FXa cleavages at Arg372 in both mutants were significantly delayed, suggesting a contribution of K408 for FXa cleavage at Arg372. Furthermore, FXa generation assays with these mutants demonstrated that the K m values were 1.4- to 1.7-fold greater, and overall catalytic efficiency (k cat/K m) was 0.49- to 0.89-fold lower than with WT-FVIII, suggesting a significant contribution of K408 for FVIII–FX interaction in tenase assembly. We concluded that the K408 in the A2 domain provided an interactive-site for FX.

We describe an 8-year-old boy with acquired hemophilia A (AHA) associated with streptococcal infection and amoxicillin. Laboratory data revealed low factor VIII activity (FVIII:C, 1.5 IU/dl), and FVIII inhibitor (15.9 BU/ml). Comprehensive coagulation function assays, including rotation thromboelastometry (ROTEM®), revealed a markedly prolonged clotting time. Thrombin and plasmin generation (TG/PG) appeared to be moderately impaired. The inhibitor epitope of his anti-FVIII autoantibody recognized light and heavy chains. He was treated with Novoseven® and prednisolone, resulting in rapid improvement. ROTEM showed the return of coagulation time to normal level on day 20, and TG gradually improved. PG was moderately reduced in the clinical early phase, but improved at day 20. The patient’s IgG subtype was IgG4 at onset. IgG1 was transiently positive on day 20, but negative on day 46. FVIII inhibitor gradually decreased and was completely absent after day 46, along with the elevated FVIII:C. IgG4 was again elevated on day 83, followed by a rapid decrease, indicative of the presence of non-neutralizing antibody, which remains currently undetected. We for the first time report changes in comprehensive coagulation function and IgG subtype of anti-FVIII antibody in a rare pediatric case of AHA.

Aerosol medicine exhalation through the nose (ETN) is one of promising and comprehensive treatment methods for Eosinophilic Chronic Rhinosinusitis (ECRS) with asthma. In this treatment, the patient inhales aerosol of inhaled corticosteroid (ICS) medicine from mouth using portable inhaler. Then a part of the aerosol still floats and remains in upper airway. When the patient exhales inhaled air through the nose, the aerosol is effectively transported on the walls of middle meatus and olfactory fissure. This study performed Computational Fluid Dynamics (CFD) analysis for the transport phenomena of aerosol medicine during exhalation period in order to evaluate the curative effect of ETN numerically. As a result of CFD analysis, ETN formed impinging flow toward upper wall of nasopharynx, subsequently complex swirl and circulation flow in the nasopharynx region. In addition, main flow of ETN passed upper region of nasal cavity. Such the tendencies affected on aerosol transport characteristics; a part of aerosol particles moved into ethmoindal sinuses.

Factor (F) VIII functions as a cofactor in the tenase complex responsible for phospholipid surface-dependent conversion of FX to FXa by FIXa. FIXa binding sites were identified on A2, A3, and C2 domains of FVIII. Some earlier studies confirmed the FIXa-binding sites on residues 1811-1818 in FVIII A3 domain. According to the 3-D model of FVIIIa, the residues 1790-1798 in FVIII A3 domain form a loop and exist just close to residues 1811-1818 on the FVIIIa extended surface and might contribute to one of the FIXa binding regions. We, therefore, hypothesized that residues 1790-1798 might be one of the FIXa-binding components, and prepared synthetic peptides (1811-1818 and 1790-1798). The 1811-1818 peptide inhibited the FVIII light chain-EGR FIXa interaction (apparent Ki;10.5 ± 4.0 μM) on ELISA. The 1790-1798 peptide also inhibited these interaction (apparent Ki ;4.2± 1.2 μM), suggesting that the 1790-1798 region contributed to FIXa-interactive site. In general, the binding sites of serine protease in FVIII contain the acidic or basic rich residues. The residues 1790-1798, and 1811-1818 contain basic residues E1793, E1794, D1795, E1811, K1813, and K1818. To investigate the significance of these residues for FIXa-binding, the mutant forms of the A3 domain, converted to alanine, in BHK system and purified. Furthermore, because previous study demonstrated that F1816 might contribute to FIXa binding, we also prepared F1816A. Compared with wild type FVIII (Kd; 6.3± 0.3 nM), the binding affinity of F1816A and E1793A/E1794A/D1795A mutants for EGR FIXa were decreased by 1.4-fold (Kd; 9.1± 0.2 nM) and 1.3-fold (Kd; 8.4± 0.4 nM), respectively, on SPR-based assay, suggesting contribution of F1816, and E1793/E1794/D1795 to the binding interactions. On the other hand, the binding affinities of E1811A (Kd; 6.3± 2.1 nM) and K1818A (Kd; 5.1± 1.8 nM) mutants for FIXa were almost the same as that of wild type. Interestingly, the binding affinity of K1813A (Kd; 3.9± 0.7 nM) for FIXa was increased compared to wild type FVIII. For the functional evaluation of the association with FVIII mutants to FIXa, FVIII mutants were reacted with varying concentrations of FIXa in a FXa generation assay. F1816A and E1793A/E1794A/D1795A mutants decreased the FIXa affinity by 1.6-fold (Km; 10.6± 1.0 nM) and 2.8-fold (Km; 18.5± 4.3 nM), respectively, compared to wild type FVIII (Km; 6.6 ± 1.0 nM). These data suggested that not only F1816A but E1793A/E1794A/D1795A mutations contributed high Kmand low catalytic efficiency in FXase complex. E1811A (Km; 7.2 ± 0.7 nM), K1813A (Km; 4.5 ± 0.7 nM), and K1818A (Km; 4.5 ± 0.2 nM) mutants showed the similar FIXa affinities to wild type FVIII. Furthermore, to confirm that the F1816A and E1793A/E1794A/D1795A mutants were responsible for FIXa association, FIXa cleavages in these mutants were evaluated by SDS-PAGE and Western blot using anti-A1 monoclonal antibody. Compared with wild type FVIII, cleavages at Arg336 were slightly delayed in F1816A. On the other hand, those in E1793A/E1794A/D1795A were significantly delayed, indicative of contribution of these residues for FIXa bindings. After all, these results indicate that the 1790-1798 region in the FVIII A3 domain, and in particular a cluster of basic amino acids at residues 1793-1795, contributes to one of the FIXa-interactive sites. Disclosures Nogami: Chugai Pharmaceutical Co., Ltd: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Anti-FIXa/X bispecific antibodies , Research Funding, Speakers Bureau. Shima:Chugai Pharmaceutical Co., Ltd: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Anti-FIXa/X bispecific antibodies , Research Funding, Speakers Bureau; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees.

Essentials von Willebrand factor levels don't always reflect the severity of von Willebrand disease (VWD). Relationship between new flow system (T-TAS®) and bleeding score (BS) in type 1 VWD was studied. Patients with PL-T10 > 10 min had higher BS and particularly, PL-T10 > 8 min correlated best. T-TAS could be a useful tool for discriminating and predicting the BS in VWD type 1 patients. SummaryBackground The clinical phenotype of von Willebrand disease (VWD) is heterogeneous, and von Willebrand factor ristocetin cofactor activity (VWF:RCo) does not always reflect clinical severity, especially in VWD type 1. We have reported the potential of a microchip flow-chamber system (Total-Thrombus Formation Analysis System [T-TAS®]) for assessing physiologic hemostasis in VWD. Aim To evaluate the relationship between T-TAS, bleeding score (BS) and laboratory test results in type 1 VWD patients. Methods Microchips coated with collagen (platelet chip [PL-chip]) or collagen/thromboplastin (AR-chip) were used to assess platelet thrombus formation (PTF) at high shear rates or fibrin-rich PTF at low shear rates, respectively, in whole blood from 50 patients. The times needed for the flow pressure to increase by 10 kPa and 30 kPa (T10 and T30) from baseline were calculated from flow pressure curves. BS was determined by the use of a standardized questionnaire. Results PL-T10 values correlated with BS (R2 ~ 0.45) better than VWF:RCo (R2 ~ 0.36), irrespective of the flow rate, whereas AR-T10 showed only a weak correlation with BS (R2 ~ 0.18). Patients with PL-T10 > 10 min or AR-T10 > 30 min had lower VWF levels and higher BS than those with PL-T10 ≤ 10 min or AR-T10 ≤ 30 min, and the greatest differences were observed with PL-T10. Clinical severity appeared to correlate best with PL-T10 > 8 min. BS was significantly higher in patients with VWF:RCo of 8 min than in those with PL-T10 ≤ 8 min. Conclusion T-TAS could be a useful technique for discriminating and predicting BS in VWD type 1 patients.

Summary Background In mild hemophilia A (MHA) patients, the risk of inhibitor development is generally low, but some factor VIII (FVIII) gene missense mutations are associated with a higher inhibitor incidence. Objective To investigate the mechanism(s) of inhibitor development in MHA. Methods and results A patient, HA78, with MHA with a novel P1809L missense mutation in the A3 domain, exhibited significant residual FVIII activity (FVIII:C ~10 IU dL−1), despite the development of an inhibitor (5.6 BU mL−1). Purified HA78-IgG significantly depressed FVIII:C from normal plasma but not from patient's plasma without inhibitor, indicating that this IgG inhibited allogeneic but not autologous FVIII. The HA78-IgG blocked thrombin and FXa-catalyzed FVIII cleavage but had little effect on FVIII binding to von Willebrand factor and phospholipid. The IgG recognized a C2 epitope close or overlapping the previously described anti-C2 ESH8 epitope. Similarly, a recombinant FVIII-P1809L mutant was little inactivated by HA78-IgG. This mutant demonstrated ~3-fold lower binding affinities to von Willebrand factor and phospholipid compared with wild-type, while reactions with thrombin or FXa were not impaired. Reaction of FVIII-P1809L with the alternative anti-C2 ESH4 showed only an ~20% inhibition compared with wild-type FVIII but was similar to wild-type after incubation with ESH8. A surface plasmon resonance-based assay demonstrated that anti-C2 ESH4 bound to FVIII-P1809L with ~102-fold lower affinity compared with ESH8. Conclusion These results indicated that the P1809L mutation in A3 induced the conformational change in the FVIII molecule that hampered antigenic determinant(s) located in the C2 domain and might result in the inhibitor development.

Factor (F)VIII functions as a cofactor in the tenase complex responsible for phospholipid (PL) surface-dependent conversion of FX to FXa by FIXa. On the other hand, protein S (PS) functions as a cofactor of activated protein C that inactivates FVIII(a) and FV(a). We have reported a new regulatory mechanism on coagulation that PS directly impaired the FXase complex by competing the FIXa-FVIIIa interaction (Takeyama, Br J Haematol. 2008;143:409), and identified the PS-interactive site on the FVIII A2 domain (Takeyama, Thromb Haemost. 2009;102:645). However, the contribution of FVIII light chain (LC) to PS-binding has not been determined. In this study, several approaches were employed to assess a PS-FVIII LC interaction. The binding of FVIII LC to active site-modified FIXa (EGR-FIXa) was inhibited by PS dose-dependently (Ki; 4.6 nM) on ELISA. Because FVIII C2 domain has a binding site for FIXa, we examined whether FVIII C2 domain bound to PS. PS bound to FVIII C2 domain (Kdapp; 283 nM) by the ELISA. A SPR-based assay also revealed that FVIII C2 domain bound to PS (Kd; 62 nM). We have reported that a FIXa-interactive site exits on FVIII C2 domain (residues 2228-2240) (Soeda, J Biol Chem. 2009;284:3379). Therefore, we assessed the interaction of the synthetic peptide spanning the residues (2228-2240) with PS. ELISA showed that the peptide bound to PS (Kdapp; 104 µM). SPR-based assay also revealed that the peptide bound to PS (Kd; 31.4 µM), although scrambled peptide failed to bind to PS. Covalent cross-linking was observed between the biotynated 2228-2240 peptide and PS following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) using SDS-PAGE. This cross-linking formation was blocked by the addition of the unlabeled peptide. Furthermore, N-terminal sequence analysis of the peptide-PS product showed that one basic residue (K2239) could not be detected, supporting that this residue participates in cross-link formation. These results indicate that the 2228-2240 residues in the FVIII C2 domain, in particular K2239, may contribute to a PS-interactive site. To inquire further into the interactive region of FVIII C2 domain to PS, we prepared a stably expressed recombinant B-domainless FVIII mutants (E2228A, D2233A, K2236A, and K2239A), which were polar amino acids in the 2228-2240 residues, subsequently compared interaction with PS of the mutants with B-domainless FVIII wild type. To evaluate the binding affinity to PS, we performed SPR-based assay with the wild type FVIII and the FVIII mutants. The assay showed K2239A bound to PS with ~1.9-fold higher Kd value (28.1 nM) than that of wild type (Kd; 14.7 nM), although E2228A, D2233A, or K2236A bound to PS (Kd; 12.7, 16.3, and 10.3 nM, respectively) with no significant difference compared with wild type. In addition, to evaluate the effect of mutants for FXa generation, we assessed FXa generation assay with wild type or K2239A in the presence or absence PS, because K2239 might contribute to a PS interaction of FVIII. After each FVIII (1 nM) was reacted with various concentrations of PS in the presence of PL (20 µM) for 30 minutes, FVIII was activated by thrombin (30 nM), followed by the reaction with FIXa (40 nM) and FX (300 nM) for 1 minute. Although generated FXa with both wild type and K2239A were reduced in the presence of PS dose-dependently, compared with its absence, the inhibition ratio of K2239A was less than that of wild type (18.2% and 31%, respectively in the presence of 500 nM PS). On the other hand, the Km value on FXa generation of K2239A for various concentrations of FIXa was ~1.8-fold higher than that of wild type (5.5±0.9 and 3.1±0.2 nM, respectively), suggesting that K2239 residue, involved in the FIXa-interactive site, might contribute to the inhibition of FVIII function by PS. In conclusion, FVIII C2 domain, in particular K2239, was possible to play an important role of the inhibitory mechanism to FVIII function by PS, due to the binding to PS. Disclosures Shima: Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Nogami:Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.