Young age is a key determinant of body weight gain after switching from tenofovir disoproxil fumarate to tenofovir alafenamide in Japanese people living with HIV.

BACKGROUND: Treatment with tenofovir alafenamide fumarate (TAF) is associated with body weight gain. However, little or no information is available on this issue in Asian populations. METHODS: This single-center retrospective study included Japanese people living with HIV (PLWH) who satisfied the following criteria; 1) switching from TDF to TAF after HIV-suppression, 2) follow-up for ≥2 years while on TDF and TAF, and 3) no switching of the third antiretroviral agent. Changes in annual body weight and lipid profiles were compared between the TDF and TAF periods. RESULTS: Of 328 patients, dolutegravir (DTG) was used in 118 PLWH. Overall, no significant difference in weight gain was observed between TDF and TAF (0.76 vs. 0.9 kg/year, p = 0.331). In TAF-period, younger (<50 years of age) group showed significantly greater weight gain than older group (1.03 vs. 0.12 kg/year, p = 0.037). In DTG group, weight gain was larger in TAF-period (0.74 vs. 1.31 kg/year, p = 0.046), especially in younger subgroup (1.43 kg/year) compared with older one (-0.12 kg/year). Multivariate regression analysis showed that TAF was not associated with weight gain (estimates 0.201, p = 0.170) except for DTG group, whereas young age was associated with weight gain in all subjects (estimates -0.033/1 year older, p < 0.001), DTG, RAL, and EFV groups. CONCLUSION: In Japanese PLWH, annual body weight change was comparable in TDF- and TAF-period, while TAF plus DTG correlated with weight gain. Since young age was a key determinant of weight change, careful interpretation is needed for TAF-associated weight gain.

Crystal Structures and Conduction Paths of Sc-Doped CaTiO3 Fast Oxide-Ion Conductors with Orthorhombic Symmetry.

The crystal structures and electron density distributions (EDDs) of Ca-deficient Sc-doped CaTiO3 fast oxide-ion conductors, Ca0.97(Ti0.97Sc0.03)O3-δ (CTS3) and Ca0.96(Ti0.9Sc0.1)O3-δ (CTS10), were investigated in the temperature range of 298-1173 K in N2 to analyze the effect of composition on the perovskite structure and oxide-ion transport mechanism. CTS3 and CTS10 exhibited orthorhombic Pnma symmetry in temperature ranges of 298-1173 K and 973-1173 K, respectively, with CTS10 exhibiting lower symmetry and reduction in oxide-ion conductivity below 973 K. The EDDs of CTS3 and CTS10 at 1173 K indicated unique chemical bonds and conduction paths. CTS3 and CTS10 showed covalent bonds between (Ti,Sc) and O1 (or O2) sites. CTS3, with a lower oxide-ion conductivity than that of CTS10, exhibited pseudo-one-dimensional (1D) zig-zag curved conduction paths for oxide-ions along the a-axis, unlike previously reported curved migration paths along the b-axis in CaTiO3, and chemical bonds between Ca and O1 sites, indicating oxide-ion conduction suppression. In CTS10, additional conduction paths were observed along the a-axis, forming three-dimensional (3D) zig-zag curved conduction paths in the ac-plane and along the b-axis, with the weakening of the chemical bonds between the Ca and O1 sites. The oxide-ion conductivity and mobile oxide-ion concentration of CTS10 were 3.6 and 2.0 times those of CTS3, respectively, at 1173 K; the higher oxide-ion conductivity of CTS10 could be attributed to an increase in the mobile oxide-ion concentration and mobility with a 1D to 3D change in the conduction paths and a weakening of chemical bonds between the Ca and O1 sites.

Change of wrist motion before and after fixation of the distal radioulnar joint and resection of the distal ulna in a cadaveric model.

OBJECTIVE: Recent study suggests the distal radioulnar joint (DRUJ) plays a role in flexion and extension of the wrist. We examined the range of motion (ROM) of the wrist before and after DRUJ fixation and distal ulnar resection in a cadaveric model. METHODS: Twenty fresh cadaveric human wrists were transected and treated with two sequential interventions: (a) DRUJ fixation, and (b) distal ulnar resection. The angle of maximum flexion and extension of the wrist was measured before and after the procedures. Maximum force to the wrist was determined before the procedures using a digital pressure monitor. RESULTS: The mean maximum wrist flexion ROM was 84.2° before the procedures. The ROM decreased to 82.5° after DRUJ fixation, and significantly increased to 88.2° after subsequent resection of the distal ulna. The mean maximum wrist extension ROM before the procedures was 73.5°. The ROM decreased to 71.6° after DRUJ fixation, and significantly increased to 77.1° after subsequent resection of the distal ulna. CONCLUSIONS: Motion of the wrist is affected by DRUJ. This study suggests that the DRUJ might contribute to the ROM in flexion and extension of the wrist.

Long-term administration of pegylated liposomal doxorubicin at almost twice the recommended lifetime dose in 10 years without cardiotoxicity in a Japanese patient with HIV-associated Kaposi sarcoma.

We report a Japanese patient with HIV-associated Kaposi sarcoma (KS) who had many cutaneous KS lesions with extensive bilateral groin edema. As the KS was refractory to antiretroviral therapy and pegylated liposomal doxorubicin (PLD), he was administered PLD up to a cumulative dose of 940 mg/m2 in 10 years, which exceeded the recommended lifetime dose (550 mg/m2). However, the patient showed no major adverse events, including cardiotoxicity, and he eventually died of pancreatic cancer.

[Undetectable anti-platelet factor 4/heparin antibodies with IgG-specific chemiluminescent immunoassays in a heparin-induced thrombocytopenia patient].

A 51-year-old man with a 9-month history of narrowing of visual fields and papilledema was admitted to the Department of Neurosurgery. Upon admission, glycerol was intravenously administered and heparin flushes were initiated to maintain intravenous access. Brain MRI revealed right transverse and sigmoid sinus thrombosis on hospital day 2, and the patient was treated with unfractionated heparin. On hospital day 9, the patient had a seizure and impaired mental status. Moreover, on hospital day 10, the platelet count decreased to less than half compared with that documented upon admission. The patient was then switched from heparin to argatroban because thrombosis exacerbation due to heparin-induced thrombocytopenia (HIT) was suspected. Despite negative IgG-specific chemiluminescent immunoassay for anti-platelet factor 4 (PF4) /heparin antibodies, positive functional assay led to the diagnosis of HIT. Warfarin was initiated and the platelet count was restored. Because maintaining the patient's PT-INR within the therapeutic range was difficult probably due to concomitant antimicrobial administration for complicating pneumonia, anticoagulation was switched to rivaroxaban. No bleeding or thrombotic complications developed. Thus, the presentation and clinical course should be considered for an accurate diagnosis of HIT. This is particularly important when the immunological assay is negative for anti-PF4/heparin antibodies. Furthermore, anticoagulation with rivaroxaban can be useful in the management of the subacute phase of HIT.

Serum HER2 as an adjunct to assess HER2 status for advanced gastric cancer: A prospective multicenter trial (SHERLOCK).

BACKGROUND: Intratumoral human epidermal growth factor receptor 2 (HER2) heterogeneity of gastric cancer can be an obstacle to accurate HER2 assessment. Serum HER2, concentrations of the HER2 extracellular domain shed into the bloodstream, has a potential to compensate HER2 immunohistochemistry (IHC) but has not been scrutinized in gastric cancer. This study sought to explore the clinical utility of serum HER2 in gastric cancer. METHODS: We performed a prospective multicenter trial (SHERLOCK trial) involving patients with all-stage gastric or gastro-esophageal junction cancer. Serum HER2 was measured using direct chemiluminescence while tissue HER2 status was determined using IHC and fluorescent in situ hybridization. For stage IV cases, concordance between local and central laboratories in tissue HER2 assessment was also evaluated. RESULTS: Of 224 patients enrolled, both tissue HER2 status and serum HER2 levels were successfully determined in 212 patients and 21% (45/212) were tissue HER2-positive. Serum HER2 levels, ranged from 4.5 to 148.0 ng/ml (median 10.3), correlated with tissue HER2 status (p = 0.003). At a cut-off level of 28.0 ng/ml determined by receiver operating characteristics analysis, sensitivity, specificity, positive and negative predictive values of serum HER2 were 22.6%, 100%, 100% and 82.3%, respectively. All nine cases with elevated serum HER2 were tissue HER2-positive stage IV cases. Among 61 stage IV cases, the agreement rate for IHC scoring between the local and the central laboratories was 82% and tissue HER2 judgment was conflicting in five (8.2%) cases. Of these five cases, four were confirmed as false-negative and two of these four patients demonstrated elevated serum HER2. CONCLUSIONS: Serum HER2 levels correlated with tissue HER2 status in gastric cancer. Although the low sensitivity is a drawback, serum HER2 might be a useful adjunct tool to detect tissue HER2 false-negative gastric cancer.

[Syphilis Testing and High Rate of Infection Among HIV-infected Patients].

Background: The incidence of syphilis has globally increased over the last decade, particularly among men who have sex with men coinfected with the human immunodeficiency virus (HIV). HIV infection may make the clinical symptoms and seroreactivity of syphilis atypical, which requires careful consideration in terms of diagnoses and treatments by clinicians. Syphilis is known as a great imitator, and is often difficult to be diagnosed or it can be overlooked if clinicians depend only on its symptoms or signs. It is also highly contagious and could be transmitted without sexual intercourse, and reinfection is common. Guidelines recommend that all HIV-infected persons be provided with STD screening, including syphilis, at least annually. However, to our knowledge, there are no published data on the actual frequency of testing and instances of syphilis among HIV-infected persons in Japan. Materials and Methods: We collected data from HIV infected male patients who had sex with men (MSM) at Tokyo Medical University Hospital from June 2011 to June 2012. Data from the patients, who had been tested with the rapid plasma reagin assay (RPR) at least once during the study period, were retrospectively obtained from clinical records and were analyzed. Results: Among 1000 patients with HIV infection, 935 patients were MSM. 723 patients (77.4%) were tested using the Treponema pallidum latex agglutination test (TPLA) and RPR more than once during the study period. Out of the 723 patients, 443 patients (61.3%) were reactive for TPLA and 238 patients (32.9%) had reactive tests for RPR. All patients who were reactive for RPR were reactive for TPLA. Among the patients who were reactive for RPR, 93 patients (12.9%) were considered newly diagnosed or with a repeat infection. In this cohort, all patients were MSM with a median age of 37 years, and a median CD4+T-lymphocyte cell count of 465/uL. A total of 76 patients had been prescribed antiretroviral therapy, and 61 patients had a documented HIV-1 RNA viral load of <40 copies/mL at their most recent test. Two patients both developed two episodes of syphilis during the study period. Of the 95 episodes, 44% were symptomatic syphilis and the most common symptom among them was a skin rash at the second stage. Nearly half of the patients (47%) were diagnosed at regular screenings. Two thirds (67%) had syphilis infections before the study period, whereas at least 20% of them were newly diagnosed during the study period. Conclusions: A substantial percentage of the participants were newly or recurrently diagnosed with syphilis during the study period. More public health awareness should be encouraged regarding the current epidemic of syphilis among HIV-infected persons in Japan. It is also important for clinicians to provide HIV-infected persons with periodical syphilis screening, regardless of the apparent clinical signs or symptoms to achieve earlier treatment intervention.

[Prevalence of chronic kidney disease among HIV-infected individuals in Japan--a report from two tertiary hospitals].

BACKGROUND: The improved survival of subjects with human immunodeficiency virus (HIV) has been accompanied by an increased prevalence of chronic kidney disease (CKD). Epidemic of CKD among those with HIV has not yet been evaluated in multiple tertiary hospitals in Japan. METHODS: A cross-sectional study was conducted in 2011 at Tokyo Metropolitan Komagome Hospital (TMKH) and Tokyo Medical University Hospital (TMUH). A total of 1482 HIV-infected subjects (1384 men, 98 female, mean age: 44.2 +/- 11.4 years old) were consecutively enrolled in the study. Random urine and blood samples were collected to study prevalence of CKD. CKD was diagnosed as a decrease in glomerular function and/or proteinuria and classified into 5 stages based on National Kidney Foundation guidelines. The estimated glomerular filtration rate based on serum creatinine was calculated using the 3-variable equation, constructed by the Japanese Society of Nephrology. Proteinuria was defined as > or = 1+ on urine dipstick examination. All electronic medical charts were reviewed to determine comorbidities, including hypertension and diabetes mellitus (DM). The proportion of subjects receiving tenofovir disoproxil fumarate (TDF) was investigated. Risk factors for CKD were determined using multivariate logistic regression analysis. RESULTS: The mean CD4 cell count was 487 +/- 216/microL and 80.5% had undetectable HIV-RNA level in the combined cohort. Of the 90.2% of subjects taking antiretroviral agents, 61.5% was using TDF. The prevalence of overall CKD and CKD > or = stage 3 was 12.9% and 6.7%, respectively, both of which were nearly 3-fold higher in the TMKH cohort (p < .0001). Mean age and proportional prevalent hypertension and DM were significantly higher in the TKMH cohort than in the TMUH cohort. Multivariate analysis showed significant CKD to be associated with age > or =50 years (odds ratio [OR], 2.81), hypertension (OR, 3.04), and DM (OR, 2.05). CONCLUSIONS: CKD prevalence was 12.9% among combined cohorts, but differed significantly between them. Differences in age distribution and the proportion of comorbidities, including hypertension and DM, are likely involved.

Comprehensive comparison of global coagulation assays to differentiate lupus anticoagulant from acquired hemophilia A in patients with prolonged APTT.

There is no established method for differentiating acquired hemophilia A (AHA) from lupus anticoagulant (LA) positivity because both present with prolonged activated partial thromboplastin time. We compared various parameters of rotational thromboelastometry (ROTEM), thrombin generation assay (TGA), and clot waveform analysis (CWA) in patients with AHA (n = 10) and LA (n = 44). Compared with AHA, possible (n = 12) and definite (n = 32) LA showed significantly shorter clotting time (CT) in NATEM mode of ROTEM (> 3600 vs. 501/533). In TGA, peak height was significantly lower in AHA (16 vs. 242/174 nM). In CWA, CT was significantly longer (81 vs. 36/41 s) and Ad|min1| was lower (2.1 vs. 8.7/6.7) in AHA. Notably, CT by NATEM and peak height in TGA completely discriminated between AHA and LA, whereas Ad|min1| did not discriminate between them in 4 cases of AHA and 1 of LA. Comparison of 3 patients with both AHA and LA against a patient with only LA and markedly low FVIII activity (3.5%) showed that both CT by NATEM and peak height of TGA precisely classified the former 3 cases as AHA and the latter 1 case as LA, whereas Ad|min1| classified all 4 cases as AHA. ROTEM and TGA can comparably distinguish between AHA and LA.

Combination therapy with von Willebrand factor concentrate plus recombinant factor VIII during cesarean section in a patient with type 3 von Willebrand disease and a low inhibitor titer: a case report.

Type 3 von Willebrand disease (VWD), a rare and severe subtype, can produce inhibitors in roughly 5% to 10% of cases. We present a case of type 3 VWD with inhibitors in late pregnancy, which was successfully managed with a combination of neutralization and factor (F)VIII replacement during cesarean delivery. The patient, a 30-year-old woman, had no history of inhibitors despite over 100 exposures to VWF/FVIII. She developed inhibitors after 28 weeks of weekly pd VWF/FVIII prophylaxis for recurrent urolithiasis-associated hematuria during pregnancy. Genetic analysis detected two novel frameshift mutations: VWF Exon7 c.777_784dup and Exon14 c.1625_1646del. Titers of inhibitors to factors VIII and VWF using the Bethesda assay were 1.2 and 1.1 BU/mL, respectively. Pharmacokinetics revealed significantly low in vivo recovery of FVIII:C and VWF:Rcof and shortened half-life. During cesarean delivery, a combination of bolus pd VWF/FVIII once daily for neutralizing inhibitors plus continuous infusion of recombinant FVIII Fc fusion protein resulted in minimal bleeding without allergic reactions. Both VWF:Rcof and FVIII:C levels increased transiently during the 7-h of combination therapy without thrombotic events. In conclusion, combination therapy with neutralization and continuous FVIII replacement was effective for hemostasis with a low VWD inhibitor titer, though further optimization is required.

The effect of cooling process on the structure and charge/discharge capacities of Li-rich solid-solution layered oxide cathode materials for the Li-ion battery.

The effect of cooling process after calcination at 900 °C in the preparation of cathode materials, on the crystal structure and charging/discharging capacities of Li2MnO3-LiNi1/2Mn1/2O2-LiNi1/3Mn1/3Co1/3O2 Li-rich solid-solution layered oxide (LLO) cathode materials for the lithium ion battery was examined in twenty-one LLO samples having different compositions. This was achieved by applying two types of cooling processes: (i) quenching the calcinated LLO samples with liquid nitrogen (quenched cooling), and (ii) slow cooling of LLO samples in the furnace at a controlled decreasing rate of the temperature (slow cooling). The results of the comparison between discharging capacities observed with LLO samples prepared with two types of cooling processes indicated that the cooling process for LLO samples to exhibit high discharge capacity was not limited to either one. The process that can be more effective for LLO samples to exhibit the high discharge capacity depended on the composition of LLO samples. LLO samples containing Li2MnO3 of over 60% exhibited higher discharge capacity when samples were quenched with liquid nitrogen than those prepared with the slow cooling process. Among LLOs examined, the effect of quenching was maximum when the Li2MnO3 content was 60%. As the LLO composition deviated from the line of 60% Li2MnO3 in the Li[Li0.20Mn0.58Ni0.18Co0.04]O2 sample compositions, the effect of quenching became smaller and the slow cooling process was superior to the quenching process. A connection was thus made between the structural difference of LLO samples prepared with the two types of cooling processes and the cathode performance was observed.

Genetic analysis of carrier status in female members of Japanese hemophilia families.

BACKGROUND: Genetic characteristics and genetic carrier diagnosis in Japanese hemophilia female carriers have not been evaluated. OBJECTIVES: To provide genetic information on Japanese hemophilia female carriers and demonstrate the advantages of genetic testing in carrier diagnosis. METHODS: DNA sequencing combined with long polymerase chain reaction for inversion and multiplex ligation-dependent probe amplification for large mutations. RESULTS: Genetic analysis was performed in 69 male hemophiliac patients (48 hemophilia A [HA] and 21 hemophilia B [HB]) and 112 female family members (FFM) (80 from 50 families with HA and 32 from 22 families with HB). In 72 hemophiliac families, the identified F8 mutations were inversion (42%), missense (26%), and other variations (32%), while 74% of F9 mutations were point mutations. Among the 112 FFM, 53/80 (66%) with HA and 21/32 (66%) with HB were diagnosed genetically as carriers based on detection of heterozygous mutations. Low factor VIII activity (FVIII:C) levels (<50 IU/dL) were detected in only 10% of gene-confirmed carriers, suggesting that FVIII:C is not suitable for HA carrier prediction. Low FVIII/von Willebrand factor ratio (<0.9) was observed in 67% of gene-confirmed carriers. Half of the gene-confirmed HB carriers had low FIX:C (<60 IU/dL). Importantly, 32 mothers of 37 sporadic cases (86%) (24/27 [89%] HA and 8/10 [80%] HB) showed the relevant mutations, suggesting low incidence of de novo mutations in males. CONCLUSIONS: This study is the first to provide genetic information on Japanese hemophilia female carriers. Gene analysis is the gold standard for carrier diagnosis as it well identifies undetected female carriers based on pedigree information and hemostatic measurements.

The treatment choices and outcome of hepatocellular carcinoma in hemophilic patients with human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfection due to contaminated blood products in Japan.

BACKGROUND: Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection through unheated blood product for hemophilia caused in early 1980s has been significantly serious problem in Japan. After the development of HIV treatment in 1990s, HCV-related hepatocellular carcinoma (HCC) has been one of the most significant problem in these population. Treatment choices for HCC might be limited in hemophilia patients because of their bleeding tendency. The aim of this study was to elucidate the treatment choices and outcome of HCC in hemophilic patients coinfected with HIV/HCV due to contaminated blood products. METHODS: We asked 444 Japanese centers that specialize in treating HIV patients for participation, whether they have HIV/HCV coinfected cases with HCC, and the patient characteristics, treatments for HCC and survival after treatments were retrospectively reviewed according to each institutional medical records. RESULTS: Of 444 centers, 139 centers (31%) responded to the first query, and 8 centers (1.8%) ultimately provided 26 cases of HCC in coinfected hemophilic patients, diagnosed between December 1999 and December 2017. All 26 were male hemophilic patients, with a median age at HCC diagnosis of 49 (range, 34-73) years. Thirteen cases (50%) were HCV-RNA positive, and 14 cases (54%) had a solitary tumor. Even in the cases of Child-Pugh grade A, only 1 case underwent resection, and 18 cases (69%) did not receive the standard treatment recommended by the Japanese Society of Hepatology. CONCLUSIONS: Hemophilic HCC patients with HIV/HCV coinfection may not routinely receive standard treatment due to their bleeding tendency and several complications related to HIV/HCV coinfection.

Vascular Complication after Collagenase Injection and Manipulation for Dupuytren's Contracture: A Case Report.

A case of a vascular complication after collagenase injection and manipulation for Dupuytren's contracture in a 57-year-old Japanese man is described. The patient presented with a 10-year history of worsening primary Dupuytren's contracture. The metacarpophalangeal joint of his left little finger had a flexion contracture of 40° and was treated by collagenase injection. When the patient returned to our hospital for manipulation 24 hours later, however, his left little finger was almost completely improved because he hit his finger on the car's gear lever. Then, 9 months after collagenase injection, in the first winter, he complained of a painful and pale left little finger occurring a few times a day, lasting for about 10 minutes. Now, two years after collagenase injection, the episodes of Raynaud's phenomenon remain. Although Raynaud's phenomenon after collagenase injection and manipulation for Dupuytren's contracture is considered rare, it is a complication to be noted.

[Case of ulcerative colitis refractory to intravenous cyclosporine therapy successfully treated with infliximab].

A 26-year-old woman was admitted to our hospital with relapse of ulcerative colitis (UC). We diagnosed it as a refractory UC because intravenous corticosteroid therapy had no effect. Intravenous cyclosporine therapy and other conventional therapies did not lead to remission. Then the possibility of infliximab was discussed with the patient and her parents and treatment with infliximab was started. Infliximab was infused intravenously at a dose of 5mg per kilograms of body weight. Immediately after the first infusion, clinical symptoms improved, and clinical remission was achieved within 12 weeks. It is suggested that infliximab can be effective for refractory UC.

Improvement in symptoms after H2-receptor antagonist-based therapy for eradication of H pylori infection.

AIM: To investigate the therapeutic effects of triple therapy combining lafutidine with clarithromycin and amoxicillin on H pylori infection and the resolution of gastroesophageal symptoms after eradication. METHODS: We conducted a randomized, multicenter, open-label controlled trial to compare the effectiveness of a triple therapy of lafutidine, clarithromycin, and amoxicillin (lafutidine group) with that of a triple therapy of lansoprazole, clarithromycin, and amoxicillin (lansoprazole group) in patients with H pylori infection. The study group comprised 22 patients with gastric ulcers and 18 patients with duodenal ulcers who had H pylori infection. RESULTS: H pylori eradication rates were similar in the lafutidine group (14/20, 70%) and the lansoprazole group (14/20, 70%). Gastroesophageal reflux and abdominal symptoms improved after eradication therapy in both groups, whereas abdominal discomfort, diarrhea, and constipation were unchanged. H pylori status had no apparent effect on improvement of gastroesophageal reflux or abdominal symptoms after treatment. Adverse events were similar in both groups. CONCLUSION: The triple therapy including lafutidine is equivalent to triple therapy including lansoprazole in terms of H pylori eradication rates and improvement in gastroesophageal reflux and abdominal symptoms. These results are attributed to the fact that lafutidine has strong, continuous antisecretory activity, unaffected by CYP2C19 polymorphisms.

Factor X M402T: a homozygous missense mutation identified as the cause of cross-reacting material-reduced deficiency.

We investigated a mildly hemorrhagic patient with factor X (FX) deficiency to identify the nature of his defect by comprehensive analyses. A 42-year-old Japanese man was admitted to our hospital for uncontrolled gingival hemorrhage. His FX activity based on prothrombin time (PT) and activated partial thromboplastin time (aPTT) and FX antigen were <1, 6.5 and 11 %, respectively. A homozygous M402T missense mutation (c.1205 t>c; p.Met402Thr) was identified in the FX gene (F10) from both the patient and his brother. The mutation was not detected in the F10 of 82 unrelated normal Japanese individuals. We studied the functional consequences of this mutation by expressing mutant FX-M402T protein in HEK293 cells. This analysis revealed that the antigen of the FX-M402T mutants was approximately 26 % that of the wild-type FX in conditioned media. The FX-specific activity of FX-M402T mutants measured by a one-stage clotting assay based upon PT and aPTT, and a chromogenic assay using Russell's viper venom in the concentrated media was 7.7, 31.7, and 41.2 % of wild type, respectively. The results suggest that the mutation FX-M402T may cause a secretion defect and a molecular abnormality in FX.

Genotypic and phenotypic features of Japanese patients with mild to moderate hemophilia A.

Hemophilia A is the most common inherited bleeding disorder. To better understand the genotypic and phenotypic features of Japanese patients with mild to moderate hemophilia A, we studied 29 unrelated patients with more than 1 % FVIII activity (FVIII:C). Differences were observed in nine of 21 patients in measured FVIII:C levels between the one-stage clotting and chromogenic assays. We identified a mutation in F8 in 28 of the 29 patients. Mutations in two amino acids, Y492 and R550, were detected at a much higher frequency in our patients than in the international hemophilia A mutation database. We demonstrated that all five patients with the Y492C mutation have an identical F8 haplotype that is unique to them, suggesting that the mutation may have originated from a common ancestor. Because non-severe, moderate to mild, hemophilia patients have a longer lifespan, mutations that cause non-severe phenotypes tend to persist in the population. We believe that the Y492C mutation is a distinctive feature of Japanese patients with mild hemophilia A. The identification of a high frequency of R550 mutation that underlies the discrepancies in FVIII:C measurements in the present study suggests that Japanese patients with mild hemophilia may require careful characterization.

Two double heterozygous mutations in the F7 gene show different manifestations.

We sequenced the factor VII gene (F7) in two unrelated Japanese patients with factor VII (FVII) deficiency. In the first (an asymptomatic 46-year-old man with FVII activity and antigen levels of 1.2% and 21% of normal respectively), novel E25K and H348Q mutations were identified in the doubly heterozygous state. In transiently transfected HEK293 cells, the level of FVII-E25K mutant activity in the culture media was significantly lower than that of FVII wild type, whereas the antigen levels of both proteins were similar. This suggests that the E25K mutation is associated with a dysfunctional FVII molecule. In the second patient (a 47-year-old woman with FVII activity and antigen levels of less than 1% and 6% respectively), an IVS4+1 mutation and a novel -96C to T transition were detected in the double heterozygous state. In electrophoretic mobility shift assays, the -96T mutation was shown to disrupt binding of Sp1.