[Prediction of Coagulation Factor â § Level in Chinese Hemophilia A Patients by the Pharmacokinetic Management Tool myPKFiT].

Objective To evaluate the performance of myPKFiT,a tool guiding the dosing of antihemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM),in maintaining the coagulation factor Ⅷ (FⅧ) level above a target threshold at the steady state and estimating the pharmacokinetics (PK) parameters in hemophilia A patients in China. Methods The data of 9 patients with severe hemophilia A in a trial (CTR20140434) assessing the safety and efficacy of rAHF-PFM in the Chinese patients with hemophilia A were analyzed.The myPKFiT was used to predict the adequate dose to maintain a patient's FⅧ level above target threshold at the steady state.Furthermore,the performance of myPKFiT in estimating the pharmacokinetics parameters of individuals was evaluated. Results Twelve combinations of two dosing intervals and six sparse sampling schedules were investigated,and 57%-88% of the patients remained the FⅧ level above the target threshold of 1 U/dl (1%) for at least 80% of the dosing interval.The clearance and time to FⅧ level of 1% obtained from sparse sampling by myPKFiT were similar to those obtained from extensive sampling. Conclusions The myPKFiT can provide adequate dose estimates to maintain the FⅧ level above the target threshold at the steady state in Chinese patients with severe hemophilia A.Moreover,it demonstrates good performance for estimating key pharmacokinetics parameters,including clearance and time to FⅧ level of 1%.

[Phenotype and Genotype Analysis in Two Pedigrees with Hereditary Coagulation Factor â ª Deficiency].

OBJECTIVE: To analyze the phenotype and genotype in two pedigrees with hereditary coagulation factor Ⅺ (FⅪ) deficiency, and investigate the molecular mechanisms of FⅪ deficiency. METHODS: Two patients with hereditary coagulation FⅪ deficiency were admitted to Chaozhou Central Hospital in Nov 2014 and Jan 2018. The prothrombin time (PT), activated partial thromboplastin time (APTT), FⅪ activity (FⅪ∶C) and FⅪ antigen (FⅪ∶Ag) were tested for phenotypic diagnosis. All the exons and exon-intron boundaries of FⅪ gene of proband were analyzed by PCR and sequencing. The family members were tested for the mutant site of proband. Then the mRNA of FⅪ in the proband was analyzed with RT-PCR. RESULTS: The proband-1 was a 7-year-old boy, PT was 10.7 s and APTT was 97.4 s (reference range: 9-12.8 s; 24-40 s), FⅪ∶C (0.6%) and FⅪ∶Ag<1% (reference range: 65%-150%; 72.1%-122.3%). The proband-2 was a 30-year-old female, and showed the PT (11.7 s), APTT (71.3 s), FⅪ∶C (0.7%) and FⅪ∶Ag<1%. FⅧ∶C, FⅨ∶C and FⅫ∶C of two proband were within the normal range. DNA sequencing showed that the proband-1 had a combined mutation of c.326-1G>A and c.1107C>A (p.Tyr351X) in exon 10. His grandmother, mother and brother had a heterozygous splicing mutation of c.326-1G>A, his grandmother and father had a homozygous mutation of c.1107C>A. FXI mRNA was undetected in the proband-1. The proband-2 had a homozygous mutation of c.841C>T (p.Gln263X) in exon 8, and this mutation was also found in her father, mother, daughter and son. CONCLUSION: The c.326-1G>A, c.1107C>A(p.Tyr351X) and c.841C>T (p.Gln263X) might be the molecular pathogenesis for two probands with hereditary coagulation factor Ⅺ deficiency.

[Possibility of using coagulation factor â ¡ and factor â © for warfarin monitoring in Chinese pulmonary embolism patients].

Objective: To explore the possibility of using coagulation factor Ⅱ and Ⅹ (FⅡ and FⅩ) for warfarin monitoring among Chinese pulmonary embolism patients. Methods: Blood samples were collected from pulmonary embolism patients who were taking warfarin as anticoagulant and who were from Peking Union Medical Collaege Hospital during Mar 2016 and Oct 2018. Activity of coagulation factor Ⅱ/Ⅹ and International Normalized Ratio (INR) level were detected. Correction analysis was used to investigate the relationship between activity of coagulation factor Ⅱ/Ⅹ and INR. Receiver Operating Characteristic (ROC) curve was used to analyze the diagnostic ability of FⅡ and FⅩ. Results: A total of 157 blood samples were collected in this research. When 1.5≤INR≤3.0, FⅡ (r=-0.768, P<0.001) and FⅩ(r=-0.690, P<0.001) were in inverse correlations with INR. Area under ROC curve (AUC) for FⅡ and FⅩ was 0.961 and 0.965 (P<0.001) when we used INR<2.0 as the criteria of anticoagulant inadequacy. AUC of ROC for FⅡ and FⅩ was 0.885 and 0.890 (P<0.001) when we used INR≤3.0 as the criteria of not over-anticoagulation. Conclusion: FⅡ and FⅩ activity can be used as the therapeutic markers of warfarin in Chinese pulmonary embolism patients.

[Pharmacokinetic Study of Coagulation Factor â § in Adults with Severe Hemophilia A].

OBJECTIVE: To detect the pharmacokinetic (PK) parameters of coagulation factor Ⅷ (FⅧ) in adult patients with severe hemophilia A, identify the potential factors influencing FⅧ PK, and optimize the use of FⅧ in individual prophylaxis regimens. METHODS: PK characteristics of FⅧ were studied in a total of 23 severe hemophilia A adults. The correlation of patients' characteristics including age, von Willebrand factor antigen (vWF:Ag), blood group, weight, body mass index (BMI) and FⅧ genotype, with FⅧ PK were evaluated. Individual prophylaxis regimens were given based on FⅧ PK parameters. RESULTS: The mean terminal half­life (t1/2) of FⅧ was 20.6±9.3 h, ranged from 11.47 h to 30.12 h. The age (r =0.580) and vWF:Ag (r =0.814) were significantly positively correlated with t1/2 of FⅧ. The mean area under the plasma concentration curve (AUC) of FⅧ was 913±399 (328-1 878) IU·h/dl, and the AUC of FⅧ was positively correlated with age (r =0.557) and vWF:Ag (r =0.784). The mean residence time (MRT) of FⅧ was 24.7±12.4 (13.2-62.2) h, and the MRT of FⅧ was positively correlated with age (r =0.664) and vWF:Ag (r =0.868). The mean in vivo recovery (IVR) of FⅧ was 2.59±0.888 (1.5-4.29) IU/dl per IU/kg, the mean clearance (CL) of FⅧ was 3±1.58（0.97-7.18）ml/(kg·h)，and there was no significant correlation of IVR and CL with age and vWF:Ag. According to the individual PK parameters, ultra low-dose, low-dose and moderate-dose FⅧ were applied to 15, 6, 2 adults patients with severe hemophilia A for prophylaxis, respectively. CONCLUSION: There are significant individual differences in the FⅧ half-life of adult patients with severe hemophilia A. The older the patient, the higher the vWF:Ag level, and the longer the FⅧ half-life. Individual administration is required based on the FⅧ PK parameters to optimize prophylaxis treatment.

[Analysis of the effects of low/intermediate dose of coagulation factor â § on 30 adult patients with severe hemophilia A in a single center].

Objective: To evaluate the clinical effects of low- and intermediate-dose factor Ⅷ (F Ⅷ) prophylaxis in Chinese adult patients with severe hemophilia A. Methods: Thirty adult patients with severe hemophilia A who received low- (n=20) /intermediate-dose (n=10) F Ⅷ prophylaxis at Nanjing Drum Tower Hospital affiliated with Nanjing University Medical College were included in the study. The annual bleeding rate (ABR), annual joint bleeding rate (AJBR), number of target joints, functional independence score of hemophilia (FISH), quality of life score, and health status score (SF-36) before and after preventive treatment were retrospectively analyzed and compared. Results: The median follow-up was 48 months. Compared with on-demand treatment, low- and intermediate-dose prophylaxis significantly reduced ABR, AJBR, and the number of target joints (P<0.05) ; the improvement in the intermediate-dose prophylaxis group was better than that in the low-dose prophylaxis group (P<0.05). Compared with on-demand treatment, the FISH score, quality of life score, and SF-36 score significantly improved in both groups (P<0.05), but there was no significant difference between the two groups (P>0.05) . Conclusion: In Chinese adults with severe hemophilia A, low- and intermediate-dose prophylaxis can significantly reduce bleeding frequency, delay the progression of joint lesions, and improve the quality of life of patients as compared with on-demand treatment. The improvement in clinical bleeding was better with intermediate-dose prophylaxis than low-dose prophylaxis.

[Analysis of APTT Mixing Test Results in Factor â § Inhibitor-Positive Hemophilia Patients].

OBJECTIVE: To analyze the results of activated partial thromboplastin time (APTT) mixing test in coagulation factor Ⅷ inhibitor-positive hemophilia patients, so as to increase the value of APTT mixing test in the screen of factor Ⅷ inhibitor. METHODS: Eighty plasmas samples with different titers of coagulation factor Ⅷ inhibitors had been collected and diluted for routine immediate APTT mixing test and at 37 ℃ 2 hours incubation APTT mixing test. Fifteen samples were selected for immediate and normal temperature incubation for 15 min, 30min, 1 hour, 2 hours and 37 ℃ for 30 min, 1 hour, 2 hours APTT mixing test. RESULTS: The results of APTT mixing test were significantly correlated with the titers of coagulation factor Ⅷ inhibitors. The ROC curve result showed that the best diagnostic cut-off value for 2 hours incubation APTT mixing test at 37 ℃ to determine the presence or absence of coagulation factor Ⅷ inhibitors was 43.8 s (sensitivity and specificity was 85.90% and 100%, respectively), while the best diagnostic cut-off value for distinguishing high-titer and low-titer Ⅷ inhibitors was 52.4 s (sensitivity and specificity was 98.18% and 95.65%, respectively). The critical coagulation factor Ⅷ inhibitor titer that could not be corrected by immediate APTT was 5.14 BU/ml, while that could not be corrected by 37 ℃ 2 hours incubation APTT was 1.31 BU/ml. Paired samples t -test was performed on the APTT mixing test results at different times and temperatures, and the differences were statistically significant (P < 0.05). CONCLUSIONS: The APTT mixing test can be used as a screening index for coagulation factor Ⅷ inhibitors. APTT mixing test result shows a significant time-temperature dependence with lower titers of coagulation factor Ⅷ inhibitor. Patients with hemophilia who cannot be corrected by immediate APTT mixing test should be alert to the possibility of high titer of coagulation factor Ⅷ.

[Analysis of A Pedigree with Hereditary Coagulation Factor â « Deficiency Caused by Compound Heterozygous Mutations].

OBJECTIVE: To analysis clinical phenotype and potential genetic cause of a family affected with hereditary coagulation factor Ⅻ deficiency. METHODS: The prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-Dimer (D-D), coagulation factor Ⅻ activity (FⅫ:C) and coagulation factor Ⅻ antigen (FⅫ:Ag) were determined for phenotype diagnosis of the proband and his family members(3 generations and 5 people). Targeted capture and whole exome sequencing were performed in peripheral blood sample of the proband. Possible disease-causing mutations of F12 gene were obtained and further confirmed by Sanger sequencing. The corresponding mutation sites of the family members were analyzed afterwards. The online bioinformatics software AutoPVS1 and Mutation Taster was used to predict the effects of mutation sites on protein function. RESULTS: The APTT of the proband was significantly prolonged, reaching 180.9s. FⅫ:C and FⅫ:Ag of the proband was significantly reduced to 0.8% and 4.17%, respectively. The results of whole exome sequencing displayed that there were compound heterozygous mutations in F12 gene of the proband, including the c.1261G＞T heterozygous nonsense mutation in exon 11 (causing p.Glu421*) and the c.251dupG heterozygous frameshift mutation in exon 4 (causing p.Trp85Metfs*53). Both mutations are loss of function mutations with very strong pathogenicity, leading to premature termination of the protein. AutoPVS1 and Mutation Taster software predicted both mutations as pathogenic mutations. The results of Sanger sequencing revealed that c.1261G＞T heterozygous mutation of the proband was inherited from his mother, for which his brother and his daughter were c.1261G＞T heterozygous carriers. Genotype-phenotype cosegregation was observed in this family. CONCLUSION: The c.1261G＞T heterozygous nonsense mutation in exon 11 and the c.251dupG heterozygous frameshift mutation in exon 4 of the F12 gene probably account for coagulation factor Ⅻ deficiency in this family. This study reports two novel pathogenic F12 mutations for the first time worldwide.

[Analysis of a pedigree with inherited factor V deficiency caused by compound heterozygous mutation].

Objective: To explore the molecular pathogenesis of a family with hereditary factor Ⅴ (FⅤ) deficiency. Methods: All the exons, flanking sequences, 5' and 3' untranslated regions of the F5 of the proband, and the corresponding mutation sites of the family members were analyzed via direct DNA sequencing. The CAT measurement was used to detect the amount of thrombin produced. The ClustalX software was used to analyze the conservation of mutation sites. The online bioinformatics software, Mutation Taster, PolyPhen-2, PROVEAN, LRT, and SIFT were applied to predict the effects of mutation sites on protein function. The Swiss-PdbViewer software was used to analyze the changes in the protein model and intermolecular force before and after amino acid variation. Results: The proband had a heterozygous missense mutation c.1258G>T (p.Gly392Cys) in exon 8 of the F5, and a heterozygous deletion mutation c.4797delG (p.Glu1572Lys fsX19) in exon 14, which results in a frameshift and produces a truncated protein. Her grandfather and father had p.Gly392Cys heterozygous variation, whereas her maternal grandmother, mother, little aunt, and cousin all had p.Glu1572LysfsX19 heterozygous variation. The ratio of proband's thrombin generation delay to peak time was significantly increased. Conservation analysis results showed that p.Gly392 was located in a conserved region among the 10 homologous species. Five online bioinformatics software predicted that p.Gly392Cys was pathogenic, and Mutation Taster also predicted p.Glu1572Lys fsX19 as a pathogenic variant. Protein model analysis showed that the replacement of Gly392 by Cys392 can lead to the extension of the original hydrogen bond and the formation of a new steric hindrance, which affected the stability of the protein structure. Conclusion: The c.1258G>T heterozygous missense mutation in exon 8 and the c.4797delG heterozygous deletion mutation in exon 14 of the F5 may be responsible for the decrease of FⅤ levels in this family.

[Clinical and genetic analyses of hereditary factor â ¤ deficiency cases].

Objective: To analyze the clinical phenotype and molecular pathogenesis of nine patients with hereditary factor Ⅴ (FⅤ) deficiency. Methods: Nine patients with hereditary FⅤ deficiency who were admitted to the Institute of Hematology and Blood Diseases Hospital from April 1999 to September 2019 were analyzed. The activated partial thromboplastin time, prothrombin time, and FⅤ procoagulant activity (FⅤ∶C) were measured for phenotypic diagnosis. High-throughput sequencing was employed for the F5 gene mutation screening, Sanger sequencing was adopted to confirm candidate variants and parental carrying status, Swiss-model was used for three-dimensional structure analysis, and ClustalX v.2.1 was used for homologous analysis. Results: The FⅤ∶C of the nine patients ranged from 0.1 to 10.6. Among them, eight had a hemorrhage history, with kin/mucosal bleeding as the most common symptom (three cases, 37.5%) , whereas one case had no bleeding symptom. There were five homozygotes and four compound heterozygotes. A total of 12 pathogenic or likely pathogenic mutations were detected, of which c.6100C>A/p.Pro2034Thr, c.6575T>C/p.Phe2192Ser, c.1600_1601delinsTG/p. Gln534*, c.4713C>A/p.Tyr1571*, and c.952+5G>C were reported for the first time. Conclusion: The newly discovered gene mutations enriched the F5 gene mutation spectrum associated with hereditary FⅤ deficiency. High-throughput sequencing could be an effective method to detect F5 gene mutations.

Evaluation of Coagulation, Fibrinolysis and Endothelial Biomarkers in Cirrhotic Patients With or Without Portal Venous Thrombosis.

To evaluate variations in coagulation, fibrinolysis and endothelial marker expression in cirrhotic patients and to explore their clinical value and predictive performance in cirrhotic patients with or without portal vein thrombosis (PVT), we performed a case-control study with 175 cirrhotic patients and 50 healthy individuals. 99 patients had PVT and another 76 patients did not. All participants were evaluated for plasma levels of conventional hemostatic markers. Thrombin-antithrombin complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC), thrombomodulin (TM), tissue plasminogen activator inhibitor complex (t-PAIC), von Willebrand factor antigen (vWF: Ag) and coagulation factor Ⅷ (FⅧ: c) were also assessed and the ratio of TAT/t-PAIC was calculated. We analyzed differences in these biomarkers among the three groups and constructed receiver operating characteristic (ROC) curves. Patients with PVT exhibited significantly higher TAT and TAT/t-PAIC than cirrhotic patients without PVT (both P < 0.001). Areas under the curve (AUC) of ROC analyses for TAT and TAT/t-PAIC were 0.68 and 0.66, the cut-off levels were 1.55 ng/ml and 0.46, with sensitivities and specificities of 78.79% and 51.32% regarding TAT, 39.8% and 90.79% regarding TAT/t-PAIC. Levels of FⅧ: c and vWF: Ag in patients with PVT were significantly lower than those without PVT (p = 0.026 and p = 0.027, respectively). The AUCROC, cut-off level, sensitivity and specificity of FⅧ: c were 0.64, 111.1%, 66.67% and 60%, respectively. For vWF: Ag they were 0.61, 429%, 89.66% and 38.71%, respectively. Cirrhotic patients have disorders of coagulation, fibrinolysis and the endothelial system. TAT, TAT/t-PAIC, FⅧ: c and vWF: Ag can be used as potential biomarkers for predicting PVT in cirrhotic patients.