Analysis of APTT Mixing Test Results in Factor Ⅷ Inhibitor-Positive Hemophilia Patients / 中国实验血液学杂志

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.

Pharmacokinetics of Recombinant Human Coagulation Factor Ⅷ Preparations in Patients with Severe Hemophilia A / 中国实验血液学杂志

OBJECTIVE@#To calculate the pharmacokinetic parameters of recombinant human coagulation factor Ⅷ using myPKFiT in patients with severe hemophilia A, and provide an individualized treatment plan for patients.@*METHODS@#A total of 42 patients with severe hemophilia A who were treated with recombinant human coagulation factor Ⅷ were included from January 2021 to December 2021. myPKFiT was used to calculate the pharmacokinetic parameters of FⅧ, and the individualized treatment plan for hemophilia A patients was formulated.@*RESULTS@#The median age of 42 patients with severe hemophilia A was 31（16-50） years old, the average weight was 54.0±9.9 kg, the half-life of FⅧ was 12.05±1.6 h, the time to more than 1% of the baseline was 62.3±15.3 h, and the 0 bleeding rate after the guidance of myPKFiT was significantly increased from 39% to 49%, the Annual bleeding rate was reduced from 3.6±2.5 to 2.1±2.0, and the Annual joint bleeding rate was reduced from 3.2±2.2 to 1.9±0.9, all of which were statistically different (P<0.05).@*CONCLUSION@#Individualized therapy in patients with severe hemophilia A who were guided by myPKFiT assay of pharmacokinetics parameters can significantly reduce the annual bleeding rate and annual joint bleeding rate of patients.

Quality evaluation of cryoprecipitate coagulation factors from buffy coat-derived plasma at different time periods / 中国输血杂志

【Objective】 To investigate the quality of cryoprecipitates prepared from buffy coat-derived plasma of fresh whole blood at room temperature 20℃-24℃ isolated at different time periods, explore the optimal time for preparing cryoprecipitates, so as to improve the utilization rate of blood. 【Methods】 A total of 250 bags of whole blood collected by CPDA-1 and stored at 20℃-24℃ from October 2020 to December 2020 were randomly selected as the experimental group, and divided into groups A1 (0-8 h), A2 (8-10 h), A3 (10-12 h), A4 (12-14 h) and A5 (14-16 h) (with 50 bags in each group) according to the preparation time point. The upper-buff-coat plasma was separated and quickly frozen as the source for cryoprecipitates. Meanwhile, another 50 bags of fresh frozen plasma prepared within 0-16h after routine storage at 2℃-6℃ were randomly selected as the control group (group B), which was used as the raw plasma to make cryoprecipitate. Coagulation factor Ⅷ (Ⅷ factor) and fibrinogen (FIB) were detected, and the effect of different preparation time and different storage temperature on the content of factor Ⅷ and FIB and the pass rate were compared. 【Results】 In comparison to the control group, the Ⅷ factor content of groups A4 and A5 was significantly decreased, and the differences between groups A4, A5 and B were statistically significant (P0.05). The Factor Ⅷ content ≥60 IU/ bag prepared from buffy coat-derived plasma accounted for 96.4% (1.5 U) in the experimental group. 【Conclusion】 The buffy coat-derived plasma prepared within 12 h at 20℃-24℃ is suitable for preparing 2 U cryoprecipitate coagulation factor, while that prepared within 12-16 h is suitable for preparing 1.5 U cryoprecipitate coagulation factor.

Selection of sterilizing-grade filter for preparation of human coagulation factor Ⅷ/ von Willebrand factor complex / 中国输血杂志

【Objective】 To screen the sterilizing-grade filters applicable for production of human coagulation factor Ⅷ/von Willebrand factor complex(FⅧ/VWF)and study the sterilization filtration process. 【Methods】 Four sterilizing-grade filters for FⅧ/VWF were evaluated through indicators such as filtration capacity, filtration flux, recovery rate of FⅧ activity, recovery rate of VWF activity, recovery rate of VWF antigen, recovery rate of protein and VWF molecular distribution. The sterilizing-grade filter with the best filtration performance was selected for further study. The study was designed by general full-factor design to determine the appropriate filitered protein concentration and filitered speed range through evaluating the total filtered protein amount, recovery rate of protein and filtration efficiency, and then the process operation parameters was determined. 【Results】 The filtration flux of Sartobran P, Sartopore 2 XLG, Sartopore Platinum and Sartopore 2 XLI were 1.71±0.01, 1.80±0.01, 1.34±0.01, and 1.81±0.04 L·(m2)-1·min-1, respectively; the recovery rates (%) of FⅧ activity were 97.09±2.82, 99.22±0.99, 96.87±1.85 and 93.76±1.21, respectively; the recovery rates (%) of VWF activity were 98.12±1.42, 99.95±1.85, 94.80±1.62 and 92.09±1.67, respectively. Between Sartopore 2 XLG and Sartobran P, the difference of filtration flux (P<0.001) was statistically significant; between Sartopore 2 XLG and Sartopore Platinum, the differences of the filtration flux (P<0.001) and VWF potency recovery rate (P<0.05) were statistically significant; between Sartopore 2 XLG and Sartopore 2 XLI, the differences of FⅧ potency recovery rate (P<0.01) and VWF potency recovery rate (P<0.01) were statistically significant. The optimal process operating space of Sartopore 2 XLG was protein concentration of 0.45-0.58 mg/mL, and filtration rate of 1.48-2.95 L·(m2)-1·min-1. 【Conclusion】 Sartopore 2 XLG is the most suitable filter for the production of FⅧ/VWF and the DoE test proves that it has good process operation space.

Efficacy and safety evaluation of plasma-derived human coagulation factor Ⅷ in patients with hemophilia A / 中国输血杂志

【Objective】 To evaluate the efficacy and safety of plasma-derived human coagulation factor Ⅷ (FⅧ) in the treatment of patients with hemophilia A. 【Methods】 A multi-center and open, SAT(single-arm trials) clinical study was conducted. A total of 54 subjects with hemophilia A were enrolled in 5 research centers. FⅧ was injected according to the subjects' weight, severity of disease and other factors, and the transfusion efficiency of FⅧ activity at 10 min after the first infusion of the first bleeding event was taken as the main efficacy indexes. The improvement scores of bleeding symptoms and signs within 24 h after the first infusion of the first bleeding event were the secondary efficacy indexes. The pathogenic microbial indexes and FⅧ inhibitors were detected on 90(th) and 180(th) day after treatment. 【Results】 The transfusion efficiency of FⅧ activity of 54 subjects at 10 min after the first infusion was 171.9% on average, with median of 169.5%, both higher than the target value of 100%. Within 24 h after the first infusion, the improvement of bleeding symptoms and signs of the subjects were scored, among which 19 cases (35.2%) were "obvious", 35 cases (64.8%) were "good", and the total clinical effective rate reached 100%. Five subjects (9.3%) had six drug-related adverse events. On 90(th) and 180(th) day after treatment, hepatitis B surface antigen, hepatitis C antibody, HIV antibody, treponema pallidum antibody and FⅧ inhibitors were detected, and no negative to positive cases were found. 【Conclusion】 After infusion, the FⅧ preparation can significantly improve the FⅧ activity level in hemophilia A patients in a short period of time, which has high infusion efficiency and can achieve better treatment efficacy, and can also effectively control and relieve bleeding symptoms and signs, with good overall safety.

Hemophilia A with reduced coagulation factor Ⅺ: a case report and literature review / 中国输血杂志

【Objective】 To investigate the possible molecular pathogenesis of a child with hemophilia A accompanied by coagulation factor Ⅺ reduction by testing coagulation-related indicators and genotyping in the child and his family. 【Methods】 Peripheral blood from the patient and his parents for detection of coagulation factors Ⅷ, Ⅸ, Ⅺ, Ⅻ, VWF∶Ag, lupus anticoagulants and F VIII, F XI inhibitors were collected. All exons and flanking sequences of the genes encoding FⅧ and FⅪ were sequenced and bioinformatically analyzed. 【Results】 The child had low FⅧ and FⅪ activity and no parental abnormalities were observed. The sequencing results showed that there was a c. 1834(exon12) C>T heterozygous mutation in the FⅧ gene and a c. 1817 (exon15) G>A heterozygous mutation in the FⅪ gene, which was de novo. Bioinformatics analysis shows that the FⅪ mutation changes the original protein structure and increases the number of carboxyl groups. 【Conclusion】 For patients with prolonged APTT, in addition to excluding factors that interfere with APTT testing, all coagulation factors related to APTT should be tested to clarify the diagnosis.

Analysis of the effects of low/intermediate dose of coagulation factor Ⅷ on 30 adult patients with severe hemophilia A in a single center / 中华血液学杂志

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.

Prediction of Coagulation Factor Ⅷ Level in Chinese Hemophilia A Patients by the Pharmacokinetic Management Tool myPKFiT / 中国医学科学院学报

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%.

Current status and development trend of coagulation factor Ⅷ activity / 中华检验医学杂志

The detection of coagulation factor Ⅷ activity plays an important role in the diagnosis, typing, efficacy monitoring and detection of inhibitor titer in hemophilia A, acquired hemophilia A and von Willebrand disease. However, due to the diversity of detecting systems, the difference of reagent composition, the existence of interfering substances and other influence factors, the detection of coagulation factor Ⅷ activity in the laboratories in China still needs to be improved.

Chinese Expert Consensus on Pharmacokinetics Guided Treatment for Hemophilia A / 罕见病研究

@#Hemophilia A is an X-chromosome-linked recessive genetic disease that lacks coagulation factor Ⅷ (Factor Ⅷ, FⅧ) and is clinically manifested as spontaneous or excessive bleeding after injury.The current main treatment for hemophilia A is alternative infusion of FⅧ, but the fixed infusion mode is still used for the dosage and frequency of infusion, which cannot achieve the optimal curative effect under the principle of individualized treatment.Among the factors that affect the efficacy of FⅧ replacement therapy, the difference in the pharmacokinetics (PK) of FⅧ products by individuals is an important factor.The clinical understanding of individualized FⅧ replacement therapy under the guidance of PK is not sufficient.Therefore, this article reviews the PK characteristics, analysis models, clinical application scenarios and specific treatment plan formulation of FⅧ.

Changes of cryoprecipitate coagulation factors prepared by different preparation methods and quick-freezing time / 中国输血杂志

【Objective】 To analyze the changes of fibrinogen (Fg) and Ⅷ factor levels of cryoprecipitated coagulation factors prepared by different methods and post-preparation quick-freezing time. 【Methods】 The fresh frozen plasma (FFP), prepared from 400mL whole blood, was randomly divided into 6 groups(group A1, A2, A3, B1, B2, B3) with 20 eliquots each, to prepare cryoprecipitate coagulation factors. Group A1, B1 were prepared by automatic cryoprecipitation preparation instrument. group A2, B2 applied the instrument after centrifugation and group A3, B3 were prepared manually. The quick-freezing time after preparation in group A1-A3 and B1-B3 were different(within 1 hour vs. more than 1 hour after preparation). The automated coagulation analyzer was used to measure Fg and Ⅷ factor levels in six groups, and further statistical analysis was carried out. 【Results】 The Fg content (mg) of six groups were 245.29±27.44 in group A1, 227.13±18.68 in group A2, 221.11±20.95 in group A3, 182.12±9.15 in group B1, 163.68±15.50 in group B2, and 155.61±19.28 in group B3, respectively. The Ⅷ factor levels(IU) were of six groups were 115.86±27.99 in group A1, 93.79±36.29 in group A2, 91.92±34.75 in group A3, 83.04±18.82 in group B1, 66.33±19.57 in group B2, and 69.34±13.26 in group B3, respectively. There were no significant differences in gender or age between group As and groups Bs. The levels of Fg and Ⅷ factors in group A1 were significantly higher than those in group A2 and group A3 (P<0.05). In addition, the levels of Fg and Ⅷ factors in group B1 were also obviously higher than those in group B2 and group B3 (P<0.05). Further, the levels of Fg and Ⅷ factors in group As were significantly higher than those in group Bs (P<0.05). 【Conclusion】 The automatic cryoprecipitation preparation instrument plus quick-freezing within 1 hour after preparation contribute to a higher efficiency and better quality than others.

Matrix effect on the determination of Potency in Recombinant Coagulation Factor Ⅷ for injection / 中国输血杂志

【Objective】 To investigate the matrix effect on the determination of potency in Recombinant Human Coagulation Factor Ⅷ for Injection (rFⅧ). 【Methods】 Two different detection matrices were used to establish two methods for detecting the potency in Recombinant Human Coagulation Factor Ⅷ for Injection. And the matrix effect on the determination of potency was determined, including specificity, linearity, repeatability, accuracy and intermediate precision. 【Results】 As to the specificity, the recoveries of the two substrates at high vs low concentration level were 112% and 110% vs 104% and 109%, respectively. As to the linearity, in the range of (0.125-1.000) IU/mL, the correlation coefficient between concentration and coagulation time of standard/ sample was higher than 0.99. As to the accuracy/repeatability, the recoveries of two matrices was 104% and 102%, and RSD was 2.4% and 1.9%. As to the intermediate precision, personnel factor of two matrices was 0.72 and 0.23, date factor was 0.79 and 0.85, and RSD(for 12 times) was 4.2% and 3.0%. Comparison of two matrices was as follows: Deviation in test results of 6 batches of rFⅧ was all lower than 5%. There was no significant difference between two matrices. 【Conclusion】 The two matrices for potency detection show good performance including specificity, linearity, repeatability, accuracy, and intermediate precision. They are suitable for the determination of potency in rFⅧ products.

Evaluation of the efficacy and safety of human coagulation factor Ⅷ in the treatment of hemophilia A patients / 中国输血杂志

【Objective】 To evaluate the efficacy and safety of human coagulation factor Ⅷ developed by Shenzhen Weiguang Biological products Co, Ltd in the treatment of patients with hemophilia A. 【Methods】 A prospective, multi-center, open, single-group clinical study was conducted. A total of 65 subjects with hemophilia A were enrolled, and human coagulation factor Ⅷ(FⅧ) was injected according to the patients’ bleeding severity. The improvement score of bleeding symptoms and signs after the first infusion of the first bleeding event and the transfusion efficiency of FⅧ activity at 10 min and 1 hour after infusion were taken as the main efficacy indexes. The improvement scores of bleeding symptoms and signs after the first infusion and the increase of FⅧ activity at 10 min and 1 hour after infusion were the secondary efficacy indexes. 【Results】 The 65 subjects were enrolled in safety analysis set (SS) and full analysis set (FAS), and 58 of them were enrolled in protocol analysis set (PPS). Ten minutes and one hour after the first infusion, the level of factor Ⅷ activity in the subjects increased significantly, and the FⅧ activity increased by 100% or more in more than 79% of the subjects. The average infusion efficiency of FⅧ activity in all subjects was more than 100%. In 70% of the subjects, the pain was relieved rapidly and /or the bleeding symptoms were significantly improved 8 hours after each bleeding infusion, and the improvement rate of bleeding symptoms and signs reached 100% 72 hours after infusion. 【Conclusion】 After infusion of human coagulation factor Ⅷ, the activity level of factor Ⅷ in patients with hemophilia A significantly increased. The infusion efficiency can reach a optimal level, and the bleeding symptoms can be significantly improved.

Effect of ABO blood group on coagulation factor Ⅷ activity and fibrinogen content in fresh plasma products / 中国输血杂志

【Objective】 Tostudy the effect of ABO blood group on the FⅧ∶C and Fib content in human plasma, so as to provide the oretical guidance for the quality control of fresh plasma products and the establishment of relevant quality standards. 【Methods】 Samples determined included fresh plasma collected and fresh plasma separated manually. The FⅧ∶C and Fib content were determined by coagulation method. The exon6 of ABO gene was amplified and sequenced to determine the genotype. 【Results】 The FⅧ∶C in fresh plasma collected was (147.421±45.773)%, and that in fresh plasma separated manually was (119.083±35.130)%, showing significant differences(P0.05). The FⅧ∶C in non-O type (A, B, AB type) fresh plasma collected and fresh plasma separated manually were (167.048±40.862)% and (129.251±33.503)%, respectively, significantly higher than that in O type fresh plasma collected and fresh plasma separated manually as(121.386±38.632)% and (91.589±22.328)%, respectively. The Fib contents in non-O type fresh plasma collected and fresh plasma separated manually were (2.242±0.385)g/L and (2.329±0.472)g/L, respectively. The Fib contents in O type fresh plasma collected and fresh plasma separated manually were (2.287±0.370)g/L and (2.307±0.462)g/L, respectively, and no significant difference was noticed (P>0.05). 【Conclusion】 There was no significant correlation between Fib content and ABO blood group, while FⅧ∶C was significantly correlated with ABO blood group. In the preparation and quality control of FⅧ related blood products, the effect of ABO blood group on the FⅧ∶C should be considered, and the quality standard of FⅧ in plasma products should be established based on the ABO blood group.

Quality of cryoprecipitated antihemophilic factor: Impact of storage time following whole blood collection, gender, ABO blood group, age, and preparation method / 中国输血杂志

【Objective】 To investigate the factors affecting the quality of cryoprecipitated antihemophilic factor. 【Methods】 The quality test results of cryoprecipitated antihemophilic factor in Xuzhou Central Blood Station from 2017 to 2020 were selected and compared. The fresh frozen plasma (FFP) was stratifying by storage time following whole blood collection: less than 2h, 2~4 h, 4~6 h, and 6~8 h; by gender: males and females; by blood group: A, B, O, and AB groups; by age: 18~30, 30~45, and 45~60 ages; by preparation method: centrifugation and siphonage. The contents of fibrinogen (FIB) and factor Ⅷ in cryoprecipitated antihemophilic factor in each group were compared. 【Results】 The content of FIB and factor Ⅷ in females were higher than those in males(P<0.05). The content of factor Ⅷ differed statically by blood groups (P<0.05), which was lower in group O than others [graup A(180.5±75.2)IU, graup B(155.1±59.4)IU, graup O(109.3±46.4)IU, graup AB(168.5±65.1)IU]. The content of factor Ⅷ increased with age statistically (P<0.05). The content of FIB prepared by centrifugation [(373.3±126.1)mg] was superior to siphonage [(309.4±85.6)mg] (P<0.05), while the content of factor Ⅷ prepared by siphonage [(172.4±71.3)IU] was superior to centrifugation [(124.0±49.1)mg] (P<0.05). 【Conclusion】 Gender and preparation method are the influencing factors of FIB. Gender, age, blood group and preparation method are the influencing factors of the content of factor Ⅷ. The FFP prepared by whole blood preserved with the ACD (citrate, sodium citrate and glucose) solution at any time within 8h after the collection has no impact on the quality of cryoprecipitated antihemophilic factor.

Related quality indexes of different common plasma products: A comparative study / 中国输血杂志

【Objective】 To explore the difference of total protein (TP) content, coagulation factor VIII (FⅧ) activity and Fib content in different common plasma products, and to further provide basis for the establishment and refinement of relevant quality standards of common plasma products. 【Methods】 Samples involved in the experiment included frozen plasma and cryoprecipitated frozen plasma derived from whole blood and eukocyte-depleted whole blood. The TP content determination was carried out by biuret method. The FⅧ activity (FⅧ: C) and Fib content were determined by coagulation method. 【Results】 The TP content( g/L) in frozen plasma and cryoprecipitated frozen plasma derived from whole blood and eukocyte-depleted whole blood were 59.64±4.78 vs 58.09±4.1 vs 52.20±3.57 vs 51.89±1.50, respectively, and the FⅧ: C( %) were 109.63±43.38 vs 27.06±7.09 vs 71.83±21.64 vs 21.66±3.86,, and the Fib content (g/L) were 2.19±0.39 vs 1.30±0.24 vs 2.04±0.37 vs1.22±0.15, respectively. There was a significant difference in TP content between other common plasma products (P0.05). There was significant difference in FⅧ: C among four common plasma products (P0.05). 【Conclusion】 The TP content and FⅧ: C of common plasma products are closely related to the initial blood and preparation process. It is suggested that the quality standard of common plasma products should be further refined, and the establishment of cryoprecipitated frozen plasma relevant quality standard and clinical indications should be considered.

Preparation of cryoprecipitate coagulation factor from liquid-state plasma by supercooling method / 中国输血杂志

【Objective】 To establish a novel preparation method of cryoprecipitate coagulation factor from overcooled liquid-state plasma. 【Methods】 The fresh liquid plasma was kept at -11℃ to -13℃ for a period of time. It can remain in the liquid state with some coagulation factors generated due to supercooling. Then cryoprecipitate can be obtained from the liquid plasma by siphon method. 【Results】 The average fibrinogen content yielded in cryoprecipitate, prepared from 50 samples of 16-hour-stored fresh liquid plasma, was (186.02±22.72) mg, with the average recovery rate of (37.51±7.42) %, and the average content of coagulation FⅧ was (104.66±22.88) IU, with the average recovery rate of (46.62±5.58) %. 【Conclusion】 The cryoprecipitate coagulation factors could be obtained not only from fresh frozen-thawed plasma, but also from overcooled liquid plasma which is simple and stable, also meets the requirements of relative standards.

Optimized AAV package and experimental application of recombinant AAV8/hFⅧ for gene therapy on hemophilia A mice / 中华血液学杂志

Objective: To evaluate the effects of adeno-associated virus (AAV) carrying hFⅧ by serotype 8 (AAV8/hFⅧ) on hemophilia A (HA) mice by gene therapy strategy. Methods: pAAV-CB-EGFP, pH22 (serotype 2) and pfΔ6 (adenovirus helper) were used to package AAV into HEK-293 cells in different conditions (ratios of cells to plasmids). The efficiency of transfection and infection were evaluated using immunofluorescence microscope to seek an optimized package condition. pAAV-TTR-hFⅧ, pH 28 (serotype 8) and pfΔ6 were applied to package AAV8/hFⅧ in HEK-293 cells using the optimized package condition. The purified AAV8/hFⅧ were intravenously injected into HA mice and the effects of gene therapy were estimated. Results: The efficiency of package was evaluated according to the amount and intensity of enhanced green fluorescent protein (EGFP) under immunofluorescence microscope. Four package conditions including 10 cm-dish to transfect 10 μg plasmids, 20 cm-dish to 20 μg, 30 μg and 40 μg plasmids were employed, and the condition of 20 cm-dish to transfect 20 μg plasmids reached the highest transfection efficiency at 24 h, 48 h and 72 h after transfection. The small scale AAV-EGFP was packaged using the optimized condition and an AAV crude extract was harvested by a freeze-thaw method. HEK-293 and 16095 cells were infected by the AAV crude extract, and the preferential infection efficiency was recognized in 16095 cells under immunofluorescence microscope. Then, AAV8/hFⅧ was packaged and purified based on the optimized transfection condition, and the high purity of AAV8/hFⅧ was detected by Western blot. Fractions of AAV8/hFⅧ at the dose of 8×10(12) vg/kg were injected into HA mice through tail vein, an eye-bleeding was performed at every two weeks, and the activity of FⅧ was measured by aPTT assay. Results showed that the activity of FⅧ maintained at the therapeutic level and lasted up to 12 weeks after injection. Conclusion: The purified AAV8/hFⅧ based on the optimized package condition could play a role in HA mice gene therapy, and the long-term therapeutic effects of AAV8/hFⅧ were observed in vivo.

Optimized AAV package and experimental application of recombinant AAV8/hFⅧ for gene therapy on hemophilia A mice / 中华血液学杂志

Objective@#To evaluate the effects of adeno-associated virus (AAV) carrying hFⅧ by serotype 8 (AAV8/hFⅧ) on hemophilia A (HA) mice by gene therapy strategy.@*Methods@#pAAV-CB-EGFP, pH22 (serotype 2) and pfΔ6 (adenovirus helper) were used to package AAV into HEK-293 cells in different conditions (ratios of cells to plasmids). The efficiency of transfection and infection were evaluated using immunofluorescence microscope to seek an optimized package condition. pAAV-TTR-hFⅧ, pH 28 (serotype 8) and pfΔ6 were applied to package AAV8/hFⅧ in HEK-293 cells using the optimized package condition. The purified AAV8/hFⅧ were intravenously injected into HA mice and the effects of gene therapy were estimated.@*Results@#The efficiency of package was evaluated according to the amount and intensity of enhanced green fluorescent protein (EGFP) under immunofluorescence microscope. Four package conditions including 10 cm-dish to transfect 10 μg plasmids, 20 cm-dish to 20 μg, 30 μg and 40 μg plasmids were employed, and the condition of 20 cm-dish to transfect 20 μg plasmids reached the highest transfection efficiency at 24 h, 48 h and 72 h after transfection. The small scale AAV-EGFP was packaged using the optimized condition and an AAV crude extract was harvested by a freeze-thaw method. HEK-293 and 16095 cells were infected by the AAV crude extract, and the preferential infection efficiency was recognized in 16095 cells under immunofluorescence microscope. Then, AAV8/hFⅧ was packaged and purified based on the optimized transfection condition, and the high purity of AAV8/hFⅧ was detected by Western blot. Fractions of AAV8/hFⅧ at the dose of 8×1012 vg/kg were injected into HA mice through tail vein, an eye-bleeding was performed at every two weeks, and the activity of FⅧ was measured by aPTT assay. Results showed that the activity of FⅧ maintained at the therapeutic level and lasted up to 12 weeks after injection.@*Conclusion@#The purified AAV8/hFⅧ based on the optimized package condition could play a role in HA mice gene therapy, and the long-term therapeutic effects of AAV8/hFⅧ were observed in vivo.

Population pharmacokinetics of two recombinant human coagulation factor Ⅷ preparations in patients with hemophilia A / 中华血液学杂志

Objective: To compare the differences in population pharmacokinetic (PK) parameters between two recombinant coagulation factor Ⅷ (FⅧ) preparations, Kogenate FS and Advate, in patients with hemophilia A, and to provide the theoretical basis of precise individualized treatment for those patients. Methods: Patients with moderate or severe hemophilia A who had at least one injection of Kogenate FS or Advate at 41 international hemophilia centers were enrolled as subjects from the WAPPS-Hemo project since January 2015 to December 2017. The half-lives of the two drugs and the time of FⅧ activity reaching 2% (TAT 2%) were calculated, and the differences of PK between the two drugs among different age and dose subgroups were further analyzed. Results: ①The mean age of patients in the Kogenate FS (n=117) and Advate groups (n=120) were (27.6±17.7) and (23.4±16.2) years old, respectively. All patients in the two groups were males. ②The administration doses in the Kogenate FS and Advate groups were (31.5±13.1) IU/kg and (38.17±14.83) IU/kg, respectively; the half-lives of the two drugs were (12.3±3.5) h and (10.8±2.9) h, respectively; and the TAT 2% were (65.2±21.7) h and (57.0±17.9) h, respectively. ③In the Kogenate FS group, the drug half-lives in patients aged ≥12 and <12 years old were (12.7±3.7) h and (11.1±2.5) h, respectively; the TAT 2% were (68.6±22.9) h and (55.8±14.6) h, respectively. In the Advate group, the drug half-lives in patients aged ≥12 and <12 years old were (11.4±3.1) h and (9.4±1.8) h, respectively; and the TAT 2% were (61.1±18.0) h and (45.2±11.3) h, respectively. ④In the Kogenate FS group, the drug half-lives in <20 IU/kg, (20-29) IU/kg, (30-39) IU/kg and ≥40 IU/kg groups were (13.3±4.0) h, (12.3±3.6) h, (12.2±3.5) h and (11.6±2.6) h, respectively; and the TAT 2% were (61.5±21.4) h, (63.9±22.4) h, (67.0±24.3) h and (68.0±19.5) h, respectively. In the Advate group, the drug half-lives in <20 IU/kg, (20-29) IU/kg, (30-39) IU/kg and <40 IU/kg groups were (11.5±3.8) h, (11.4±3.7) h, (11.0±2.9) h and (10.4±2.3) h, respectively; and the TAT 2% were (50.8±19.2) h, (56.7±21.0) h, (58.2±18.8) h and (58.1±15.8) h, respectively. Conclusion: The PK parameters of Kogenate FS are superior to those of Advate among different age and dose subgroups.