Influence of Factor IX on Overall Plasma Coagulability and Fibrinolytic Potential in Hemophilia B as Measured by Global Assay.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1034-1034
Author(s):  
Neil A. Goldenberg ◽  
William E. Hathaway ◽  
Christopher Bombardier ◽  
Kelly McFarland ◽  
Linda Jacobson ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Ex Vivo ◽  
Acute Infection ◽  
Age Groups ◽  
Factor Ix ◽  
Hemophilia B ◽  
Analytical Sensitivity ◽  
Severe Hemophilia ◽  
Normal Plasma

Abstract BACKGROUND: The Clot Formation and Lysis (CloFAL) global assay is a turbidimetric plasma assay utilizing coagluation activation by lipidated tissue factor and fibrinolytic enhancement by tissue plasminogen activator, and has recently been shown to be sensitive for factor VIII (FVIII) deficiency (Goldenberg et al., Thromb Res 2005; Goldenberg et al., Haemophilia 2006, in press). Deficiency of factor IX (FIX) is often clinically less severe than that of FVIII. We sought to evaluate the analytical sensitivity of the CloFAL assay for FIX deficiency, both in vitro and ex vivo. METHODS: The influence of FIX activity upon the CloFAL assay was examined in vitro in FIX-deficient plasma by mixing study with pooled normal plasma, addition of plasma-derived FIX concentrate, and repletion with recombinant FIX. The analytical sensitivity of the CloFAL assay for FIX deficiency was then studied clinically via comparison of healthy individuals to FIX-deficient adults (n=25) and children (n=19), of whom greater than 1/3 had mild hemophilia B (FIX activity >/= 5.0 U/dL). FIX-deficient subjects had not received exogenous FIX within the prior 96 hours and had no evidence of active hepatitis. Healthy adult and pediatric groups (n=25 each) were without chronic illness or family history of bleeding or thrombosis. None of the study subjects were taking medications that affect hemostasis or had recent active bleeding or acute infection. RESULTS: Alteration of FIX activity in vitro exerted considerable influence upon the CloFAL assay (Figure 1). Ex vivo, the CloFAL assay coagulation index (CI), a measure of the area under the clotting curve, was significantly decreased in FIX-deficient versus healthy subjects among adults and children alike (median CI, adults: 10% vs. 94%, respectively; median CI, children: 10% vs. 63%, respectively; P < 0.0001 for each), and correlated significantly with FIX activity in both age groups (r = 0.80 and r = 0.77; P < 0.0001 for each). In addition, the CloFAL assay fibrinolytic index (FI) was increased in FIX-deficient versus healthy subjects (median FI, adults: 228% vs. 109%, respectively, p<0.0001; median FI, children: 276% vs. 202%, respectively; p=0.7), although this difference was not statistically significant in children. Interestingly, severe hemophilia B patients (n=8; FIX activity < 1.0 U/dL) showed considerable heterogeneity in CloFAL assay waveforms (Figure 2). Nevertheless, the assay uniformly discriminated these patients from healthy controls. CONLUSION: This work demonstrates that the CloFAL global assay, which is highly influenced by FVIII activity, is also analytically sensitive to FIX deficiency. Figure 1. Coagulative response of severe FIX-deficient plasma to increasing FIX activity in vitro, as measured by coagulation Index (CI) in the CloFAL global assay. Figure 1. Coagulative response of severe FIX-deficient plasma to increasing FIX activity in vitro, as measured by coagulation Index (CI) in the CloFAL global assay. Figure 2. CloFAL global assay waveforms for pooled normal plasma (grey) as compared to patients with severe hemophilia B (FIX activity < 1 U/dL; n=8). Figure 2. CloFAL global assay waveforms for pooled normal plasma (grey) as compared to patients with severe hemophilia B (FIX activity < 1 U/dL; n=8).

scholarly journals Delivery of human factor IX in mice by encapsulated recombinant myoblasts: a novel approach towards allogeneic gene therapy of hemophilia B

Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5095-5103 ◽  
Author(s):  
G Hortelano ◽  
A Al-Hendy ◽  
FA Ofosu ◽  
PL Chang
Keyword(s):  
Gene Therapy ◽  
Human Factor ◽  
Ex Vivo ◽  
Cost Effective ◽  
Factor Ix ◽  
Hemophilia B ◽  
Therapy Strategy ◽  
Human Factor Ix

A potentially cost-effective strategy for gene therapy of hemophilia B is to create universal factor IX-secreting cell lines suitable for implantation into different patients. To avoid graft rejection, the implanted cells are enclosed in alginate-polylysine-alginate microcapsules that are permeable to factor IX diffusion, but impermeable to the hosts' immune mediators. This nonautologous approach was assessed by implanting encapsulated mouse myoblasts secreting human factor IX into allogeneic mice. Human factor IX was detected in the mouse plasma for up to 14 days maximally at approximately 4 ng/mL. Antibodies to human factor IX were detected after 3 weeks at escalating levels, which were sustained throughout the entire experiment (213 days). The antibodies accelerated the clearance of human factor IX from the circulation of the implanted mice and inhibited the detection of human factor IX in the mice plasma in vitro. The encapsulated myoblasts retrieved periodically from the implanted mice up to 213 days postimplantation were viable and continued to secrete human factor IX ex vivo at undiminished rates, hence suggesting continued factor IX gene expression in vivo. Thus, this allogeneic gene therapy strategy represents a potentially feasible alternative to autologous approaches for the treatment of hemophilia B.

scholarly journals Plasma Tissue Factor Pathway Inhibitor (TFPI) Levels in Healthy Subjects and Patients with Hemophilia A and B

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4672-4672 ◽  
Author(s):  
Jian-Ming Gu ◽  
Chandra Patel ◽  
Katalin Kauser
Keyword(s):  
Tissue Factor ◽  
Healthy Subjects ◽  
Tissue Factor Pathway Inhibitor ◽  
Hemophilia A ◽  
Hemophilia B ◽  
Severe Hemophilia ◽  
Capture Assay ◽  
Healthy Donors ◽  
Tissue Factor Pathway

Abstract BAY 1093884 is a fully human monoclonal antibody against tissue factor pathway inhibitor (TFPI) developed as a potential bypass agent for patients with hemophilia with or without inhibitors. It restores insufficient thrombin burst, leading to stable clot formation in hemophilic conditions in vitro, and effectively stops bleeding in vivo. TFPI is a potent inhibitor of factor Xa (FXa) and the factor VIIa tissue factor complex in the extrinsic pathway. The majority of TFPI is associated with vascular endothelial cells. The mean plasma TFPI concentration in healthy individuals is ~70 ng/mL (1.6 nM) and about 80% of the circulating TFPI is bound to lipoproteins [Dahm, et al. Blood. 2003;101(11):4387-4392; Broze,et al. Front Biosci. 2012;17:262-280]. Some reports indicate that patients with hemophilia B have lower free TFPI levels than patients with hemophilia A, irrespective of phenotypic severity (Tardy-Poncet, et al. Haemophilia 2011;17:312-313). The objective of this study is to determine the plasma TFPI concentration in healthy donors and patients with hemophilia by a newly developed functional TFPI capture assay and to evaluate this assay with inhibition of TFPI by anti-TFPI neutralizing antibody (BAY 1093884) in vitro. A quantitative enzyme-linked immunosorbent assay using FXa as capture agent was developed and validated to measure TFPI levels in human plasma. The assay shows very good precision, accuracy, and reproducibility and should capture all coagulation-relevant forms of TFPI from plasma. Plasma TFPI was determined in 30 healthy donors (15 males and 15 females) and 30 patients with severe hemophilia (hemophilia A [n=12], hemophilia A with inhibitors [n=9], hemophilia B [n=9]). The plasma TFPI levels (mean ± SD) in healthy individuals, patients with severe hemophilia A without and with inhibitors, and severe hemophilia B were 59.5±18.4 ng/mL, 62.9±14.6 ng/mL, 47.3±4.3 ng/mL, and 68.1±8.8 ng/mL, respectively (Table 1). No statistical differences were found based on sex or race (Hispanic, African American, white) in the healthy population and between patients with hemophilia with and without inhibitors. TFPI levels were also not affected by addition of corn trypsin inhibitor (CTI) in citrate plasma. Furthermore, the concentration that inhibits 50% of TFPI levels (IC50) of anti-TFPI antibody (BAY 1093884) was determined to be 4.76 nM in normal human plasma using this assay. In conclusion,plasma TFPI does not appear to be affected by sex or race in healthy subjects, or the deficiency of factor VIII or IX in patients with hemophilia. The functional TFPI capture assay could potentially be used as a pharmacodynamic marker for monitoring plasma TFPI levels after the administration of anti-TFPI antibody and guide dosing strategies. Table 1. Plasma TFPI Levels in Healthy Subjects and Patients With Severe Hemophilia A and B HealthyHuman Donors(n=30) SevereHem A(n=12) Severe Hem AWith inhibitors(n=9) SevereHem B(n=9) TFPI, ng/mL Mean ± SD 59.5±18.4 62.9±14.6 47.3±4.3 68.1±8.8 Hem=hemophilia; TFPI=tissue factor pathway inhibitor. Disclosures Gu: Bayer HealthCare: Employment. Patel:Bayer HealthCare: Employment. Kauser:Bayer HealthCare LLC: Employment.

scholarly journals Pharmacokinetics of Human Factor IX in a dog with Severe Hemophilia B.

1977 ◽  
Author(s):  
P.A. Gentry ◽  
A.R. Thompson ◽  
A.W. Forrey
Keyword(s):  
Human Factor ◽  
Numerical Procedure ◽  
Factor Ix ◽  
Hemophilia B ◽  
High Yield ◽  
Severe Hemophilia ◽  
Activity Data ◽  
Human Factor Ix

In preparing a factor IX concentrate with a high yield and low hepatitis and thromboembolic risks, we have tested this material for survival in an in vivo system, the hemophiliac dog. By following the disappearance of radiolabeled, isolated factor IX in addition to the classic clotting assays, data on protein survival and more accurate kinetic parameters were obtained.Crude factor IX concentrate was prepared by batchwise adsorption-elution with DEAE-Sephadex using cryoprecipitate-poor human plasma. Isolated human factor IX was radiolabeled with 125I by chloramine-T without in vitro loss of clotting activity (Thompson, J Clin Invest, in press, 1977). A preparation containing both crude and isolated factor IX was then subjected to filtration (0.22 μm) and lyophilization; clotting and radioactivity were not altered by these steps.Following infusion of the combined preparation into a dog with severe hemophilia B (0% baseline factor IX) 10 post infusion samples were taken over 96 h for determination of radioactivity and factor IX clotting activity. These data were then analyzed by fitting to a two exponential expression using a Marquart non-linear least squares numerical procedure for a two compartment open model. The central volume was 14.5% of the animal’s body weight; the total volume of distribution was 28% with a t 1/2 distribution of 114 min. The t 1/2 elimination was 20 h; the slower phase of elimination (β, or that affected by redistribution) had a t 1/2 of 40 h. Factor IX clotting activity from the crude concentrate closely paralleled radioactivity from the isolated factor IX throughout the 96 h; t 1/2 β was slightly longer from the clotting activity data.

scholarly journals Circulating Factor IX Antigen-Inhibitor Complexes in Hemophilia B- Following Infusion of a Factor IX Concentrate

1977 ◽  
Author(s):  
S.H. Goodnight ◽  
C.W. Britell ◽  
K.D. Wuepper ◽  
B. Østerud
Keyword(s):  
Specific Antibody ◽  
Fast Moving ◽  
Protein A ◽  
Factor Ix ◽  
Hemophilia B ◽  
Two Dimensional ◽  
Severe Hemophilia ◽  
Normal Plasma ◽  
Post Infusion ◽  
Sepharose 4B

A persistent low titer IgG factor IX inhibitor (0.8–2.3u/ml) has been previously described in an 11 year old boy with severe hemophilia B-. Since the disappearance of factor IX antigen (IXAGN) following Konyne(R) infusion was markedly delayed ( 60 hr) compared to factor IX clotting activity (T 8 hr) (Blood 48:977, 1976), a search for circulating factor IX antigen-inhibitor complexes was undertaken. The inhibitor binds firmly to staphlococcal protein A – Sepharose 4B (SPA-Sepharose) but may be eluted in the IgG 1, 2, and 4 fraction with 3M NaSCN. SPA-Sepharose chromatography of post-infusion plasma (IXAGN 2.7u) from the patient with the inhibitor showed IXAGN (0.5u) in the IgG 1, 2, and 4 fraction, whereas IXAGN was not found in that fraction of chromatographed samples of post infusion plasma from non-inhibitor patients with hemophilia B- or B+. Using a highly specific antibody to factor IX, two dimensional Immunoelectrophoresis of purified factor IX or normal plasma showed a single symmetrical fast moving peak. When an equal volume of inhibitor plasma was added to either factor IX or normal plasma a second, slower moving component was also seen. Two dimensional Immunoelectrophoresis of plasma obtained from the patient 45 minutes after infusion showed both the slow and fast components. The presence of IXAGN in the IgG 1, 2, and 4 peak after SPA-Sepharose chromatography and the demonstration of 2 components on two dimensional Immunoelectrophoresis indicates the presence of circulating factor IX antigen-inhibitor complexes in the plasma of this patient following the infusion of a factor IX concentrate.

A typical Response To Infusion Prior To The In Vitro Appearance Of Inhibitor In A Hemophilia B Patient

1981 ◽  
Author(s):  
C H Miller ◽  
M W Hilgartner
Keyword(s):  
Immune Complexes ◽  
Half Life ◽  
Response Pattern ◽  
Factor Ix ◽  
Hemophilia B ◽  
Similar Response ◽  
Severe Hemophilia ◽  
Before And After ◽  
Post Infusion

Infusion studies were performed on six patients with severe hemophilia B, in whom factor IX clotting activity (IX: C) was less than 1%. All had no detectable factor IX antigen (IX: Ag) on testing with heterologous anti-IX prior to the study (and no measurable F. IX inhibitor). Each patient received the same factor IX concentrate in a 50 u/kg dose. Samples were drawn at 0, 15 minutes, 1 hour, 4 hours, and 24 hours post-infusion and were tested for IX: C and IX: Ag. Five of the patients showed similar response to transfusion with average half-life of IX: C of 12 hours and of IX:Ag 10 hours. One patient showed quite different results. He had a half-life of IX: C of 31 hours and of IX:Ag of 24 hours. Although routine tests for a F. IX inhibitor were negative both before and after the study, he developed a rapidly rising inhibitor 15 months later. In retrospect it can be seen that this patient resembled the patient with a low titer inhibitor and prolonged IX: Ag survival described by Goodnight et al. However, our patient showed the atypical infusion response pattern before his inhibitor was detectable in vitro. Thus the finding of a prolonged survival of IX: Ag can be taken as evidence of inhibitor formation. Inhibitor presence can be confirmed by detection of circulating immune complexes containing IX: Ag prior to the appearance of a measurable inhibitor to clotting.

Markers of Hypercoagulability in Patients with Hemophilia B Given Repeated, Large Doses of Factor IX Concentrates during and after Surgery

1994 ◽  
Vol 71 (06) ◽  
pp. 737-740 ◽  
Author(s):  
E Santagostino ◽  
P M Mannucci ◽  
A Gringeri ◽  
G Tagariello ◽  
F Baudo ◽  
...  
Keyword(s):  
High Risk ◽  
Ex Vivo ◽  
Factor Ix ◽  
Hemophilia B ◽  
Coagulation System ◽  
Prolonged Treatment ◽  
Orthopedic Procedures ◽  
Factor X ◽  
Prothrombin Complex Concentrates ◽  
Increased Risk

SummaryPurer factor IX (FIX) concentrates have been produced for the treatment of hemophilia B in the attempt to reduce the risk of thrombotic complications associated with the use of prothrombin complex concentrates. To evaluate ex vivo whether or not FIX concentrates activate the coagulation system in conditions associated with a high risk for thrombosis, we measured markers of hypercoagulability in 10 patients with hemophilia B who underwent surgery, mainly orthopedic procedures, covered by multiple concentrate infusions (40-80 U/kg/day). Postinfusion plasma levels of prothrombin fragment 1+2 and factor X activation peptide did not differ significantly from the presurgical levels, neither before nor after each concentrate dose. Therefore, it appears that prolonged treatment of patients with hemophilia B undergoing high risk surgical procedures with high doses of FIX concentrate does not cause systemic activation of coagulation. This suggests that purified FIX concentrates are preferable to prothrombin complex concentrates for conditions associated with an increased risk of thrombosis.

scholarly journals Can Be miR-126-3p a Biomarker of Premature Aging? An Ex Vivo and In Vitro Study in Fabry Disease

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 356 ◽  
Author(s):  
Alessia Lo Curto ◽  
Simona Taverna ◽  
Maria Assunta Costa ◽  
Rosa Passantino ◽  
Giuseppa Augello ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Fabry Disease ◽  
Healthy Subjects ◽  
Aging Process ◽  
Replicative Senescence ◽  
Ex Vivo ◽  
Umbilical Vein ◽  
Quantitative Polymerase Chain Reaction ◽  
Premature Aging

Fabry disease (FD) is a lysosomal storage disorder (LSD) characterized by lysosomal accumulation of glycosphingolipids in a wide variety of cytotypes, including endothelial cells (ECs). FD patients experience a significantly reduced life expectancy compared to the general population; therefore, the association with a premature aging process would be plausible. To assess this hypothesis, miR-126-3p, a senescence-associated microRNA (SA-miRNAs), was considered as an aging biomarker. The levels of miR-126-3p contained in small extracellular vesicles (sEVs), with about 130 nm of diameter, were measured in FD patients and healthy subjects divided into age classes, in vitro, in human umbilical vein endothelial cells (HUVECs) “young” and undergoing replicative senescence, through a quantitative polymerase chain reaction (qPCR) approach. We confirmed that, in vivo, circulating miR-126 levels physiologically increase with age. In vitro, miR-126 augments in HUVECs underwent replicative senescence. We observed that FD patients are characterized by higher miR-126-3p levels in sEVs, compared to age-matched healthy subjects. We also explored, in vitro, the effect on ECs of glycosphingolipids that are typically accumulated in FD patients. We observed that FD storage substances induced in HUVECs premature senescence and increased of miR-126-3p levels. This study reinforces the hypothesis that FD may aggravate the normal aging process.

scholarly journals Production of human factor IX in animals by genetically modified skin fibroblasts: potential therapy for hemophilia B

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 438-445
Author(s):  
TD Palmer ◽  
AR Thompson ◽  
AD Miller
Keyword(s):  
Human Factor ◽  
Normal Skin ◽  
Human Fibroblasts ◽  
Retroviral Vectors ◽  
Factor Ix ◽  
Skin Fibroblasts ◽  
Hemophilia B ◽  
Clotting Factor ◽  
Human Factor Ix

Inherited diseases might be treated by introducing normal genes into a patient's somatic tissues to correct the genetic defects. In the case of hemophilia resulting from a missing clotting factor, the required gene could be introduced into any cell as long as active factor reached the circulation. We previously showed that retroviral vectors can efficiently transfer genes into normal skin fibroblasts and that the infected cells can produce high levels of a therapeutic product in vitro. In the current study, we examined the ability of skin fibroblasts to secrete active clotting factor after infection with different retroviral vectors encoding human clotting factor IX. Normal human fibroblasts infected with one vector secreted greater than 3 micrograms factor IX/10(6) cells/24 h. Of this protein, greater than 70% was structurally and functionally indistinguishable from human factor IX derived from normal plasma. This suggests that infected autologous fibroblasts might provide therapeutic levels of factor IX if transplanted into patients suffering from hemophilia B. By transplanting normal diploid fibroblasts infected with the factor IX vectors, we showed that human factor IX can be produced and is circulated at readily detectable levels in rats and mice.

scholarly journals Impact of Systematic Pharmacokinetic (PK) Profiles in a Cohort of 29 Patients Treated with Conventional and Extended-Half Life (EHL) Products

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1123-1123
Author(s):  
Teresa Ceglie ◽  
Berardino Pollio ◽  
Irene Ricca ◽  
Maria Messina ◽  
Claudia Linari ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Factor Ix ◽  
Hemophilia B ◽  
Null Mutation ◽  
Severe Hemophilia ◽  
Factor Level ◽  
On Demand ◽  
Active Life ◽  
Genetic Assessment

Introduction. Prophylaxis with factor concentrates reduces bleeding events and improves quality of life for adults and children with severe hemophilia. However, the optimal dosing and infusion frequency is not yet established. Integration of PK data into decision making is gaining support, in particular at the transition between conventional and EHL products. Here we report about 29 PK data of patients affected by hemophilia treated at our centre since childhood. Improved quality of life was our first aim, supposed that decreasing frequency of infusions or increasing the target through factor level allows a more active life without increased risk of bleeding. Patients' characteristics and methods. 18 patients (62%) were ≤ 18 years of age at PK time. 16 were affected by severe hemophilia A, 5 by moderate hemophilia A, 6 by severe hemophilia B and 2 by moderate hemophilia B. At PK time, 28 patients were on prophylaxis and 1 was on demand with recombinant factor IX. Median age at onset of prophylaxis was 9 years (range 3 months-38 years). Genetic assessment was available in 24 patients. Of these, 37.5% and 62.5% were carriers of null and not null mutations respectively. 4 patients were undergone to PK with standard products (1 Octocog alfa, 1 Simoctocog alfa, 1 Octocog alfa-Kovaltry®, 1 Turoctocog alfa) in order to define timing and dosage of successive infusions, while 25 patients switched to EHL factors (15 Efmoroctocog alfa, 2 Ionoctocog alfa, 7 Albutrepenonacog alfa, 1 Eftrenonacog alfa). In 15 patients a population-based PK (popPK) according to WAPPS-Hemo program was also performed. The annualized bleeding rate (ABR) was counted from patient's home bleeding records for one year before PK until now. Results. According to PK data, 21 patients (75%) decreased infusion frequency (100% hemophilia B and 67% hemophilia A patients). The remaining 7 hemophilia A patients maintained the same timing in order to increase the through factor level. Notably, 1 hemophilia B patient switched from on demand treatment to prophylaxis with EHL product due to the more acceptable schedule. 66% of null mutation patients and 73% of not null mutation patients decreased timing. Of 28 patients available at follow-up, 32%, 50% and 18% decreased, increased and maintained the same annual average factor consumption/kg, respectively. All patients had a good adherence after switch. In particular, the on demand patient started a regular prophylaxis with optimal compliance. ABR displayed a reduction with a median of 0 (range 0-5) after PK analysis compared to 1 (range 0-12) before the switch. Full PK vs popPK data obtained using at least two individual PK sampling points were almost similar. Conclusions. Our results remark the necessity of PK study especially in children due to the inter-individual variability independent of genetic assessment. Regarding factor IX, PK allowed us to propose timing even longer than that recommended by prescribing indications resulting in a better personalized prophylaxis. Moreover, our study demonstrates that a full PK analysis is feasible also in children. However, given similar results, popPK could be more feasible in most patients. Regarding consumption, the reduction of only 32% of patients reflects our aim to maintain a high safety profile in an active pediatric population. Nevertheless, the mean annualized consumption was just 0.6-fold increased in the remaining patients. This approach led us to further reduce ABR and in some cases to obtain a persistent no-bleeding status even with a full active life. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document