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.

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).

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.

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.

scholarly journals Development of Monospecific Antibodies to Human Factor IX

1977 ◽  
Author(s):  
Cheryl Y. Tiarks ◽  
Chin-Hai Chang ◽  
Liberto Pechet
Keyword(s):  
Neutralizing Antibodies ◽  
Human Factor ◽  
Human Albumin ◽  
Factor Ix ◽  
Hemophilia B ◽  
Red Cross ◽  
Factor X ◽  
Normal Plasma ◽  
Human Factor Ix ◽  
Monospecific Antibodies

The purpose of this research was to develop neutralizing and precipitating antibodies to factor IX. Human factor IX, purified by the method of Rosenberg et.al. (J. Biol. Chem. 250:8883, 1975), was electrophoresed on acrylamide gel. Two major bands migrating adjacently were eluted. They contained factor IX activity only. The eluates and their homogenized gel segments 7 and 8 were injected separately into two rabbits, Rl and R2, respectively. On immunodiffusion the antiserum Rl showed one precipitating line with normal plasma. It neutralized human factor IX (20 Bethesda units) and also slightly neutralized factor X. It had no effect on factors II and VII. Following absorption of this antiserum with purified factor X it neutralized factor IX only. With continuous immunization, however, this antiserum revealed two new precipitating contaminants. The antiserum R2 neutralized only factor IX; it reached 220 Bethesda inhibitory units. On immunodiffusion it showed two precipitating lines, one of which disappeared after absorption with human albumin. On immunodiffusion and Laurell immunoelectrophoresis, the albumin-absorbed R2 antiserum showed one precipitin line of identity, or one rocket, with normal plasma, a Red Cross factor IX preparation (rich in factors IX, II and X), the original eluates 7 and 8, and a Hemophilia-B antigen-positive plasma. No line or rocket developed with normal plasma absorbed with aluminum hydroxide or with antigen-negative Hemophilia-B plasma. We conclude that the antisera Rl and R2 contain factor IX neutralizing antibodies and that albumin-absorbed R2 has monospecific precipitating antibodies to human non-activated factor IX.

scholarly journals Factor IX New London: substitution of proline for glutamine at position 50 causes severe hemophilia B

Blood ◽  
1990 ◽  
Vol 75 (5) ◽  
pp. 1097-1104 ◽  
Author(s):  
JN Lozier ◽  
DM Monroe ◽  
S Stanfield-Oakley ◽  
SW Lin ◽  
KJ Smith ◽  
...  
Keyword(s):  
Translation Termination ◽  
Factor Ix ◽  
Hemophilia B ◽  
Molar Ratio ◽  
Carrier Status ◽  
Severe Hemophilia ◽  
Base Pairs ◽  
Human Factor Ix ◽  
Restriction Endonuclease Cleavage Site ◽  
Status Analysis

Abstract We describe a novel point mutation in the fourth exon of human factor IX (encoding the first EGF-like domain) in which cytosine is substituted for adenosine at position 10,401, resulting in the substitution of proline for glutamine at position 50 in the polypeptide chain. Sequence analysis of all eight exons, all exon-intron junctions, 160 base pairs (bp) of DNA 5′ to the proposed translation start site, and 60 bp 3′ to the translation termination site shows no other difference from the normal factor IX gene, with the exception of a previously described benign polymorphism at position 148 in the protein (Ala----Thr). The affected subject has severe hemophilia B with no detectable factor IX activity despite normal factor IX antigen levels. We purified the abnormal factor IX by immunoaffinity chromatography and demonstrated that its activation by factor Xla is markedly delayed compared with normal factor lX. Once activated, the abnormal factor lX binds antithrombin III in a 1:1 molar ratio, and the activated protein demonstrates catalytic activity, suggesting an intact active site. The mutation creates a new Bst Yl restriction endonuclease cleavage site. Restriction with Bst Yl shows the mutation in maternal DNA and offers the possibility of direct carrier status analysis and prenatal diagnosis in kindreds with this mutation. We designate this new mutation factor lXNew London. This is the only reported mutation in the first EGF-like domain that causes severe hemophilia B.

Mutation of Factor IX Cys178 is intolerant and may cause severe hemophilia B

2019 ◽  
Vol 183 ◽  
pp. 108-110 ◽  
Author(s):  
Xiong Wang ◽  
Linna Gao ◽  
Na Shen ◽  
Aiguo Liu ◽  
Yanjun Lu ◽  
...  
Keyword(s):  
Factor Ix ◽  
Hemophilia B ◽  
Severe Hemophilia

scholarly journals Favorable pharmacokinetics in hemophilia B for nonacog beta pegol versus recombinant factor IX-Fc fusion protein: A randomized trial

2019 ◽  
Vol 3 (2) ◽  
pp. 268-276 ◽  
Author(s):  
Carmen Escuriola Ettingshausen ◽  
Inga Hegemann ◽  
Mindy L. Simpson ◽  
Adam Cuker ◽  
Roshni Kulkarni ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Randomized Trial ◽  
Protein A ◽  
Factor Ix ◽  
Hemophilia B ◽  
Fc Fusion Protein ◽  
Recombinant Factor Ix

Successful Desensitization in a Severe Hemophilia B patient with IgE-mediated Anaphylaxis to Factor IX

2007 ◽  
Vol 119 (1) ◽  
pp. S35
Author(s):  
Y. Moonsup ◽  
S. Benjaponpitak ◽  
A. Chuansumrit ◽  
W. Kamchaisatian ◽  
C. Direkwattanachai
Keyword(s):  
Factor Ix ◽  
Hemophilia B ◽  
Severe Hemophilia ◽  
Ige Mediated

Novel Treatment Approaches in Combination with Rituximab for Immune Tolerance Induction in Severe Hemophilia B.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3975-3975 ◽  
Author(s):  
Amanda M. Brandow ◽  
Rowena C. Punzalan ◽  
Karen Stephany ◽  
Craig Helsell ◽  
Joan C. Gill
Keyword(s):  
Immune Tolerance ◽  
High Titer ◽  
Tolerance Induction ◽  
Factor Ix ◽  
Hemophilia B ◽  
High Dose ◽  
Subdural Hemorrhage ◽  
Severe Hemophilia ◽  
Immune Tolerance Induction ◽  
Novel Approaches

Abstract Although only 4–5% of patients with severe Hemophilia B (HB) develop factor IX (FIX) antibodies that cause inactivation of transfused FIX concentrate (conc), about 1/3 of these are associated with life-threatening anaphylactic reactions; immune tolerance induction (ITI) with high-dose FIX conc is often unsuccessful. We present individualized novel approaches to ITI in 2 boys with severe HB and high-responding inhibitors. ELISA assays utilizing recombinant FIX (rFIX) to capture patient IgG followed by detection with subclass specific monoclonal antibodies were developed to evaluate the characteristics of the factor IX inhibitors before, during and following ITI. Patient 1, a 2 yo boy, presented with a subdural hemorrhage; his inhibitor titer was 14 BU. He was treated with recombinant VIIa (rVIIa), 200 mcg/kg followed by 100 mcg/kg q2 hours plus rFIX conc (BeneFix), 1000 U/kg prior to and post subdural hematoma evacuation; a continuous infusion, 40U/kg/hour rFIX conc was started. FIX:C was >100%, so rVIIa was discontinued and the rFIX infusion was continued to maintain FIX:C levels above 50%. Rituximab (375 mg/m2 q week x 4) was started. On the 6th day, he developed anamnesis; plasma FIX:C dropped to the 20% range in spite of increases in his rFIX conc drip to 68 u/kg/hour. Investigation of right leg edema revealed a large thrombus involving the popliteal, iliac and inferior vena cava with pulmonary embolism. In order to remove the inhibitor antibody and achieve plasma FIX levels that would allow safe anticoagulation with heparin, plasmapheresis with an immunoadsorption Protein A sepharose column (Fresenius) was undertaken. FIX:C levels were unexpectedly lower immediately following each cycle. Investigation of FIX: Ag and anti-FIX IgG, IgG1 and IgG4 by ELISA assays before and after each cycle revealed the presence of FIX: Ag and specific anti-FIX IgG in the column eluates. After the 5th cycle, increasing FIX:C levels allowed weaning of the rFIX conc; the thromboses completely resolved. The patient currently is on standard prophylactic doses of rFIX conc with expected recoveries with no evidence of inhibitor. Patient 2 was a 9 year old boy with a high responding anaphylactoid inhibitor; he had severe and frequent hemarthroses treated with rVIIa with variable success resulting in significant hemophilic arthropathy. He had previously received 2 courses of rituximab with recurrence of inhibitor 3 weeks post-therapy. Therefore, in order to suppress T-cell as well as B-cell immune responses, after desensitization with increasing infusions of rFIX conc, he was treated with cyclophosphamide (10 mg/kg IV on days 2, 3 and PO on days 4 and 5) a standard course of rituximab (375 mg/m2 on days 1, 8, 15, 22), IVIG (100 mg/kg on days 2–5) initially, and high dose rFIX conc, 100U/kg/day. He is now maintained on every-other monthly doses of rituximab and replacement doses of IVIG. As FIX levels rose during ITI, rFIX conc was weaned; eight months after initiation of ITI, he has expected recoveries of FIX: C on standard prophylactic doses of rFIX conc. Investigation of the nature of the patient’s inhibitors revealed that both patients had high titer IgG1 and IgG 4 anti-factor IX antibodies that disappeared after ITI. Unlike the persistence of non-inhibitory IgG4 factor VIII antibodies reported in some patients with hemophilia A, in these two patients, there was no detectable FIX-specific pan-IgG, IgG1 or IgG4 following ITI. We conclude that novel approaches to ITI can be successfully undertaken in severe HB patients with high titer factor IX inhibitors.

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