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J M Lusher

Publications and source records attributed to J M Lusher.

At least 37 records · Page 2Linked to original sources
PubMed1999

Anaphylactic response to factor IX replacement therapy in haemophilia B patients: complete gene deletions confer the highest risk.

Haemophilia B is an X-linked recessive coagulopathy due to mutations in the factor IX gene. Occasionally, patients receiving factor IX replacement therapy develop inhibiting antibodies to the factor IX protein, and it has been recently documented that a subset of these patients have had anaphylactic responses to factor IX replacement therapy in association with the development of inhibiting antibodies. To determine the relationship between mutation type and the risk of anaphylaxis, eight unrelated patients from families in whom anaphylaxis had occurred were genotyped. The mutations were compared to those in 550 haemophilia B patients and to those in 276 patients with clinically severe disease. Individuals with complete gene deletions were found to be at greatest risk for anaphylaxis, with an estimated risk of 26% or greater. Anaphylaxis was less likely to occur in patients with protein truncation mutations or partial gene deletions and least likely to occur with missense mutations. Genotypes can help physicians and patients anticipate the likelihood of anaphylaxis, a potentially life-threatening complication of factor IX replacement therapy. The very high risk of anaphylaxis associated with a complete gene deletion suggests that the lack of expression of a partial protein product may predispose to anaphylaxis and/or that the absence of a closely linked, codeleted gene enhances the anaphylactic immune response.

Anaphylaxis↗
PubMed1999

Systemic causes of excessive uterine bleeding.

In assessing a patient with excessive uterine bleeding, the clinician should consider systemic causes in the differential diagnosis. Both hereditary and acquired conditions can result in mucous membrane bleeding, including menorrhagia, epistaxis, and gum bleeding, as well as excessive bruising. Among hereditary conditions, von Willebrand disease (vWD) is by far the most common, affecting an estimated 1% of the population worldwide. It is important to consider the possibility of vWD, and to establish the proper diagnosis (including subtype), as safe, effective, and easy-to-use treatment is available for most persons with this disorder. This review also covers a number of other systemic conditions that can be manifested by excessive uterine bleeding, including congenital deficiency of factor XI, idiopathic thrombocytopenic purpura and other acquired platelet disorders, acquired autoantibodies against factor VIII (FVIII), and vitamin K deficiency states.

Female↗
PubMed1998

A randomized, double-blind comparison of two dosage levels of recombinant factor VIIa in the treatment of joint, muscle and mucocutaneous haemorrhages in persons with haemophilia A and B, with and without inhibitors. rFVIIa Study Group.

Recombinant factor VIIa (rFVIIa) was developed to provide an improved procoagulant component capable of 'by-passing' inhibitor antibodies in the treatment of haemophilic patients. The primary objective of this study was to compare the efficacy of two dosage regimens of rFVIIa (given intravenously at periodic intervals) in the treatment of joint, muscle and mucocutaneous haemorrhages in persons with haemophilia A and B with and without inhibitors. The study was designed as a randomized, double-blind, parallel group, international multicenter trial. Patients were randomly allocated to treatment A: 35 mu kg-1 or B: 70 mu kg-1, in blocks of 2. Within each block, one patient was assigned to the 35 mu kg-1 dosing regimen and the other to 70 mu kg-1 dose. One hundred and fifty subjects from 20 sites were screened for this study and 116 had baseline assessments. Of these, 84 were treated on the protocol and 32 were not treated in the study, in most cases because they did not return to the clinic with an eligible bleeding episode. One hundred and seventy-nine bleeding episodes were treated, of which 145 (81%) were acute haemarthroses. Both treatments were efficacious, with 71% having an excellent (59% and 60%) or effective (12% and 11%) response. Overall, the mean and median number of doses given per episode of joint bleeding were 3.1 and 2, respectively. The mean number of doses was 3.1 for the 70 mu kg-1 group and 2.7 for the 35 mu kg-1 group (P value = 0.142). The study concluded that rFVIIa in a dosage of 35 mu kg-1 or 70 mu kg-1 is both safe and reasonably effective in the treatment of joint or muscle haemorrhages in haemophilic patients with inhibitor antibodies to factor VIII or factor IX. It is concluded that the appropriate dose for the treatment of joint and peripheral muscle bleeding in haemophilic patients with inhibitors is 35-70 mu kg-1 given at 2-3 h intervals until haemostasis is achieved.

Adult↗
PubMed1998

Clinical guidelines for treating von Willebrand disease patients who are not candidates for DDAVP--a survey of European physicians.

While certain plasma-derived factor VIII/von Willebrand factor (FVIII/vWF) concentrates have proven to be quite useful in preventing or controlling bleeding in persons with von Willebrand disease who are not candidates for DDAVP, most of the information concerning dosage and effectiveness has been anecdotal. Additionally, the laboratory tests used to quantify vWF (the vWF:RCoF assay and collagen binding assay) are not well standardized. Thus, the US Food and Drug Administration (FDA) has been reluctant to grant licensed indication for use of these products in von Willebrand disease. This brief report describes a survey of non-US physicians (from major centres) who are recognized experts in haemophilia and von Willebrand disease. Twenty-four of 27 questionnaires were completed, returned and analysed. Products thought to be effective in von Willebrand disease included Haemate P, Facteur von Willebrand, Alphanate, and the UK's BPL '8Y'. In calculating dosage to stop or prevent bleeding, most aim for a certain level of both FVII and vWF:RCoF. Postoperatively, 16/24 respondents follow both of these laboratory tests once daily. Twenty-two of 24 would follow FVIII levels once daily. It is noteworthy that FVIII assay results are generally the only test results readily available to guide the respondents' clinical decisions. For treatment of significant mucous membrane bleeding, respondents often individualize dosage and monitoring, depending on the type, location and extent of bleeding. Gastrointestinal bleeding is generally treated more aggressively. Patient monitoring varies between merely looking for cessation of bleeding, to a battery of laboratory tests, including haemoglobin and haematocrit. Seven out of 24 would monitor BT as well. In addition to FVIII content, 22/24 respondents noted that they would find it helpful to have vWF:RCoF listed on the label, while 15/24 would like to know the vWF multimeric composition.

Deamino Arginine Vasopressin↗
PubMed1998

In vivo recovery with products of very high purity--assay discrepancies.

In view of reports of FVIII assay discrepancies in post-infusion plasma samples depending on methods used, we compared FVIII results run by each of four different methods following infusion of rFVIII (Kogenate). Nine persons with haemophilia A were infused with each of two lots of product. Plasma samples were obtained at baseline, and at 10 min, 30 min, 1, 2, 4, 8, 12, 14, 30 and 48 h post-infusion for measurement of FVIII. FVIII assay methods were chromogenic, and one-stage APTT using three different types of activators: micronized, silica, ellagic acid, and kaolin. The same reference plasma standard was used throughout. Results demonstrated a consistent difference in FVIII values, with chromogenic assays being considerably higher than those run by one-stage assays. The discrepancy was greatest when kaolin was the activator. These results point out the problems in attempting to determine the "correct" FVIII level in patient plasma samples following infusion of high purity FVIII preparations. Potential "pitfalls" include the standard used for defining product potency, the methods, reagents, instrumentation and standards used in assaying plasma samples and, in some instances, the characteristics of the product itself. This situation has considerable cost implications, potential impact on patient care, and makes it difficult to compare results between laboratories.

Adolescent↗
PubMed1998

Early treatment with recombinant factor VIIa results in greater efficacy with less product.

Early treatment of bleeding episodes in haemophilia patients offers advantages over later treatment, including minimizing the damage caused by the haemorrhage and reducing the amount of product needed to control it. Self-administration at home also offers greater convenience and time and cost savings for both patient and physician. We compared the amount of recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) used in the treatment of peripheral intramuscular haemorrhages in people with haemophilia A and B with inhibitors and in those with acquired haemophilia, in the compassionate use, dose-finding and US home treatment studies. We also compared the response rates in each of the 3 studies. In the compassionate use setting, in which the mean time from onset of bleeding to initiation of treatment with rFVIIa was 5 d, the mean number of doses given per bleeding episode was 13.6, with 63.1% of episodes without compartment syndrome and 73% with tense muscle/compartment syndrome having an excellent or effective response. In the dose-finding study, average time from onset of bleeding to treatment with rFVIIa was 9 h. The average number of doses given was 3.55, and 72% in the high-dose arm were judged to have an excellent or effective response. In the US home treatment study in which bleeding episodes were treated earlier (mean 1.2 h from onset of bleeding), the mean number of doses given was 2.3, and 92% had an effective response to treatment. These findings indicate that early treatment with rFVIIa has a greater success rate, with fewer doses being required. Home treatment results in cost savings, greater convenience, and less morbidity.

Antibodies↗
PubMed1998

Recombinant activated factor VII for treatment of intramuscular haemorrhages: a comparison of early versus late treatment.

In the compassionate-use protocols, treatment with recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) was almost always instituted quite late, after the patient's bleeding had failed to respond to other forms of treatment. In the case of intramuscular haemorrhages, this resulted in worsening of the haemorrhage by the time treatment with rFVIIa was started. The mean number of doses given was 13.6 (64.8 for tense muscle and compartment syndrome), and 62% of episodes were judged to have an excellent or effective response. In the dose-finding study protocol, patients were required to come to the haemophilia centre for treatment, thus resulting in some delay (of at least a few hours and often longer) before rFVIIa was given. In the dose-finding study, the average time from onset of bleeding to the first dose of rFVIIa was 9 h. The average number of doses given was 3.6 for the 70 microg/kg dosage group and 3.5 for the 35 microg/kg dosage group. In contrast, patients on the US home treatment study with rFVIIa could be treated quite soon after the onset of bleeding. We have analysed the response to treatment of intramuscular haemorrhages, based on the time interval from onset of bleeding to initiation of treatment with rFVIIa. Our analysis includes cases of full-blown 'compartment syndrome', as well as other less severe peripheral intramuscular haemorrhages. The mean number of doses given was 13.6 (64.8 for tense muscle and compartment syndrome, response rated as excellent or effective in 62% of bleeding episodes) in the compassionate use study; 3.6 and 3.5 for the 70 microg/kg (72% effective) and 35 microg/kg dosage groups, respectively, in the dose-finding study, and 2.3 (92% effective) in the home treatment study. The findings clearly indicate a greater success rate, and with fewer doses, when rFVIIa was started early.

Adult↗
PubMed1998

Development of anaphylactic shock in haemophilia B patients with inhibitors.

The development of inhibitor antibody is a serious complication of haemophilia in young children. The incidence of factor IX (FIX) inhibitors in haemophilia B patients is five- to 10-times less common (1.5-3%) than the incidence of FVIII inhibitors in haemophilia A (15-30%). Inhibitors are commonly associated with the total absence of FIX antigen due to total deletions or other major derangements of the FIX gene. Unlike those with haemophilia A, patients with haemophilia B often experience anaphylactic reactions to FIX concentrates at the time of inhibitor development. Although the reasons for anaphylaxis at the time of inhibitor development are not yet clear, several hypotheses can be considered. One relates to the smaller molecular size of FIX compared with FVIII. With a molecular size of 55000, FIX diffuses into extravascular spaces more readily. Secondly, since the normal plasma FIX concentration is much higher compared with FVIII (5 microg/ml versus 0.1 microg/ml), haemophilia B patients are exposed to higher amounts of exogenous protein when a standard dose of 40-80 units/kg FIX is used. The routine exposure of haemophilia B patients to such large amounts of exogenous protein without any endogenous FIX antigen may contribute to the development of hypersensitivity. A third reason to consider is the absence of tolerance. Whether the lack of tolerance is due to the total absence of any FIX antigen or co-deletion of neighbouring genes that modulate the immune system is unknown. Management of bleeding in patients with inhibitors and anaphylaxis is complicated because the only readily available products for treatment are the FIX-containing prothrombin complex concentrates or activated prothrombin complex concentrates, the very same products that induce anaphylaxis. Recently, recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) has been used effectively in several of these children, but in the USA rFVIIa is only available on a compassionate basis for the treatment of life- or limb-threatening bleeding. Eradication of the inhibitor by immune tolerance induction (ITI) has only been minimally successful in haemophilia B patients with inhibitors and anaphylaxis. Despite initial successful desensitization, the majority of these patients have had recurrent allergic reactions to FIX requiring administration of antihistamines and steroids. Recently, the development of nephrotic syndrome has been reported as a serious complication of ITI in these patients. Since inhibitor antibody is seen in association with complete gene deletions or major derangements of the FIX gene, it may be possible to select those patients with the highest risk for close monitoring during the early period of treatment by obtaining molecular diagnosis at the time of presentation.

Anaphylaxis↗
PubMed1998

Home treatment of mild to moderate bleeding episodes using recombinant factor VIIa (Novoseven) in haemophiliacs with inhibitors.

OBJECTIVE: To assess the safety and efficacy of a fixed dose of recombinant activated factor VII (rFVIIa; NovoSeven) in the home setting for mild to moderately severe joint, muscle; and mucocutaneous bleeding episodes in patients with haemophilia A or B with inhibitors. DESIGN: Multicentre, open-label, single arm, phase III study of one year duration. METHODS; Patients or their caregivers administered up to three doses of rFVIIa (90 microg/kg i.v.) at 3 h intervals within 8 h of the onset of a mild to moderate bleeding episode. Once the subject considered that rFVIIa had been "effective" with regard to haemostasis (after 1-3 injections), one further (maintenance) dose of rFVIIa was administered. RESULTS: Of 60 patients enrolled, 56 experienced at least one bleed, and 46 completed the one year study. 614 of 877 bleeds (70%) were evaluable according to protocol definitions. Haemostasis was rated as "effective" in 92% (566/614) of evaluable bleeds after a mean of 2.2 injections. For successfully treated episodes, the time from onset of bleeding until administration of the first injection was 1.1+/-2.0 h (mean+/-SD). Twenty-four hours after initial successful response, haemostasis was reported as having been maintained in 95% of cases. Efficacy was comparable for muscle, joint and target joint, and mucocutaneous bleeding episodes. In an intent-to-treat analysis of all 877 bleeding events, efficacy outcomes were equivalent to the evaluable bleeds, with an effective response in 88% of treated episodes. Treatment-related adverse events occurred in 32 (3% of all) bleeding episodes and consisted of re-bleeds/new bleeds in more than 50% (18/32) of these events. A single episode of superficial thrombophlebitis was the only thrombotic complication encountered, and there were no patient withdrawals due to adverse events. Development of FVII(a) antibodies could not be detected, and hypersensitivity reactions to rFVIIa were not reported. CONCLUSION: rFVIIa is effective and well tolerated when used in the home setting to treat mild to moderate bleeding episodes in patients with haemophilia A or B with inhibitors.

Adolescent↗
PubMed1996

Hematology.

Explore the source record for details and available documents.

Blood Coagulation Factors↗
PubMed1996

Screening and diagnosis of coagulation disorders.

After clinical assessment, pertinent history, and family history, the clinician often has a good idea concerning the cause of a patient's bleeding. The most appropriate laboratory tests can then be ordered. Routine screening tests include a complete blood cell count, platelet count, and evaluation of a peripheral blood sample, a prothrombin time, and an activated partial thromboplastin time. Thrombocytopenia may result from idiopathic thrombocytopenic purpura, disseminated intravascular coagulation, or, less commonly, acute leukemia, aplastic anemia, thrombotic thrombocytopenic purpura, or a particular drug that a patient is taking. Again, the patient's history, physical findings, and evaluation of a well-prepared peripheral blood smear will be helpful in determining the cause of the patient's thrombocytopenia. An isolated prolongation of the activated partial thromboplastin time may result from low levels of factors VIII, IX, or XI. A slightly prolonged activated partial thromboplastin time and a moderate decrease in factor VIII may reflect von Willebrand disease or the "carrier" state for hemophilia A. In women a greatly prolonged activated partial thromboplastin time and very low levels of factor VIII (< 3%) most often result from an acquired factor VIII inhibitor (autoantibody against factor VIII) or from severe (type III) von Willebrand disease. If von Willebrand disease is suspected (because of menorrhagia with or without other mucous membrane bleeding, a positive family history, and a prolonged activated partial thromboplastin time), more specific laboratory tests for this disease should be done. These include assays of factor VIII, von Willebrand factor antigen, von Willebrand factor activity (measured by the ristocetin cofactor assay), and template bleeding time. In von Willebrand disease the defect is in von Willebrand factor. The affected individual may have subnormal levels of structurally and functionally normal von Willebrand factor (this is called "classic" or type I von Willebrand disease) or may produce von Willebrand factor that is structurally and functionally abnormal (von Willebrand disease type 2). Individuals who inherit a gene for von Willebrand disease from both parents have severe (type 3) von Willebrand disease and will have extremely low levels (< 3%) of von Willebrand factor and factor VIII and will have a very prolonged bleeding time. In most populations type I disease is the most common form, whereas type 3 is the least commonly encountered form. It should be noted that levels of von Willebrand factor can be influenced by the patient's blood type (persons who have blood type AB have 60% to 70% higher levels than do persons who have blood type O) and can be elevated during pregnancy, stress, and hyperthyroidism. The two major functions of von Willebrand factor are to serve as a "bridge" between platelets and injury sites in blood vessel walls and to protect circulating factor VIII from rapid proteolytic degradation. Thus, if a patient has either too little or functionally abnormal von Willebrand factor, the bleeding time will be prolonged and factor VIII will be decreased (because it is not being protected by von Willebrand factor). It should be determined which type of von Willebrand disease a particular patient has because treatment depends on type. Multimeric analysis of von Willebrand factor can be done with use of sodium dodecyl sulfate gels, radiolabeled antibody to von Willebrand's factor, and autoradiography. This will allow visualization of the multimeric structure of von Willebrand factor. In type I disease all bands are present, whereas in the type 2 variants 2A and 2B no high-molecular-weight multimers are seen. Desmopressin acetate (which is available in parenteral form for intravenous use and in a highly concentrated intranasal spray formulation) is the treatment of choice for classic type I disease. The drug effects a rapid release of von Willebrand factor from endothelial cell stor

Blood Coagulation Disorders↗
PubMed1996

Pharmacokinetics of von Willebrand factor and factor VIIIC in patients with severe von Willebrand disease (type 3 VWD): estimation of the rate of factor VIIIC synthesis. Cooperative Study Groups.

Nine patients (10 infusions) with a confirmed diagnosis of type 3 VWD were infused with von Willebrand factor (human), a preparation of von Willebrand factor (VWF) with a very low factor VIII content. Each patient was infused with one dose of approximately 50 or 100 iu ristocetin cofactor activity (VWF:RiCoF) per kg body weight. Bleeding times were performed during the 24 h period after infusion. Plasma samples were obtained over the 96 h period after infusion and were analysed for factor VIII coagulant activity (FVIIIC), VWF:RiCoF, von Willebrand factor antigen (VWF:Ag), and multimers. The FVIIIC data were analysed by non-linear least-squares analysis assuming constant FVIIIC 'synthesis' and exponential decay. The VWF data were fitted for exponential decay. The average decay rates for FVIIIC, VWF:RiCoF and VWF:Ag were 0.041, 0.061 and 0.056 respectively. The average calculated 'synthesis' rate for FVIIIC was 6.4 u/dl/h. The synthesis of FVIIIC was slightly faster and the decay slightly slower following the infusion of 100 iu VWF:RiCoF/kg than of 50 iu VWF:RiCoF/kg. Correction of the bleeding time was strongly dose dependent. At 4 h post infusion the median bleeding time was 9 min following a dose of 50 iu VWF:RiCoF/kg versus 3 min with a dose of 100 iu VWF:RiCoF/kg. There was no decrease in the bleeding time until the level of VWF:Ag or VWF:RiCoF reached > 100 u/dl.

Adolescent↗
PubMed1996

Recombinant factor VIIa (NovoSeven) in the treatment of internal bleeding in patients with factor VIII and IX inhibitors.

Recombinant factor VIIa (NovoSeven) was used on a compassionate use basis to treat 51 episodes of internal bleeding in 43 patients. All had become refractory to (or were not candidates for) other therapeutic agents. 26 of the 43 patients had hemophilia A and FVIII inhibitor antibodies, 13 had acquired FVIII inhibitors, 2 had hemophilia B and FIX inhibitors, and 2 had other coagulopathies, of 50 episodes of internal bleeding evaluated 76% had an excellent or effective response to rFVIIa. The average dosage given was 84 mu g/kg; the median number of doses given was 38. rFVIIa appears to be a very valuable addition to one's therapeutic armamentarium for treating serious bleeding episodes in inhibitor patients.

Antibody Formation↗
PubMed1996

Safety and efficacy of monoclonal antibody purified factor IX concentrate in previously untreated patients with hemophilia B.

The safety and efficacy of a monoclonal antibody purified factor IX concentrate were evaluated in two continuing trials of 32 previously untreated patients with mild, moderate, or severe hemophilia B. Patients were evaluated every 2 weeks for 24 weeks and every 3 months thereafter for at least 1 year. No patients became positive for human immunodeficiency virus antibody or hepatitis C virus antibody during the trial. Two patients developed a false-positive hepatitis B core antibody, one transiently, but neither had elevated levels of alanine aminotransferase (ALT). None of the 25 patients evaluable for non-A, non-B, non-C hepatitis by strict International Society of Thrombosis and Hemostasis criteria developed elevated levels of ALT indicative of posttransfusion infection. Anaphylaxis occurred in one subject who also developed an inhibitor to factor IX (19.3 Bethesda units). Five of the eight adverse events reported (63%) were mild in severity, and the relationship of three of these to therapy was considered remote. Hemostasis with monoclonal antibody purified factor IX concentrate was excellent in all patients.

Adolescent↗