Effect of danazol on clotting factor levels, bleeding incidence, factor infusion requirements, and immune parameters in hemophilia

Several recent studies have reported conflicting results on the effectiveness of danazol, an attenuated androgen, in raising plasma levels of clotting factors VIII and IX in patients with hemophilia. We undertook a randomized, double-blind cross-over trial using 8 weeks' administration of danazol (D), 600 mg/d, and 8 weeks' administration of placebo (P) separated by 2 weeks of rest in 12 patients with hemophilia A and four patients with hemophilia B. Plasma factor VIII and IX levels, frequency and type of bleeding episodes, amount of factor concentrate infused, fibrinogen, fibrinolysis assays, antithrombin III, liver function, and immune parameters were followed. During the danazol phase a minimal increase was noted in the average clotting factor levels, an increase that, although statistically significant, was of hemostatically marginal magnitude. Significant increases in protein C and plasminogen levels, however, were observed during the danazol period, suggestive of danazol-mediated enhanced fibrinolysis. Clinically, bleeding frequency was significantly increased, and more clotting factor was consumed during the danazol period. Furthermore, eight episodes of hematuria and oral mucosal bleeding was reported during the danazol phase in contrast to only one episode of hematuria during the placebo phase, consistent with an enhancement of fibrinolytic activity with danazol. We conclude that danazol does not have a hemostatically significant effect on plasma levels of factor VIII and IX but may be associated with enhancement of fibrinolytic activity, resulting in increased bleeding frequency and requiring more clotting factor infusions. Therefore, danazol is not a viable alternative in the treatment of hemophilia.     

Proposal of a standard approach to dental extraction in haemophilia patients. A case-control study with good results

We found no case-control studies on dental extraction in haemophilia patients in the literature even though the use of antifibrinolytic agents following a single infusion of factor VIII or IX has been accompanied by a lower number of bleeding complications in dental extractions. In this study we verified the incidence of bleeding complications after dental extraction in a group of 77 haemophilia patients. One hundred and eighty-four male patients requiring dental extraction represented the control group. All haemophilia patients received 20 mg kg-1 of tranexamic acid and a single infusion of factor VIII or IX to achieve a peak level about 30% of factor VIII or IX in vivo prior to dental extraction. Forty-five of 98 (45.9%) dental extractions in haemophilia patients and 110 of 239 (46%) dental extractions in the control group were surgical ones. We registered two bleeding complications in the group of haemophilia patients (one late bleeding and one haematoma in the site of the anaesthetic injection) and one (a late bleeding) in the control group. The difference of bleeding complications in the two groups of patients were not statistically significant (P=0.2; OR 0.2; CI 0.01-2.22). The protocol proposed in this study, characterized by the feasibility and the number of haemorrhagic complications not different from normal population, make dental extractions in haemophilia patients possible on an out-patient basis with a cost reduction for the community and minor discomfort for the patients.     

Contribution of natural anticoagulant and fibrinolytic factors in modulating the clinical severity of haemophilia patients

The role of natural anticoagulants, fibrinolytic cascade factors and common prothrombotic gene polymorphisms in modulating disease severity were studied in 35 'clinically mild' and 37 'clinically severe' haemophilia patients with severe factor VIII or IX deficiency (<0.01 IU/ml). Strong association of deficiencies of proteins C and S, antithrombin III, tissue factor pathway inhibitor and tissue plasminogen activator, together with factor V Leiden and endothelial protein C receptor 23 bp insertion polymorphisms were observed in the 'clinically milder' group as compared with the 'clinically severe' group. These results indicate a synergistic modulation of bleeding tendency in haemophilia patients by factors in the anticoagulant and fibrinolytic systems.     

Immunosuppressive Treatment in Haemophiliacs with Inhibitors to Factor VIII and Factor IX

9 patients with severe haemophilia A and inhibitors (inhibitor levels between 0.1 to 5.8 U/ml) and 3 patients with severe haemophilia B and inhibitors (inhibitor levels between 0.1 to 11 U/ml) were treated on a total of 16 and 13 occasions, respectively, with a large dose of antigen (factor VIII or factor IX) and cyclophosphamide (10–15 mg/kg b.w. i.v. initially and then 2–3 mg/kg b.w. orally for 7–10 days) in connection with severe bleeding and surgery. All the patients had proved not to respond to treatment with factor VIII or factor IX concentrate alone, and all except one had shown strong secondary antibody increases. In 6 of the patients with haemophilia A the treatment (11 occasions) had a satisfactory haemostatic effect and even permitted neurosurgery without bleeding complications. The inhibitor level remained at zero for 5–10 days, after which it gradually began to return towards its original level. In these cases it was possible to give factor VIII in amounts which neutralised the inhibitor and afterwards raised the factor VIII initially to at least 50%. In the 3 patients with haemophilia B treatment (13 occasions) was successful except on one occasion, and surgery was performed without abnormal bleeding. The factor IX level was initially raised to at least 50% except in the one failure. The inhibitor level remained at zero for 12 days to 3 months, after which it gradually rose towards its original level. One patient was treated on 8 occasions.     

The Use of Non-activated Prothrombin Concentrate in the Management of Haemophilia A with Factor VIII Antibodies

Summary: The use of non-activated prothrombin concentrate in the management of haemophilia A with factor VIII antibodies.
Three children with haemophilia and antibodies to factor VIII were treated with a non - activated prothrombin concentrate (Prothrombinex) for 12 bleeding episodes. There was clear clinical response and joint aspirations were performed after infusions of prothrombinex in a dose of 30–50 factor IX units/kg body weight and there was no clinical evidence of thrombosis or febrile reactions. There was a significant shortening of the activated partial thromboplastin time (PTT) at one and four hours after the initial infusion with a return to pre-infusion levels 9–24 hours after infusion. The shortening in the PTT was less marked in subsequent infusions. There were no changes in the level of factor VIII procoagulant activity, factor VIII related antigen or factor VIII antibodies after the infusion. In two patients platelet function studies were unaltered by the infusion and in one patient procoagulant levels of factor II, IX and X were no greater than expected from the infusion. We conclude that infusions of non-activated prothrombin concentrates are clinically effective in the treatment of children with haemophilia and factor VIII antibodies but the mechanism of action is unknown.     

Subcutaneous injection of desmopressin (DDAVP): evaluation of a new, more concentrated preparation

A more concentrated desmopressin (DDAVP) preparation (40 micrograms/ml), which required small injection volumes (less than 1 ml), was studied in a double-blind trial in 10 healthy volunteers, 12 patients with haemophilia A, and 8 patients with uraemic bleeding. DDAVP was administered by subcutaneous injection at a dose of 0.4 micrograms/kg body weight. In healthy subjects, peak levels of DDAVP ranging from 480 to 638 pg/ml were reached 1 h after the subcutaneous injection and DDAVP was eliminated with a mean half-life of 3.1 h. DDAVP produced a 2.5-fold (3.0-fold) increase of factor VIII:C (factor VIII:Ag) and a 1.9-fold (2.2-fold) increase of von Willebrand factor:Ag (ristocetin cofactor) over baseline levels. Additionally, a 2.1-fold increase of tissue-type plasminogen activator antigen was observed. Factor VIII and von Willebrand factor were rapidly eliminated with a half-life ranging from 1.3 to 5.7 h and from 1.1 to 11.4 h, respectively. In haemophilia A patients, DDAVP produced a 2.3-fold increase of factor VIII:C 1 h after the injection. DDAVP was given on 8 occasions for management of bleeding, and only in 1 patient did a wound haematoma (after herniotomia) occur. In 7 of the 8 patients with uraemia the bleeding time shortened, and in all patients an increase of platelet retention and a decrease of platelet count was observed (p less than 0.05). No serious local or systemic untoward side effects were observed.     

Pelvic haemophilic pseudotumour occurring in a patient with mild haemophilia: a brief report

Haemophilic pseudotumour is a rare but well-recognized complication of moderate and severe haemophilia, particularly in patients who have developed a factor VIII inhibitor. It has only been reported in haemophiliacs with factor VIII or IX levels less than 5%. We report a patient with mild haemophilia (factor VIII 11%, factor IX 78%) who developed a pelvic pseudotumour that was successfully treated with a novel surgical technique and who has no evidence of recurrence five years after operation.     

How to manage invasive procedures in children with haemophilia

Invasive procedures can be performed safely in children with haemophilia due to the availability of factor VIII/IX for patients without inhibitors. Most guidelines are based on the experiences in adults, but still there is no established consensus on the optimal factor levels or duration of replacement therapy for adults undergoing surgery. Few publications have focused on surgery in children with haemophilia. Children who have developed inhibitors to factor VIII/IX have to be treated with bypassing agents and constitute a group at higher risk for bleeding complications during surgery. The aim of this review is to summarize the experiences and opinions in the literature on replacement treatment of children with haemophilia, with and without inhibitors, during and after surgery, with a focus on the most prevalent clinical situations.     

Evaluation of prophylactic replacement therapy in haemophilia B.

Prophylaxis replacement therapy has been assessed for a period of 12 months in 10 patients with severe haemophilia B showing a high incidence of spontaneous bleeding episodes. Two different schedules of administration of a freeze-dried factor IX concentrate were randomly evaluated: according to scheme A, 7.5 U/kg were administrated biweekly, whereas scheme B was based on the weekly infusion of 15 U/kg. On prophylaxis the frequency of bleeding episodes was significantly reduced (P less than 0.005) when compared with that observed in one-year period preceding the trial. Biweekly infusions were superior to weekly infusion (P less than 0.01), and the benefit appeared to be related to the higher number of days in which measurable levels of factor IX were attained in plasma. Range of motion, which was redeced at the start of the trial in 26 joints, was found to have improved in 23. Favourable changes of the joint radiological picture were observed in 6 cases. Hepatitis and factor IX inhibitors did not develop during the trial period. Side effects were rare and mild.     

Similar bleeding phenotype in young children with haemophilia A or B: a cohort study

The bleeding phenotype has been suggested to differ between haemophilia A and B. More knowledge on the bleeding phenotype at initiation of treatment is important to optimize patient care. The aim of this study was to investigate the severity of the bleeding phenotype and the variation in bleeding in children with severe or moderate haemophilia A and B. Consecutive, previously untreated patients with severe or moderate haemophilia A and B (factor VIII or IX activity <0.01 or 0.01–0.05 IU mL^?1 respectively) born between January 1st 2000 and January 1st 2010 were included. Primary outcome was severity of bleeding tendency. Secondary outcome was variation in bleeding pattern. A total of 582 patients with severe haemophilia A and 76 with severe haemophilia B did not differ in age at first exposure to clotting factor (0.81 vs. 0.88 years, P = 0.20), age at first bleed (0.82 vs. 0.88 years, P = 0.36), and age at first joint bleed (1.18 vs. 1.20 years, P = 0.59). Patients with moderate haemophilia were older compared to patients with severe haemophilia. In patients with moderate haemophilia there were no clear differences between haemophilia A and B. Severity and variation in bleeding phenotype are similar during the early stage of treatment in patients with severe and moderate haemophilia A and B respectively. The findings imply that children with haemophilia B should be observed and treated as vigilantly as those with haemophilia A.     

DDAVP (desmopressin; 1-deamino-cys-8-D-arginine-vasopressin) treatment in children with haemophilia B

We tested the response to desmopressin (1-deamino-cys-8-D-arginine-vasopressin; DDAVP) in four patients with haemophilia B [factor IX (F IX) at diagnosis 1.4-5%]. The activated partial thromboplastin time (aPTT) was significantly shortened in all patients. Although there was an up to 1.4-fold increase in F IX levels in three patients, maximal F IX activity remained below 10%. Much more prominent were the increases in F VIII (three- to fourfold), in von Willebrand factor antigen (VWF:Ag; 2.5-fold) and particularly in VWF collagen-binding activity (VWF:CBA; fivefold). These changes were reflected by the prophylactic efficacy of DDAVP for dental surgery. After pretesting, DDAVP could be a useful drug for reducing the need for plasma products for prevention of minor surgical bleeding in patients with mild to moderate haemophilia B.     

Inhibitors in young boys with haemophilia.

The development of an inhibitor antibody to factor VIII (or factor IX) in a child with haemophilia presents a major challenge to the paediatric haematologist. This article provides an overview of the incidence of inhibitor development in early childhood (30-52% in boys with severe haemophilia A), genetic risk factors, detection, high titre, low titre and transient inhibitors, and management. Treatment of patients with inhibitors is time-consuming and expensive. One should make every attempt to ensure that the boy's family has an understanding of inhibitors, treatment options, and just what is being recommended for their child and what this involves. Immune tolerance induction is successful in approximately 85% of boys with factor VIII inhibitors, but in only 40-50% of those with factor IX inhibitors. For treatment of bleeding episodes in children with high-titre (> or = 5 Bethesda Units) inhibitors, therapeutic options include activated prothrombin complex concentrates (APCC), rF VIIa, and (for factor VIII inhibitors) porcine factor VIII. The advantages and disadvantages of each are discussed. Although factor IX inhibitors are far less common (occurring in 2-3% of boys with haemophilia B), approximately 50% are accompanied by the occurrence of anaphylaxis or severe allergic reactions to any factor IX-containing product.     

Immunological studies in HIV seronegative haemophiliacs: relationships to blood product therapy

Immunological studies were performed on a group of 44 haemophilia A and 15 haemophilia B patients who were treated exclusively with blood products manufactured by the Scottish National Blood Transfusion Service (SNBTS). All patients were HIV seronegative throughout the study. Of the haemophilia A patients 14 (32%) had CD4+ lymphocyte subset counts less than or equal to 0.5 x 10(9)/l, compared with one (6%) haemophilia B patient and four (8%) controls. The percentage of activated T cells was greater than 5% in 19/33 (57%) with haemophilia A, 5/9 (55%) haemophilia B and 14/50 (28%) of control subjects. beta 2 microglobulin values greater than or equal to 2.0 mg/l were observed in 19 (43%) haemophilia A and four (26%) haemophilia B patients, compared with one (2%) control. No significant increases in serum interleukin-2 receptor concentrations were observed in 15 haemophilia A and one haemophilia B patients. Significantly elevated levels of IgG, IgM and IgA were observed in the haemophilia A group, but elevation of immunoglobulins was restricted to the IgG class in the haemophilia B group. Of the haemophilia A patients 16/30 (53%) and 6/11 (54%) haemophilia B patients had depression of cell-mediated immunity (CMI) as assessed by delayed-type hypersensitivity responses to intradermally injected recall antigens. There was no correlation between factor VIII or factor IX usage and changes in lymphocyte subsets, beta 2 microglobulin, and immunoglobulin levels. There was, however, a strong correlation between annual factor VIII usage and the degree of depression of CMI for those with haemophilia A but not for those with haemophilia B. No correlation between alterations in the immune parameters and disturbance of liver function tests was observed in either haemophilia A or haemophilia B patients. We conclude that alloantigen or non-HIV viral exposure due to repeated administration of factor concentrates brings about alterations in the immune response, and that these changes are more marked following exposure to intermediate purity factor VIII compared with factor IX concentrate.     

Lithuanian haemophilia A and B registry comprising phenotypic and genotypic data

Haemophilia represents the most common hereditary severe bleeding disorder in humans. About 100 families with this condition live in Lithuania, one of the Baltic states with a population of 3.7 million. Haemophilia care and genetic counselling are still rendered difficult owing to limited availability of clotting factor concentrate and molecular genetic diagnosis. In the present study, a haemophilia registry, comprising phenotypic and genotypic data of the majority of Lithuanian haemophilia A and B patients, was established. The phenotype includes the degree of severity, factor VIII:C, factor VIII:Ag, factor IX:C, von Willebrand factor and antigen (VWF:RiCoF, vWF:Ag) and inhibitor status. Genotyping of the factor VIII and IX genes was performed using mutation screening methods and direct sequencing. In 61 out of 63 patients with haemophilia A (96.8%) and all eight patients with haemophilia B (100%), the causative mutations could be detected. Nineteen of the factor VIII gene defects and two of the factor IX gene mutations are reported for the first time. Identified mutations allowed direct carrier diagnosis in 83 female relatives revealing 44 carriers, 38 non-carriers and one somatic mosaicism. The information provided by this registry will be helpful for monitoring the treatment of Lithuanian haemophilia patients and also for reliable genetic counselling of the affected families in the future.     

Analysis of low frequency bleeding data: the association of joint bleeds according to baseline FVIII activity levels

Summary. Many studies in the field of haemophilia and other coagulation deficiencies require analyses of bleeding frequencies. In haemophilia, the association of bleeding frequency with factor VIII (FVIII) activity levels is known from experience, but significant results are lacking. Bleeding frequencies in haemophilia are highly skewed count data, with large proportions of zeros. Both the skewness and the high amount of zeros pose a problem for standard (linear) modelling techniques. This study investigated the optimal analysing strategy for bleeding data by using the association of residual clotting factor level and number of joint bleeds in moderate and mild patients treated on demand as example. In total, 433 patients with moderate (27%) and mild (73%) haemophilia A treated on demand were included in this study. One year of self‐reported data on joint bleed frequency and baseline clotting factor activity were analysed using Poisson, negative binomial, zero‐inflated Poisson, and zero‐inflated negative binomial distributions. Multivariate regression analysis using negative binomial distribution provided the optimum data analytical strategy. This model showed 18% reduction [Rate ratio (RR) 0.82; 95%confidence interval (CI) 0.77–0.86] of bleeding frequency with every IU dL^‐1 increase in residual FVIII activity. The actual association is expected to be higher because of exclusion (30 out of 463 patients) of patients on prophylaxis (baseline FVIII levels 0.01–0.06 IU mL^?1). The best way to analyse low frequency bleeding data is using a negative binomial distribution.     

Management of factor VIII inhibitors: evolution and current status.

Management of patients with factor VIII (and IX) inhibitors includes management of acute bleeds and methods to induce immune suppression and tolerance and to detect patients at risk of developing inhibitors. The methods used over the years to treat acute bleeding have been more or less successful. The best method is to raise factor VIII levels by human or porcine factor VIII concentrate, but this is not usually possible. Prothrombin complex concentrates, activated or non-activated, have enjoyed some success as factor VIII by passing agents, but the development of recombinant activated factor VII represents a new and promising method of inducing haemoslasis at the site of bleeding whilst minimizing the risk of disseminated intravascular coagulation. Alternatively, the use of tissue factor is under consideration to exploit the extrinsic system. Methods to induce immunological tolerance by use of the 'Bonn' regime or by the introduction of immunomodulation with the 'Malm?' regime of extracorporeal immunodepletion, cyclophosphamide, and intravenous immunoglobulin continue to be attempted with significant but variable success. Gradually the inhibitor problem is being contained, but it is still an important complication of haemophilia therapy.     

Inhibitors in factor IX deficiency a report of the ISTH-SSC international FIX inhibitor registry (1997–2006)

Summary.  Haemophilia B is an X-linked disorder resulting in coagulation factor IX deficiency. Patients with severe deficiency (<1% factor IX activity) may have significant bleeding complications similar to patients with haemophilia A or factor VIII deficiency. The development of inhibitory antibodies to the missing coagulation factor is a major complication in patients with haemophilia. While the incidence of inhibitors in patients with haemophilia A is higher than that in haemophilia B, the occurrence of allergic and or anaphylactic reactions with the development of inhibitors is unique to haemophilia B patients. Since haemophilia B is a rare bleeding disorder and the incidence of inhibitors is an even rarer entity, a registry was established by Dr Indira Warrier under the auspices of the FVIII/FIX subcommittee of the International Society of Thrombosis and Haemostasis, to gather information on the occurrence and characteristics of patients with inhibitors and also the incidence of allergic and anaphylactic reactions in this group of patients. This is the first report from this registry and helps us to gather some insight on haemophilia B patients with inhibitors and complications related to inhibitor development and difficulties with immune tolerance.     

Combined factor VIII and IX deficiency in a family

A family with combined deficiency of factor VIII and factor IX is reported. Family study showed that the father and his nephew had mild factor VIII deficiency with normal von Willebrand factor antigen and factor IX levels while his two sons had a reduced level of factor IX and normal factor VIII levels. His wife was found to have marginally reduced factor IX levels, whereas his daughter had reduced or normal levels of both factors VIII and IX. DNA analysis using the intra- and extragenic markers of factor VIII and IX genes showed that mother is a carrier of haemophilia B and the daughter is a carrier for both haemophilia A and B. Thus, the combined deficiency observed was due to a chance association of two distinct genetic defects.     

DDAVP challenge tests in boys with mild/moderate haemophilia A

Desmopressin (DDAVP) increases plasma factor VIII coagulant activity (FVIII:C) levels in patients with mild/moderate haemophilia A. In some subjects, FVIII can be increased to haemostatic levels, thereby avoiding use of factor VIII concentrates. We reviewed our hospital's experience with 62 boys with FVIII:C levels 0.01-0.3 IU/ml who had a DDAVP challenge test (i.v. 0.3 microg/kg) following diagnosis. A therapeutic response was defined as a 1 h post-FVIII:C increase at least twofold over baseline and > 0.3 IU/ml. Of the total group, 29 (47%) boys responded to DDAVP, all of them with mild haemophilia (baseline FVIII:C > or = 0.05 IU/ml), yielding a response rate of 57% in this subgroup. Boys who responded to DDAVP had higher baseline FVIII:C levels (mean +/- SEM, 0.17 +/- 0.01 vs 0.10 +/- 0.01 IU/ml, P < 0.01) and were older (5.2 +/- 0.8 vs 3 +/- 0.4 years, P = 0.02) than those who failed to do so. The association between DDAVP response and age, however, remains unclear: seven boys who failed the initial challenge test responded to re-challenge after a mean of 6.3 years (median 4.9, range 0.5-12.5), increasing the response rate in boys with mild haemophilia to 71%. Age and FVIII:C association with DDAVP response are both important in boys with mild/moderate haemophilia A. Absence of response to DDAVP should therefore be confirmed by later re-challenge.     

Carrier detection and prenatal diagnosis in haemophilia A and B

Sixty probable carriers of haemophilia from 25 families were studied by using coagulation phenotype and DNA analysis: 33 with haemophilia A and 27 with haemophilia B. Coagulation phenotype was based on factor VIII/IX assay and DNA analysis on the examination of restriction fragment length polymorphisms (RFLPs) within and closely linked to factor VIII or IX: 3 RFLP for factor VIII and 3 for factor IX. The comparison between the coagulation phenotype and RFLP analysis showed the misclassification of 15 females (6 for haemophilia A and 9 for haemophilia B). Four prenatal haemophilia A diagnosis were made by DNA analysis of chorionic villi, taken with a transcervical trophoblastic biopsy, between the 18th and the 11th week.