Ezio Zanon

A Randomized Trial of Factor VIII and Neutralizing Antibodies in Hemophilia A.

BACKGROUND The development of neutralizing anti-factor VIII alloantibodies (inhibitors) in patients with severe hemophilia A may depend on the concentrate used for replacement therapy. METHODS We conducted a randomized trial to assess the incidence of factor VIII inhibitors among patients treated with plasma-derived factor VIII containing von Willebrand factor or recombinant factor VIII. Patients who met the eligibility criteria (male sex, age <6 years, severe hemophilia A, and no previous treatment with any factor VIII concentrate or only minimal treatment with blood components) were included from 42 sites. RESULTS Of 303 patients screened, 264 underwent randomization and 251 were analyzed. Inhibitors developed in 76 patients, 50 of whom had high-titer inhibitors (≥5 Bethesda units). Inhibitors developed in 29 of the 125 patients treated with plasma-derived factor VIII (20 patients had high-titer inhibitors) and in 47 of the 126 patients treated with recombinant factor VIII (30 patients had high-titer inhibitors). The cumulative incidence of all inhibitors was 26.8% (95% confidence interval [CI], 18.4 to 35.2) with plasma-derived factor VIII and 44.5% (95% CI, 34.7 to 54.3) with recombinant factor VIII; the cumulative incidence of high-titer inhibitors was 18.6% (95% CI, 11.2 to 26.0) and 28.4% (95% CI, 19.6 to 37.2), respectively. In Cox regression models for the primary end point of all inhibitors, recombinant factor VIII was associated with an 87% higher incidence than plasma-derived factor VIII (hazard ratio, 1.87; 95% CI, 1.17 to 2.96). This association did not change in multivariable analysis. For high-titer inhibitors, the hazard ratio was 1.69 (95% CI, 0.96 to 2.98). When the analysis was restricted to recombinant factor VIII products other than second-generation full-length recombinant factor VIII, effect estimates remained similar for all inhibitors (hazard ratio, 1.98; 95% CI, 0.99 to 3.97) and high-titer inhibitors (hazard ratio, 2.59; 95% CI, 1.11 to 6.00). CONCLUSIONS Patients treated with plasma-derived factor VIII containing von Willebrand factor had a lower incidence of inhibitors than those treated with recombinant factor VIII. (Funded by the Angelo Bianchi Bonomi Foundation and others; ClinicalTrials.gov number, NCT01064284; EudraCT number, 2009-011186-88.).

Effects of secondary prophylaxis started in adolescent and adult haemophiliacs

Summary.  While primary prophylaxis is a well‐established and recommended method of care delivery for children with severe haemophilia, fewer studies have documented the benefits of secondary prophylaxis started in adolescence or adulthood. To evaluate the role of secondary prophylaxis started in adolescent and adult severe haemophiliacs, a retrospective observational cohort study was conducted in 10 Italian Centres that investigated 84 haemophiliacs who had bled frequently and had thus switched from on‐demand to prophylactic treatment during adolescence (n = 30) or adulthood (n = 54). The consumption of clotting factor concentrates, the orthopaedic and radiological scores, quality of life and disease‐related morbidity were compared before and after starting secondary prophylaxis. Prophylaxis reduced the mean annual number of total and joint bleeds (35.8 vs. 4.2 and 32.4 vs. 3.3; P < 0.01) and of days lost from work/school (34.6 vs. 3.0, P < 0.01). A statistically significant reduction in the orthopaedic score was observed during prophylaxis in adolescents, but not in the whole cohort. Patients used more factor concentrates with corresponding higher costs on prophylaxis, but experienced a better quality of life. With respect to on‐demand treatment, higher factor consumption and cost of secondary prophylaxis were balanced by marked clinical benefits and greater well‐being in this cohort of adolescent/adult haemophiliacs.

Venous thromboses of upper limbs are more frequently associated with occult cancer as compared with those of lower limbs.

Three hundred and forty-three consecutive patients with deep vein thrombosis (DVT) were investigated for the possible presence of occult or undiagnosed cancer, of whom 305 patients had DVT of the lower limbs whereas 38 had DVT of the upper limbs. Cancer was diagnosed during a 12-month follow-up in nine patients with DVT of the upper limbs (23.7%) and in 34 patients with DVT of the lower limbs (11.1%). The difference was statistically significant. Furthermore, it was shown that the majority of cancers (seven of nine) in the case of DVT of the upper limbs were discovered during the first week of hospital admission. In contrast, in the case of DVT of lower limbs, only eight of 34 cancers were discovered during the initial investigation. Lung cancer and lymphomas represented the majority of cancers associated with upper limb venous thrombosis (seven of nine). In the case of DVT of the lower limbs, cancers were heterogeneous; however, 12 of 34 were cancers of the colon or prostate.

The Italian AICE-Genetics hemophilia A database: results and correlation with clinical phenotype

This study reports a wide spectrum of factor 8 mutations in the large Italian database. Findings of the study indicate hat the type of mutations is a strong predictor of the clinical phenotype. Background The high mutational heterogeneity of hemophilia A is a challenge for the provision of genetic services. We plan to identify the mutation in patients with hemophilia A in order to create a confidential national database of mutations for the optimization of genetic services in Italy. Design and Methods The factor VIII gene (F8) was analyzed in 1296 unrelated patients with hemophilia A using screening methods for intron 22 and 1 inversions and rare mutations (denaturing high performance liquid chromatography, conformation sensitive gel electrophoresis) and/or direct sequencing. Results F8 mutations were identified in 874 (89%), 146 (89%), and 133 (94%) families with severe, moderate, or mild hemophilia A, respectively. Mutations predicting a null allele were responsible for 80%, 15%, and less than 1% of cases of severe, moderate, or mild hemophilia A, respectively. About 40% of missense and nonsense mutations occurred at a CpG site, arginines being most frequently affected. Of the small deletions or insertions, 29% occurred at one of two stretches of adenines, codons 1191–1194 (8As) and 1439–1441 (9As). Overall, these “hotspots” accounted for 31% of the point mutations in the patients with hemophilia A. Inhibitors developed in 22% of the patients with severe hemophilia A, 8% of those with moderate disease and in 4% of patients with mild hemophilia A. Patients who had severe hemophilia A and mutations predicting a null allele developed inhibitors more frequently (22 to 67%) than patients with missense mutations (5%). Conclusions We report a wide spectrum of mutations in a large national database. The type of mutation was a strong predictor of the clinical phenotype. This database is expected to considerably improve the genetic counselling and medical care of families with hemophilia A in Italy.

Systematic review of the role of FVIII concentrates in inhibitor development in previously untreated patients with severe hemophilia a: a 2013 update.

Nowadays, patients with hemophilia A receive a high standard of care; therefore, the most challenging complication of factor VIII (FVIII) replacement therapy has become the development of FVIII inhibitors, which render the concentrate infusion ineffective and expose patients to an increased risk of morbidity and mortality. Among environmental risk factors influencing inhibitor development, the type of FVIII products has always drawn the attention of investigators. Conflicting results are reported in the literature concerning rates of inhibitor development after either plasma-derived or recombinant FVIII concentrates. To help elucidate this controversial issue, we have performed a systematic review and meta-analysis of prospective studies evaluating the incidence of inhibitors in previously untreated patients with severe hemophilia A receiving plasma-derived or recombinant FVIII products. The quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS), the STrenghtening the Reporting of OBservational studies in Epidemiology and an ad hoc quality score. Overall, 28 prospective studies, including 1,421 patients with hemophilia A, fulfilled our selection criteria and were included in the systematic review. No statistically significant differences were observed in the inhibitor incidence between plasma-derived and recombinant FVIII concentrates considering all (weighted means: 23%, 95% CI: 15-33% vs. 29%, 95% CI: 26-32%) and high titer (16%, 95% CI: 10-26% vs. 18%, 95% CI: 15-21%) inhibitors. Similarly, no significant differences were found in the inhibitor incidence among the different classes of recombinant products. In conclusion, the results of our meta-analysis show that the different types of FVIII products are not associated with different risks of inhibitor development.

Management of dental extraction in patients undergoing anticoagulant treatment. Results from a large, multicentre, prospective, case-control study.

Following favourable results from a previous study, a large, multicentre, prospective, case-control study was performed to further assess the incidence of bleeding complications after dental extraction in patients taking oral anticoagulant therapy (OAT). Four hundred fifty-one patients being treated with warfarin who required dental extraction were compared with a control group of 449 non-anticoagulated subjects undergoing the same procedure. In the warfarin-treated group, the oral anticoagulant regimen was maintained unchanged, such that the patients had an International Normalised Ratio ranging between 1.8 and 4, and local haemostatic measures (i.e. fibrin sponges, silk sutures and gauzes saturated with tranexamic acid) were adopted. All the procedures were performed in an outpatient setting. Seven bleeding complications occurred in the OAT group and four in the control group; the difference in the number of bleeding events between the two groups was not statistically significant (OR=1.754; 95% CI 0.510 - 6.034; p=0.3727). No post-operative late bleeds requiring hospitalisation and/or blood transfusions were recorded, and the adjunctive local haemostatic measures were adequate to stop the bleeding. The results of our protocol applied in this large, multicenter study show that dental extractions can be performed easily and safely in anticoagulated outpatients without any modification of the ongoing anticoagulant therapy, thus minimising costs and reducing discomfort for patients.

Non-catheter associated venous thrombosis in hemophilia A and B. A critical review of all reported cases

All reported cases of non-catheter induced venous thrombosis in patients with hemophilia A or B have been carefully evaluated. A total of 27 cases were reported,12 patients with hemophilia A and 15 patients with hemophilia B. The age of patients varied between 9 and 67 years. There were 10 cases of deep vein thrombosis, 8 patients with pulmonary embolism accompanied or not by deep vein thrombosis, 5 cases of superficial vein thrombosis. In addition, there were 3 cases of thrombosis in unusual sites (1 retinal central vein thrombosis and 2 portal vein thrombosis). Finally, in one case, venous thrombosis was multiple. There was a fatality in a hemophilia B patient with pulmonary embolism.The most frequent risk or triggering factor in hemophilia A was the administration of Feiba or rFVIIa concentrates in patients with inhibitors. Surgery together with Prothrombin Complex concentrates was the most frequent cause in hemophilia B patients. Congenital associated prothrombotic risk factors were present in two patients.No or very few therapeutic procedures were initiated in these patients but for a suspension or reduction of concentrates infusion. In a few instances low molecular weight heparin was given for a few days. The frequent association of venous thrombosis with infusion of concentrates indicates the need for a careful evaluation of patients about to receive such therapy.

Does Hemophilia Protect Against Atherosclerosis? A Case-Control Study

Whether carriers of hemophilia are protected against the development of atherosclerosis is controversial. In a case-control study, the presence of atherosclerosis was assessed and quantified with echo-color Doppler of all explorable arterial districts in 50 carriers of hemophilia and in 50 age-matched control individuals. All participants submitted to echo-color Doppler of carotid and femoral axis, of brachial arteries, and of the abdominal aorta. The presence and grade of atherosclerotic plaques were assessed, as well as the intima-media thickness (IMT). At least one atherosclerotic plaque was found in six cases (12.0%) versus 15 controls (30.0%); referring to the total number of plaques, 30% of them were evaluated in patients affected by decreased coagulation while 70% in subjects with normal levels of FVIII. In all the examined districts, the mean IMT was significantly lower in patients with hemophilia than in controls. Hemophilia protects against asymptomatic atherosclerosis.

Myocardial Infarction, Other Arterial Thrombosis and Invasive Coronary Procedures, in Hemaophilia B: A Critical Evaluation of Reported Cases

Myocardial infarction and other arterial thrombosis are commonly maintained to be rare in hemophilia patients. This, in general, seems true but the occurrence of a thrombotic event in hemophilia B is not exceptional. A thorough search of the literature has yielded 13 patients with myocardial infarction and 1 patient with a cerebrovascular accident. There were three fatalities. In five cases MI occurred after infusion of Prothrombin Complex Concentrates. In three additional patients the event occurred after infusion of plasma, Feiba or cryoprecipitate supernatant.Four patients had an antero-lateral infarction. Two had a non-Q infarction and one each showed a multiple or a posterior-inferior form. Several therapeutic coronary procedures (GABG and PTCA) were carried out in hemophilia B patients without undue complication providing adequate level of FIX were maintained. Heparin prophilaxis was used in all patients but one. The analysis of the literature indicates that (1) MI may occur in hemophilia B patients and (2) that invasive coronary artery therapeutic procedures may be carried out without complications.

Hemophilia A, von Willebrand disease, and atherosclerosis of abdominal aorta and leg arteries: factor VIII and von Willebrand factor defects appear to protect abdominal aorta and leg arteries from atherosclerosis.

We hypothesized that patients with hemophilia or von Willebrand disease might be protected from atherosclerosis because of their coagulation defect. We studied 40 subjects affected by these two coagulation diseases using echocolor Doppler of the abdominal aorta and leg arteries, and compared the results with those obtained in 40 control patients who were homogenous with study patients in terms of sex, age, and risk factors for atherosclerosis. The probands presented a lower number of plaques than the 40 control subjects in the aorta and in the leg arteries. The most serious hemophilic patients had fewer plaques than controls or than patients with mild hemophilia. Both hemophilia and von Willebrand disease seem to protect against atherosclerosis.