Management of inherited von Willebrand disease in Italy : results from the retrospective study on 1234 patients

Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is due to quantitative and/or qualitative defects of von Willebrand factor (VWF). Despite the improved knowledge of the disease, detailed data on VWD types requiring specific treatments have not been reported thus far. To determine the number and types of VWD requiring therapy with desmopressin (DDAVP) and/or VWF/FVIII concentrates in Italy, a national registry on VWD (RENAWI) was organized. Only 16 of 48 centers included VWD in the RENAWI with diagnoses performed locally. Patients with uncertain results were retested by two expert laboratories using multimeric analysis and mutations of the VWF gene. A total of 1234 of 1529 (81%) cases satisfied the inclusion criteria and could be classified as VWD1 (63%), VWD2A (7%), VWD2B (6%), VWD2M (18%), VWD2N (1%), and VWD3 (5%). VWD types were also confirmed by DNA analyses and occur in young adults (83%), mainly in women (58%). Mucosal bleedings (32 to 57%) are more frequent than hematomas (13%) or hemarthrosis (6%). Most patients were exposed to an infusion trial with desmopressin (DDAVP) and found responsive with the following rates: VWD1 (69%), VWD2A (26%), VWD2M (29%), and VWD2N (71%). However, DDAVP was not always used to manage bleeding in all responsive patients and VWF/FVIII concentrates were given instead of or together with DDAVP in VWD1 (30%), VWD2A (84%), VWD2B (62%), VWD2M (63%), VWD2N (30%), and VWD3 (91%). Data of the RENAWI showed that correct VWD identification and classification might be difficult in many Italian centers. Therefore, evidence-based studies should be organized only in well-characterized patients tested by laboratories that are expert in the clinical, laboratory, and molecular markers of VWD

Treatment-related risk factors for inhibitor development in non-severe hemophilia A after 50 cumulative exposure days: a case-control study

Background Non-severe hemophilia A patients have a life-long inhibitor risk. Yet, no studies have analyzed risk factors for inhibitor development after 50 factor VIII (FVIII) exposure days (EDs). Objectives This case-control study investigated treatment-related risk factors for inhibitor development in non-severe hemophilia A and assessed whether these risk factors were different for early versus late inhibitor development. Patients/Methods Non-severe hemophilia A patients (FVIII:C 2%-40%) were selected from the INSIGHT study. Inhibitor-positive patients were defined as early (50EDs) cases and matched to 1-4 inhibitor-negative controls by year of birth, cumulative number of EDs, and center/country. We investigated treatment intensity during the last 10 EDs prior to inhibitor development. Intensive treatment was defined as: surgery, peak treatment (10 consecutive EDs), and high mean FVIII dose (>45 IU/kg/ED). Odds ratios (OR) were calculated by logistic regression. Results Of 2709 patients, we analyzed 63 early and 26 late cases and 195 and 71 respectively matched controls. Peak treatment was associated with early and late inhibitor risk (crude OR 1.8, 95% confidence interval [CI] 1.0-3.4; 4.0, 95%CI 1.1-14.3). This association was slightly less pronounced after adjustment for mean FVIII dose. High mean FVIII dose was also associated with early and late inhibitor risk (crude OR 2.8, 95%CI 1.5-5.1; 4.5, 95%CI 1.2-16.6). Surgery increased inhibitor risk for early cases. This was less pronounced for late cases. Conclusions Our findings suggest that intensive FVIII treatment remains a risk factor for inhibitor development in non-severe hemophilia A after more than 50 EDs. Therefore, persistent caution is required throughout the life-time treatment course.Clinical epidemiolog

Timing and severity of inhibitor development in recombinant versus plasma-derived factor VIII concentrates: a SIPPET analysis

Essentials Recombinant factor VIII (rFVIII) was contrasted with plasma-derived FVIII (pdFVIII). In previously untreated patients with hemophilia A, rFVIII led to more inhibitors than pdFVIII. Inhibitors with rFVIII developed earlier, and the peak rate was higher than with pdFVIII. Inhibitors with rFVIII were more severe (higher titre) than with pdFVIII. Summary: Background The development of neutralizing antibodies (inhibitors) against factor VIII (FVIII) is the most severe complication in the early phases of treatment of severe hemophilia A. Recently, a randomized trial, the Survey of Inhibitors in Plasma-Product Exposed Toddlers (SIPPET) demonstrated a 2-fold higher risk of inhibitor development in children treated with recombinant FVIII (rFVIII) products than with plasma-derived FVIII (pdFVIII) during the first 50 exposure days (EDs). Objective/Methods In this post-hoc SIPPET analysis we evaluated the rate of inhibitor incidence over time by every 5 EDs (from 0 to 50 EDs) in patients treated with different classes of FVIII product, made possible by a frequent testing regime. Results The highest rate of inhibitor development occurred in the first 10 EDs, with a large contrast between rFVIII and pdFVIII during the first 5 EDs: hazard ratio 3.14 (95% confidence interval [CI], 1.01\ue2\u80\u939.74) for all inhibitors and 4.19 (95% CI, 1.18\ue2\u80\u9314.8) for high-titer inhibitors. For patients treated with pdFVIII, the peak of inhibitor development occurred later (6\ue2\u80\u9310 EDs) and lasted for a shorter time. Conclusion These results emphasize the high immunologic vulnerability of patients during the earliest exposure to FVIII concentrates, with the strongest response to recombinant FVIII products

Efficacy and safety of highly purified, doubly virus-inactivated VWF/FVIII concentrates in inherited von Willebrand's disease : results of an Italian cohort study on 120 patients characterized by bleeding severity score

The efficacy of highly purified VWF/FVIII concentrates with standardized ristocetin cofactor content (VWF:RCo) has been already proven in patients with von Willebrand's disease (VWD). Aim of this retrospective study is to confirm efficacy and safety of two highly purified, doubly virus-inactivated VWF/FVIII concentrates in a large cohort of patients with VWD who were characterized at enrolment by bleeding severity score. Study drugs Alphanate or Fanhdi were given to 120 cases (51 males, 69 females, median age 50 years, range 6-83 years). Patients had VWD3 (10), VWD2A (19), VWD2B (25), VWD2M (10) and DDAVP-unresponsive VWD1 (56) and a median bleeding severity score of 8 (range 0-27). A total of 114 bleeding episodes in 55 cases and 131 surgical procedures in 85 cases could be analysed. Excellent-good clinical responses were seen in 97% of bleeding episodes and in 99% of surgical procedures. To prevent recurrent gastrointestinal (GI) bleeding, cerebral (CNS) haemorrhage, haemarthroses, urogenital or multisite bleeding in more severe patients, secondary prophylaxis was also carried out in 15 cases with VWD3 (3), VWD2A (3), VWD2B (2), VWD1 (7). A median dose of 42 IU VWF:RCo kg-1 given every other day or twice a week over a median period of 334 days (range 24-799) prevented bleeding completely in 13 cases and reduced its incidence in the remaining two. These results confirm the efficacy and safety of the study concentrates, not only in the management of bleeding and surgery but also in secondary prophylaxis of severe VWD

Studies of von Willebrand factor in essential thrombocythemia patients treated with alpha-2b recombinant interferon

The crucial role of the von Willebrand Factor (vWF) and its interaction with platelets in myeloproliferative disorders (MPD) have emerged in recent years. Recently, many authors have reported the therapeutical efficacy of interferon (IFN) in MPD with thrombocytosis in decreasing platelet number. The purpose of our report is to study the modifications of vWF in a series of 20 patients affected by essential thrombocythemia (ET) or MPD with thrombocytosis, treated with alpha 2b recombinant IFN (alpha 2b-rIFN). Patients were studied before treatment and after complete or partial response: vWF-related properties, bleeding time (BT) and ristocetin-induced platelet aggregation (RIPA) were evaluated. Before treatment, we found prolonged BT in 5 patients (25%), abnormal RIPA in 8 (40%), reduced factor VIII coagulant activity (VIII:C) in 2 (10%), reduced vWF-related antigen (vWF:Ag) in 5 (25%) and low vWF:ristocetin cofactor (vWF:Ricof) in 5 (25%). Twelve subjects were evaluated after hematologic remission: in all patients, BT, VIII:C, vWF:Ag and vWF:Ricof were within normal range or upper normal limits. RIPA was abnormal in 7 subjects. Multimer patterns of vWF were performed in 3 patients before and after treatment: 2 of them showed loss of high-molecular-weight multimers that seemed to recover at remission. IFN seems to induce improvement of platelet number and their functions in MPD with thrombocytosis