Emanuela Marchesini

Rate of inhibitor development in previously untreated hemophilia A patients treated with plasma-derived or recombinant factor VIII concentrates: a systematic review

Summary.  Background: Different rates of inhibitor development after either plasma‐derived (pdFVIII) or recombinant (rFVIII) FVIII have been suggested. However, conflicting results are reported in the literature. Objectives: To systematically review the incidence rates of inhibitor development in previously untreated patients (PUPs) with hemophilia A treated with either pdFVIII or rFVIII and to explore the influence of both study and patient characteristics. Methods: Summary incidence rates (95% confidence interval) from all included studies for both pdFVIII and rFVIII results were recalculated and pooled. Sensitivity analysis was used to investigate the effect of study design, severity of disease and inhibitor characteristics. Meta‐regression and analysis‐of‐variance were used to investigate the effect of covariates (testing frequency, follow‐up duration and intensity of treatment). Results: Two thousand and ninety‐four patients (1167 treated with pdFVIII, 927 with rFVIII; median age, 9.6 months) from 24 studies were investigated and 420 patients were observed to develop inhibitors. Pooled incidence rate was 14.3% (10.4–19.4) for pdFVIII and 27.4% (23.6–31.5) for rFVIII; high responding inhibitor incidence rate was 9.3% (6.2–13.7) for pdFVIII and 17.4% (14.2–21.2) for rFVIII. In the multi‐way anova study design, study period, testing frequency and median follow‐up explained most of the variability, while the source of concentrate lost statistical significance. It was not possible to analyse the effect of intensity of treatment or trigger events such as surgery, and to completely exclude multiple reports of the same patient or changes of concentrate. Conclusions: These findings underscore the need for randomized controlled trials to address whether or not the risk of inhibitor in PUPs with hemophilia A differs between rFVIII and pdFVIII.

The good use of plasma. A critical analysis of five international guidelines

BACKGROUND The clinical use of fresh-frozen plasma (FFP) is progressively increasing both nationally and internationally, despite the fact that many studies have shown the weaknesses of the indications for its use. Guidelines on the good use of plasma have, therefore, been adopted in various countries. The aim of the present study was to analyse some of the existing guidelines on the good use of plasma, applying a scientifically validated method, as a preliminary step in the implementation of Regional guidelines. METHODS Abibliographic search (1990-2006) was conducted in databases, websites, and the archives of scientific societies. Relevant articles were recovered in full. The selected guidelines were evaluated using theAGREE instrument, which assesses the completeness and structural quality of the guidelines and, in some aspects, the contents of the recommendations. The project, co-ordinated by the Regional Centre for Co-ordination and Compensation (CRCC) and carried out by four Services of Immunohaematology and Transfusion (SIT) in Umbria, was funded by the Region of Umbria and approved by the four health care institutions involved. RESULTS The bibliographic search yielded 3067 abstracts of which 239 were considered relevant. The analysis of these led to the recovery of 11 guidelines, among which five were selected: those from the British Committee for Standards in Haematology, theAgence Française de Securité Sanitaire de Produits de Sante, the Canadian Members of the Expert Working Group, the American Society of Anesthesiologists Task Force on Blood Component Therapy and the National Health and Medical Research Council (NHMRC)/Australasian Society of Blood Transfusion. CONCLUSIONS None of the guidelines analysed obtained a score higher than 50% in all the domains of the AGREE score. There was no evidence of a tendency to improvement over time in the guidelines analysed. Objective evaluation of the guidelines analysed could provide the starting point for the subsequent production of similar documents.

IDO1 suppresses inhibitor development in hemophilia A treated with factor VIII

The development of inhibitory antibodies to factor VIII (FVIII) is a major obstacle in using this clotting factor to treat individuals with hemophilia A. Patients with a congenital absence of FVIII do not develop central tolerance to FVIII, and therefore, any control of their FVIII-reactive lymphocytes relies upon peripheral tolerance mechanisms. Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulatory enzyme that supports Treg function and peripheral tolerance in adult life. Here, we investigated the association between IDO1 competence and inhibitor status by evaluating hemophilia A patients harboring F8-null mutations that were either inhibitor negative (n = 50) or positive (n = 50). We analyzed IDO1 induction, expression, and function for any relationship with inhibitor occurrence by multivariable logistic regression and determined that defective TLR9-mediated activation of IDO1 induction is associated with an inhibitor-positive status. Evaluation of experimental hemophilic mouse models with or without functional IDO1 revealed that tryptophan metabolites, which result from IDO1 activity, prevent generation of anti-FVIII antibodies. Moreover, treatment of hemophilic animals with a TLR9 agonist suppressed FVIII-specific B cells by a mechanism that involves IDO1-dependent induction of Tregs. Together, these findings indicate that strategies aimed at improving IDO1 function should be further explored for preventing or eradicating inhibitors to therapeutically administered FVIII protein.

Peginterferon Plus Ribavirin for Chronic Hepatitis C in Patients With Human Immunodeficiency Virus

OBJECTIVES:The aim of this study was to assess the effects of peginterferon plus ribavirin for chronic hepatitis C in patients with human immunodeficiency virus (HIV).METHODS:Trials were identified through manual and electronic searches. Randomized trials comparing peginterferon plus ribavirin with other antiviral treatments for patients with chronic hepatitis C and HIV were included. The primary outcome measure was virological response at the end of treatment and after ≥6 months (sustained). Intention-to-treat meta-analyses including data on all patients who were randomized were carried out.RESULTS:Seven randomized trials were eligible for inclusion. The patients included had chronic hepatitis C and stable HIV and were not previously treated with interferon or ribavirin (treatment naive). The mean dosages were 180 or 1.5 μg/kg once weekly for peginterferon and 800 mg daily for ribavirin. The treatment duration ranged from 24 to 48 weeks. Peginterferon plus ribavirin increased the proportion of patients with an end-of-treatment or sustained virological response compared with interferon plus ribavirin or peginterferon alone. In subgroup analyses of trials comparing peginterferon plus ribavirin with interferon plus ribavirin, the proportion with a sustained virological response was 26% (109 of 423) for patients with genotype 1 or 4 and 57% (130 of 230) for genotype 2 or 3. Several adverse events occurred, including fatal lactic acidosis and liver failure, but there were no significant differences in mortality rates between treatment groups.CONCLUSIONS:Peginterferon plus ribavirin may be considered for treatment-naive patients with HIV and chronic hepatitis C. Adverse events should be monitored carefully.

Pharmacokinetics of plasma-derived vs. recombinant FVIII concentrates: a comparative study

Only very few pharmacokinetic (PK) studies comparing plasma derived FVIII (pd‐FVIII) against recombinant FVIII (rFVIII) concentrates are available. The studies have been generally conducted to demonstrate the bioequivalence of a new product with an old one. The switch from a plasma‐derived FVIII (pd‐FVIII) to a rFVIII concentrate is a good moment to enrol the patients in a comparative PK study. To achieve information on the PK characteristics of two different classes of FVIII concentrates, according to two different designs: a 10 FVIII concentration/time point design and a reduced 4‐point design. A single dose PK comparing pd‐ and rFVIII concentrates has been performed in four Haemophilia Centres of Italy. Seventeen haemophilia A patients underwent two subsequent single dose PK studies at the moment of switching. Two‐compartment‐ and Non‐compartment‐analysis did not show significant differences between the outcomes of PK of pd‐FVIII and rFVIII, due to inter‐patient variability. In vivo recovery (IVR) of rFVIII was slightly higher than that of pd‐FVIII and rFVIII/pd‐FVIII AUC ratio was 1.37 in 11/17 patients. The difference is only due to the initial distribution phase because after the first 10 h from the end of the infusion, the two decay curves are overlapping. The elimination half‐life of the concentrates was very similar even though a complete bioequivalence was not demonstrated because of a higher AUC of rFVIII concentrates, limited to the distribution phase. The higher Cmax and IVR of rFVIII may be due to the presence of heterodimers activated forms of the recombinant molecules.

Vitamin K and non-vitamin K antagonist oral anticoagulants for non-valvular atrial fibrillation in real-life.

BACKGROUND Current guidelines recommend vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in patients with non-valvular atrial fibrillation (AF). METHODS We compared the clinical features of consecutive in- and out-patients with non-valvular AF newly-treated with NOACs or on treatment with VKAs. RESULTS Overall, 1314 patients newly-treated with NOACs and 1024 on treatment with VKAs were included in the study. The mean CHA2DS2-VASc score was 4.3±1.5 and 4.0±1.5 and the mean HAS-BLED score was 2.8±1.2 and 2.2±1.1 in the two groups, respectively (both p<0.001). Hypertension, previous stroke, female gender, vascular diseases and previous bleeding were more prevalent in NOACs patients. Renal failure, age ≥75years and congestive heart failure were more prevalent in VKAs patients. Among NOACs patients, 438 were given dabigatran, 463 rivaroxaban and 413 apixaban (33%, 35% and 31%, respectively). The mean CHA2DS2-VASc and HAS-BLED scores were higher in rivaroxaban or apixaban patients compared with dabigatran (both p<0.001) and VKAs patients (both p<0.001). A lower mean age was observed in patients newly-treated with dabigatran. Patients newly-treated with reduced doses of NOACs (599 patients, 45.5%) had a higher CHA2DS2-VASc (4.8±1.4 vs. 3.9±1.5 vs. 4.0±1.5) and HAS-BLED (2.9±1.1 vs. 2.8±1.2 vs. 2.2±1.1) scores compared with those treated with regular doses of NOACs or VKAs. CONCLUSION Patients given rivaroxaban and apixaban in clinical practice have a higher thrombotic and hemorrhagic risk in comparison with patients given dabigatran or VKAs. A considerable proportion of patients receive reduced doses of NOACs.

Risk of inhibitors in previously untreated patients with hemophilia: a meta-analysis of literature studies

To the editor: We read with interest the articles published by Calvez et al and Collins et al[1][1],[2][2] reporting an increased inhibitor rate in previously untreated patients (PUPs) with severe hemophilia A receiving Kogenate FS compared with those receiving Advate. These results somehow

Patients with cancer and atrial fibrillation treated with doacs: A prospective cohort study

BACKGROUND Limited data are available on the use of direct oral anticoagulants (DOACs) in patients with cancer and atrial fibrillation (AF). METHODS Consecutive patients with non-valvular AF treated with DOACs were enrolled in a prospective cohort with the aim of evaluating thromboembolic (ischemic stroke or transient ischemic attack or systemic embolism) and major bleeding (MB) events according to presence and type of cancer. The risk of study outcomes over time was compared using Kaplan-Meier method and log-rank test or Cox proportional hazards regression. RESULTS 2304 patients with non-valvular AF receiving DOACs were enrolled and 16 excluded: 2288 analysed of whom 289 (12.6%) had cancer. Gastrointestinal (21%), genitourinary (15%), prostate (15%), haematological (14%), breast (13%), and lung (8%) were the more frequent sites of cancer. After a mean follow-up of 451 days, thromboembolic events occurred in 2.1% and 0.8% patient-year of cancer and non-cancer patients (adjusted-HR 2.58, 95% CI 1.08-6.16, p = 0.033). The rate of MB was 6.6% and 3.0% patient-year in cancer and non-cancer patients (adjusted-HR 2.02, 95% CI 1.25-3.27, p = 0.004). The differences in bleeding were mainly accounted for by bleeding at gastrointestinal and genitourinary sites. No significant differences were found concerning the rates of non-cancer-related mortality, fatal bleeding or fatal thrombotic events. CONCLUSIONS In this study, the higher bleeding risk found in cancer compared to non-cancer patients was mainly due to an excess of bleeding at gastrointestinal and at genitourinary sites. Larger studies on the optimal management of cancer patients with AF are needed.

Rate and appropriateness of polypharmacy in older patients with hemophilia compared with age-matched controls

In older people, multiple chronic ailments lead to the intake of multiple medications (polypharmacy) that carry a number of negative consequences (adverse events, prescription and intake errors, poor adherence, higher mortality). Because ageing patients with haemophilia (PWHs) may be particularly at risk due to their pre‐existing multiple comorbidities (arthropathy, liver disease), we chose to analyse the pattern of chronic drug intake in a cohort of PWHs aged 60 years or more.