Study of the effect of HFE gene mutations on iron overload in Egyptian thalassemia patients

Background: HFE gene mutations have been shown to be responsible for hereditaryhemochromatosis. Their effect on iron load in β-thalassemia patients and carriers remains controversial.Objectives: We aimed to determine the prevalence of HFE gene mutations (C282Y and H63D) in β-thalassemia patients and carriers and to investigate its effect on their serum ferritin levels.Patients and methods: A total of 100 β-thalassemia subjects; 75 patients and 25 carriers were screened for HFE gene mutations by PCR-RFLP. Serum ferritin measured by ELISA was evaluated in relation to HFE mutations.Results: Twenty-eight β-thalassemia patients (37.3%) were heterozygotes for H63D mutation (H/D), 8 (10.7%) were D/D and 39 (52%) were negative (H/H). Among carriers, 4 (16%) were D/D and 21 (84%) were H/H homozygotes. C282Y mutant allele was not detected in any of the subjects. Serum ferritin levels were significantly higher in β-thalassemia patients heterozygotes or homozygotes for H63D mutation compared to those without mutation (p= 0.000). Carriers homozygotes for H63D mutation showed significantly higher serum ferritin levels compared to those without mutation (p< 0.001).Conclusion: Homozygosity for H63D mutation tends to be associated with higher ferritin levels in beta-thalassemia patients and carriers suggesting its modulating effect on iron load in these cases

Efficacy and safety of deferasirox at low and high iron burdens: results from the EPIC magnetic resonance imaging substudy

The effect of deferasirox dosing tailored for iron burden and iron loading based on liver iron concentration (LIC) was assessed over 1 year in less versus more heavily iron-overloaded patients in a substudy of the Evaluation of Patients' Iron Chelation with ExjadeA (R). Deferasirox starting dose was 10-30 mg/kg/day, depending on blood transfusion frequency, with recommended dose adjustments every 3 months. Therapeutic goals were LIC maintenance or reduction in patients with baseline LIC < 7 or a parts per thousand yen7 mg Fe/g dry weight (dw), respectively. Changes in LIC (R2-magnetic resonance imaging) and serum ferritin after 1 year were assessed. Adverse events (AEs) and laboratory parameters were monitored throughout. Of 374 patients, 71 and 303 had baseline LIC < 7 and a parts per thousand yen7 mg Fe/g dw, respectively; mean deferasirox doses were 20.7 and 27.1 mg/kg/day (overall average time to dose increase, 24 weeks). At 1 year, mean LIC and median serum ferritin levels were maintained in the low-iron cohort (-0.02 A +/- 2.4 mg Fe/g dw, -57 ng/mL; P = not significant) and significantly decreased in the high-iron cohort (-6.1 A +/- 9.1 mg Fe/g dw, -830 ng/mL; P < 0.0001). Drug-related gastrointestinal AEs, mostly mild to moderate, were more frequently reported in the < 7 versus a parts per thousand yen7 mg Fe/g dw cohort (39.4 versus 20.8 %; P = 0.001) and were not confounded by diagnosis, dosing, ethnicity, or hepatitis B and/or C history. Reported serum creatinine increases did not increase in low- versus high-iron cohort patients. Deferasirox doses of 20 mg/kg/day maintained LIC < 7 mg Fe/g dw and doses of 30 mg/kg/day were required for net iron reduction in the high-iron cohort, with clinically manageable safety profiles. The higher incidence of gastrointestinal AEs at lower iron burdens requires further investigation

Epistasis and the sensitivity of phenotypic screens for beta thalassaemia

Genetic disorders of haemoglobin, particularly the sickle cell diseases and the alpha and beta thalassaemias, are the commonest inherited disorders worldwide. The majority of affected births occur in low-income and lower-middle income countries. Screening programmes are a vital tool to counter these haemoglobinopathies by: (i) identifying individual carriers and allowing them to make informed reproductive choices, and (ii) generating population level gene-frequency estimates, to help ensure the optimal allocation of public health resources. For both of these functions it is vital that the screen performed is suitably sensitive. One popular first-stage screening option to detect carriers of beta thalassaemia in low-income countries is the One Tube Osmotic Fragility Test (OTOFT). Here we introduce a population genetic framework within which to quantify the likely sensitivity and specificity of the OTOFT in different epidemiological contexts. We demonstrate that interactions between the carrier states for beta thalassaemia and alpha thalassaemia, glucose-6-phosphate dehydrogenase deficiency and Southeast Asian Ovalocytosis have the potential to reduce the sensitivity of OTOFTs for beta thalassaemia heterozygosity to below 70%. Our results therefore caution against the widespread application of OTOFTs in regions where these erythrocyte variants co-occur

Role of the factor VIII-binding capacity of endogenous von Willebrand factor on the development of factor VIII inhibitors in patients with severe hemophilia A

International audienc

Eliglustat maintains long-term clinical stability in patients with Gaucher disease type 1 stabilized on enzyme therapy

In the phase 3 trial of eliglustat in patients with Gaucher disease type 1 already stabilized with enzyme therapy (ENCORE), at one year, eliglustat was non-inferior to imiglucerase enzyme therapy in maintaining stable platelet counts, hemoglobin concentrations, and spleen and liver volumes. After this primary analysis period, patients entered a long-term extension phase in which all received eliglustat. Duration on eliglustat ranged from 2 to 5 years, depending on timing of enrollment (which spanned 2 years), treatment group to which patients were randomized, and whether they lived in the United States when commercial eliglustat became available. Here we report long-term safety and efficacy of eliglustat for 157 patients who received eliglustat in the ENCORE trial; data are available for 46 patients who received eliglustat for 4 years. Mean hemoglobin concentration, platelet count, and spleen and liver volumes remained stable for up to 4 years. Year to year, all four measures remained collectively stable (composite endpoint relative to baseline values) in ≥85% of patients, as well as individually in ≥92%. Mean bone mineral density Z-scores (lumbar spine and femur) remained stable and were maintained in the healthy reference range throughout. Eliglustat was well-tolerated over 4 years; 4 (2.5%) patients withdrew due to adverse events that were considered related to the study drug. No new or long-term safety concerns were identified. Clinical stability assessed by composite and individual measures was maintained in adults with Gaucher disease type 1 treated with eliglustat who remained in the ENCORE trial for up to 4 years.The ENCORE trial was funded and conducted by Sanofi Genzyme

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