Common Genetic Variants in ABO and CLEC4M Modulate the Pharmacokinetics of Recombinant FVIII in Severe Hemophilia A Patients.

Common Genetic Variants in ABO and CLEC4M Modulate the Pharmacokinetics of Recombinant FVIII in Severe Hemophilia A Patients. Thromb Haemost. 2020 Jul 29;: Authors: Garcia-Martínez I, Borràs N, Martorell M, Parra R, Altisent C, Ramírez L, Álvarez-Román MT, Nuñez R, Megias-Vericat JE, Corrales I, Alonso S, Vidal F Abstract The pharmacokinetic (PK) response of severe hemophilia A (HA) patients to infused factor VIII (FVIII) shows substantial variability. Several environmental and genetic factors are associated with changes in FVIII plasma levels and infused FVIII PK. Based on the hypothesis that factors influencing endogenous FVIII can affect FVIII PK, the contribution of single-nucleotide variants (SNVs) in candidate genes was investigated in 51 severe HA patients. The effects of blood group, F8 variant type, von Willebrand factor antigen and activity levels, age, and weight were also explored. The myPKFiT device was used to estimate individual PK parameters, and SNVs and clinically reportable F8 variants were simultaneously analyzed in an Illumina MiSeq instrument, using the microfluidics-based Fluidigm Access Array system. The contribution of SNVs to FVIII half-life and clearance was addressed by robust regression modeling, taking into account other modulators. In line with previous studies, we provide robust evidence that age, body weight, and blood group, as well as SNVs in ABO and CLEC4M, participate in the v...
Source: Thrombosis and Haemostasis - Category: Hematology Authors: Tags: Thromb Haemost Source Type: research

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The deficiency or abnormal activity of von Willebrand factor, a multi-adhesive protein which binds platelets to exposed subendothelium and carries factor VIII in circulation, is responsible for von Willebrand disease, the most frequent inherited bleeding disorder. Clinical symptoms are characterized by mucous membrane and soft tissue bleeding, bleeding after surgery and rarely joint and gastrointestinal bleeding. Intriguingly, also factor VIII, the protein deficient in hemophilia A, may be variably reduced because VWF stabilizes it into circulation.
Source: Thrombosis Research - Category: Hematology Authors: Tags: Review Article Source Type: research
This study also emphasized the need for inclusion of the VWF:FVIIIB in suspected hemophilia A to achieve an optimal treatment strategy.
Source: Blood Coagulation and Fibrinolysis - Category: Hematology Tags: ORIGINAL ARTICLES Source Type: research
roup Abstract BACKGROUND:  von Willebrand factor (VWF) is crucial for optimal dosing of factor VIII (FVIII) concentrate in hemophilia A patients as it protects FVIII from premature clearance. To date, it is unknown how VWF behaves and what its impact is on FVIII clearance in the perioperative setting. AIM:  To investigate VWF kinetics (VWF antigen [VWF:Ag]), VWF glycoprotein Ib binding (VWF:GPIbM), and VWF propeptide (VWFpp) in severe and moderate perioperative hemophilia A patients included in the randomized controlled perioperative OPTI-CLOT trial. METHODS:  Linear mixed effects modeling...
Source: Thrombosis and Haemostasis - Category: Hematology Authors: Tags: Thromb Haemost Source Type: research
CONCLUSIONS: pdFVIII/VWF showed a non-additive effect on TG when combined in vitro with emicizumab. This finding suggests that emicizumab has limited ability to promote factor X activation in the presence of pdFVIII/VWF, thus reducing the risk of thrombotic events. PMID: 32379931 [PubMed - as supplied by publisher]
Source: Thrombosis and Haemostasis - Category: Hematology Authors: Tags: J Thromb Haemost Source Type: research
CONCLUSIONS: We conclude that in non-severe HA ABO and VWF levels do not substantially influence the variability of FVIII levels and age has only minor effects on it, which is important information for the diagnostic procedures. PMID: 32073230 [PubMed - as supplied by publisher]
Source: Thrombosis and Haemostasis - Category: Hematology Authors: Tags: J Thromb Haemost Source Type: research
This article gives an overview of the bleeding risks involved and therapeutic options to overcome them. [...] Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.Article in Thieme eJournals: Table of contents  |  Abstract  |  Full text
Source: Seminars in Thrombosis and Hemostasis - Category: Hematology Authors: Tags: Review Article Source Type: research
We describe the results of the (to our knowledge) longest long-term noninterventional study so far performed to obtain real-life data on the treatment of hemophilia A patients with a single plasma-derived FVIII concentrate containing von Willebrand factor (pdFVIII; Haemoctin/Faktor VIII SDH Intersero). A total of 198 patients (146 in Germany and 52 in Hungary), of whom 160 had severe and 38 nonsevere hemophilia A, representing all age groups (0-88 years; mean ∼25 years at inclusion) were analyzed during prophylactic or on-demand treatment over 18 years (overall 1,418 patient-years; mean>7 years). pdFVIII was very ef...
Source: Hamostaseologie - Category: Hematology Authors: Tags: Hamostaseologie Source Type: research
We present a case of a 68-year-old Hispanic female with a history of factor VII deficiency who presented with shortness of breath, chest pain, and palpitations and was found to have pulmonary embolism. Our patient did not have any of the above-mentioned thrombotic risk factors. Our case and review of the literature show that factor VII deficiency does not provide protection against thrombosis. PMID: 31590173 [PubMed - as supplied by publisher]
Source: Acta Haematologica - Category: Hematology Authors: Tags: Acta Haematol Source Type: research
CONCLUSION: This population PK model derived from real world data adequately describes FVIII levels following perioperative administration of the FVIII/VWF plasma-derived concentrate (Haemate® P/Humate P®) and will help to facilitate future dosing in VWD patients. PMID: 31557387 [PubMed - as supplied by publisher]
Source: Thrombosis and Haemostasis - Category: Hematology Authors: Tags: J Thromb Haemost Source Type: research
CONCLUSIONS: Our results provide HLAcII peptidomic level explanations for several important clinical observations/issues including the differential immunogenicity of distinct FVIIIs and the role of HLAcII genetics in inhibitor development. PMID: 31556206 [PubMed - as supplied by publisher]
Source: Thrombosis and Haemostasis - Category: Hematology Authors: Tags: J Thromb Haemost Source Type: research
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