Introduction
Previous studies reported the efficacy and safety profile of extended half‐life PEGylated recombinant factor VIII (FVIII) rurioctocog alfa pegol (TAK‐660, SHP660, BAX 855) in preventing ...bleeding in haemophilia A patients.
Aim
This study evaluated long‐term safety and efficacy of rurioctocog alfa pegol for prophylaxis and treatment of bleeding in previously treated children and adults.
Methods
In this phase 3b, prospective, open‐label, multicentre study (NCT01945593), eligible patients ≤ 75 years with severe haemophilia A (FVIII < 1%) received prophylactic rurioctocog alfa pegol in a fixed dose (FD, twice‐weekly or less frequent) or pharmacokinetic (PK)‐tailored dose regimen. Co‐primary endpoints were incidence of confirmed FVIII inhibitory antibody development and spontaneous annualized bleed rate (ABR), analysed using a generalised linear model. Secondary endpoints included overall haemostatic efficacy, occurrence of adverse events and health‐related quality of life (HRQoL).
Results
Overall, 216 patients were included; mean (SD) age at enrolment was 22.8 (15.7) years. No patients developed confirmed FVIII inhibitors. The point estimate (95% CI) of mean spontaneous ABR was 1.20 (0.92‐1.56) among 186 patients receiving twice‐weekly FD prophylaxis and 0.96 (0.54‐1.71) among 25 patients receiving PK‐tailored prophylaxis. Overall haemostatic efficacy was rated good or excellent in 88.6% of all bleeds. No new safety signals were observed. Patients reported improvements in HRQoL measures of pain, and physical and mental well‐being.
Conclusion
These results highlight the long‐term safety and efficacy of rurioctocog alfa pegol prophylaxis in previously treated children and adults with severe haemophilia A, with a safety profile similar to previous studies and continuing ABR reduction.
The morphology and other phenotypic characteristics of erythrocytes in sickle cell disease (SCD) have been analyzed for decades in patient evaluation. This involves a variety of techniques, including ...microscopic analysis of stained blood films, flow cytometry, and cell counting. Here, we analyzed SCD blood using imaging flow cytometry (IFC), a technology that combines flow cytometry and microscopy to enable simultaneous rapid‐throughput analysis of cellular morphology and cell‐surface markers. With IFC, we were able to automate quantification of poikilocytes from SCD blood. An important subpopulation of poikilocytes represented dense cells, although these could not be distinguished from other poikilocytes without first centrifuging the blood through density gradients. In addition, CD71‐positive RBCs from SCD patients had two subpopulations: one with high CD71 expression and a puckered morphology and another with lower CD71 expression and biconcave morphology and presumably representing a later stage of differentiation. Some RBCs with puckered morphologies that were strongly positive for DAPI and CD49d were in fact nucleated RBCs. IFC identified more phosphatidylserine‐expressing red cells in SCD than did conventional flow cytometry and these could also be divided into two subpopulations. One population had diffuse PS expression and appeared to be composed primarily of RBC ghosts; the other had lower overall PS expression present in intense, punctate dots overlying Howell‐Jolly bodies. This study demonstrates that IFC can rapidly reveal and quantify RBC features in SCD that require numerous tedious methods to identify conventionally. Thus, IFC is likely to be a useful technique for evaluating and monitoring SCD.
Reproductive tract bleeding in women is a naturally occurring event during menstruation and childbirth. In women with menorrhagia, however, congenital bleeding disorders historically have been ...underdiagnosed. This consensus is intended to allow physicians to better recognize bleeding disorders as a cause of menorrhagia and consequently offer effective disease-specific therapies.
We have previously shown that a single portal vein infusion of a recombinant adeno-associated viral vector (rAAV) expressing canine Factor IX (F.IX) resulted in long-term expression of therapeutic ...levels of F.IX in dogs with severe hemophilia B. We carried out a phase 1/2 dose-escalation clinical study to extend this approach to humans with severe hemophilia B. rAAV-2 vector expressing human F.IX was infused through the hepatic artery into seven subjects. The data show that: (i) vector infusion at doses up to 2 × 1012 vg/kg was not associated with acute or long-lasting toxicity; (ii) therapeutic levels of F.IX were achieved at the highest dose tested; (iii) duration of expression at therapeutic levels was limited to a period of ∼8 weeks; (iv) a gradual decline in F.IX was accompanied by a transient asymptomatic elevation of liver transaminases that resolved without treatment. Further studies suggested that destruction of transduced hepatocytes by cell-mediated immunity targeting antigens of the AAV capsid caused both the decline in F.IX and the transient transaminitis. We conclude that rAAV-2 vectors can transduce human hepatocytes in vivo to result in therapeutically relevant levels of F.IX, but that future studies in humans may require immunomodulation to achieve long-term expression*.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract Antithrombin (AT) deficiency is a high-risk thrombophilia and a rare condition. Despite full anticoagulation during pregnancy and the postpartum period, women with AT deficiency may still be ...vulnerable to developing venous thromboembolism (VTE), including fatal events. There is limited guidance on the management of AT deficiency in pregnancy, including the role of AT concentrates. Following a comprehensive review of the state of the art with respect to recommendations and guidelines, our expert panel in maternal-fetal medicine, hematology and basic science reached consensus on key issues in the recognition and management of AT deficiency in pregnancy. This paper summarizes the state of the art and summarizes what we believe are best practices with special emphasis on a multidisciplinary approach involving obstetrics and hematology in the care of women with AT deficiency.
The risk of venous thromboembolism (VTE) is elevated in the postpartum period. Low-molecular-weight heparin (LMWH) reduces the risk of VTE in many settings but is costly, inconvenient and increases ...bleeding. Randomised controlled trials (RCT) are required to determine if LMWH prophylaxis provides a clinical benefit in high-risk postpartum women. We sought to determine if a placebo-controlled RCT was feasible. We conducted a multi-national, double-blind pilot RCT in "high risk" postpartum women comparing 21 days of prophylactic dose LMWH to identical saline placebo injections. The primary pilot outcome was mean number of recruited women per centre per month. The planned primary outcome for the full trial was symptomatic objectively confirmed VTE or asymptomatic proximal deep-vein thrombosis diagnosed by a screening bilateral leg vein ultrasound at day 21. In six centres, a total of 1,346 potentially eligible women were approached to participate; 968 were ineligible, leaving 378 (31.5%) eligible patients. Of these, only 25 (6.6%) were randomised at a rate of 0.7 per centre per month. The primary reasons for declining participation were to avoid study injections and being too overwhelmed to participate in research. None of the participants had a VTE during follow-up. In conclusion, despite an adequate number of eligible participants, our double-blind RCT design was not feasible due to a very low consent rate. Other experimental approaches may be necessary to generate evidence in this important area of research.
Abstract
Exonic variants present some of the strongest links between genotype and phenotype. However, these variants can have significant inter-individual pathogenicity differences, known as variable ...penetrance. In this study, we propose a model where genetically controlled mRNA splicing modulates the pathogenicity of exonic variants. By first cataloging exonic inclusion from RNA-sequencing data in GTEx V8, we find that pathogenic alleles are depleted on highly included exons. Using a large-scale phased whole genome sequencing data from the TOPMed consortium, we observe that this effect may be driven by common splice-regulatory genetic variants, and that natural selection acts on haplotype configurations that reduce the transcript inclusion of putatively pathogenic variants, especially when limiting to haploinsufficient genes. Finally, we test if this effect may be relevant for autism risk using families from the Simons Simplex Collection, but find that splicing of pathogenic alleles has a penetrance reducing effect here as well. Overall, our results indicate that common splice-regulatory variants may play a role in reducing the damaging effects of rare exonic variants.
In March 2020, there were no treatment options for COVID‐19. Passive immune therapy including anti‐SARS‐CoV‐2 hyperimmune globulin (hIVIG) was a logical candidate for COVID‐19 therapeutic trials, ...given past success treating emerging pathogens with endogenous neutralizing antibodies. We established a plasma collection protocol for persons recovered from COVID‐19. To speed recruitment in the first U.S. hotspot, Seattle, Washington, federal and state public health agencies collaborated with Bloodworks Northwest to collect convalescent plasma (CP) for manufacturing hIVIG. During March–December 2020, we identified and recruited prospective CP donors via letters to persons recovered from COVID‐19 with laboratory‐confirmed SARS‐CoV‐2 infection. Prospective donors were pre‐screened and administered a medical history survey. Anti‐SARS‐CoV‐2 neutralizing antibody (NAb) titers were classified as qualifying (≥1:80) or non‐qualifying (<1:80) for enrollment based on a live virus neutralization assay. Generalized estimating equations were used to identify characteristics of donors associated with qualifying versus nonqualifying NAb titers. Overall, 21,359 letters resulted in 3207 inquiries, 2159 prescreenings with laboratory‐confirmed SARS‐CoV‐2 infection, and 573 donors (27% of all pre‐screenings with confirmed infection) who provided a screening plasma donation. Of 573 donors screened, 254 (44%) provided plasma with qualifying NAb titers, resulting in 1284 units for hIVIG manufacture. In a multivariable model, after adjusting for other factors, time (60 days) from COVID‐19 symptom onset to screening was associated with lower odds of qualifying NAb (adjusted odds ratio = 0.67, 95% CI: 0.48–0.94). The collaboration facilitated a rapid response to develop and provide hIVIG for clinical trials and CP for transfusion. Only 1 in 12 donor inquiries resulted in a qualifying plasma donation. Challenges included recruitment and the relatively low percentage of persons with high NAb titers and limited screening capacity. This resource‐intensive collaboration may not be scalable but informs preparedness and response strategies for plasma collection in future epidemics. Operational readiness plans with templates for screening, consent, and data collection forms are recommended.
Transfusion Medicine in Obstetrics Konkle, Barbara A.; Fogerty, Annemarie E.
Transfusion medicine reviews,
October 2018, 2018-10-00, 20181001, Letnik:
32, Številka:
4
Journal Article
Background/Objective
Coagulation factor V (FV), a multidomain glycoprotein, is an essential cofactor in the blood clotting cascade. FV deficiency is a rare bleeding disorder that results in poor ...clotting after an injury or surgery. The only treatment for the disease is infusions of fresh frozen plasma and blood platelets. Glycosylation affects the biological activity, pharmacokinetics, immunogenicity, and in vivo clearance rate of proteins in the plasma. The glycan profile of FV, as well as how it affects the activity, stability, and immunogenicity, remains unknown.
Methods
In this study, we comprehensively mapped the glycosylation patterns of human plasma‐derived FV by combining multienzyme digestion, hydrophilic interaction chromatography enrichment of glycopeptides, and alternated fragmentation mass spectrometry analysis.
Results/Conclusion
A total of 57 unique N‐glycopeptides and 51 O‐glycopeptides were identified, which were categorized into 40 N‐glycan and 17 O‐glycan compositions. Such glycosylation details are fundamental for future functional studies and therapeutics development. In addition, the established methodology can be readily applied to analyze glycosylation patterns of proteins with more than 2000 amino acids.
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