Patient preference and ease of use for different coagulation factor VIII reconstitution device scenarios: a cross-sectional survey in five European countries

The epitopes of four monoclonal antibodies against coagulation Factor VIII were mapped with the use of recombinant DNA techniques. Full-length Factor VIII cDNA and parts thereof were inserted into the vector pSP64, permitting transcription in vitro with the use of a promoter specific for SP6 RNA polymerase. Factor VIII DNA inserts were truncated from their 3′-ends by selective restriction-enzyme digestion and used as templates for ‘run-off’ mRNA synthesis. Translation in vitro with rabbit reticulocyte lysate provided defined radiolabelled Factor VIII fragments for immunoprecipitation studies. Two antibodies are shown to be directed against epitopes on the 90 kDa chain of Factor VIII, between residues 712 and 741. The 80 kDa chain appeared to contain the epitopes of the other two antibodies, within the sequences 1649-1778 and 1779-1840 respectively. The effect of antibody binding to these sequences was evaluated at two distinct levels within the coagulation cascade. Both Factor VIII procoagulant activity and Factor VIII cofactor function in Factor Xa generation were neutralized upon binding to the region 1779-1840. The antibodies recognizing the region 713-740 or 1649-1778, though interfering with Factor VIII procoagulant activity, did not inhibit in Factor Xa generation. These findings demonstrate that antibodies that virtually inhibit Factor VIII in coagulation in vitro are not necessarily directed against epitopes involved in Factor VIII cofactor function. Inhibition of procoagulant activity rather than of cofactor function itself may be explained by interference in proteolytic activation of Factor VIII. This hypothesis is in agreement with the localization of the epitopes in the proximity of thrombin-cleavage or Factor Xa-cleavage sites.

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Characterization and visualization of murine coagulation factor VIII-producing cells in vivo

Scientific Reports ◽

10.1038/s41598-021-94307-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Morisada Hayakawa ◽

Asuka Sakata ◽

Hiroko Hayakawa ◽

Hikari Matsumoto ◽

Takafumi Hiramoto ◽

...

Keyword(s):

Endothelial Cells ◽

Factor Viii ◽

Fluorescent Protein ◽

Coagulation Factor ◽

Coagulation Factors ◽

Genetically Engineered ◽

Coagulation Factor Viii ◽

Liver Sinusoidal Endothelial Cells ◽

Genetically Engineered Mice

AbstractCoagulation factors are produced from hepatocytes, whereas production of coagulation factor VIII (FVIII) from primary tissues and cell species is still controversial. Here, we tried to characterize primary FVIII-producing organ and cell species using genetically engineered mice, in which enhanced green fluorescent protein (EGFP) was expressed instead of the F8 gene. EGFP-positive FVIII-producing cells existed only in thin sinusoidal layer of the liver and characterized as CD31high, CD146high, and lymphatic vascular endothelial hyaluronan receptor 1 (Lyve1)+. EGFP-positive cells can be clearly distinguished from lymphatic endothelial cells in the expression profile of the podoplanin− and C-type lectin-like receptor-2 (CLEC-2)+. In embryogenesis, EGFP-positive cells began to emerge at E14.5 and subsequently increased according to liver maturation. Furthermore, plasma FVIII could be abolished by crossing F8 conditional deficient mice with Lyve1-Cre mice. In conclusion, in mice, FVIII is only produced from endothelial cells exhibiting CD31high, CD146high, Lyve1+, CLEC-2+, and podoplanin− in liver sinusoidal endothelial cells.

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Commentary on “Development of a novel fully functional coagulation factor VIII with reduced immunogenicity utilizing an in silico prediction and deimmunization approach” ‐ Will we ever be able to avoid inhibitor formation in hemophilia A?

Journal of Thrombosis and Haemostasis ◽

10.1111/jth.15404 ◽

2021 ◽

Vol 19 (9) ◽

pp. 2125-2126

Author(s):

Daniel P. Hart

Keyword(s):

Factor Viii ◽

In Silico ◽

Hemophilia A ◽

Coagulation Factor ◽

Coagulation Factor Viii ◽

In Silico Prediction

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Being useful among persons aged over 65: social representations from a cross-sectional European study

Aging Clinical and Experimental Research ◽

10.1007/s40520-020-01767-x ◽

2021 ◽

Author(s):

Paul de Boissieu ◽

Serge Guerin ◽

Véronique Suissa ◽

Fiona Ecarnot ◽

Aude Letty ◽

...

Keyword(s):

Social Representations ◽

Oldest Old ◽

Educational Status ◽

Well Being ◽

European Countries ◽

City Size ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Socially Isolated ◽

Quota Sampling

Abstract Background There is a compelling need to prepare our societies and healthcare systems to deal with the oncoming wave of population ageing. The majority of older persons maintain a desire to be valued and useful members of society and of their social networks. Aims We sought to investigate the perception of usefulness among persons aged 65 years and over in four European countries. Methods We performed a cross-sectional survey with a representative sample of individuals aged 65 years or older from the population of retired persons (including recently retired persons and oldest-old individuals) from 4 European countries selected using quota sampling. In February 2016, an internet questionnaire was sent to all selected individuals. The characteristics used for the quota sampling method were sex, age, socio-professional category, region, city size, number of persons in household, autonomy, marital status, place of residence, income and educational status. The questionnaire contained 57 questions. Sociodemographic characteristics were recorded. Responses were analysed with principal components analysis (PCA). Results A total of 4025 persons participated; 51% were males, and 70% were aged 65–75 years. PCA identified six classes of individuals, of which two classes (Classes 2 and 3) were characterized by more socially isolated individuals with little or no sense of usefulness, low self-esteem and a poor sense of well-being. These two classes accounted for almost 20% of the population. Younger and more autonomous classes reported a more salient sense of usefulness. Conclusions The loss of the sense of usefulness is associated with dissatisfaction with life and a loss of pleasure, and persons with profiles corresponding to Classes 2 and 3 should, therefore, be targeted for interventions aimed at restoring social links.

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