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Aims The interaction between the R506Q mutation of factor V and the G20210A mutation of prothrombin with oral contraceptives on venous thromboembolism was evaluated.Methods and Results Three hundred and one women of reproductive age who had venous thromboembolism (140 while using oral contraceptives) and 650 healthy women (173 on oral contraceptives at presentation) were examined. Of the patients, 19·3% were carriers of R506Q (two homozygotes) and 9·6% were heterozygous carriers of G20210A; eight patients (2·7%) were heterozygous for both mutations. Among controls, 2·9% were carriers of R506Q, 3·1% of G20210A, while one case was a heterozygous carrier of both mutations. The relative risk (odds ratio) associated with carriership of R506Q or G20210A mutations was 10·3 and 4·7, respectively; it was 45·6 in carriers of both mutations. The odds ratio of using oral contraceptives in the absence of both mutations was 2·4. The odds ratios according to oral contraceptives use and the presence of R506Q or G20210A or both mutations were 41·0, 58·6 and 86·5, respectively. While the odds ratio for R506Q remains elevated (8·9) in non-oral contraceptive users, the odds ratio for G20210A was 2·0 and did not reach statistical significance.Conclusions Our data showed a strong interaction between oral contraceptive use and the presence of either R506Q or G20210A mutations. In non-oral contraceptive users the risk of venous thromboembolism was significantly increased in carriers of R506Q but not in those with the G20210A mutation. [ABSTRACT FROM PUBLISHER]

Background: We reported that roflumilast, a phosphodiesterase 4 inhibitor, given orally at 5 mg/ kg to mice prevented the development of emphysema in a chronic model of cigarette smoke exposure, while at 1 mg/kg was ineffective. Here we investigated the effects of roflumilast on the volume density (VV) of the inflammatory cells present in the lungs after chronic cigarette smoke exposure. Methods: Slides were obtained from blocks of the previous study and VV was assessed immunohistochemically and by point counting using a grid with 48 points, a 20x objective and a computer screen for a final magnification of 580x. Neutrophils were marked with myeloperoxidase antibody, macrophages with Mac-3, dendritic cells with fascin, B-lymphocytes with B220, CD4+ T-cells with CD4+ antibody, and CD8+T-cells with CD8-α. The significance of the differences was calculated using one-way analysis of variance. Results: Chronic smoke exposure increased neutrophil VV by 97%, macrophage by 107%, dendritic cell by 217%, B-lymphocyte by 436%, CD4+ by 524%, and CD8+ by 417%. The higher dose of roflumilast prevented the increase in neutrophil VV by 78%, macrophage by 82%, dendritic cell by 48%, B-lymphocyte by 100%, CD4+ by 98% and CD8+ VV by 88%. The lower dose of roflumilast did not prevent the increase in neutrophil, macrophage and B-cell VV but prevented dendritic cells by 42%, CD4+ by 55%, and CD8+ by 91%. Conclusion: These results indicate (i) chronic exposure to cigarette smoke in mice results in a significant recruitment into the lung of inflammatory cells of both the innate and adaptive immune system; (ii) roflumilast at the higher dose exerts a protective effect against the recruitment of all these cells and at the lower dose against the recruitment of dendritic cells and T-lymphocytes; (iii) these findings underline the role of innate immunity in the development of pulmonary emphysema and (iiii) support previous results indicating that the inflammatory cells of the adaptive immune system do not play a central role in the development of cigarette smoke induced emphysema in mice. [ABSTRACT FROM AUTHOR]

Background: Coagulation factor V (FV) deficiency is a rare bleeding disorder that is usually managed with fresh-frozen plasma. Patients with nonsense mutations may respond to treatment with readthrough agents., Objectives: To investigate whether the F5 p.Arg1161Ter mutation, causing severe FV deficiency in several patients, would be amenable to readthrough therapy., Methods: F5 mRNA and protein expression were evaluated in a F5 p.Arg1161Ter-homozygous patient. Five readthrough agents with different mechanisms of action, i.e. G418, ELX-02, PTC-124, 2,6-diaminopurine (2,6-DAP), and Amlexanox, were tested in in vitro and ex vivo models of the mutation., Results: The F5 p.Arg1161Ter-homozygous patient showed residual F5 mRNA and functional platelet FV, indicating detectable levels of natural readthrough. COS-1 cells transfected with the FV-Arg1161Ter cDNA expressed 0.7% FV activity compared to wild-type. Treatment with 0-500 μM G418, ELX-02, and 2,6-DAP dose-dependently increased FV activity up to 7.0-fold, 3.1-fold, and 10.8-fold, respectively, whereas PTC-124 and Amlexanox (alone or in combination) were ineffective. These findings were confirmed by thrombin generation assays in FV-depleted plasma reconstituted with conditioned media of treated cells. All compounds except ELX-02 showed some degree of cytotoxicity. Ex vivo differentiated megakaryocytes of the F5 p.Arg1161Ter-homozygous patient, which were negative at FV immunostaining, turned positive after treatment with all 5 readthrough agents. Notably, they were also able to internalize mutant FV rescued with G418 or 2,6-DAP, which would be required to maintain the crucial platelet FV pool in vivo., Conclusion: These findings provide in vitro and ex vivo proof-of-principle for readthrough-mediated rescue of the F5 p.Arg1161Ter mutation., Competing Interests: Declaration of competing interests T.M.H. is cofounder and shareholder of Coagulation Profile BV as well as coinventor on the thermostable inhibitor of contact activation patent WO2013028069A1. The other authors declare no conflicts of interest., (Copyright © 2023 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)

Whole-exome sequencing (WES) in families with an unexplained tendency for venous thromboembolism (VTE) may favor detection of low-frequency variants in genes with known contribution to hemostasis or associated with VTE-related phenotypes. WES analysis in six family members, three of whom affected by documented VTE, filtered for MAF < 0.04 in 192 candidate genes, revealed 22 heterozygous (16 missense and six synonymous) variants in patients. Functional prediction by multi-component bioinformatics tools, implemented by a database/literature search, including ClinVar annotation and QTL analysis, prioritized 12 missense variants, three of which ( CRP Leu61Pro, F2 Asn514Lys and NQO1 Arg139Trp) were present in all patients, and the frequent functional variants FGB Arg478Lys and IL1A Ala114Ser. Combinations of prioritized variants in each patient were used to infer functional protein interactions. Different interaction patterns, supported by high-quality evidence, included eight proteins intertwined in the "acute phase" (CRP, F2, SERPINA1 and IL1A) and/or in the "fibrinogen complex" (CRP, F2, PLAT, THBS1, VWF and FGB) significantly enriched terms. In a wide group of candidate genes, this approach highlighted six low-frequency variants ( CRP Leu61Pro, F2 Asn514Lys, SERPINA1 Arg63Cys, THBS1 Asp901Glu, VWF Arg1399His and PLAT Arg164Trp), five of which were top ranked for predicted deleteriousness, which in different combinations may contribute to disease susceptibility in members of this family.

Introduction: Gene variation in receptors for circulating factor VIII (FVIII) is candidate to explain the large inter-patient variability of infused FVIII pharmacokinetics (PK) in haemophilia A (HA)., Aim: To compare in an Italian HA cohort (n = 26) the influence on FVIII PK of genetic components in four von Willebrand factor (VWF)/FVIII receptors., Methods: Genotypes of low-density lipoprotein receptor (LDLR), asialoglycoprotein receptor minor subunit (ASGR2), family 4 member M (CLEC4M), stabilin2 (STAB2) and ABO blood-group, and VWF:Ag levels were included as independent variables in linear regression analyses of two-compartment model (TCM) - standard half-life (SHL) FVIII PK parameters., Results: In the initial FVIII distribution phase, the STAB2 rs4981022 AA, ASGR2 rs2289645 TT and LDLR rs688 TT genotypes may contribute to increase C max , and prolong or shorten AlphaHL. In the elimination phase, a shorter BetaHL was associated with the CLEC4M rs868875 GG (beta-coefficient .366, p = .025) and ASGR2 rs2289645 TC (beta-coefficient .456, p = .006) genotypes, which also showed shorter mean residence time (MRT) than TT genotypes (p = .021). The alpha and beta phase effects were independent of ABO and VWF:Ag levels at baseline. The association of the LDLR rs2228671 genotypes with clearance was independent of ABO (beta-coefficient -.363, p = .035) but not of other receptors or VWF:Ag, which may point out multiple and competing interactions., Conclusions: With the limitation of the small number of HA patients, these observations highlight multiple genetic components acting in distinct phases of FVIII PK and contributing to explain FVIII PK variability. This analysis provides candidates for genotype-based, individual tailoring of FVIII substitutive treatment., (© 2022 John Wiley & Sons Ltd.)

Background: The index case is a 21-year-old Italian woman with a mild hemorrhagic syndrome and von Willebrand factor antigen (VWF:Ag) = 34.3 U/dl, VWF recombinant glycoprotein Ib (VWF:GpIbR) = 32.8 U/dl, and factor VIII (FVIII) = 55.3 IU/dl., Aims: The aim of this study is to characterize from a genetic and biochemical standpoint this low VWF phenotype., Methods: Coagulation and biochemical methods were used to study the structural and functional pattern of VWF multimers in the index case's plasma. Recombinant wild-type and p.P1127S VWF variants were produced using human embryonic kidney (HEK)-293 cells. In addition, genetic screening was carried out to detect single nucleotide variants of some scavenger VWF/FVIII receptor genes such as CLEC4M, STAB2, and ASGR2., Results: Genetic investigation revealed that the index case inherited from her mother the heterozygous missense mutation c.3379C > T (VWF exon 25), causing the p.P1127S substitution in the VWF D'D3 domain. The index case was also homozygous for the scavenger receptor ASGR2 c.-95 CC-genotype. Desmopressin normalized the VWF level of the patient, although its clearance was faster (t 1/2  = 6.7 h) than in normal subjects (t 1/2  = 12 ± 0.7 h). FVIII-VWF interaction, A Disintegrin And Metalloprotease with ThromboSpondin type 1 motif-13 levels, ristocetin-induced-platelet-aggregation, and VWF multimeric pattern were normal. The p.P1127S variant was normally synthesized and secreted by HEK-293 cells, and molecular modeling predicts a conformational change showing higher affinity for the macrophagic scavenger receptor lipoprotein receptor-related protein 1 (LRP1), as also experimentally verified., Conclusions: The p.P1127S variant may cause a low VWF phenotype, stemming from an increased VWF affinity for the scavenger receptor LRP1 and, consequently, an accelerated clearance of VWF., (© 2022 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)

Background: The asialoglycoprotein receptor (ASGPR) binds with high affinity factor VIII (FVIII) through its N -linked oligosaccharides. However, its contribution to the wide inter-individual variation of infused FVIII pharmacokinetics (PK) in hemophilia A (HA) is unknown., Objective: To investigate the variability in FVIII PK outcomes in relation to genetic variation in the ASGR2, encoding the ASGPR2 subunit., Methods: Thirty-two HA patients with FVIII:C ≤2 IU/dL underwent 66 single-dose FVIII PK studies. PK parameters were evaluated in relation to ASGR2 5' untranslated region (5'UTR) polymorphisms, which were investigated by recombinant and white blood cell reverse transcription-polymerase chain reaction approaches., Results: The 5'UTR polymorphisms determine a frequent and conserved haplotype (HT1) in a regulatory region. The HT1 homozygotes may differ in the amounts of alternatively spliced mRNA transcripts and thus ASGPR2 isoforms. Compared with the other ASGR2 genotypes, the c.-95TT homozygotes ( n  = 9), showed threefold longer Alpha HL (3.60 hours, 95% confidence interval: 1.44-5.76, p  = 0.006), and the c.-95TC heterozygotes ( n  = 17) showed 25% shorter mean residence time (MRT; 18.5 hours, 15.0-22.0, p  = 0.038) and 32% shorter Beta HL (13.5 hours, 10.9-16.0, p  = 0.016). These differences were confirmed in patients ( n  = 27) undergoing PK studies ( n  = 54) with full-length FVIII only. In different linear regression models, the contribution of the ASGR2 genotypes remained significant after adjustment by ABO genotypes and von Willebrand factor (VWF) antigen levels, and explained 14% (MRT), 15 to 18% (Beta HL), and 22% (Alpha HL) of parameter variability., Conclusion: Infused FVIII distribution was modulated by frequent ASGR2 genotypes, independently from and together with ABO and VWF antigen levels, which has potential implications for genetically tailored substitutive treatment in HA., Competing Interests: M. Morfini reports personal fees from Kedrion, grants from Pfizer, personal fees from Novo Nordisk, personal fees from Sobi, personal fees from Bayer, personal fees from Bioverativ, personal fees from Octapharma, personal fees from CSL Behring, outside the submitted work. D. Balestra reports grants and personal fees from Bayer. A. Branchini reports grants and personal fees from Pfizer, grants from Bayer, grants and nonfinancial support from Grifols, outside the submitted work. G. Castaman reports personal fees from Roche, personal fees from Bayer, personal fees from Shire, grants and personal fees from CSL Behring, grants and personal fees from Sobi, personal fees from Uniqure, grants from Pfizer, personal fees from Kedrion, personal fees from Novo Nordisk, personal fees from Werfen, outside the submitted work. F. Bernardi reports grants from Bayer, during the conduct of the study; grants from Pfizer, outside the submitted work. The other authors state that they have no conflict of interest., (Thieme. All rights reserved.)

The C-type lectin CLEC4M binds and internalizes factor VIII (FVIII). Common CLEC4M variants have been associated with FVIII pharmacokinetic (PK) profiles in hemophilia A (HA) patients. The two-compartment PK analysis of plasma-derived (pd-) and full length recombinant FVIII concentrates was conducted in twenty-six patients (FVIII:C ≤ 2 IU/dL). F8 , ABO blood-groups, and the CLEC4M rs868875A/G polymorphism were genotyped. CLEC4M genotype groups differed for the elimination rate constant K 1-0 ( p < 0.001), half-life (K 1-0 HL), and the Beta rate constant. Patients treated with pd-FVIII also differed in the Alpha phase. In linear regression models, the contribution of the CLEC4M genotypes to FVIII PK parameters remained significant after correction for ABO , age, and VWF antigen levels at PK. Combined CLEC4M rs868875A/G and ABO genotypes displayed significant interaction (K 1-0, p = 0.014). Compared to other combined genotypes, the G-carriers/O genotypes showed half-reduced K 1-0 HL ( p = 0.008), and faster FVIII clearance (mean 7.1 ± 2.2 mL/h/kg SE) than in the G-carriers/non-O (mean 2.4 ± 0.3 mL/h/kg SE), ( p = 0.038). Comparison in HA patients recruited in several countries suggests that CLEC4M genotypes coherently influence infused FVIII half-life and clearance. Our analysis supports substantially faster FVIII decay associated with the rs868875 G-carrier/ ABO O genotypes, which has potential implications for genetically tailored substitutive HA treatment.