Thromb Haemost 2022; 122(05): 715-725
DOI: 10.1055/a-1591-7869
Coagulation and Fibrinolysis

The Asialoglycoprotein Receptor Minor Subunit Gene Contributes to Pharmacokinetics of Factor VIII Concentrates in Hemophilia A

Barbara Lunghi
1   Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
,
Massimo Morfini
2   Italian Association Hemophilia Centers (AICE), Naples, Italy
,
Nicola Martinelli
3   Department of Medicine, University of Verona, Verona, Italy
,
Dario Balestra
1   Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
,
Silvia Linari
4   Department of Oncology, Center for Bleeding Disorders, Careggi University Hospital, Florence, Italy
,
Sabrina Frusconi
5   Genetic Diagnostics Unit, Laboratory Department, Careggi University Hospital, Florence, Italy
,
1   Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
,
Christian F. Cervellera
1   Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
,
Giovanna Marchetti
6   Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
,
Giancarlo Castaman
4   Department of Oncology, Center for Bleeding Disorders, Careggi University Hospital, Florence, Italy
,
Francesco Bernardi
1   Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
› Author Affiliations
Funding This work was supported by the Bayer Hemophilia Awards Program, the Italian Medicines Agency (AIFA, MRAR08T001), and the University of Ferrara.

Abstract

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.

Author Contributions

F.B. and M.M. designed the research. S.L., G.C., and M.M. recruited patients. M.M. performed the PK analysis. S.F. performed F8 sequencing and genotyping for F8 IVS22 inversion. B.L. genotyped ABO blood group and ASGR2 polymorphisms. D.B. performed bioinformatics analysis of the ASGR2 sequences, designed and analyzed recombinant expression experiments. C.F.C. performed expression experiments. B.L., F.B., A.B., G.M., N.M., and M.M. analyzed and interpreted data. N.M., B.L. and M.M. performed statistical analysis. B.L., F.B., N.M., G.M., A.B., and M.M. contributed to data discussion. B.L., F.B., N.M., and M.M. wrote the manuscript.


Supplementary Material



Publication History

Received: 13 May 2021

Accepted: 17 August 2021

Accepted Manuscript online:
18 August 2021

Article published online:
12 October 2021

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