Abstract
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.