aHA mice are protected against joint bleeding after injury. (A) Joint bleeding after knee injury in WT C57Bl/6J mice (n = 9-12; filled squares) that received different doses of the inhibitory anti-FVIII antibody (0-1 mg/kg; GMA-8015). Bleeding was determined by measuring Hct at day 2 (D2) postinjury. D2 Hct values for injured FVIII^−/− BALB/c mice (n = 9; filled circles) are shown to illustrate typical joint bleeding in congenital HA mice. Hct of WT C57Bl/6J (open square) or FVIII^−/− BALB/c (open circle) mice at baseline (BL; no injury) are provided as a no-bleeding reference (n = 8-10). (B) Weight-bearing ratio of left (uninjured) vs right (injured) hind paw at BL (n = 5) and at D2 after right knee injury in WT C57Bl/6J (n = 6) or FVIII^−/− BALB/c (n = 4) mice at the indicated doses (mg/kg) of anti-FVIII antibody. Kruskal-Wallis test followed by Dunn’s post hoc multiple comparison test was used to compare experimental mice with WT mice at baseline. BL indicates baseline without knee injury; injured indicates right knee injury. **P < .01, ****P < .0001. ns, not significant.