ΔE 15.5, loose: different enough that you should pick on purpose. Quinacridone Crimson is more saturated, warmer than Blood Thorn.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Quinacridone Crimson is more saturated, warmer than Blood Thorn.
The same difference applies the other way round: Blood Thorn is more muted, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Blood Thorn on the colour wheel See Quinacridone Crimson on the colour wheel
All matches: Blood Thorn equivalents · Quinacridone Crimson equivalents