The density shift and broadening of the transition lines of antiprotonic he
lium have been evaluated in the impact approximation using an interatomic p
otential calculated ab initio with the symmetry-adapted perturbation theory
. The results help to remove an uncertainty of up to 10 ppm in the laser sp
ectroscopy data on antiprotonic helium and are of importance in experimenta
l tests of bound state QED and CPT invariance.