MSBase Study Group MSBase Study Group Brown Brown JWL JWL Coles Coles A A Horakova Horakova D D Havrdova Havrdova E E Izquierdo Izquierdo G G Prat Prat A A Association of initial disease-modifying therapy with later conversion to secondary progressive multiple sclerosis Association of initial disease-modifying therapy with later conversion to secondary progressive multiple sclerosis JAMA JAMA 2019 2019 321 321 2 2 175 175 187 187 10.1001/jama.2018.20588 10.1001/jama.2018.20588 30644981 30644981. Here, PPAT is linked to secondary progressive multiple sclerosis.