deq = {pr[x] + a y'[x] + b pr'[x] - c pr''[x] == 0,
e pt[x] + e2 pr'[x] + l pt'[x] + b2 pr[x]/x - dd pt''[x] == 0,
v0 pr'[x] + v0 pr[x]/x - dd y'[x]/x - dd y''[x] == 0, y[L] == y0,
pt[L] == pt0, pr[L] == pr0, y'[L] == v0 pr[L]/dd,
pr'[L] == (pr[L] + v0 y[L])/(2 dd),
pt'[L] == v0 (b2 pr[L] + e pt[L])/(2 dd)} /.
Thread[Rule[{a, b, c, e, e2, l, b2, dd, L, pt0, pr0, v0},
 ConstantArray[1, 12]]];

DSolve[deq, {pr, pt, y}, x]