Might Oort cloud comets be exchanged between solar systems? Considering their distance from their parent stars, might Oort cloud object such as comets be exchanged between passing stars (assuming that other stars have similar Oort clouds)?
You can exclude the 'considering the distance' piece - of course Oort Cloud objects could transfer between different gravitational fields.

However what is it you think will make this transfer? Without some sort of gravitational impetus why would one of these objects leave the solar system? And if you do manage to slingshot one out of the solar system at a high enough speed to exit the Sun's gravity, remember that most directions end up very far away from any other solar systems.

Tl;Dr sure, but not very likely