From what I can tell, there are none of the traditional Skyrim type companions you can hire. And it's too bad, because the game can be quite difficult with arcane fever following you around even when using the high quality health potions.
There are two companions that appear in the main quest, one male and one female. You will get to know both of them as you progress. But they only are with you if you remain on the path to each objective. If you stray off and explore during the main quest, they will not follow, but will meet up later when you get back on track. They will not be with you at all on side quests. You also have the option of romancing either of these companions, and can decide that with your dialog choices. It also appears that you can choose either one to romance regardless of the sex of your character. Although I can't say that for sure, as I did not pursue a same sex relationship. But it certainly seemed like I had that choice.