UserID to associate to devices in Cisco Prime Infrastructure?

Greetings all.

Just wondering if anyone has any success in getting userID fields in the client device pages in Prime Infrastructure filled without Cisco ISE?

We just purchased ISE but don't have it implemented yet. I'd like to get our 3rd party NAC userID information into Prime in the meantime if at all possible. I've looked at the Prime APIs and don't see any way to do it and I don't recall seeing anything in the GUI to set up anything other than ISE. Our current NAC does have the capability of doing Identity Publishing to other systems (I think I can even do a syslog format) but, of course, there has to be a way to ingest that on Prime for it to work.

Thanks!