Keep looking at kidney resources but also see if there are other diseases that use Prednisone for treatment. We have a neighbor who has a bunch of conditions. She was taken to the hospital for hallucinations related to Prednisone last week. They were giving her Prednisone for pulmonary and lung issues... I don't know what.
I know all steriods get used for arthritis including Prednisone, Have a look at http://drugs.emedtv.com/prednisone/prednisone-uses.html
for a more complete list. If you look for support groups on these diseases, you might find someone who has dropped Prednisone... perhaps even another lupus patient.