@dragonflylady It would be great if your brother can get in to see a renal dietician, who can help him set up a sound diet plan. Keeping close track of his kidney function is critical, and coordination/communication between everyone on his medical team is important. And your brother is part of that team, don't forget!

If his doctor can tell him what autoimmune condition he feels is the cause, that should be noted, also. Has he found out what that might be? There are several autoimmune conditions that can be behind the glomerulonephritis.
Ginger