What is your approach to the treatment of fibrillary glomerulonephritis coexistent with monoclonal gammopathy?

Fibrillary glomerulonephritis was initially considered to be an idiopathic disorder, but it is now known to be secondary to malignancy, monoclonal gammopathy, infection (such as HCV), or autoimmune disease in up to 50% of patients.

This is a rare disease, and few practitioners outside of glomerulonephritis centers have much experience with it. I personally have only seen 1 case in my career. In the largest published series of 186 patients with either fibrillary or the closely-related though even rarer immunotactoid glomerulopathy, optimal treatment was not determined, with many progressing to ESRD requiring dialysis or transplantation (Pronovost et al., PMID 8671905). Thirty years later, there are still no randomized controlled trials to gu...