Combined treatment with cyclophosphamide and prednisolone can induce remission of nephrotic syndrome in a patient with renal amyloidosis, associated with rheumatoid arthritis.

A 67-year-old woman, who had been diagnosed with classical rheumatoid arthritis (RA), was admitted to our hospital because of massive proteinuria. Biopsy of the kidney revealed deposition of amyloid fibrils in the subepithelial and subendothelial spaces of the glomerular capillary walls. Though the treatment with prednisolone and dipyridamole against nephrotic syndrome and amyloidosis due to RA was not effective, cyclophosphamide, which was added after tapering of prednisolone, was able to induce remission of nephrotic syndrome after two years. The levels of CRP and serum amyloid A protein (SAA) returned to within the normal limits. As the impairment of renal function is thought to be due to deposition of amyloid supplied from the precursors of amyloid fibrils filtered from the general circulation in RA patients, remission of nephrotic syndrome might result from the suppression of production of SAA or removal of amyloid fibrils. Cyclophosphamide, which has the potential both to suppress disease activity in RA and to produce degradation of amyloid fibrils in glomeruli, may be useful against renal or systemic amyloidosis complicated by RA.