[Minimal change nephrotic syndrome developing in a rheumatoid arthritis patient under etanercept treatment].

A 67-year-old female patient with rheumatoid arthritis (RA) developed minimal change nephrotic syndrome (MCNS) while under treatment with etanercept (ETN). Histopathological examination of renal biopsy specimens showed minimal-change nephropathy. Almost complete resolution of the MCNS was achieved by discontinuation of ETN and initiation of steroid therapy. There have been no reports from Japan of the occurrence of MCNS caused by ETN administration in RA patients, and only very few cases have been reported from around the world. Therefore, this case was considered to be very uncommon and worthy of reporting, and herein is a report of our patient.