Gold nephropathy due to auranofin obscured by tolmetin pseudoproteinuria

A 63-year-old woman with seropositive rheumatoid arthritis was successfully treated with auranofin for 12 months. Heavy proteinuria then developed and the drug was stopped. However, the proteinuria apparently became worse. This was later recognised to be a spurious effect due to the introduction of tolmetin. Renal biopsy showed a type I membranous glomerulonephropathy.