Chronic interstitial nephritis associated with gold therapy.

A patient suffered chronic interstitial nephritis after receiving large quantities of gold salts for rheumatoid arthritis. Gold deposits were seen with transmission electron microscopy and confirmed by microprobe x-ray analysis both within renal tubular epithelial cells and interstitial macrophages and free within the renal interstitium. Clinical resolution of renal failure followed discontinuation of therapy with gold salts. Probable mechanisms of injury to renal tubular epithelial cells include uptake of gold by tubular epithelial cells and incorporation of gold into mitochondria, with subsequent cellular injury; interstitial deposits probably occur after necrosis of tubular epithelial cells, with release of gold into the interstitium and resultant inflammation. Thus, chronic interstitial nephritis can be added to the patterns of renal injury seen after gold therapy for rheumatoid arthritis.