Immunoglobulin G4 related tubulointerstitial nephritis.

Tubulointerstitial nephritis is an uncommon manifestation of IgG4 related disease. A case of tubulointerstitial nephritis with special features including isolated renal involvement in this multisystem disorder and the absence of response to steroid therapy in a young male is reported here. There was no nephromegaly, eosinophilia or other organ involvement. The importance of early detection and treatment for preservation of kidney function is highlighted.