[Hypocomplementemic tubulointerstitial nephritis in IgG4-related disease].

A novel lymphoproliferative disorder producing plasma cell expansion in the affected organ with fibrotic or sclerosing changes, known as ''IgG4-related disease'', was defined in Japan by Umehara's group in 2010. We present the first case reported in Italy. In 2007, a 63-year-old man presented with epigastric pain and elevated serum lipase levels.