title: Granulomatous interstitial nephritis and Crohn's disease.
abstract: Granulomatous interstitial nephritis has been observed in <1% of native renal biopsies. Here, we describe two patients with granulomatous interstitial nephritis in relation to Crohn's disease. Circulating helper and cytotoxic T cells were highly activated, and both cell types predominated in the interstitial infiltrate, indicating a cellular autoimmune response. After immunosuppressive treatment, renal function either improved or stabilized in both patients. In conclusion, granulomatous interstitial nephritis is a genuine extraintestinal manifestation of Crohn's disease, the treatment of which should include immunosuppressive agents.
authors.affiliation: Department of Internal Medicine, Division of Nephrology and Clinical Immunology , Maastricht University Medical Centre, Maastricht.
authors.forename: Sjoerd A M E G
authors.initials: SA
authors.lastname: Timmermans
authors.affiliation: Department of Internal Medicine, Division of Nephrology and Clinical Immunology , Maastricht University Medical Centre, Maastricht.
authors.forename: Maarten H L
authors.initials: MH
authors.lastname: Christiaans
authors.affiliation: Department of Pathology , Maastricht University Medical Centre , Maastricht , The Netherlands.
authors.forename: Myrurgia A
authors.initials: MA
authors.lastname: Abdul-Hamid
authors.affiliation: Department of Internal Medicine , Zuyderland Hospital , Sittard , The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Stifft
authors.affiliation: Central Diagnostic Laboratory , Maastricht University Medical Centre , Maastricht , The Netherlands.
authors.forename: Jan G M C
authors.initials: JG
authors.lastname: Damoiseaux
authors.affiliation: Department of Internal Medicine, Division of Nephrology and Clinical Immunology , Maastricht University Medical Centre, Maastricht.
authors.forename: Pieter
authors.initials: P
authors.lastname: van Paassen
keywords: Crohn's disease; T cells; calcineurin inhibitors; granulomatous interstitial nephritis; inflammatory bowel disease