Interstitial and glomerular renal involvement in sarcoidosis.

Sarcoidosis is a systemic disease characterized by chronic granulomatous inflammation. Chronic kidney disease (CKD) was reported in less than 1% of patients of sarcoidosis. The prevalence of tubulo-interstitial nephritis (TIN) in sarcoidosis varies from 7 to 27%. In this retrospective study, we present 15 patients with interstitial or glomerular renal involvement secondary to sarcoidosis diagnosed in our center from 1975 to 2006. Patients were 13 (96.6%) females and two males with a mean age of 56.5 years. CKD was present in 14(93.3%) patients, proteinuria in 13(96.6%), and nephrotic syndrome in one. Pulmonary involvement was present in 10 (66.6%) patients. Renal biopsy performed in 12 (80%) patients revealed TIN lesions in 10 (66.6%) patients, extracapillary proliferative glomerulonephritis (GN) in one, and membranous GN type 2 in another. Corticosteroid therapy using prednisolone 0.5 to 1 mg/kg per day was used in 12(80%) patients. Ten (66.6%) patients were followed up for a mean period of 25 months (ranged from 2 to 48 months). The outcome was favorable with 7 (46.6%) patients improved their renal function, 6 (40%) remained with a moderate CKD, one normalized his renal function, and one died suddenly after 2 months of initiating the treatment corticosteroids. We conclude that corticosteroid treatment is efficient in TIN and variably efficient in GN. Patients with sarcoidosis may cause advanced renal failure, which renders it a serious nephrological condition.