Isolated sarcoid granulomatous interstitial nephritis: review of five cases at one center

Aims: To identify any clinical or biochemical parameters which determine pr ognostic outcome in isolated sarcoid granulomatous interstitial nephritis p resenting with renal failure. Methods: A review of five cases of renal fail ure due to isolated sarcoid granulomatous interstitial nephritis, which pre sented to Hope Hospital over the 7-year period 1994 to 2000. Follow-up aver aged 35 months with a range of 11 to 73 months. Results: Only one patient h ad an elevated serum ACE at presentation, reflecting the suboptimal sensiti vity of this test as a marker in sarcoidosis and the limited extent of dise ase in these patients. Four of the five cases had a marked improvement in c reatinine clearance within 10 days of starting oral prednisolone. Two patie nts required acute hemodialysis on presentation. Their renal failure respon ded to treatment with steroids, enabling withdrawal of dialysis within 10 d ays. All patients remained dialysis-independent although serum creatinine l evels rose during follow-up. One patient experienced a relapse that respond ed to an increased dose of steroid. Conclusions: Serum ACE is not reliable in the diagnosis of renal failure due to sarcoid interstitial nephritis and the diagnosis can only be made on renal biopsy. First-line treatment with oral prednisolone results in a rapid improvement in creatinine clearance al though prolonged treatment may be needed to prevent a relapse.