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

AIMS

To identify any clinical or biochemical parameters which determine prognostic outcome in isolated sarcoid granulomatous interstitial nephritis presenting with renal failure.

METHODS

A review of five cases of renal failure due to isolated sarcoid granulomatous interstitial nephritis, which presented to Hope Hospital over the 7-year period 1994 to 2000. Follow-up averaged 35 months with a range of 11 to 73 months.

RESULTS

Only one patient had an elevated serum ACE at presentation, reflecting the suboptimal sensitivity of this test as a marker in sarcoidosis and the limited extent of disease in these patients. Four of the five cases had a marked improvement in creatinine clearance within 10 days of starting oral prednisolone. Two patients required acute hemodialysis on presentation. Their renal failure responded to treatment with steroids, enabling withdrawal of dialysis within 10 days. All patients remained dialysis-independent although serum creatinine levels rose during follow-up. One patient experienced a relapse that responded 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 although prolonged treatment may be needed to prevent a relapse.