Renal Sarcoidosis

Abstract

We conducted the current study to investigate the clinical, laboratory, and histologic features at presentation and the outcome of renal sarcoidosis (RS). Exhaustive retrospective data were collected by the French Sarcoidosis Group. Forty-seven adult patients were assessed (30 male/17 female, M/F ratio: 1.76). Median estimated glomerular filtration rate (eGFR) was 20.5 mL/min per 1.73 m(2) (range, 4-93 mL/min per 1.73 m(2)). Moderate proteinuria was found in 31 (66%) patients (median, 0.7 g/24 h; range, 0-2.7 g/24 h), microscopic hematuria in 11 (21.7%) patients, aseptic leukocyturia in 13 (28.7%) patients. Fifteen of 47 (32%) patients had hypercalcemia (>2.75 mmol/L). Eleven of the 22 (50%) patients diagnosed between June and September had hypercalcemia compared with only 4 of the 25 (16%) cases diagnosed during the other months (p < 0.001). Thirty-seven patients presented with noncaseating granulomatous interstitial nephritis (GIN), and 10 with interstitial nephritis without granulomas. Apart from hypercalcemia, the clinical phenotype was also remarkable for the high frequency of fever at presentation. All patients initially received prednisone (median duration, 18 mo), 10 received intravenous pulse methylprednisolone. eGFR increased from 20 +/- 19 to 44 +/- 24.7 mL/min per 1.73 m(2) at 1 month (p < 0.001, n = 38), to 47 +/- 19.9 mL/min per 1.73 m(2) at 1 year (p < 0.001, n = 46), to 49.13 +/- 25 mL/min per 1.73 m(2) at last follow-up (p < 0.001, n = 47). A complete response to therapy at 1 year and at last follow-up was strongly correlated with complete response at 1 month (p < 0.01). Renal function improvement was inversely related to initial histologic fibrosis score. A complete response to therapy at 1 year was strongly correlated with hypercalcemia at presentation (p = 0.003). Relapses were purely renal (n = 3) and purely extrarenal (n = 10) or both (n = 4), often a long time after presentation, with in some cases severe cardiac or central nervous system involvement. We conclude that hypercalcemia and fever at presentation are often associated with RS; RS is most often and permanently responsive to corticosteroid treatment, but some degree of persistent renal failure is highly frequent and its degree of severity in the long run is well predicted from both histologic fibrotic renal score and response obtained at 1 month.

Management of extrapulmonary sarcoidosis: challenges and solutions

“…Co-occurrence with other renal disease, primarily IgA nephropathy, is not uncommon 28. Although sarcoidosis-associated end-stage renal disease is very uncommon and more likely due to other causes, a significant degree of renal insufficiency was common in one retrospective series, and hypercalcemia might be a contributing factor 29,30. Moreover, relapses may occur in up to a quarter of patients who undergo kidney transplantation because of sarcoidosis and may negatively impact graft survival 31…”

“…The long-term prognosis of renal sarcoidosis seems to correlate with response to therapy after 1 month of treatment and inversely with the initial fibrosis score on histopathological examination 29. In refractory renal sarcoidosis or failure of treatment leading to end-stage renal disease, renal transplantation is an option 38.…”

Single-centre experience of granulomatous interstitial nephritis—time for a new approach?

“…Sarcoidosis has a better prognosis, compared with TB, with the majority responding to steroid treatment [5, 8, 9]. In one series, 36% patients required initiation of renal replacement therapy (RRT) within 6 months of diagnosis of TB-related GIN [5] contrasting with 4% of patients who developed end-stage renal disease with sarcoidosis-related disease [10]. Patients with TB are often identified late in the disease course and this may explain the inferior outcome.…”

Acute renal failure as a form of presentation of sarcoidosis in a young adult: a case report

“…Sarcoidosis is a systemic disease caused by noncaseating granulomas in multiple organs [1]. Its etiology is unknown [2].…”