Treatment of renal sarcoidosis: is there a guideline? Overview of the different treatment options

Sarcoidosis is a multisystem granulomatous disease of unknown aetiology characterized by the presence of noncaseating granulomas. It may affect any organ including the kidney. A disordered calcium metabolism is most often responsible for the development of renal failure. Granulomatous interstitial nephritis is the most typical histological finding, but it rarely leads to renal insufficiency. Since development of renal insufficiency in sarcoidosis is uncommon, we lack large (randomized) trials concerning the treatment of this disorder. We gather most information from case reports and small series. Our knowledge of pulmonary sarcoidosis is more comprehensive. It is, however, impossible to treat renal manifestations identically because some of the drugs used in pulmonary sarcoidosis are nephrotoxic. Moreover, renal sarcoidosis is a specific entity with its own characteristics and response to therapy. A guideline for treatment is currently missing. Based on a review of the literature, we present an overview of the different treatment options to promote a more uniform and scrutinized approach of this disease. Hypercalcaemia and hypercalciuria can be treated with corticosteroids, (hydroxy)chloroquine or ketoconazole. Preventive measures play a supportive role. In granulomatous interstitial nephritis, glucocorticoids are the standard of care. In patients with failure of or a contraindication to corticosteroids or in those patients who need a high maintenance dose of corticosteroids, azathioprine or mycophenolate mofetil can be used. TNF-alpha inhibitors are useful in case of steroid-resistant sarcoidosis or in patients who develop severe steroid toxicity. With increasing insight in the pathogenesis of sarcoidosis, other immunosuppressive drugs have been proposed, but more research is necessary before their routine use can be advocated.