Renal sarcoidosis — most often granulomatous interstitial nephritis, but also hypercalciuria, nephrocalcinosis, and glomerular disease — is an under-recognized cause of kidney injury that usually responds well to prompt treatment.
Corticosteroids and steroid-sparing therapy
Glucocorticoids are first-line and usually highly effective, especially in granulomatous interstitial nephritis: most patients improve within weeks if treated early, though delayed therapy may leave irreversible fibrosis. Prednisone is typically started at 0.5–1 mg/kg/day and tapered over months. For steroid-resistant, relapsing, or intolerant disease — or when steroid toxicity is significant — azathioprine or mycophenolate mofetil serve as steroid-sparing agents, the latter often better tolerated. A useful predictor: patients with hypercalciuria at baseline appear more likely to respond to immunosuppression.
Emerging options and supportive care
No biologic is established as standard for renal sarcoidosis, but anti-TNF therapy (infliximab) has helped in severe, refractory multi-system disease in case reports, and B-cell- and Th17-directed strategies are being explored. Correcting hypercalcemia and hypercalciuria (to prevent nephrocalcinosis and stones), monitoring for CKD, and interdisciplinary care given the frequent multi-organ involvement round out management.
| Therapy | Role | Note |
|---|---|---|
| Glucocorticoids | First-line | Effective; treat early |
| Azathioprine / mycophenolate | Steroid-sparing | For refractory/relapsing disease |
| Anti-TNF (experimental) | Refractory | Case-level evidence |
| Supportive care | All | Correct calcium; monitor CKD |
Further reading: reviews of renal sarcoidosis (Nephrology Dialysis Transplantation 2023; Journal of Nephrology 2023); hypercalciuria as a predictor of steroid response (Zhao et al., 2023).