Isolated sarcoid granulomatous interstitial nephritis responding to infliximab therapy.

Sarcoidosis is a systemic disease with multiorgan involvement. In children, renal impairment of sarcoidosis usually is caused by either hypercalcemia leading to nephrocalcinosis or interstitial nephritis with or without granulomata. We report the case of a 13-year-old boy presenting with severe arterial hypertension and acute renal failure caused by an isolated sarcoid granulomatous interstitial nephritis (GIN). Other known causes of GIN, eg, drug intake or fungal or mycobacterial infection, were excluded, and there was no evidence of extrarenal sarcoid involvement. Renal function improved initially with prednisone treatment. Blood pressure was controlled using ramipril, nifedipine, furosemide, dihydralazine, and metoprolol. Later, the patient showed signs of severe steroid toxicity and progressive renal failure. Monthly treatment with infliximab, a tumor necrosis factor-alpha antibody, was started, resulting in steady improvement in renal function and resolution of renal granulomata. In addition, antihypertensive medication could be reduced, and low-dose prednisone therapy was maintained. To our knowledge, this is the first report of successful treatment with infliximab of a patient with sarcoid GIN.