SARCOIDOSIS AND HYPERCALCIURIA: A STONE COLD INDICATION FOR TREATMENT

Abstract

TOPIC: Diffuse Lung Disease TYPE: Fellow Case Reports INTRODUCTION: Sarcoidosis may cause renal disease by several different mechanisms. Symptomatic nephrolithiasis is a rare occurrence as the initial manifestation of sarcoidosis. Hypercalciuria may occur commonly in sarcoidosis and warrants treatment. There is lack of data supporting screening for hypercalciuria. Herein we present a patient with asymptomatic sarcoidosis until she developed nephrolithiasis with a normal serum calcium but an elevated urine calcium. CASE PRESENTATION: 62 year old woman with a history of diabetes mellitus II and obesity was followed in the pulmonology clinic for abnormal chest imaging. She had previously presented to the emergency department for chest pain that lead to a chest radiograph and Chest CT scan. CT scan showed mediastinal adenopathy and pulmonary nodules. Bronchoscopy was performed with biopsies which revealed non necrotizing granulomas consistent with sarcoidosis. Patient had a normal spirogram, and no other extrapulmonary manifestations that would warrant treatment for sarcoidosis. Serum calcium and albumin were normal. 25 hydroxy vitamin D levels were 23 ng/ml. She did take over the counter Vitamin D supplements. Later she developed nephrolithiasis. Analysis of the stone revealed 65% calcium oxalate monohydrate and 15% calcium oxalate dihydrate. A 24 hour urine calcium showed 328 mg of calcium per volume of urine. Patient had a history of diabetes mellitus so treatment with steroids was avoided and she was started on 10 mg of methotrexate. Follow up urine calcium levels are pending. DISCUSSION: While there are guideline recommendations to screen for hypercalcemia with a serum calcium level and for measuring vitamin D levels for replacement, there is scant literature on screening for hypercalciuria in the setting of normal calcium levels, despite hyercalciuria being the most common renal manifestation of renal sarcoidosis. The incidence of renal disease in sarcoidosis varies from 1.1% to 9.7% with hypercalciuria occurring in up to 50% while hypercalcemia may occur in only 10-20% of cases, making hypercalciuria the most common renal manifestation of sarcoidosis. Hypercalciuria is the result of increasing calcium load filtered at glomerulus as a result of decreased PTH secretion secondary to elevated circulating calcitriol levels leading to a diminished tubular reabsorption of calcium. Hypercalciuria predisposes to calcium oxalate nephrolithiasis. Approximately 10 % of patients with sarcoidosis have 1 symptomatic stone. For 1 % of these patients it may be the initial presentation. Approximately 2.7% of sarcoidosis patients have asymptomatic stones. CONCLUSIONS: Hyercalciuria is the most common renal manifestation of sarcoidosis, yet it is not commonly screened for in asymptomatic sarcoidosis patients. Timely treatment may attenuate renal impairment secondary to sarcoidosis. It is suggested that hypercalciuria in the setting of sarcoidosis always be treated. REFERENCE #1: Adam R. Berliner, Mark Haas, Michael J. Choi, Sarcoidosis: The Nephrologist's Perspective, American Journal of Kidney Diseases, Volume 48, Issue 5,2006, Pages 856-870, ISSN 0272-6386, https://doi.org/10.1053/j.ajkd.2006.07.022. REFERENCE #2: Thomas KW, Hunninghake GW. Sarcoidosis. JAMA. 2003 Jun 25;289(24):3300-3. doi: 10.1001/jama.289.24.3300. PMID: 12824213 DISCLOSURES: No relevant relationships by Jonathan gwizdala, source=Web Response Grant for research relationship with Sanofi Please note: January 2021 Added 04/20/2021 by Daniel Ouellette, source=Web Response, value=Grant/Research No relevant relationships by Rajaninder Sharma, source=Web Response