Abstract: FR-PO031

Sarcoidosis Associated AKI: The Path Less Traveled

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Murad, Haris Farooq, Yale School of Medicine, New Haven, Connecticut, United States
  • Jorge Cabrera, Valerie, Yale School of Medicine, New Haven, Connecticut, United States
  • Shah, Mamta, Yale School of Medicine, New Haven, Connecticut, United States
Background

Mechanisms of kidney injury in sarcoidosis include interstitial nephritis with or without granuloma formation and/or abnormal calcium metabolism with nephrolithiasis and nephrocalcinosis. Calcium phosphate deposition on biopsy is uncommon and prior case reports have speculated its association with the more common calcium oxalate crystals, representing an underreported finding in sarcoid related kidney injury.

Methods

A 43 year-old Caucasian man presented with worsening wrist pain and swelling following a traumatic injury. He had noticed recent fatigue and weight loss. Further questioning revealed excessive milk and calcium carbonate intake. His examination was remarkable for a palpable tender mass on his right wrist. He was noted to have an elevated serum creatinine of 4.3mg/dL and serum calcium of 14mg/dL. Other investigations included parathyroid hormone of 9.3 pg/mL, ionized calcium of 6.02 mg/dL and 1,25-OH vitamin D (vit D) level of 112 pg/mL. Imaging of the wrist was suspicious for secondary tumoral calcinosis and computed tomography (CT) of the chest showed ground glass opacities and hilar lymphadenopathy. Ultrasound demonstrated bilateral non obstructing renal calculi. Kidney biopsy revealed non necrotizing granulomas and calcium phosphate crystals with surrounding giant cell formation. The diagnosis of sarcoidosis was established. In addition to management of hypercalcemia, he was started on oral prednisone. Serum creatinine improved to 2.2mg/dL along with normalization of 1,25-OH vitamin D and serum calcium in the following weeks.

Conclusion

Although the most common pathological lesion in renal sarcoidosis is non caseating granuloma formation, nephrocalcinosis with calcium oxalate deposition may be seen. Calcium phosphate deposition with surrounding giant cell formation is less common and has been pathologically associated with kidney injury in sarcoid. Although our patient had granulomas, the proximity of the giant cell formation to the calcium phosphate crystals suggests a localized reaction and may potentially be a significant contributor to kidney injury. This case highlights the importance of renal biopsy in patients with sarcoidosis. Findings are important to help clarify the pathology, prognosis and guide treatment.