Sarcoidosis is a multisystem inflammatory disease characterized by the presence of non-caseating granulomas. Although sarcoidosis can virtually affect any organ in the body, the lung is the most common organ affected followed by the liver, skin, and eye.
Despite multiple investigations, the etiology was unclear. Currently, the most likely etiology is an infectious or noninfectious environmental agent that triggers an inflammatory response in a genetically susceptible host.
Renal Manifestations Of SARCOIDOSIS:
- CALCIUM DYSREGULATION
- OBSTRUCTIVE UROPATHY
- RETROPERITONEAL FIBROSIS & LYMPHADENOPATHY
- TUBULOINTERSTITIAL DISEASE
- GRANULOMATOUS INTERSTITIAL NEPHRITIS
- NON-GRANULOMATOUS INTERSTITIAL NEPHRITIS
- GLOMERULAR DISEASE(RARE) Pathophysiology
Clinically apparent renal involvement is considered rare, occurs in less than 5% of sarcoidosis patients, usually associated with granulomas in the kidney itself, and can lead to nephritis. However, hypercalcemia is the most likely cause of sarcoidosis-related renal disease. The cause for hypercalcemia is 1 -hydroxylation of 25(OH) vitamin D to form 1,25 (OH)2 vitamin D in the macrophages of sarcoid granulomas. Usually, treatment with corticosteroids shows a good response but relapses are frequent particularly while tapering steroids. Patients who are steroid intolerant/steroid-resistant are treated with cyclophosphamide, infliximab, azathioprine, and mycophenolate mofetil. Rarely sarcoidosis may lead to end-stage renal disease.