Sarcoidosis With Renal Involvement

Sarcoidosis is a multisystem granulomatous disorder that can manifest in the kidneys, often leading to increased morbidity and complications. Renal involvement typically presents as abnormalities in calcium metabolism, such as hypercalcemia and hypercalciuria, caused by activated macrophages in sarcoid granulomas producing excess calcitriol. This results in increased calcium absorption and urinary excretion, predisposing affected individuals to nephrolithiasis, nephrocalcinosis, and potentially tubular injury. The most common histopathological finding is granulomatous interstitial nephritis, but glomerulonephritis and tubulointerstitial nephropathy may also occur.

Clinical features include polyuria, dehydration, and reduced glomerular filtration, which can be reversible in the acute phase but may progress to irreversible renal damage if fibrosis develops. Diagnosis involves renal function assessment, calcium metabolism evaluation, and biopsy in unexplained cases. Treatment generally requires corticosteroids, with immunosuppressive agents considered for refractory cases; early intervention is crucial to prevent chronic kidney disease.?