Chronic Interstitial Nephritis

Chronic Interstitial Nephritis (CIN) is a long-term inflammatory kidney disorder that primarily affects the renal interstitium and tubules. Over time, persistent inflammation leads to fibrosis, tubular atrophy, and irreversible kidney damage that may progress to chronic kidney disease. The condition develops gradually, often due to prolonged drug or toxin exposure, chronic infection, metabolic abnormalities like hypercalcemia or hyperuricemia, and autoimmune disorders.

Symptoms are generally nonspecific and include fatigue, nausea, flank pain, and increased urination, which may later progress to signs of renal failure such as edema or high blood pressure. Diagnosis involves urinalysis, imaging, and renal biopsy, showing interstitial fibrosis and tubular scarring.

Management focuses on identifying and removing underlying causes, controlling infections or autoimmune activity, and slowing progression through supportive therapy. Corticosteroids or immunosuppressants may be used if inflammation is immune-mediated. Early detection and cessation of nephrotoxic agents are essential to preserve renal function and delay end-stage kidney disease.?