Acute tubulointerstitial nephritis as a cause of acute renal failure in a patient with class III diabetic nephropathy

A  case report.

Abstract

Introduction: Acute tubulointerstitial nephritis (TIN) with eosinophilia and acute tubular injury is a rare but clinically significant cause of acute kidney injury (AKI), especially in patients with chronic comorbidities.

Clinical case: A 44-year-old woman with type 2 diabetes, a history of hypertension and a previous episode of diabetic ketoacidosis, was admitted with severe metabolic decompensation secondary to infectious gastroenteritis and dehydration. During her course in the intensive care unit, she developed KDIGO stage III AKI, requiring renal replacement therapy. A kidney biopsy confirmed the diagnosis of acute TIN with tubular injury, attributed to multiple factors: severe hypovolemia, recent exposure to potentially nephrotoxic drugs (allopurinol, antibiotics, and nonsteroidal anti-inflammatory drugs), and gastrointestinal sepsis.

Treatment: Treatment included hemodynamic support, insulin therapy, culture-adjusted antibiotics, and intermittent hemodialysis. Outcome: The patient showed metabolic improvement and partial recovery of renal function after three dialysis sessions. Her creatinine level remained at 1.6 mg/dL without requiring hemodialysis.

Conclusions: This case presents acute renal deterioration in the context of previously undiagnosed chronic kidney failure. ITN was suspected due to the presence of eosinophiluria, non-nephrotic proteinuria, absence of evident glomerular findings, and exposure to potentially nephrotoxic drugs.