Granulomatous interstitial nephritis

Excerpt

A 75-year-old female was referred to a hospital for acute renal failure (serum creatinine level of 3.6 mg/dl). The patient reported increased fatigue, but denied nausea, vomiting, or dyspnea. She had otherwise been in good health without symptoms or recent illnesses, infections, hospitalizations, studies, or procedures. Four months prior to admission, the serum creatinine level had been at a baseline of 1 mg/dl, but had increased to 1.7 mg/dl 1 month prior to admission. Her past medical history was significant for type 2 diabetes mellitus and hypertension. She had been taking metformin, lisinopril, and hydrochlorothiazide for several years without changes. She denied any recent non-steroidal antiinflammatory drug use. On examination, vital signs were normal, and the physical examination was unremarkable. Renal ultrasound did not show any evidence of hydronephrosis or medical renal disease. Renal artery Doppler imaging was unremarkable. Pertinent admission laboratory values were white cell count 6,000/mm³ with 2.9 % eosinophils, blood urea nitrogen 32 mg/dl, serum creatinine 3.6 mg/dl, serum albumin 2.7 g/dl, and HbA1c 7.7. Urinalysis showed trace protein and white blood cells (6–10/hpf). The Hansel stain in urine was negative. Complement profile, ANCA titers, urine and serum protein electrophoresis, and immunofixation were unremarkable. …