A 43-year-old man comes to the office due to fatigue and worsening pedal edema over the past several weeks. The patient was diagnosed with advanced HIV infection and started on antiretroviral therapy 3 months ago. He also has a history of hypertension. Physical examination shows bilateral lower extremity pitting edema. Serum creatinine is elevated and serum phosphorus is decreased compared to test results 3 months ago. Urinalysis reveals moderate proteinuria and glucosuria. Renal biopsy shows cytoplasmic vacuolization in the proximal tubules accompanied by loss of brush border and basement membrane denudation. Intracytoplasmic eosinophilic inclusions are also seen in the proximal tubules. There are no significant interstitial inflammatory infiltrates, and the glomeruli appear normal. Which of the following is the most likely diagnosis in this patient?

Question

A 43-year-old man comes to the office due to fatigue and worsening pedal edema over the past several weeks.  The patient was diagnosed with advanced HIV infection and started on antiretroviral therapy 3 months ago.  He also has a history of hypertension.  Physical examination shows bilateral lower extremity pitting edema.  Serum creatinine is elevated and serum phosphorus is decreased compared to test results 3 months ago.  Urinalysis reveals moderate proteinuria and glucosuria.  Renal biopsy shows cytoplasmic vacuolization in the proximal tubules accompanied by loss of brush border and basement membrane denudation.  Intracytoplasmic eosinophilic inclusions are also seen in the proximal tubules.  There are no significant interstitial inflammatory infiltrates, and the glomeruli appear normal.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

Eductional Objective: Tenofovir is a nucleotide reverse transcriptase inhibitor that is a common component of HIV therapy.  This drug is generally well tolerated but may occasionally cause damage to the proximal tubule of the kidney, leading to acute kidney injury and/or proximal tubule impairment (eg, phosphoruria, glucosuria, proteinuria, water retention).  Biopsy typically reveals a normal glomerulus and renal interstitium but damage to the proximal tubule.

A 43-Year-Old Man Comes to the Office Due to Fatigue