Biopsy-proven acute phosphate nephropathy: A case report

BACKGROUND: Acute phosphate nephropathy (APN) is a disease that can occur when exposed to high doses of phosphate. The most common cause of APN is the use of oral sodium phosphate for bowel cleansing preparations. However, there are other less commonly known sources of phosphate that are equally important. To date, our literature search did not identify any report of excessive dietary phosphate as a cause of APN. CASE SUMMARY: We report an unusual case of a 39-year-old diabetic male who presented with epigastric pain and oliguria. Work-up showed elevated serum creatinine, potassium, and calcium-phosphate product, and metabolic acidosis. The patient was admitted in the intensive care unit and received emergent renal replacement therapy. Kidney biopsy revealed tubular cell injury with transparent crystal casts positive for Von Kossa staining, which established the diagnosis of APN. CONCLUSION: This case confirmed that APN may occur with other sources of phosphorus, highlighting the importance of good history taking and kidney biopsy in patients with predisposing factors for APN. Raising awareness on the possibility of APN and its timely recognition and management is imperative so that appropriate measures can be instituted to prevent or delay its progression to end stage renal disease.