title: Tiopronin-induced membranous nephropathy: a case report.
abstract: BACKGROUND
  Tiopronin, a glycine derivative extensively used to treat cystinuria and hepatic cell injury, can give rise to rare complications such as proteinuria and nephrotic syndrome. However, the pathological characteristics of this secondary nephropathy are poorly understood. Here, we report a case of tiopronin-induced nephrotic syndrome.
  
  
  METHODS
  A 65-year-old Chinese man with a history of myasthenia gravis admitted tiopronin for hepatoprotection therapy. After 3 months later, he presented with rapid weight gain, massive peripheral edema, and proteinuria in the nephrotic range. Laboratory findings included serum albumin (20 g/L), total protein (38 g/L), and total cholesterol (11.78 mmol/L). A 24-hour urine protein collection contained 8620 mg. Percutaneous renal biopsy revealed a uniformly thickened glomerular and rigid basement membrane with immunoglobulin G (IgG) and complement C3 deposited along the glomerular capillary wall. Withdrawal of tiopronin-induced proteinuria complete remission and clinical resolution of nephrotic syndrome.
  
  
  CONCLUSIONS
  Potential risk of kidney injury exists with long-term tiopronin treatment. Membranous nephropathy was a common renal pathologic feature. Proteinuria in the nephrotic range may spontaneously remit after tiopronin withdrawal. Periodic urine analysis and patient follow-up are recommended with tiopronin therapy.
authors.affiliation: Department of Nephrology, General Hospital of Tianjin Medical University , Tianjin , China.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Zheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Xue
authors.forename: Junya
authors.initials: J
authors.lastname: Jia
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.forename: Wenya
authors.initials: W
authors.lastname: Shang
authors.forename: Shan
authors.initials: S
authors.lastname: Lin
mesh_terms: D000368:Aged; D015433:Glomerulonephritis, Membranous / Q000139:chemically induced* / Q000175:diagnosis; D006801:Humans; D007668:Kidney / Q000473:pathology*; D008297:Male; D009404:Nephrotic Syndrome / Q000139:chemically induced* / Q000175:diagnosis; D011507:Proteinuria; D008625:Tiopronin / Q000009:adverse effects*
chemical_list: D008625:Tiopronin
keywords: Membranous nephropathy; nephrotic syndrome; proteinuria; tiopronin