Nephroquiz 6: A 67-Year-Old Kidney Transplant Recipient With Nephrotic-Range Proteinuria

A 67-year-old female kidney transplant recipient with nephrotic-range proteinuria was admitted for kidney biopsy. She had undergone living unrelated kidney transplantation in 1999 due to kidney failure of unknown cause after being on hemodialysis for 8 months. Her donor was a 23-year-old female who was homozygous for human leukocyte antigen (HLA) B5, DR 52, DQ 1, and CW 4. The patient’s HLA type was A2, B5, B35, DR11, DR52, DQ1, and CW4. Immunosuppressive therapy consisted of cyclosporine, azathioprine, and steroids. Two months after transplantation, she had developed an episode of acute allograft dysfunction due to calcineurin toxicity which had responded to dose reduction. Her high blood pressure had been treated with atenolol, to which enalapril had been added 2 years later. Six years after transplantation, azathioprine had been converted to mycophenolate mofetil. Her clinical course was uneventful until a year after conversion when she developed progressive proteinuria without hematuria or worsening of graft function.