CASE 20: Recurrent Primary Focal Sclerosis

28-year-old woman with end stage kidney disease secondary to steroid resistant nephrotic syndrome who received a living related donor kidney. Although she had immediate urine output and good renal function, on the second postoperative day she exhibited a decrease in output coupled with an increase in creatinine values. Duplex Doppler ultrasound evaluation showed good perfusion of the kidney and no evidence of hydronephrosis. Dipstick revealed 3+ proteinuria.

Allograft biopsy showed non-specific changes on light microscopy (Figure 112-77) and extensive effacement of podocyte foot processes on electron microscopy (Figure 112-78), suggesting recurrent diffuse podocyte disease due to circulating factor (recurrent primary focal sclerosis or FSGS). Initially, these lesions have no segmental or global sclerosis, but have an appearance equivalent to minimal change disease (MCD), suggesting that MCD and primary FSGS are two ends of the same disease spectrum.