Steroid-resistant focal segmental glomerulosclerosis (FSGS) is the primary renal disease in approximately 10% of pediatric renal transplant recipients.1 Although posttransplant immunosuppressive medications are essential for prevention of renal allograft rejection, they could also portend salutary impact on the underlying glomerular disease of the native kidneys.
A 38-year-old African American man was referred to nephrology clinic to reestablish care for his transplanted kidney after he was lost to follow-up for about 20 years. He had a history of end-stage renal disease secondary to idiopathic FSGS and received a living-related donor kidney transplant from his father at the age of 10 years. He did not receive plasmapheresis perioperatively. Although he was on dialysis briefly before transplant, he was never anuric. Posttransplant, he received azathioprine and prednisone for about 10 years with a baseline serum creatinine of approximately 1.6 mg/dL. Then, the patient stopped taking all immunosuppressive medications and was lost to follow-up.
At the time of presentation to our clinic, serum creatinine was found to be 3.4 mg/dL with a urine albumin-creatinine ratio of 75 mg/g. He was presumed to have developed chronic allograft nephropathy (rejection), leading to chronic kidney disease stage 4T (“T” is used to denote transplanted kidney) because he was not taking immunosuppressive medications for over 2 decades. Surprisingly, ultrasound of the right lower quadrant, performed twice, could not identify any allograft tissue due to its significant atrophy and blending in with the hyperechogenic surrounding fat tissue (Figure 1C)]. Retroperitoneal ultrasound showed approximately 9 cm long, echogenic native kidneys consistent with chronic kidney disease [(Figures 1A and B). Therefore, a radionuclide renogram was obtained, which revealed complete absence of flow to the right lower quadrant allograft while perfusion to the native kidneys was present (Figure 1D); his renal function was entirely provided by the native kidneys rather that the allograft. He was initiated on appropriate medical therapy for chronic kidney disease to slow down progression. Seven years later, his renal function has remained stable with minimal proteinuria without immunosuppression.
The patient received azathioprine and prednisone for 10 years after transplant before being lost to follow-up and stopping these medications. Although he subsequently lost his allograft likely due to rejection, the salutary impact of immunosuppressive medications on underlying FSGS of the native kidneys resulted in partial recovery that has lasted for more than 25 years. The main teaching point in this case is that renal function in renal transplant recipients could still be partially (or completely) provided by the native kidneys even decades later, because posttransplant immunosuppression could induce remission in certain underlying diseases. In cases where there is a doubt, complementary studies, such as radionuclide renogram, could be beneficial.
There are rare instances where glomerular diseases, such as membranous glomerulonephritis and IgA nephropathy of native kidneys, showed recovery after renal transplantation.2,3 To the best of our knowledge, this case represents the first report on the recovery of FSGS in the native kidneys after renal transplantation. The retaining of renal function for such a long period is also uncharacteristic.
1. Shah SS, Akhtar N, Sunbleen F, et al. Histopathological patterns in paediatric idiopathic steroid resistant nephrotic syndrome. J Ayub Med Coll Abbottabad
2. Hidalgo P, Jiménez T, Blanca L, et al. Recovery of native renal function after kidney transplantation. Transplant Proc
3. Descoeudres B, Giannini O, Aschwanden M, et al. Silent recovery of native kidney function after transplantation in a patient with membranous nephropathy. Nephrol Dial Transplant