Background: Obesity is an important problem associated with worsening cardiovascular
disease and the progression of proteinuria in kidney transplant recipients. We describe a
case of de novo focal segmental glomerulosclerosis (FSGS) associated with progressive
obesity after kidney transplantation (KTx).
Case Presentation: A 41-year-old male patient underwent an allograft kidney biopsy
because of nephrotic range proteinuria. The donor was his father who was aged 70
years at transplantation. In addition, there was a substantial difference in body weight
(BW) between the recipient and donor. At 56 months after kidney transplantation, the
patient’s BW increased from 83.1 kg (BMI, 29.3 kg/m2
) before kidney transplantation to
93.9 kg (BMI, 33.1 kg/m2
). An allograft biopsy showed glomerular hypertrophy and focal
segmental sclerotic lesions with partial epithelial cell hyperplasia. The histologic diagnosis
was FSGS, not otherwise specified (NOS) variant. A comparison between the kidney
volume before and after kidney transplantation, evaluated using volumetric computed
tomography, revealed prominent kidney hypertrophy (1.77 times).
Conclusions: Our case demonstrated that de novo FSGS after kidney transplantation is
induced by progressive obesity, as manifested by glomerular hypertrophy as well as kidney
hypertrophy. This is a hyperdynamic state contributed to the pathogenesis of de novo
FSGS. Our report is important to understand the pathogenesis of FSGS.