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Abstract: PO1875

Fractional Excretion of Total Protein in Nephrotic Syndrome

Session Information

Category: Glomerular Diseases

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Kuno, Hideaki, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Kanzaki, Go, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Sasaki, Takaya, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Okabayashi, Yusuke, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Haruhara, Kotaro, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Koike, Kentaro, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Tsuboi, Nobuo, The jikei university school of medicine, Minato-ku, Tokyo, Japan
  • Yokoo, Takashi, The jikei university school of medicine, Minato-ku, Tokyo, Japan
Background

Lower estimated glomerular filtration rate (eGFR) and higher proteinuria are the most sensitive predictor of the development of progressive renal insufficiency in various glomerular diseases. Fractional excretion of total protein (FETP) calculated by dividing the total protein clearance by the creatinine clearance is tightly associated with both proteinuria and GFR. However, few studies have analyzed in glomerular diseases the FETP to evaluate their relationship with renal function and histologic lesions. This study aimed to evaluate the relationship between FETP and the clinical features and histologic lesions and to assess whether FETP predicts outcome in nephrotic syndrome (NS).

Methods

Subjects who exhibited NS with a histological diagnosis were retrospectively analyzed at the Jikei University School of Medicine Hospital, Tokyo, Japan, during biopsy performed between 2002 and 2018. We analyzed 24-h urinary protein excretion, FETP, and other clinicopathological findings at kidney biopsy. The FETP was determined by the standard clearance technique based on 24-h urine collection: FETP = (urinary total protein / serum total protein) / (urinary creatinine / serum creatinine) × 100.

Results

A total of 113 subjects with NS were identified (Age 53.7 ± 17.3 [mean ± SD] years old; Male 71.7%, eGFR 57.6 ± 27.7 mL/min/1.73m2; urinary protein excretion 7.02 ± 3.67 g/day; minimal change nephrotic syndrome [n = 41]; focal segmental glomerular sclerosis [n = 10]; membranous nephropathy [n = 36]; diabetic nephropathy [n = 26]). FETP was significantly associated with eGFR (ρ = -0.65, P <0.01), urinary protein excretion (ρ = 0.58, P <0.01), interstitial fibrosis and tubular atrophy (ρ = 0.24, P <0.05), and glomerulosclerosis (ρ = 0.24, P <0.05). Interestingly, patients with diabetic nephropathy showed the highest level of FETP with the poor renal outcome, while membranous nephropathy revealed the lowest level of FETP.

Conclusion

These results suggest that FETP would be a useful marker combining the two predictors of the decline of renal function in NS showing increased glomerular protein permeability and decreased glomerular filtration function.