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Abstract: SA-PO940

Low eGFRcys/eGFRcreat Ratio Indicates Glomerular Filtration Impairment in the Patients with IgA Nephropathy

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Nobayashi, Hiroki, Tokyo Jikeikai Ika Daigaku Igakubu Igakuka Jinzo Koketsuatsu Naikagaku, Minato-ku, Tokyo, Japan
  • Kanzaki, Go, Tokyo Jikeikai Ika Daigaku Igakubu Igakuka Jinzo Koketsuatsu Naikagaku, Minato-ku, Tokyo, Japan
  • Koike, Kentaro, Tokyo Jikeikai Ika Daigaku Igakubu Igakuka Jinzo Koketsuatsu Naikagaku, Minato-ku, Tokyo, Japan
  • Tsuboi, Nobuo, Tokyo Jikeikai Ika Daigaku Igakubu Igakuka Jinzo Koketsuatsu Naikagaku, Minato-ku, Tokyo, Japan
  • Yokoo, Takashi, Tokyo Jikeikai Ika Daigaku Igakubu Igakuka Jinzo Koketsuatsu Naikagaku, Minato-ku, Tokyo, Japan
Background

Most glomerular diseases are characterised by disruption of the glomerular filtration barrier (GFB). The reduced pore size of GFBs as a result of endothelial damage is thought to result in lower clearance of medium-sized molecules (5000-3000 Da) such as cystatin C (cys) compared to small molecules (<900Da) such as creatinine (creat). Recently, the Shrunken pore syndrome (SPS) has been highlighted as a new phenotype of renal dysfunction characterised by an eGFRcys/eGFRcreat ratio < 60-70%. However, no reports examined the pathological association between the eGFRcys/eGFRcreat ratio and glomerular capillary wall. In the present study, we analyzed the clinical and pathological features associated with eGFRcys/eGFRcreat ratio in the patients with IgA nephropathy (IgAN).

Methods

62 patients diagnosed with IgAN by kidney biopsy were analyzed. Thickness of capillary wall was determined by measuring the distance from endothelial to podocyte plasma membrane according to the past study. To evaluate the effect of muscle mass to creatinine, we measured surface of iliopsoas using CT images.

Results

Subjects with low eGFRcys/eGFRcreat ratio had more iliopsoas muscle mass, higher creatinine, thinner capillary wall, more severe microscopic hematuria (Table 1). The eGFRcys/eGFRcreat ratio was correlated with iliopsoas muscle mass (r=0.36, p=0.012), thickness of capillary wall (r=0.44, p<0.001) and severity of microscopic hematuria (r=-0.47, p<0.001). On multiple regression analysis, only capillary wall and microscopic hematuria contributed to eGFRcys/eGFRcreat ratio.

Conclusion

Present study showed for the first time the IgAN patients with low eGFRcys/eGFRcreat ratio had thinner glomerular capillary wall and more severe microscopic hematuria. Although their renal function was preserved, they might have filtration impairment according to the concept of SPS. Therefore, it was suggested that it could also be a useful biomarker for impaired GFB in IgAN.