Usefulness of urinary biomarkers to estimate the interstitial fibrosis surface in diabetic nephropathy with normal kidney function

• Published in: Nephrology, dialysis, transplantation dialysis, transplantation, 2022-10, Vol.37 (11), p.2102-2110
• Main Authors: Gonzalez, Jorge, Jatem, Elias, Roig, Jordi, Valtierra, Naiara, Ostos, Elena, Abo, Anabel, Santacana, Maria, Garcia, Alicia, Segarra, Alfons
• Format: Article
• Language: English
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfac185

Kidney biopsies of patients with diabetic nephropathy (DN) and normal kidney function may exhibit interstitial fibrosis (IF) without reduction of glomerular filtration rate because of hyperfiltration. The aim of our study was to analyze the performance of a set of biomarkers of tubular injury to estimate the extent of IF in patients with DN and normal kidney function. This cross-sectional study included 118 adults with DN diagnosed by kidney biopsy and GFR ≥ 90 mL/min/1.73 m2 and a control group of healthy subjects. We measured the urinary excretion of MCP-1, NGAL, KIM-1, L-FABP, β2-microglobulin and DKK-3 at the time of kidney biopsy. GFR was measured by Cr-EDTA (mGFR). IF was quantified using a quantitative morphometric procedure. Predictive multivariate models were developed to estimate the IF surface. patients with DN showed significantly higher levels of DKK-3, MCP-1 and L-FABP and significantly lower levels of EGF than healthy controls. There were no significant between-group differences in the levels of β2-microglobulin, KIM-1 or NGAL. IF was negatively associated with EGF and a positively with age, proteinuria, MCP-1, DKK-3 and L-FABP but no with β2-microglobulin, KIM-1, NGAL or GFR. The best model to predict IF surface accounted for 59% of its variability and included age, proteinuria, EGF, DKK-3 and MCP-1. our study provides a model to estimate the IF in DN that can be useful to assess the progression of IF in patients with normal kidney function.