Wang H, et al. - This study sheds light on the link between urinary fibrinogen and kidney outcomes in patients with CKD. Findings demonstrated a correlation of urinary fibrinogen with interstitial fibrosis and tubular atrophy. Urinary fibrinogen was also identified as an independent risk factor for progression of CKD to ESRD.

Methods

• Researchers assessed 402 patients with CKD and kidney biopsies, including 101 with diabetic nephropathy, 94 with idiopathic membranous nephropathy, 55 with idiopathic FSGS, and 152 with IgA nephropathy.
• Using ELISA, they quantified urinary fibrinogen and, tested associations with kidney histology and progression to ESRD.

Results

• Findings demonstrated that median (interquartile range) urinary fibrinogen-to-creatinine ratio was 536 (191–1461) ng/mg for patients with CKD, significantly higher than 2 (2–3) ng/mg for healthy controls (P<0.001).
• Data also reported a positive correlation of urinary fibrinogen with urine protein (r=0.64;P<0.001) and interstitial fibrosis and tubular atrophy (r=0.10; P=0.04), and its negative correlation with eGFR (r=-0.20; P<0.001).
• Researchers found that 68 of 402 patients (17%) developed ESRD over a median follow-up period of 35 months (interquartile range, 24–78 months).
• They also noted that higher urinary fibrinogen level was related to increased risk of ESRD (hazard ratio, 2.12; 95% confidence interval, 1.31 to 3.26) per log10 higher urinary fibrinogen-to-creatinine ratio (P=0.003) adjusting for age, sex, BP, urine protein, disease type, eGFR, and interstitial fibrosis and tubular atrophy.
• In addition, it was observed that for prediction of ESRD, the addition of urinary fibrinogen to eGFR, urine protein, and BP increased the area under the receiver operating curve from 0.73 to 0.76, and the Akaike information criterion improved from 333.6 to 327.0.