Abstract: FR-PO411

Performance Evaluation and Potential Utility of Urinary L-FABP as a Point of Care Device in CKD

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 301 CKD: Risk Factors for Incidence and Progression

Authors

  • Mitsides, Nicos, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
  • Saha, Ananya, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
  • Read, Ian, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
  • Kalra, Philip A., Salford Royal Hospital NHS Trust, Salford, United Kingdom
  • Mitra, Sandip, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
Background

Liver-type fatty acid binding protein(L-FABP) is expressed by the proximal renal tubule during oxidative stress. Urinary L-FABP is released with tubular damage & is an established biomarker in acute kidney injury. However its value in Chronic Kidney Disease(CKD) & its progression has not been defined. We evaluate the clinical performance of a semi-quantitative point of care(POC) device for the detection of urinary L-FABP & assess the value of urinary L-FABP as a biomarker at different stages of CKD.

Methods

We report the baseline analysis of ELUDE, a multicentre study involving patients with CKD. Urine samples were tested for urinary protein creatinine ratio(PCR in mg/mmol) and urinary L-FABP using a semiquantitative POC & a quantitative ELISA(ug/gCr). A concomitant serum sample was analysed to calculate estimated glomerular filtration rate(MDRD eGFR in ml/min/1.73 m2). CKD was staged as per KDOQI.

Results

In 624 CKD participants, 15% had CKD1-2(eGFR=77±11.0;uPCR=103±210.3), 13 % CKD3a(eGFR= 51±4.5;uPCR=46±89.9), 25% CKD3b (eGFR=36±4.5;uPCR=72±120.4), 33% CKD4(eGFR=22±4.5;uPCR= 139±191.5) & 15% CKD5 (eGFR=11±2.4;uPCR=265±282.2). The mean urinary L-FABP ELISA measurement was 21.0 ug/gCr. L-FABP levels increased with advancing stages of CKD(1-2: 4.3±19.1;3a: 7.2±30.4ug/L; 3b: 9.0±23.6ug/L; 4: 25.4±51.5ug/L; 5: 62.5±33.6ug/L). L-FABP correlated negatively with eGFR (r= -0.516, p<0.01) and positively with uPCR (r=0.567, p<0.01). The association of L-FABP with eGFR was more pronounced at advanced stages of CKD. In an adjusted linear regression model for prediction of eGFR, L-FABP was an independent predictor in CKD stages 4 (beta= -0.185,p=0.02) & 5 (beta= - 0.241,p=0.03) while PCR was only an independent predictor in CKD 5(CKD4:beta= -0.001,p=0.99;CKD5:beta= -0.243,p=0.03). POC derived L-FABP measurements correlated well with ELISA(r=0.656,p<0.01).

Conclusion

The study findings suggest that in advanced stages of CKD, L-FABP may be a more reliable predictor eGFR than proteinuria. High levels of L-FABP in advanced CKD 4 & 5 could reflect dominant tubular damage & atrophy & may act as a useful biomarker of progressive disease. Longitudinal follow-up data from this study will further inform these findings. POC device used in this study provides a reliable way of measuring urine L-FABP & may be of utility in the clinical setting

Funding

  • Commercial Support