The Value Of Urinary L-FABP, KIM-1and NGAL In Predicting The Early Diabetic Nephropathy

Objective: Diabetic nephropathy，one of the microvascularcomplications of diabetes, has become the most important reason leadingto end-stage renal disease. In clinic practice,becaese of the limitations ofkidney biopsy, early diagnosis of diabetic nephropathy is based primarilyon urinary albumin. However, the early kidney damage which hasnormoalbuminuric is ignored. It is significance to seek a specific markerfor predicting early diabetic nephropathy. Urinary L-FABP (liver typefatty acid-binding protein), urinary KIM-1(kidney injury molecule-1),urine NGAL (neutrophil gelatinase associated lipocalin) were expressedin the proximal tubule, numerous studies have confirmed that they wereincreased significantly in a variety of acute and chronic kidney injury andpositively correlated with the degree of renal injury. The purpose of thisstudy is to investigate the levels of three tubular biomarkers in type2diabetes patients (DM) with different degree of albuminuria and toexplore the value of these biomarkers in predicting the early diabeticnephropathy (DN). Methods: A group of118type2diabetes patients and41control subjects were recruited; Of the diabetic patients,44werenormoalbuminuric,41were microalbuminuric, and33weremacroalbuminuric, according to their urine albumin/creatinine ratio(UACR); collected fresh morning urine samples and plasma, usingELISA reagent box (Hycult biotech, R&D systerm, Ray Biotech), latexenhanced immune turbidimetry respectively detected the concentration.The levels of all urinary markers were normalized for urine creatinine.Results: The levels of uL-FABP and serum cystatin C was significantlyhigher in the DM groups than in the control group, and graduallyincreased with the increasing UACR, which reached the highest in themacroalbuminuria group. The levels of uKIM-1were significantly higherin the DM groups than in the control group. The levels of uNGAL weresignificantly higher in the microalbuminuria and macroalbuminuriagroups than in the normoalbuminuria and control groups. uNGAL,uKIM-1, uL-FABP and serum Cystatin C has positive relevance withUACR(R=0.327,0.427,0.719,0.726,respectively, P <0.001), uL-FABPand serum Cystatin C has stronger positive correlations; all markers alsohas negative relevance with eGFR(improved simplified MDRD formula)(R=-0.301,-0.008,-0.091,-0.791, respectively), only uL-FABP andserum Cystatin C has significantly correlations.Conclusions:1.UNGAL,UL-FABP and serum Cystatin C may be useful to assess early diabeticnephropathy;2.UL-FABP and serum Cystatin C can predict the severityof all stages of diabetic nephropathy;3.UL-FABP are better than uKIM-1and uNGAL in predicting the early diabetic nephropathy. Because of thepreponderance of urine collection such as convenient, fast and non-invasive, uL-FABP is expected to be a good marker for identifyingthe development and progression of diabetic nephropathy.