RESUMO
Previous studies have indicated that in massive proteinuria, free fatty acids (FFAs) bound to albumin were overloaded in the proximal tubule and exacerbated tubulointerstitial damage. Liver-type fatty acid-binding protein (L-FABP) is an intracellular carrier protein of FFAs that is expressed in the proximal tubule of human kidney. We sought to evaluate urinary L-FABP as a clinical marker in chronic renal disease. Urinary L-FABP was measured in patients with nondiabetic chronic renal disease (n = 120) with the use of a newly established ELISA method. We then monitored these patients for 15 to 51 months. Clinical data were analyzed with multivariate analysis. Urinary L-FABP was correlated with urinary protein, urinary alpha(1)-microglobulin, and serum creatinine concentrations. Urinary L-FABP at the start of follow-up (F = 17.1, r =.36, P <.0001) was selected as a significant clinical factor correlated with the progression rate, defined as a slope of a reciprocal of serum creatinine over time. We next selected the patients with mild renal dysfunction (n = 35) from all 120 patients and divided them into 2 groups according to progression rate: the progression group (n = 22) and the nonprogression group (n = 13). Serum creatinine and urinary protein concentrations and blood pressure at the start of follow-up were higher in the progression group than in the nonprogression group, although we detected no significant difference between the 2 groups. Urinary L-FABP was significantly higher in the former group than in the latter (P <.05). The results showed that urinary L-FABP reflected the clinical prognosis of chronic renal disease. Urinary L-FABP may be a clinical marker that can help predict the progression of chronic glomerular disease.