Urinary fatty acid binding protein in renal disease

The number of patients with end stage renal failure has been increasing throughout the world. The importance of measuring clinical parameters in renal injury has been emphasized for administering appropriate treatment and preventing a worsening of the disease. However, there are no clinically useful markers in predicting and monitoring the progression of renal disease. Liver type fatty acid binding protein (L-FABP) of 14.4 kDa is expressed in human proximal tubules. In order to evaluate the clinical significance of urinary L-FABP as a biomarker in renal disease, a monoclonal antibody against human L-FABP was developed and a two step sandwich enzyme linked immunosorbent assay (ELISA) method was established for determining human L-FABP in urine. In some clinical studies, urinary excretion of L-FABP was shown to be an excellent clinical marker that can help predict and monitor the progression of renal disease. The dynamics of renal L-FABP in pathophysiological settings has been revealed in experimental studies using transgenic mice with the human L-FABP gene. This review presents recent findings on the function and pathophysiological role of L-FABP, and summarizes the clinical importance of measuring urinary L-FABP in renal disease.