L-FABP(L-type Fatty Acid Binding Protein)

L-FABP is a carrier protein of 14kDa excreted in the proximal tubule and plays a role in the intracellular transport of FFAs to mitochondria and/or peroxisomes for metabolism. Conventional markers are excreted in urine due to tissue damage in the glomerulus and renal tubule. But L-FABPs are excreted in urine due to ischemia or low capillary blood flow and oxidative stress on renal tubule before the progression of tissue damage. Thus, L-FABP is considered as useful biomarker for early diagnosis of renal disease accompanying tubular dysfunction.

Mechanism of expression

Conventional markers are excreted in urine due to tissue damage in the glomerulus and renal tubule.

• Excellent in Sensitivity, Accuracy, and reproducibility
• Measurement Sample：urine
• Measurement wavelength：450 nm (reference wavelength 610 nm or over)
• Test time：about 3 hours
• Measurement method：enzyme immunometric assay　(Sandwich ELISA Method)

The Change of urinary L-FABP in each drug-induced nephropathy model

Test animal: 6 week old male SD ratsAdministrated medicine:

• Gentamicin (200mg/kg, s.c.)
• Cisplatin (4mg/kg, i.v)
• Amphotelicin B (50mg/kg, i.p.)

Procedure

The level of urinary L-FABP increased significantly according to the severity of diabetic nephropathy. Urinary L-FABP in the patients with normal albuminuria was significantly higher than in normal control subjects. Thus, urinary L-FABP is a useful biomarker for early diagnosis of diabetic nephropathy

Relationship between urinary L-FABP levels and progression of diabetic nephropathy

Urinary L-FABP was measured in 147 patients who had diabetic nephropathy and was divided according to the disease stage. The average value and standard variation of each disease stage were calculated and shown in the graph to the right, together with the urinary L-FABP value of healthy volunteers.