Urinary fatty acid-binding protein as a new clinical marker of the progression of chronic renal disease.
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.
Kamijo
Atsuko
A
Second Department of Internal Medicine, University of Tokyo, Tokyo, Japan.
Kimura
Kenjiro
K
Sugaya
Takeshi
T
Yamanouchi
Masaya
M
Hikawa
Akihisa
A
Hirano
Norihito
N
Hirata
Yasunobu
Y
Goto
Atsuo
A
Omata
Masao
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D015415:Biomarkers / Q000652:urine*; D001706:Biopsy; D002352:Carrier Proteins / Q000276:immunology / Q000652:urine*; D003404:Creatinine / Q000097:blood; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000473:pathology / Q000652:urine*; D008099:Liver / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000652:urine; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011507:Proteinuria; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000652:urine; D025521:Tumor Suppressor Proteins
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D002352:Carrier Proteins; C493319:FABP1 protein, human; C107608:FABP7 protein, human; C493320:Fabp1 protein, mouse; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; C109148:SPINT2 protein, human; D025521:Tumor Suppressor Proteins; D014360:Trypsin Inhibitor, Kunitz Soybean; D003404:Creatinine