The role of Urinary Liver-Type Fatty Acid-Binding Protein in Diabetic Nephropathy

Abstract

Although Diabetic Nephropathy (DN) has long been considered a glomerular disease, tubulointerstitial injury has also been demonstrated to play a role in the pathogenesis. In this context, it is attractive to study molecules that are linked to tubular dysfunction. These molecules may serve as potential new markers for DN and may also provide additional information about clinical course or prognosis that may enable an earlier diagnosis and means to better tailor the treatment. Urinary liver-type fatty acid–binding protein (L-FABP) is mainly regarded as a urinary tubular biomarker associated with structural and functional kidney damage. Urinary levels of L-FABP are not influenced by its serum levels because urinary L-FABP originates mainly from the tubular cells. This biomarker is elevated in the early stages of diabetes. Our results regarding prediction of DN progression are due to the continuous increase in the L-FABP levels alongside the worsening of the nephropathy stage. The pathophysiological role of this continuous increase is not completely known but may mirror different mechanisms across DN stages. Our study was conducted on 90 patients were chosen randomly from inpatient and outpatient clinic of internal medicine,endocrinology department of Ain Shams University and Kobre El Koba Military Hospitals. They were 65 males and 35 females, their age ranged from 40-60 years. The studied cases were classified according to albuminuria (Albumin\creatinine ratio) into 3 groups: Group A: 30 patients with type 2 DM with normoalbuminuria (Albumin\creatinine ratio ≤ 2.5mg / mmol (men) or ≤3.5mg/mmol (women) in random urine sample consists of 18 males and 12 females. Group B: 30 patients with type 2 DM with microalbuminuria (Albumin\ creatinine ratio >2.5mg/mmol (men) or >3.5mg/mmol (women) consists of 18 males and 12 females. Group C: 30 patients with type 2 DM with macroalbuminuria (Albumin\ creatinine ratio > 30mg/mmol consists of 19 males and 11 females. All subjects will be subjected to the following: Full history taking, thorough clinical examination, laboratory investigations including: Fasting plasma glucose level (mg/dl), 2- hours post prandial plasma glucose level (mg/dl), glycatedhaemoglobin (HbA1c%), Albumin/ creatinine ratio (mg/mmol) in random urine sample and urinary L- FABP level (μg/g creatinine) by ELISA. Aim of this work to evaluate the relationship between urinary L-FABP and the severity of Diabetic nephropathy in type 2 DM.