Human Kidney Injury Molecule-1 (Kim-1) Level as an Early Marker for Diabetic Nephropathy in Egyptian Type 2 Diabetic Patients

Background: Human Kidney Injury Molecule-1 (KIM-1) is produced in the affected segments of the proximal renal tubule whenever there is a pathophysiological state resulting in dedifferentiation of the epithelium. The kidney injury molecule-1 is a type 1 transmembrane glycoprotein (339 aa). KIM-1 ectodomain is cleaved and shed in a metalloproteinase-dependent fashion. The soluble KIM-1 protein that appears in the urine of humans is about 90 KDa. All forms of chronic kidney disease, including diabetes, are associated with tubulo-interstitial injury.

Aim: The current study was performed try to assess use of urinary KIM-1/Creatinine ratio as a sensitive diagnostic tool for renal injury in the urine of patients with type 2 diabetic Egyptian patients.

Methods: Eighty subjects were subjected to clinical examination included and subdivided as 20 apparently healthy control volunteers (group I) and 60 diabetic patients which were divided into 3 subgroups (Group II, Group III and Group IV) of 20 patients each: according to ACR: (ACR<30 mg/g, 30 – 299 mg/g and ≥ 300 mg/g respectively). All were subjected to laboratory investigations which included: Morning mid-stream urine sample for: 1) Complete urine analysis. 2) Quantitative measurement of urinary albumin. 3) Urinary creatinine. 4) Calculation of urinary albumin to creatinine ratio. 5) Measurement of KIM-1 (ELISA) 6) Calculation of KIM-1 to creatinine ratio. Calculation of estimated glomerular filtration rate (eGFR). Estimation of: fasting and post prandial glucose, urea and creatinine serum levels and blood level of glyclated hemoglobin (HbA1c).

Results: Urinary KIM-1 levels were increased with the progression of nephropathy. Urinary KIM-1 levels were independent risk factor of (eGFR) and albuminuria in diabetic patients. Urinary KIM-1/Cr ratio was more sensitive than KIM-1. There was no correlation between urinary KIM-1/Cr ratio and GFR in all studied groups.

Conclusion: Urinary KIM-1/Cr ratio is a sensitive, noninvasive diagnostic tool for kidney affection in Type 2 diabetic Egyptian patients that seem to predict renal injury in early period independent of albuminuria. Due to lack of correlation, both KIM-1/Cr and Alb/Cr ratios are required to be calculated for Type 2 diabetic patients.

Recommendations: The use of KIM-1/Cr ratio as a diagnostic tool for kidney affection by measuring it in urine of Type 2 diabetic patients at risk of chronic kidney disease.

Author(s): EL-Attar HA , Khalil GI and Gaber EW

Abstract | Full-Text | PDF

Share This Article