Urinary Smad1 as a New Biomarker for Diabetic Nephropathy in Patients with Type 1 Diabetes Mellitus Mohamed Mohamed Ismail * and Sally kamal Ibrahim Cairo University Kasr Alainy, Cairo, Egypt * Corresponding authors: Mohamed Mohamed Ismail, Faculty of Medicine, Cairo University Kasr Alainy, Cairo, Egypt, Tel: 0201144479999; E-mail: mohamed_i_smail@yahoo.com Received date: July 25, 2017; Accepted date: August 16, 2017; Published date: August 20, 2017 Copyright: © 2017 Ismail MM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Introduction: Type 1 diabetes mellitus is an autoimmune disease affecting children worldwide with many consequences disturbing their quality of life. Diabetic nephropathy is among the most important complications of T1DM. The reliability of albuminuria as a predictor and prognosticator for renal injury has been frequently questioned. Many markers were investigated to replace urinary albumin. The current study aimed to assess the potential value of urinary Smad1 as a new biomarker for the early diagnosis and assessment of severity of diabetic nephropathy in children with. Material and method: A case control cross sectional study with 53 patients with type 1 diabetes mellitus. 30 patients with diabetic nephropathy including 19 patients with microalbuminuria (urinary albumin creatinine ratio: 30-300 mg/gm) and 11 patients with macroalbuminuria (urinary albumin creatinine ratio: >300 mg/gm). The remainder 23 patients had normal urinary albumin levels. In addition, there were 20 healthy age and sex matched children who served as control group. In all subjects we assessed urinary albumin, urinary creatinine and urinary albumin creatinine ratio and urinary Smad1 levels Results: Urinary Smad1 levels and urinary Smad1 creatinine ratio show good sensitivity and specificity in detection of DN as compared to urinary albumin. The performance of SCR was better than urinary Smad1 with sensitivity and specificity of 100.0% and 96.0% for SCR, compared to sensitivity and specificity of 90.0% and 91.0% for urinary Smad1. Conclusion: Urinary Smad1 is a promising new biomarker for detection of diabetic nephropathy in patients with type 1 diabetes mellitus with high sensitivity and specificity. Keywords: Urinary Smad1; Biomarkers; Diabetic nephropathy Introduction Diabetes mellitus type 1 (T1DM) is an autoimmune disease afecting children worldwide with many consequences disturbing their quality of life. Diabetic nephropathy (DN) is among the most important complications of T1DM with signifcant association to patients’ morbidity and mortality [1]. Currently, albuminuria is generally accepted as an early marker for detection of DN. However, reliability of albuminuria as a predictor and prognosticator for renal injury has been ofen questioned due to the fact that even patients with normal urinary albumin levels can sufer substantial pathological injury [2] or reduced glomerular fltration rate (GFR) [3]. In addition micro albuminuria, as an early marker for diabetic nephropathy, has numerous confusing concerns related to the efect of exercise, urinary tract infection, acute illness and cardiac failure. Also, it is known that micro albuminuria and macro albuminuria can occur in non-diabetic subjects, signifying the non- specifcity of albuminuria as a predictor designed for early diagnosis of diabetic nephropathy [4]. Tis led to a continuous pursuit for other biomarkers to overcome this essential faw. In this context, many markers were investigated. Mehta et al. classifed urinary biomarkers according to the mechanism of their secretion in urine into markers of increased glomerular permeability including albumin, Cystatin C, immunoglobulins and transferrin; markers of extracellular matrix including transforming growth factor- beta (TGF-β), connective tissue growth factor (CTGF), Type IV collagen and Fibronectin; markers of epithelial-mesenchymal transition including fbronectin, matrix metalloproteinase and α- smooth muscle actin; markers of tubulointerstitial damage including kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), Liver-type fatty acid-binding protein (L-FABP), retinol binding protein and monocyte chemoattractant protein-1 (MCP-1) [5]. In addition many other urinary biomarkers including urinary γ-glutamyl transferase, urinary alkaline phosphatase, urinary peptidome-based classifer and osteoinductive factor are being investigated [6-8]. Smad1 in human was known for the 1st time in human the TGF-β/ Smads signaling pathway. TGF-β is an eminent factor the pathway of fbrous tissue formation in many tissues. It is greatly expressed in glomerular epithelium. It is also expressed in the renal tubular epithelium [7]. Multiple animal studies provided evidence that Smad1 play a pivotal role in the development of DN. Tis is mediated by increasing synthesis of extracellular matrix via diferent pathways Ismail et al., J Diabetes Metab 2017, 8:8 DOI: 10.4172/2155-6156.1000756 Open Access J Diabetes Metab, an open access journal ISSN:2155-6156 Volume 8 • Issue 8 • 1000756 J o u r n a l o f D i a b e t e s & M e t a b o l i s m ISSN: 2155-6156 Journal of Diabetes and Metabolism Research Article