Definite diagnosis of diabetic nephropathy is currently based on renal biopsy findings. In most cases, however, the diagnosis can be reliably made in patients with macroalbuminuria in the presence of diabetic retinopathy.Microalbuminuria is often used as a prognostic marker in type 1 diabetes, because approximately 50% of type 1 diabetes patients with microalbuminuria will eventually develop diabetic nephropathy. Conversely, microalbu- minuria is of much less value as a marker in DM because it has a variety of causes, including hypertension. Thus, additional markers are needed to identify patient groups with a high risk of developing overt diabetic nephropathy. The aims of this study is checking urine UbA52 levels with ELISA to identify its significance in the diagnosis of diabetic nephropathy.

It is now well recognized that the incidence of diabetes is increasing worldwide. It is the leading cause of end-stage renal disease (ESRD) in Western countries. Diabetic nephropathy has been reported to occur in 25%-40% of people with diabetes. The appearance of microalbuminuria usually is regarded as incipient nephropathy, but recently, work has suggested that some individuals with diabetes and decreased GFR may not have an increased urinary AER.Identification of markers for prediction of the clinical course of diabetic nephropathy remains a major challenge. Previous research showed that m/z14766 protein by mass spectrometry, was selectively excreted in the urine of diabetic nephropathy patients, the m/z 14766 mass peaks were identified as UbA52. We suppose that UbA52 can be regard as a simple and practical biomarker for diagnosis of diabetic nephropathy.

Inclusion Criteria:

1. diabetes diagnostic criteria (WHO, 1999),age < 80 years old, gender not limited;
2. diabetic with macro-or microalbuminuria;
3. the subjects not took hemodialysis;
4. with proteinuria due to nondiabetic renal disease :Hypertensive renal damage,drug-induced acute interstitial nephritis, IgA, primary membranous nephropathy,FSGS or MCD, which were confirmed by renal biopsy.

Exclusion Criteria:

1. acute diabetic complications: ketoacidosis, hypertonic coma;
2. the diagnosis of malignant tumors, particularly affecting the liver and kidney function of tumor and the application of radiation and chemotherapy treatment of patients;
3. cardiac insufficiency, heart function class 3 or above;
4. data is not complete, have an impact on the results;
5. not hospitalized patients;
6. accept long-term oral or static point methods such as steroid hormone therapy, application of renal toxicity of drugs;
7. with the exception of primary kidney disease and other causes lead to eye disease;
8. the combination of respiratory system infection or other systemic diseases and patients with severe primary diseases, vigorous exercise within 24 hours;
9. pregnancy or breastfeeding women
10. there is a clear liver disease, its alanine or aspertate aminotransferase 2 times higher than normal limit;
11. reluctant to collaborators and psychiatric patients;
12. has been undergoing hemodialysis.

patients with type 2 diabetic,diabetic with macro-or microalbuminuria and proteinuria due to nondiabetic renal disease from Hebei Medical University the Third Hospital.