The value of radioimmunoassay for urinary renal function in evaluation of the development of diabetic kidney disease in type 2 diabetes

Objective To evaluate the value of glomerular protein markers(albumin & IgG) and tubular protein markers(β2-MG & α1-MG) in evaluating the development of diabetic kidney disease(DKD) in type 2 diabetics. Methods A total of 154 type 2 diabetics and 77 non-diabetic controls were recruited and divided into 3 groups of mild,moderate and severe impairment according to the level of estimated glomerular filtration rate(eGFR). Clinical parameters,markers of kidney damage and receiver operating characteristic curve(ROC) curve were employed for analyzing the values of diagnosing DKD. Results As compared with controls,albumin and IgG rose during mild impairment(a median of albumin 1.78 μg/mL vs 1.14 μg/mL,P=0.022,a median of IgG 1.44 μg/mL vs 0.84 μg/Ml,P=0.038). CysC,β2-MG and α1-MG became elevated during moderate impairment(versus control P_CysC=0.029,P_β2-MG<0.001,P_α1-MG<0.001). ROC curve indicated that albumin(AUC=0.800),IgG(AUC=0.802) and α1-MG(AUC=0.791) were more effective in diagnosing DKD. Conclusion Different markers of kidney damage are elevated during different stages. For DKD,both albumin and IgG are effective for making an early diagnosis. And α1-MG is more suitable for evaluating tubular damage. So,while evaluating the damage of kidney,both glomerular and tubular protein markers should be adopted.