Significance of joint detection of urinary proteins with low molecular weight as prognostic indicators for early diagnosis of diabetic nephropathy

Diabetic nephropathy (DN) is a main cause of end-stage renal disease. Early diagnosis and intervention can greatly increase the prognosis. This study was aimed at investigating the clinical significance of urinary excretion of proteins with low weight including microalbuminuria (MA), α1-microprotein (A1M), β2-microglobulin (β2-MG) and retinol binding protein (RBP) as indicators for early diagnosis of DN. A total of 196 DN patients were further classified into 4 groups (non-albuminuria, normoalbuminuria, microalbuminuria and macroalbuminuria) and 80 healthy subjects served as a control group. The level of urinary A1M, MA β2-MG and RBP was simultaneously evaluated. Both ACR and eGFR were measured for all subjects. The urinary level of A1M, MA and β2-MG showed a statistically significant increase in all diabetic patients compared to the healthy group. Urinary A1M, MA β2-MG and RBP were positively correlated with ACR levels in all patients and the four proteins strongly correlated with each other. Combined detection of urinary MA, A1M, β2-MG and RBP should be examined reliable for the early diagnosis of DN.