AIMS: To investigate if nuclear NF-κB p65 expression in ex vivo isolated peripheral blood mononuclear cells correlates with urinary MCP-1 or RANTES and the severity of type 2 diabetic nephropathy. METHODS: According to their urinary albumin-to-creatinine ratio (uACR), 107 patients with type 2 diabetes (eGFR >60 ml/min) were divided into normal albuminuria group (DN0 group, 38 cases), microalbuminuria group (DN1 group, 38 cases), and macroalbuminuria group (DN2 group, 31 cases), compared with matched healthy normal control group (NC group, 30 cases). Nuclear NF-κB p65 protein expression levels in peripheral blood mononuclear cells were detected by western blotting. Real-time quantitative polymerase chain reaction was used to detect NF-κB p65 mRNA expression and ELISA assay was used to detect the levels of urinary MCP-1 and RANTES. RESULTS: Nuclear NF-κB p65 protein and NF-κB p65 mRNA expression levels in peripheral blood mononuclear cells, urinary MCP-1/Cr and RANTES/Cr were all significantly higher in all diabetes groups as compared with NC group. In particular, the increase of nuclear NF-κB p65 protein and NF-κB p65 mRNA expressions, urinary MCP-1/Cr and RANTES/Cr all correlated with the severity of type 2 diabetic nephropathy as indicated by the increase in uACR. Pearson correlation analysis indicated that both urinary MCP-1/Cr and RANTES/Cr were positively correlated with nuclear NF-κB p65 protein or NF-κB p65 mRNA levels. Stepwise multiple regression analysis showed that nuclear NF-κB p65 protein or NF-κB p65 mRNA was an independent variable for urinary MCP-1/Cr, and MCP-1/Cr and RANTES/Cr were two independent variables for uACR. CONCLUSION: Our research demonstrates that nuclear NF-κB p65 protein and mRNA expressions in ex vivo isolated peripheral blood mononuclear cells well correlate with urinary MCP-1/Cr, RANTES/Cr and the severity of type 2 diabetic nephropathy.