Multiplex bead analysis of urinary cytokines of type 2 diabetic patients with normo- and microalbuminuria.

Renal damage of diabetic patients is linked to chronic low-grade inflammation. The aim of this study was to analyze urinary concentrations of 27 cytokines in type 2 diabetic patients with normo- and microalbuminuria by multiplex bead immunoassay. Urinary levels of IL-8, IP-10, MCP-1, G-CSF, EOTAXIN, RANTES, and TNF-α in microalbuminuric patients were significantly increased compared to those in normoalbuminuric patients (p < 0.05) or controls (p < 0.05). GM-CSF, MIP-1α, and MIP-1β levels were more elevated in microalbuminuric patients than in controls (both p < 0.05). IP-10 and MCP-1 levels were correlated with urinary albumin excretion rate (r = 0.668 and 0.544, both p < 0.01), and estimated glomerular filtration rate (r = -0.454 and -0.418, both p < 0.05). EOTAXIN, GM-CSF, IP-10, MCP-1, and RANTES levels were correlated with HbA1c (r = 0.457, 0.466, 0.678, 0.567, 0.542, respectively, p ≤ 0.01). These results indicate that urinary cytokine determination might be useful for the early diagnosis and management of patients with diabetic nephropathy.