Abstract
BACKGROUND: Diabetic nephropathy (DN) is the most prevalent reason for chronic kidney diseases that end up with renal failure if it is not diagnosed and treated at early stages. Therefore, low-cost, non-invasive, and easy-to-use tests are necessary for efficient follow-up and early diagnosis of DN in diabetic patients. Interleukin-8 (IL-8) as the main recruiter of neutrophils may play a role in inflammatory responses that end up with renal damage and dysfunction in DN. METHODS: In a case-control study, serum levels of IL-8 and neutrophil-to-lymphocyte ratios (NLR) were evaluated in correlation with clinical findings in 60 patients with DN, 60 type 2 diabetic patients without renal involvement, and 60 age and sex-matched healthy subjects. RESULTS: IL-8 levels were significantly higher in diabetic nephropathy patients than in diabetic patients without nephropathy and healthy controls (both p-value<0.0001). However, the frequency of neutrophils in both groups of patients was higher than that of healthy individuals. Despite increased NLRs in diabetic patients, the difference was only significant between DN and healthy groups (P-value: 0.03). A direct correlation was observed between IL-8 levels and NLR (P-value: 0.02), and a negative correlation between IL-8 and eGFR (P-value: 0.01). In addition, UACR was associated with IL-8 concentrations (P-value: 0.04) in DN patients. IL-8 level showed a higher diagnostic value for diabetic nephropathy [AUC: 0.87 (p<0.0001)] than NLR and neutrophil count. CONCLUSION: Increased level of IL-8 in DN is associated with elevated NLR and UACR, and reduced eGFR. Therefore, IL-8 levels might be considered a diagnostic or prognostic biomarker for DN.