Abstract: Objective　To investigate the clinical significance and diagnostic value of serum fibrin-3 (Ficolin-3) and S100B in diabetic peripheral neuropathy (DPN). Methods　A total of 126 patients with type 2 diabetes who were treated in our hospital from January 2019 to February 2020 were selected in this study. Sixty-eight patients with simple type 2 diabetes were included in the diabetes group, and 58 patients with type 2 diabetes complicated with DPN were included in the neuropathy group. In addition, 40 healthy people who were examined in our hospital during the same period were selected as the control group. The clinical data, biochemical indexes, motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) of median nerve were collected in the three groups of patients. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of serum Ficolin-3 and S100B. The clinical characteristics of study objects in the three groups were compared. The risk factors of type 2 diabetes patients complicated with DPN and the correlation between serum Ficolin-3, S100B and clinical indexes were analyzed. Receiver operating characteristic (ROC) curve was used to analyze the auxiliary diagnostic value of serum Ficolin-3 and S100B for DPN. Results　The levels of systolic blood pressure (SBP), fasting blood glucose (FBG), homeostasis model assessment of insulin resistance index (HOMA-IR), high sensitivity C-reactive protein (hs-CRP) and S100B were significantly higher in neuropathy group than those in diabetes group and control group, and the level of Ficolin-3 was significantly lower than that in diabetes group and control group (P＜0.05). Multivariate Logistic regression analysis showed that the level of hs-CRP≥2.1 mg/L, the level of MNCV≤50 m/s, the level of SNCV≤47 m/s and the level of S100B≥200 ng/L were the risk factors for type 2 diabetes patients complicated with DPN (P＜0.05), and the level of Ficolin-3≥22 μg/L was the protective factor for type 2 diabetes patients complicated with DPN (P＜0.05). Correlation analysis showed that serum ficolin-3 was negatively correlated with S100B (r=-0.338, P＜0.05). ROC curve analysis showed that the serum Ficolin-3 (AUC=0.747) and S100B (AUC=0.734) had diagnostic values for DPN. The diagnostic value of combined application was further improved (AUC=0.819). Conclusion　The serum Ficolin-3 and S100B are expressed abnormally in DPN, and both of them have certain auxiliary diagnostic values for DPN.

Key words: diabetic neuropathies, S100 proteins, ROC curve, Ficolin-3, S100B