AIM: To observe the concentration of RBP4 and IL-6 in vitreous of proliferative diabetic retinopathy(PDR).

METHODS: A total of 65 patients(66 eyes)were enrolled in Department of Ophthalmology, Renmin Hospital of Wuhan University from February 2017 to July 2017 with the informed consent. The patients were divided into PDR group(23 cases)and NPDR group(16 cases). Twenty-six patients without diabetic mellitus(DM)served as control group. The demography was matched among the groups, but the course of DM, the blood glucose level and the HbA1c level were elevated in the PDR group and the NPDR group(all P<0.05). Vitreous samples were collected during the procedure of vitrectomy. RBP4, IL-6, TNF-α concentrations in vitreous specimens were detected by ELISA. The differences of vitreous RBP4, IL-6 and TNF-α in various groups were statistically analyzed by ANOVA, respectively. The correlations between RBP4 and IL-6, TNF-α were calculated by Pearson correlation analysis.

RESULTS: The concentration of RBP4 in PDR group, the NPDR group and control group were 13.68±2.66, 11.03±1.12, 10.45±1.17μg/mL, and the concentration of IL-6 were 56.0±10.27, 20.92±5.77, 10.26±1.91pg/mL. RBP4 and IL-6 concentrations were elevated in PDR group compared with NPDR group and control group, with significant difference among three groups(F=12.135, 161.167; P<0.01). IL-6 concentrations in vitreous increased in the NPDR group in comparison with control group(P<0.05). RBP4 concentrations had no significant difference between the NPDR group and the group(P>0.05). Pearson correlation coefficient was significant positive between RBP4 concentration and IL-6 concentration(r=0.606, P=0.001).

CONCLUSION: RBP4 is probability involved in the inflammation pathogenesis of PDR. These results indicate that RBP4 could be a new target for the diagnosis and treatment of PDR.