A cross‐sectional study of vitreous and serum high mobility group box‐1 levels in proliferative diabetic retinopathy

PURPOSE: We determined vitreous and serum levels of high mobility group box-1 (HMGB-1) in patients with proliferative diabetic retinopathy (PDR) and elucidate their relationship with receptor for advanced glycation end products (RAGE), vascular endothelial growth factor (VEGF) and interleukin-1beta (IL-1beta). METHODS: In this cross-sectional study, patients with PDR who underwent vitrectomy were enrolled, and the control group included non-diabetic eyes. Vitreous and serum samples were analysed for HMGB-1, RAGE, VEGF and IL-1beta by ELISA. We investigated the correlation between serum and vitreous levels of each cytokine, and we analysed the influence of intravitreal anti-VEGF treatment prior to vitrectomy on the cytokine levels in PDR. RESULTS: Of 78 eyes of 78 patients enrolled consecutively, there were 32 PDR eyes and 46 control eyes. The serum levels were higher in diabetic than in non-diabetic subjects for HMGB-1, RAGE, VEGF and IL-1beta (all p < 0.001), respectively. Similarly, the vitreous levels were higher in diabetic than in non-diabetic subjects for HMGB-1 (p < 0.001), RAGE (p = 0.001), VEGF (p < 0.001) and IL-1beta (p < 0.001), respectively. We found a positive correlation between serum and vitreous levels of HMGB-1 in patient with PDR (p = 0.047, R = 0.353). There was a negative correlation between serum and vitreous levels of VEGF in patient with PDR (p = 0.001, R = -0.546). For the subgroup analysis, we detected that the vitreous levels of RAGE were significantly lower in patients who underwent anti-VEGF injection prior to vitrectomy than those who did not (p < 0.001). CONCLUSIONS: Our findings suggest that HMGB-1 is involved in PDR disorders, and it may be a novel therapeutic target to inhibit progression of PDR.