title: Increased intravitreous interleukin-18 correlated to vascular endothelial growth factor in patients with active proliferative diabetic retinopathy.
abstract: OBJECTIVE
  To determine the intravitreous levels of interleukin-18 (IL-18) and vascular endothelial growth factor (VEGF) in patients with proliferative diabetic retinopathy (PDR) and to ascertain their association with PDR activity.
  
  
  METHODS
  Thirty eyes of 30 diabetic patients with PDR were divided into two groups (active PDR, n = 17; quiescent PDR, n = 13). Fifteen eyes of 15 non-diabetic patients (macular hole, n = 9; epiretinal membrane, n = 6) served as controls. All vitreous fluid samples were obtained during vitrectomy. IL-18 and VEGF were measured by enzyme-linked immunosorbent assay. Serum glycosylated hemoglobin as well as the basic demographic data was documented.
  
  
  RESULTS
  Both IL-18 and VEGF levels were higher in patients with PDR than control (P < 0 .01 and P < 0 .01, respectively). Both IL-18 and VEGF in active PDR were higher than those in quiescent PDR (P = 0.048 and P = 0.03, respectively). A significant positive correlation (Spearman rank correlation coefficient (r s) = 0.502, P = 0.005) between IL-18 and VEGF was observed in all PDR patients but not in the control. The correlation between VEGF and IL-18 was even stronger in the subgroup of active PDR (r s = 0.684; P = 0.002), whereas no significant correlation was found in the subgroup of quiescent PDR (r s = 0.049; P = 0.873).
  
  
  CONCLUSIONS
  Both intravitreous IL-18 and VEGF were elevated in patients with PDR, which were closely correlated in active PDR. IL-18 may contribute to retinal angiogenesis by acting together with or via VEGF, and become the potential therapeutic target for treatment of PDR.
authors: Eye Hospital, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang, China, 325027.
authors: Zongming
authors: Z
authors: Song
authors: Min
authors: M
authors: Sun
authors: Fen
authors: F
authors: Zhou
authors: Fang
authors: F
authors: Huang
authors: Jia
authors: J
authors: Qu
authors: Ding
authors: D
authors: Chen
mesh_terms: D062186:Arterial Pressure; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D020382:Interleukin-18 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D006442:Glycated Hemoglobin; D020382:Interleukin-18; D042461:Vascular Endothelial Growth Factor A; C000589760:IL18 protein, human; C467484:VEGFA protein, human; C517652:hemoglobin A1c protein, human