title: Effects of intravitreal injection of bevacizumab on inflammatory cytokines in the vitreous with proliferative diabetic retinopathy.
abstract: BACKGROUND
  To investigate the effects of preoperative intravitreal injection of bevacizumab (IVB) on the levels of 27 inflammatory cytokines, including interleukins (ILs) and vascular endothelial growth factor.
  
  
  METHODS
  From among 200 patients who had proliferative diabetic retinopathy and underwent vitrectomy in our department from September 2009 to October 2010, 8 study subjects met the enrollment criteria in which both eyes at nearly equivalent stages underwent vitrectomy. The first vitrectomy for each patient was performed without IVB (control group), whereas the second vitrectomy on the contralateral eye was performed with IVB treatment (1.25 mg/0.05 mL) 3 days before surgery (IVB group). Undiluted vitreous fluid was collected at the start of each vitrectomy. A multiplex assay was used to simultaneously determine the levels of 27 inflammatory cytokines and growth factors.
  
  
  RESULTS
  Mean vascular endothelial growth factor levels were significantly lower in the IVB group (519.69 pg/mL) than in the control group (11,807.44 pg/mL) (P = 0.012, Wilcoxon signed rank test). Moreover, the mean levels (IVB/control, pg/mL) of IL-1RA (38.50/62.31, P = 0.036), IL-5 (27.75/34.00, P = 0.018), IL-10 (433.63/1,995.94, P = 0.012), IL-12 (246.69/1,033.69, P = 0.012), IL-13 (707.50/1,450.38, P = 0.012), and interferon γ (71.13/84.69, P = 0.036) were significantly lower in the IVB group. No other significant differences were observed in the levels of the other 20 cytokines and growth factors between the 2 groups.
  
  
  CONCLUSIONS
  Preoperative IVB reduced not only the intravitreal vascular endothelial growth factor level but also the intravitreal levels of other inflammatory cytokines, including IL-1RA, IL-5, IL-10, IL-12, IL-13, and interferon γ. These results indicate the interaction of some cytokines in the vitreous fluid of proliferative diabetic retinopathy patients and suggest the possibility that preoperative IVB may not only reduce vascular proliferation by its direct antivascular endothelial growth factor effect but also modulate the inflammatory response through putative cytokine networks. None of the other cytokines examined were elevated after IVB.
authors.affiliation: Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Kaori
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Yokoi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Miyagawa
authors.forename: Tomomi
authors.initials: T
authors.lastname: Metoki
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nakazawa
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D016207:Cytokines / Q000378:metabolism*; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000378:metabolism / Q000601:surgery; D005260:Female; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D016207:Cytokines; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab