Increased interleukin-6 in aqueous humor of neovascular glaucoma.
OBJECTIVE
To demonstrate the involvement of proinflammatory cytokines in intraocular neovascularization by detecting the presence of interleukin (IL)-6, IL-2, and tumor necrosis factor (TNF)-alpha in aqueous humor and serum of patients with neovascular glaucoma (NVG) secondary to central retinal vein occlusion (CRVO).


METHODS
According to the grade of iris neovascularization (NVI), patients with CRVO were divided into three groups: CRVO without NVI, CRVO with NVI, and CRVO with regressed NVI. Healthy patients with cataract were enrolled as control subjects. Enzyme-linked immunosorbent assay was used to quantitate the concentrations of the cytokines IL-6, IL-2, and TNF-alpha in aqueous humor and serum from patients with NVG and control subjects.


RESULTS
In serum, the levels of IL-6, IL-2, and TNF-alpha did not differ among groups. In aqueous humor, only IL-6 showed significant change among groups. IL-6 levels in aqueous humor of group 2, CRVO with NVI (1532.0+/-221.1 pg/ml; P < 0.001), and group 3, CRVO with regressed NVI (234+/-154.6 pg/ml; P < 0.001), were significantly higher. There was no significant difference in IL-6 levels between the control group (26.4+/-21.8 pg/ml) and group 1 (15.6+/-0.9 pg/ml).


CONCLUSIONS
The inflammatory cytokine IL-6 in aqueous humor increased spatially and temporally correlated with the grade of NVI in patients of NVG secondary to CRVO. The aqueous IL-6 increased in NVI and decreased after vessels regressed. It is possible that the significantly higher level of IL-6 was due to intraocular synthesis because of the minimal change in serum. The increased level of IL-6 may have a putative role along with other angiogenic factors in angiogenesis of NVG as a possible predictor of NVI.
Chen
K H
KH
Department of Ophthalmology, Veterans General Hospital-Taipei, National Yang-Ming University, Taiwan, Republic of China. kchen@vision.eri.harvard.edu
Wu
C C
CC
Roy
S
S
Lee
S M
SM
Liu
J H
JH
D000368:Aged; D001082:Aqueous Humor / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015355:Glaucoma, Neovascular / Q000209:etiology / Q000378:metabolism*; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D007498:Iris / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000145:classification / Q000150:complications; D012170:Retinal Vein Occlusion / Q000150:complications; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D007376:Interleukin-2; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha