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Abstract #71461 Published in IGR 18-3
Analysis of the Interleukin-6 (-174) Locus Polymorphism and Serum IL-6 Levels with the Severity of Normal Tension Glaucoma
Liang CY; Feng SC; Lin KH; Lee HN; Shen YC; Wei LC; Chang CJ; Hsu MY; Yang YY; Chiu CH; Wang CYOphthalmic Research 2017; 57: 224-229
PURPOSE: In normal tension glaucoma (NTG), factors other than elevated intraocular pressure are likely to have a role in the pathogenesis of optic neuropathy. Recent studies of glaucoma or retinal ganglion cells (RGCs) reveal that the cytokine interleukin-6 (IL-6) is linked to the pathogenesis of glaucoma and may regulate RGC survival or death. The IL-6 (-174) G allele has also been shown to increase the IL-6 protein. We hypothesized that the IL-6 (-174) polymorphism may be a predisposing genetic factor affecting the severity of glaucoma. The aim of the present study was to evaluate the IL-6 polymorphism and serum IL-6 levels as a potential risk factor related to the severity of NTG. METHODS: A total of 256 subjects with NTG in the Chinese population were enrolled. The patients were genotyped for the IL-6 (-174) C/G polymorphism. Genomic DNA was amplified by a polymerase chain reaction, followed by the enzymatic restriction fragment length polymorphism technique. Serum IL-6 levels were measured by ELISA. Patient age at diagnosis, cup/disc (C/D) ratio, rim area (RA), retinal nerve fiber layer (RNFL) thickness, and visual field (VF) were analyzed. The associations between genotypes of IL-6 (-174) C/G and the clinical parameters were calculated using a logistic regression. RESULTS: The IL-6 (-174) GC genotype in NTG patients was significantly associated with a smaller C/D ratio (p = 0.04), larger RA (p = 0.04), and thicker RNFL (p = 0.05) compared with IL-6 (-174) GG patients. The allele frequency of IL-6 (-174) C was significantly higher in the NTG patients at an early-moderate stage than at an advanced stage according to the C/D ratio (OR 0.55; 95% CI 0.31-0.99). Pattern standard deviation of VF was borderline lower in IL-6 (-174) GC patients (p = 0.06), and serum IL-6 levels were borderline higher in advanced stages than in early-moderate stages (7.66 ± 3.22 vs. 4.46 ± 3.83 pg/mL; p = 0.06). CONCLUSION: The IL-6 (-174) GC genotype is associated with a smaller C/D ratio, larger RA, and thicker RNFL compared with IL-6 (-174) GG in NTG patients. We found that the IL-6 (-174) G/C polymorphism and serum IL-6 levels may be associated with the severity of NTG.
Department of Ophthalmology, Taichung Veterans General Hospital, National Yang-Ming University, Taichung, Taiwan, ROC.
Full articleClassification:
9.2.4 Normal pressure glaucoma (Part of: 9 Clinical forms of glaucomas > 9.2 Primary open angle glaucomas)
3.4.2 Gene studies (Part of: 3 Laboratory methods > 3.4 Molecular genetics)
3.10 Immunobiology (Part of: 3 Laboratory methods)
