Serum YKL-40 levels as a novel marker of inflammation and endothelial dysfunction in patients with pseudoexfoliation syndrome

Abstract

Purpose To evaluate serum levels of YKL-40 in patients with pseudoexfoliation syndrome (PEX) in comparison with those of age-and sex-matched healthy subjects. Methods Forty patients with PEX (PEX group) and 40 age-and sex-matched control subjects (control group) were enrolled in the study. An enzyme immunoassay method using the commercially available test MicroVue YKL-40 was used to measure serum YKL-40 concentration. Systolic and diastolic blood pressures, serum levels of high sensitivity C-reactive protein (hsCRP), total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglycerides were also examined. Results The mean age was 54.4 ± 7.6 (ranging 41-65) years in each group. The mean serum YKL-40 level of the PEX group was significantly higher than that of the control group (Po0.001). In addition, the mean serum HsCRP, total cholesterol, LDL, and triglycerides levels were significantly higher, and mean serum HDL level was significantly lower in the PEX group than in the control group (all Po0.001, excluding both P ¼ 0.002 for triglycerides and HDL levels). Further, the mean systolic and diastolic blood pressures were significantly higher in the PEX group than in the control group (P 1 ¼ 0.001 and P 2 ¼ 0.01, respectively). Conclusion We have shown a relationship between PEX and elevated serum levels of YKL-40. We imply that a better understanding of the role of YKL-40 in the pathogenesis of endothelial dysfunction and atherosclerosis is necessary to develop new therapies for preventing or treating PEX. Further studies are warranted to clarify the clinical relevance of these findings.

Update on pseudoexfoliation syndrome pathogenesis and associations with intraocular pressure, glaucoma and systemic diseases

“…Additional evidence is provided by the finding of increased levels of activity of antioxidants like superoxide dismutases, aldehyde dehydrogenase 1, and microsomal GST1 in anterior lens epithelium of eyes with PEX, suggesting that diseased tissue appears to respond to oxidative stress [45]. Elevated serum levels of YKL-40, which is a proinflammatory protein used as novel marker of inflammation and endothelial dysfunction, have also been recently reported in patients with PEX compared to age-matched controls [46].…”

Elevated neutrophil-to-lymphocyte ratio in pseudoexfoliation syndrome

“…[15][16][17] The relationship between NLR and diabetic retinopathy was shown. 11 The assessment of NLR in patients with AMD was studied by Ilhan N et al 17 In their study, patients with AMD have higher NLR compared with controls and NLR correlates with age and disease severity.…”

“…The relationship between PEXS and serum YKL-40, a proinflammatory protein that has been demonstrated to have a role in the pathogenesis of endothelial dysfunction was shown. 11 Proinflammatory cytokines in eyes with early and late stages of PEX syndrome/glaucoma were studied. 12 The authors support a role for a stressinduced, spatially, and temporally restricted subclinical inflammation in the onset of the fibrotic matrix process characteristic of PEXS/PEXG.…”

Serum Levels of Omentin in Pseudoexfoliation Syndrome

“…Either serum or aqueous humor concentration of asymmetric dimethyl arginine was found to be significantly higher in patients with PES compared with healthy controls, which implies that endothelial dysfunction plays a role in this particular systemic disease. Similarly, Turkyilmaz et al 24 have shown a relationship between PES and elevated serum levels of YKL-40 (chitinase-3-like protein 1), which has a role in endothelial dysfunction and inflammation. To date, elevated serum levels of several other molecules that have definitive roles in inflammatory processes (eg, cardiovascular and cerebrovascular disease, endothelial dysfunction), including high-sensitivity C-reactive protein, 25 tumor necrosis factora, 25 antiphospholipid antibody, 26 a 1-antitrypsin, 27 homocysteine, 28 and hydroxyproline 29 have been studied in the serum of patients with PES.…”