Elevated levels of plasma tumor necrosis factor alpha in patients with pseudoexfoliation glaucoma

Abstract

BackgroundTumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine, which plays a role in glaucomatous neurodegeneration. Based on the plausible role of inflammation in the pathogenesis of pseudoexfoliation glaucoma (PEG), we investigated whether there is any relationship between the levels of plasma TNF-α and PEG or any of its clinical indices in comparison to normal controls.MethodsThe study was designed as a retrospective analysis. Plasma samples from 49 PEG patients and 88 non-glaucomatous controls were evaluated for TNF-α levels using an enzyme-linked immunosorbent assay (ELISA). The assay was performed in duplicates on a biochemical/ELISA analyzer.ResultsThe two study groups were similar in age, sex and systemic disease distribution. The mean TNF-α concentration was significantly higher in the PEG patients (5.54±4.58 pg/mL) than in the control subjects (0.93±1.49 pg/mL; 95% confidence interval [CI] =3.50–5.72; p=0.000). The overall dose–response trend was significant (χ2=57.07, df=2; p=0.000). A moderate positive and significant correlation was seen between TNF-α level and cup/disc ratio, an important clinical index for PEG. Besides, binary logistic regression analysis showed that the risk of PEG was most significantly affected by TNF-α level as compared to no association with age and sex. In receiver operating characteristic analysis, the area under the curve was 0.777 (95% CI =0.682–0.872) and statistically significant (p=0.000).ConclusionElevated systemic levels of inflammatory marker, TNF-α, are associated with PEG and may possibly serve as a biomarker for undiagnosed early glaucoma and/or as a marker for disease progression.

Association of increased levels of plasma tumor necrosis factor alpha with primary open-angle glaucoma

“… 15 In addition, based on a similar mechanism of an activated immune response, we recently demonstrated an association between plasma TNF-α and pseudoexfoliation glaucoma. 18 …”

“…However, the elevated level of TNF-α in the plasma (in this study) and the AH (previous studies) is a clear indication of an activated immune response triggered by inflammation and its plausible association with glaucomatous degeneration, 12 which is in accordance to our previous observation in pseudoexfoliation glaucoma. 18 …”

“…Plasma TNF-α level was measured using an ELISA (Catalog No STA00C, Quantikine ® ELISA; R&D Systems Inc., Minneapolis, MN, USA) in 51 POAG cases and 88 non-glaucomatous controls as described previously. 18 The assay utilizes a monoclonal antibody specific for human TNF-α that is precoated onto a microplate and was performed in duplicate on a ChemWell-T bioanalyzer (Awareness Technology Inc., Palm City, FL, USA), as per the manufacturer’s instructions (R&D Systems Inc.). The steps were programmed using a ChemWell-T Assay Editor in the standard ELISA assay mode.…”

“… 17 Moreover, we recently showed elevated levels of plasma TNF-α in a group of patients with pseudoexfoliation glaucoma. 18 …”

Association analysis of polymorphisms rs12997 in ACVR1 and rs1043784 in BMP6 genes involved in bone morphogenic protein signaling pathway in primary angle-closure and pseudoexfoliation glaucoma patients of Saudi origin

“…PACG patients (n = 101) were diagnosed based on clinical evidence of anatomically closed angle showing the occurrence of appositional or synnechial closure of the anterior chamber angle (at least 270 o of the angle is occluded); raised IOP (≥21 mmHg); presence of optic disk damage with cup/disc ratio of at least 0.7 (in at least one eye); and loss of peripheral or advanced visual field [18]. PXG patients (n = 95) showed the presence of flaky exfoliation material along the pupil edges or anterior lens capsule, glaucomatous optic neuropathy and associated visual field loss, and high IOP in either or both the eyes as described previously [19]. Patients harboring secondary forms of glaucoma, history of optic neuropathies or visual impairment unrelated to glaucoma, steroid usage, ocular trauma, absence of sufficient fundus visualization for disk assessment, or refusal to enroll were excluded.…”