Association of Plasma Tumor Necrosis Factor-alpha (tnf-α) Levels in Patients with Primary Open Angle Glaucoma

To investigate the association of plasma levels of tumor necrosis factor-alpha (TNF-α) in patients with primary open angle glaucoma (POAG) patients as compared to non-glaucomatous controls. TNF-α concentrations were measured using sandwiched enzyme-linked immunosorbent assay (ELISA) in plasma samples from 39 POAG patients and 36 controls. The assay was performed in duplicate on an automated ChemWell-T ELISA analyzer. The mean (± SD) concentration of plasma TNF-α in POAG patients (1.99 ± 2.32 pg/mL) was significantly increased (P = 0.0144) as compared to controls (0.82 ± 1.62). Similarly, the median levels were also found to be significantly different (P = 0.03). Plasma TNF-α level is significantly elevated in POAG patients as compared to non-glaucomatous control group supporting a key role of systemic TNF-α in glaucoma. The results of these findings however, need to be replicated in larger cohort in our population. INTRODUCTION Tumor necrosis factor-alpha (TNF-α) is a pleiotropic inflammatory cytokine associated with tissue ischemia, neuronal damage, and remodeling [1]. TNF-α is found to be elevated in patients with neurodegenerative diseases such as Alzheimer's disease [2], Parkinson's disease [3], and multiple sclerosis [4] suggesting a causative role of TNF-α in neurodegenerative disorders, including glaucoma. TNF-α is expressed in optic nerve and retina of human glaucomatous eyes and parallels the progression of optic nerve damage [5]. Human and animal in vivo studies have shown that serum or aqueous levels of TNF-α are elevated in patients with glaucoma and elicit retinal-ganglion cell (RGC) apoptosis suggesting that TNF-α plays a critical role in glaucomatous degeneration [6-8]. The purpose of this study is to compare human plasma