Aqueous humor hepcidin prohormone levels in patients with primary open angle glaucoma

PURPOSE This study was designed to evaluate the levels of Interleukin-6 (IL6) and Hepcidin prohormone (Hep) in the serum and aqueous humor of patients with primary open-angle glaucoma (POAG), as well as those with senile cataract as a control group. METHODS Levels of IL6 and Hep were measured by enzyme-linked immunosorbent assay (ELISA) methods in serum and aqueous humor aspirates taken from 45 patients (POAG=20, Control=25) during anterior segment surgery. RESULTS The mean aqueous humor Hep concentration in eyes with POAG was significantly higher than that controls (34.55±23.01 ng/ml versus 20.82± 24.63 ng/ml, p=0.04). There was no significant difference between the serum Hep concentration of POAG and the control group (359.46±113.03 ng/ml versus 287.36±130.53 ng/ml, p=0.08). There was also no significant difference between either serum (6.18±5.22 versus 10.84±3.37, pg/ml p=0.112) or aqueous humor (4.39±3.06 versus 5.79±2.63, pg/ml p=0.14) IL6 concentrations of POAG and the control groups. No significant correlations were found between aqueous humor and serum Hep and IL6 levels in either POAG or the control groups (p>0.05). CONCLUSIONS The aqueous humor Hep level may exist locally and independent from the IL6 increase in patients with POAG, suggesting that Hep might represent a bridge protein between local inflammation and the consequent loss of retinal ganglion cells.