Differences in Gene Expression in Lymphocytes of Patients with High-tension, PEX, and Normal-tension Glaucoma and in Healthy Subjects

Abstract

Purpose Differences in the gene expression of leukocytes between patients with normal-tension glaucoma (NTG) and controls have been described. This study was performed in order to detect the differences in gene expression in peripheral lymphocytes in patients with primary open-angle glaucoma (POAG), patients with pseudoexfoliation glaucoma (PEX), and patients with NTG, and in healthy subjects. Ten patients with POAG, 11 patients with PEX, 10 patients with NTG, and 42 sex- and age-matched healthy persons were recruited. All study subjects were Caucasian. Twenty-two preselected genes were chosen and their expression in blood lymphocytes was quantified by real-time PCR. First, a univariate comparison among all groups was performed using the nonparametric Friedman test. Second, an L1 penalized logistic regression was performed. Using the Friedman test to compare the 4 groups, 9 genes showed a different expression (p<0.05). Comparing the controls vs patients with POAG, 8 genes were differently expressed (p<0.05). Comparing patients with PEX vs controls, 9 genes were significantly different (p≤0.05). The statistical analysis of patients with NTG vs controls showed a difference in gene expression of 7 genes (p≤0.05). All these genes were upregulated in the glaucoma groups compared with the controls. The genes RhoGDI and RAR showed the most significant statistical difference in the L1-penalized logistic regression. The genes overexpressed in POAG/PEX differed from the ones in NTG. In this masked study among the preselected 22 genes, several genes are overexpressed in the blood lymphocytes of Caucasian patients with glaucoma compared with the controls. The genes upregulated in POAG/PEX differed from the ones in NTG.