CD38 Upregulation in Peripheral Blood Lymphocyte Subsets in Patients with Primary Glaucoma Correlates with Disease Severity

Introduction To evaluate cluster of differentiation (CD)38 expression in peripheral blood lymphocyte subsets in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) and explore its association with glaucoma onset and severity. Methods 46 patients each with POAG and PACG and 46 healthy controls were enrolled. Flow cytometry was utilized to determine CD38 expression levels in three lymphocyte subset groups. Spearman's correlation analysis was used to investigate the correlation of CD38 expression levels with glaucoma severity. ROC analysis evaluated the discriminatory power of CD38 expression for primary glaucoma. Results Compared with the control group, CD38 expression levels were upregulated in CD4+ T cells (P < 0.0001) and regulatory T (Treg) cells (P < 0.001) in the POAG group and in CD4+ T cells in the PACG group (P < 0.0001). Additionally, the expression levels of CD38 in CD4+ T cells (R = -0.63, P < 0.0001) and Treg cells (R = -0.44, P < 0.001) showed a negative correlation with the mean deviation in the POAG group. Areas under the ROC curve for distinguishing POAG using CD38 expression in CD4+ T and Treg cells were 0.745 and 0.683, respectively (both P < 0.05). Conclusion To our knowledge, this is the first study to report that CD38+CD4+ T cells and CD38+ Treg cells are associated with the onset and severity of POAG. Therefore, CD38 expression warrants further investigation as a potential immunological indicator associated with POAG.