Increased granulysin in the peripheral blood and tissues of patients with oral lichen planus

Oral lichen planus (OLP) is a chronic inflammatory disease of unclear etiology and pathogenesis. Granulysin (GNLY) participates in various immune responses and mediates various skin diseases. However, its expression in OLP has not been reported. This study was to investigate whether there was an abnormal expression of GNLY in the peripheral blood and tissues of patients with OLP. Twenty patients with non-erosive OLP, twenty patients with erosive OLP, and twenty healthy controls were enrolled. The mRNA expression of GNLY in the peripheral blood and tissues was detected using RT-qPCR. The protein expression of GNLY in the peripheral blood plasma was measured using ELISA. The GNLY in tissues was investigated using immunohistochemistry. The mRNA and protein expression of GNLY in non-erosive and erosive OLP patients, when compared with the controls, were upregulated both in the peripheral blood and tissue. Also, in non-erosive and erosive OLP lesion tissues, there was a weak positive expression of GNLY in the lymphocyte membrane of the lamina propria layer and was less expressed in the epithelial layer. In normal mucosa, GNLY was hardly expressed. Furthermore, the immunohistochemical levels of GNLY in non-erosive and erosive OLP lesion were significantly higher than that in the normal oral mucosa. In conclusions, the expression of GNLY in the peripheral blood and tissues of OLP patients were significantly higher than controls, suggesting that there exists an abnormality in the expression of GNLY in OLP which might be involved in the pathogenesis of OLP.