Human β2-defensin in oral lichen planus expresses the degree of inflammation

In this work, it was decided to study the role of HBD-2, an inducible and not constitutionally expressed defensin, in the pathogenesis of Oral Lichen Planus (OLP) and of Burning Mouth Syndrome (BMS). Seventeen OLP patients, with a positive histopathologic diagnosis of the disease, were recruited into this study in order to measure the relative quantity of HBD-2 in their saliva and crevicular fluid. The values were compared with those collected from a group of 9 patients affected by the Burning Mouth Syndrome (BMS) and with a control group (CTRL) of 9 patients. There was no statistically significant difference between the groups (p=0.523; p=0.897). However, patients affected by OLP showed a dycotomic distribution of values: While 10 of them showed similar values to those found out in the other two groups, 7 patients expressed high levels of HBD-2, and 3500 pg/ml was the threshold to distinguish the subgroups. During the dental visit the clinician classified OLP patients into two groups according to the clinical presentation of the disease: Reticular and hyperplastic (white OLP), atrophic and erosive forms (red OLP). There was a statistical significant correlation between the clinical and numeric classification of the patients (p=0.004; p=0.001), and the expression of HBD-2 was higher in the red OLP group than in the white OLP group (p=0.000; p=0.000). In conclusion, this study shows that HBD-2 represents an index to assess active inflammation and it is probably linked to the presence of the typical band-like CD8+ infiltrate in Oral Lichen Planus.