Bangsuwan Pear, Hirunwidchayarat Worawalun, Jirawechwongsakul Pimporn, Talungchit Sineepat, Taebunpakul Patrayu
Department of Oral Surgery and Oral Medicine, Faculty of Dentistry, Srinakharinwirot University, Bangkok, Thailand.
J Int Soc Prev Community Dent. 2021 Sep 21;11(5):566-573. doi: 10.4103/jispcd.JISPCD_97_21. eCollection 2021 Sep-Oct.
Cathepsin B (Cat-B), a cysteine protease, and cystatin A (Cys-A), a protease inhibitor, are involved in the immune response. This study determined Cat-B and Cys-A expression in oral lichen planus (OLP) by immunohistochemistry.
Thirty specimens each of OLP and healthy gingiva (HG) were included. The expression pattern, the number of positive cells, the staining intensity, and the immunoreactive score (IRS) of Cat-B and Cys-A were investigated. The data were analyzed by using unpaired -test, Chi-square, and Spearman's rank correlation.
The Cat-B expression in OLP was observed as cytoplasmic staining in the epithelial cells, whereas Cys-A expression was exhibited in the nucleus and cytoplasm of the epithelium. An increase in Cat-B staining intensity was also observed in the basal cells. Conversely, the high staining intensity of Cys-A was observed in the stratum spinosum, but not the stratum basale. In HG, Cat-B expression demonstrated a relatively consistent intensity in the epithelial layer. The Cys-A expression in HG was similar to OLP with a lower staining intensity. The mean percentage of positive cells and the IRS score of Cat-B and Cys-A in OLP were significantly higher than HG ( < 0.05). There was no correlation between Cat-B and Cys-A levels in OLP. Interestingly, Cat-B expression in erosive OLP was greater than in non-erosive OLP ( < 0.05).
The Cat-B and Cys-A expression in OLP was more outstanding than in HG, suggesting possible roles for the process of OLP pathogenesis. In addition, Cat-B expression may be an indicator of the disease severity.
组织蛋白酶B（Cat-B）是一种半胱氨酸蛋白酶，而胱抑素A（Cys-A）是一种蛋白酶抑制剂，二者均参与免疫反应。本研究通过免疫组织化学法测定口腔扁平苔藓（OLP）中Cat-B和Cys-A的表达情况。
纳入30例OLP标本和30例健康牙龈（HG）标本。研究Cat-B和Cys-A的表达模式、阳性细胞数量、染色强度及免疫反应评分（IRS）。采用非配对t检验、卡方检验和Spearman等级相关分析数据。
OLP中Cat-B表达表现为上皮细胞胞质染色，而Cys-A表达见于上皮细胞核和胞质。基底细胞中也观察到Cat-B染色强度增加。相反，Cys-A高染色强度见于棘层，而非基底层。在HG中，Cat-B在上皮层表达强度相对一致。HG中Cys-A表达与OLP相似，但染色强度较低。OLP中Cat-B和Cys-A的阳性细胞平均百分比及IRS评分显著高于HG（P<0.05）。OLP中Cat-B和Cys-A水平无相关性。有趣的是，糜烂型OLP中Cat-B表达高于非糜烂型OLP（P<0.05）。
OLP中Cat-B和Cys-A表达比HG中更显著，提示其在OLP发病机制中可能发挥作用。此外，Cat-B表达可能是疾病严重程度的一个指标。
