Lichen planus (LP) is a chronic inflammatory mucocutaneous disease involving the oral mucosa and skin. Both oral LP (OLP) and cutaneous LP (CLP) are histopathologically characterized by dense subepithelial lymphocyte infiltrates; however, the mechanisms underlying lymphocyte recruitment to sites of LP lesions are not fully understood. Here, we assessed the induction of peripheral lymph node addressin (PNAd)-expressing high endothelial venule (HEV)-like vessels in 19 OLP and 17 CLP cases. To do so, we performed immunohistochemical staining for PNAd and CD34, followed by quantitative analysis. We also conducted triple immunohistochemistry for PNAd and either CD3 and CD20 or CD4 and CD8 to identify the lymphocyte subset preferentially recruited via HEV-like vessels. PNAd-expressing HEV-like vessels were induced in and around lymphocyte aggregates in all cases of OLP and in 10 of 17 CLP cases, and these vessels were more frequently observed in OLP relative to CLP. Although the number of T-cells attached per HEV-like vessel exceeded the number of B-cells in both OLP and CLP, the number of CD4+ T-cells attached was greater than the number of CD8+ T-cells only in OLP. These findings combined suggest that PNAd-expressing HEV-like vessels play a more important role in the pathogenesis of OLP compared with CLP.

中文翻译：

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口腔和皮肤扁平苔藓中高内皮小静脉样血管的诱导：比较研究。

扁平苔藓（LP）是一种慢性炎性粘膜皮肤疾病，涉及口腔粘膜和皮肤。口服LP（OLP）和皮肤LP（CLP）的组织病理学特征均为致密的上皮下淋巴细胞浸润。然而，尚未完全了解淋巴细胞募集到LP病变部位的机制。在这里，我们评估了19例OLP和17例CLP病例中表达外周淋巴结寻址蛋白（PNAd）的高内皮小静脉（HEV）样血管的诱导。为此，我们对PNAd和CD34进行了免疫组织化学染色，然后进行了定量分析。我们还对PNAd和CD3和CD20或CD4和CD8进行了三重免疫组化，以鉴定优先通过HEV样血管募集的淋巴细胞亚群。在所有OLP病例中以及在17例CLP病例中有10例在淋巴细胞聚集物中和周围诱导了表达PNAd的HEV样血管，相对于CLP，在OLP中观察到这些血管的频率更高。尽管每个HEV样血管中附着的T细胞数量超过了OLP和CLP中的B细胞数量，但附着的CD4 + T细胞数量却大于仅OLP中的CD8 + T细胞数量。这些发现综合表明，与CLP相比，表达PNAd的HEV样血管在OLP的发病机理中起着更重要的作用。仅在OLP中，附着的CD4 + T细胞的数量大于CD8 + T细胞的数量。这些发现综合表明，与CLP相比，表达PNAd的HEV样血管在OLP的发病机理中起着更重要的作用。仅在OLP中，附着的CD4 + T细胞的数量大于CD8 + T细胞的数量。这些发现综合表明，与CLP相比，表达PNAd的HEV样血管在OLP的发病机理中起着更重要的作用。