Analysis of monoclonal T cells in benign dermatoses related to mycosis fungoides.

地衣糠疹被认为是一种良性炎症性疾病，属于副银屑病组。然而，根据其与皮肤T细胞淋巴瘤(CTCL)的相关性或浸润液中存在的单克隆性群体，人们假设地衣糠疹是CTCL疾病谱的一部分。为了验证这一假说，地衣糠疹的克隆群体应该表现出与CTCL CID4^+T淋巴细胞相同的表型。在这项研究中，我们使用石蜡包埋标本分析了7例地衣糠疹(6例尖锐湿疣和1例慢性苔藓)的浸润液。结论：1.通过扩增重排的TcR-γ基因，在7例苔藓样糠疹中有6例检测到了单克隆群。对扩增出的条带进行回收和测序。这些数据表明，基于聚合酶链式反应的方法充分扩增了重排的TcR-γ基因，并确定了重排过程中使用的基因片段。我们准备了几对镜像切片，它们提供了与镜像相同的组织学图像。在每对标本中，一张切片上用扩增条带作为探针进行原位杂交，另一张切片上用UCHL1、抗CD8或抗CD4抗体进行免疫组织化学染色。通过切片比较，确定ISH阳性细胞表型为UCHL1^+、CD8^-、CD4^+细胞，表明地衣糠疹为副银屑病的一员。此外，我们认为在CTCL疾病谱中，克隆性CD4^+细胞和反应性CD8^+细胞之间的相互关系影响疾病的生物学行为。

Pityriasis lichenoides has been regarded as a benign inflammatory disorder belonging to the parapsoriasis group. However, based on its association with cutaneous T cell lymphoma (CTCL) or the presence of monoclonal populations in infiltrates, it has been hypothesized that pityriasis lichenoides is part of the CTCL disease sectrum. For validation of this hypothesis, the monoclonal populations in pityriasis lichenoides should express the same phenotype as CTCL CID4^+ Tlymphocyte.In this study, we analysed infiltrates in 7 cases of pityriasis lichenoides (6 cases of pityriasis lichenoides et varioliformis acuta and one case of pityriasis lichenoides chronica) using praffin-embedded specimens.1. By amplifying the rearranged TCR-γ genes, monoclonal populations were detected in 6 of 7 cases of pityriasis lichenoides.2. These amplified bands were recovered and sequenced. These data showed that the PCR-based method adequately amplified the rearranged TCR-γ genes and specified the gene segments used in the rearrangement processes.3. We prepared pairs of mirror sections that gave the same histological picture as a mirror image. In each pair, in-situ hybridization (ISH) using the amplified band as a probe on one section and immunohistochemistry using UCHL1, anti-CD8, or anti-CD4 antibodies on the other section were performed. By comparing these sections, the phenotypes of the ISH-positive cells were determined as UCHL1^+, CD8^-, CD4^+ cells.These results demonstrated that pityriasis lichenoides qualified as a member of parapsoriasis. Furthermore, we suggest that the interrelationship between monoclonal CD4^+ cells and reactive CD8^+ cells affects the biological behavior of the disease in the CTCL disease spectrum.