Bosch U, Zeichen J, Skutek M, Haeder L, van Griensven M
Laboratory of Histology and Cell Biology, Department of Traumasurgery, Hannover Medical School, 30623 Hannover, Germany.
Knee Surg Sports Traumatol Arthrosc. 2001 Sep;9(5):282-9. doi: 10.1007/s001670100218.
It is thought that an excessive fibrotic healing response with diffuse intra-articular scarring leads to arthrofibrosis after trauma and surgery around joints. To clarify the specific cellular mechanism of arthrofibrosis during arthrolysis we took fibrotic tissue samples from 18 patients at varying periods after knee trauma or surgery. Sections were stained with hematoxylin and eosin to study the overall histopathological changes. Major histocompatibility complex (MHC) class II expressing cells as well as CD3, CD4, CD25, CD28, CD68, CD80, and CD83 positive cells were localized immunohistologically. The results demonstrated synovial hyperplasia with fibrotic enlargement of the subintima and infiltration of inflammatory cells. The number of MHC class II expressing cells was increased. Mainly, intimal macrophages and dendritic cells showed positive immunostaining for MHC class II antigens. In the subintima moderate infiltration of T cells including activated T cells (CD25), CD4+ T helper (Th) cells and Th1 and Th2 subsets was detected. There was a slight polarization of the Th1/Th2 balance towards Th1 differentiation. Positive immunostaining for CD80/CD28 indicated the costimulatory signal for T cell activation and clonal expansion. These findings strongly support an immune response as the cause of capsulitis leading to formation of diffuse scar tissue within the knee joint. Based on our immunohistological study we conclude that a T cell mediated immune response plays a crucial role in the mechanism of arthrofibrosis.
人们认为，创伤和关节周围手术后，过度的纤维化愈合反应伴有关节内弥漫性瘢痕形成会导致关节纤维化。为了阐明关节松解术中关节纤维化的具体细胞机制，我们在膝关节创伤或手术后的不同时期采集了18例患者的纤维化组织样本。切片用苏木精和伊红染色，以研究整体组织病理学变化。通过免疫组织化学定位主要组织相容性复合体（MHC）II类表达细胞以及CD3、CD4、CD25、CD28、CD68、CD80和CD83阳性细胞。结果显示滑膜增生，内膜下纤维化增大，并有炎性细胞浸润。MHC II类表达细胞数量增加。主要是内膜巨噬细胞和树突状细胞对MHC II类抗原呈阳性免疫染色。在内膜下检测到包括活化T细胞（CD25）、CD4 + T辅助（Th）细胞以及Th1和Th2亚群在内的T细胞中度浸润。Th1/Th2平衡略微向Th1分化极化。CD80/CD28的阳性免疫染色表明T细胞活化和克隆扩增的共刺激信号。这些发现有力地支持免疫反应是导致膝关节内弥漫性瘢痕组织形成的囊炎病因。基于我们的免疫组织学研究，我们得出结论，T细胞介导的免疫反应在关节纤维化机制中起关键作用。
