皮肌炎肌组织中浆细胞样树突状细胞的病理学特点

The pathological characteristics of plasmacytoid dendritic cells in muscle tissue of dermatomyositis

目的 研究皮肌炎肌组织中浆细胞样树突状细胞（pDC）的病理学特点,探讨其病理学意义.方法 收集30例皮肌炎及25例多发性肌炎（PM）患者的肌肉活体组织标本,全部行HE染色、免疫组织化学（抗CD303分子及抗CD68分子）染色.结果 肌活体组织检查病理示,30例皮肌炎中25例可见典型束周萎缩,伴肌束膜明显增宽,5例束周萎缩不典型,但于肌束周边可见小群坏死或再生纤维;14例可见束周凿空样纤维;17例可见肌束膜内血管周围炎,6例于肌内膜可见灶性炎症细胞浸润.免疫组织化学染色示,19例在肌束膜及血管周围可见较多巨噬细胞浸润;20例可见较多pDC浸润,其中,15例此细胞仅位于宽大肌束膜内血管周围的灶性炎细胞区域,3例仅位于肌内膜灶性炎症细胞区域,2例pDC在上述2个部位均存在.25例PM患者的主要病理改变为坏死、再生纤维及炎症细胞浸润,免疫组织化学染色在血管周围灶性炎症细胞区域未发现或偶见少量散在pDC的浸润.结论 在PM患者肌组织中未发现或偶见少量散在pDC的浸润,而在皮肌炎患者肌组织内可见显著pDC的浸润,且其主要在宽大肌束膜内的血管周围分布的特点提示可能与皮肌炎束周萎缩的形成有关.

Objective To study the histological features of plasmacytoid dendritic cells （pDC） in muscle tissue affected by dermatomyositis （DM） and to discuss the pathological significations of pDC.Methods Muscle tissues from 30 cases of DM and 25 cases of polymyositis （PM） were collected.HE stain, immunohistochemistry studies were carried out in all muscle samples.Results Pathological features of DM included： perifascicular atrophy （25/30）; punched-out fiber （14/30）; perivasculitis （17/30）,inflammatory infiltration in the endomysium（6/30）.Using immunohistochemistry study, 19 cases from DM were infiltrated by macrophages which are CD68 positive and CD303 negative, 20 cases with DM were infiltrated by pDC which are CD303 positive.The location of pDC were： perivascular of interfascicular septae only （15/20）; endomysium only （3/20） and both （2/20）.Myopathic damage such as necrotic and regenerating fibers and inflammatory infiltration could be seen in PM.There was few pDC infiltration in PM.Conclusions There is few pDC in muscle tissue affected by PM and many pDC in muscle tissue affected by DM with infiltration mainly in the wide interfascicular septae.pDC may be connected to perifascicular atrophy and play a roll in the pathogenesis of DM.