Molecular and pathological analysis of CVD-interstitial pneumonia by using lung tissue-infiltrating T lymphocytes

多发性肌炎/皮肌炎（PM/DM）相关的间质性肺炎（IP）是结缔组织病的一种严重并发症，其发病机制尚不清楚，传统的治疗方法往往不充分，然而，对浸润肺组织的淋巴细胞的精确表征可以为理解免疫-我们检测了肺组织浸润淋巴细胞的表型特征以及受影响肺组织中细胞因子的表达。还使用肺来源的RNA进行PCR，结果表明特定T细胞群的寡克隆扩增。DM患者皮损中T淋巴细胞以CD 4阳性为主，IFNγ阳性表达率较高，但1 L4和1 L5表达水平较低，提示T细胞在PM/DM的发病中起关键作用，其作用机制可能与IFN γ介导的促炎机制有关。

Interstitial pneumonia (IP) associated with polymyositis/dermatomyositis (PM/DM) has been perceived as an life-threatening complication of the connective tissue disease.Since the pathogenesis of IP remains unclear, the treatment has been conventional and often inadequate.However, the precise characterization of the lymphocytes infiltrating the lung tissue may provide clue to understanding the immune-mediated mechanisms for IP.We examined the phenotypic profiles of lung tissue-infiltrating lymphocytes as well as the expression of cytokines in the affected lung tissue.TCR-repertoire study with RT-PCR was also employed using lung derived RNA and the results suggested oligoclonal expansion of particular T cell populations.Immunohistochemical analysis of VATS biopsies from eight patients with PM/DM demonstrated that the lymphocytes in the lesions are predominantly T cells a most of which are CD4 positive, and the study also showed strong expression of IFNγ in the tissue with lesser levels of 1L4 and 1L5.These data suggest that the pivotal role of T cells which may contribute to the development of IP associated with PM/DM through the proinflammatory cytokine-mediated mechanism.