Boston University School of Medicine, Boston, Massachusetts; University of Sao Paulo School of Medicine, Sao Paulo, Brazil.
Arthritis Rheumatol. 2014 Mar;66(3):714-25. doi: 10.1002/art.38288.
Systemic sclerosis (SSc)-related interstitial lung disease (ILD) is one of the leading causes of mortality. We undertook this study to analyze the gene expression of lung tissue in a prospective cohort of patients with SSc-related ILD and to compare it with that in control lungs and with 2 prospective clinical parameters in order to understand the molecular pathways implicated in progressive lung disease.
Lung tissue was obtained by open lung biopsy in 28 consecutive patients with SSc-related ILD and in 4 controls. High-resolution computed tomography (HRCT) and pulmonary function testing (PFT) were performed at baseline and 2-3 years after treatment based on lung histologic classification. Microarray analysis was performed, and the results were correlated with changes in the HRCT score (FibMax) and PFT values. Quantitative polymerase chain reaction (qPCR) and immunohistochemistry were used to confirm differential levels of messenger RNA and protein.
Lung microarray data distinguished patients with SSc-related ILD from healthy controls. In the lungs of patients with SSc-related ILD who had nonspecific interstitial pneumonia (NSIP), expressed genes included macrophage markers, chemokines, collagen, and transforming growth factor β (TGFβ)- and interferon (IFN)-regulated genes. Expression of these genes correlated with progressive lung fibrosis defined by the change in FibMax. Immunohistochemistry confirmed increased markers of collagen (COL1A1), IFN (OAS1 and IFI44), and macrophages (CCL18 and CD163), and the positive correlation with the change in FibMax was confirmed by qPCR in a larger group of SSc patients with NSIP. Several genes correlated with both the change in FibMax (r > 0.4) and the change in % predicted forced vital capacity (r < -0.1), including IFN and macrophage markers, chemokines, and heat-shock proteins.
These results highlight major pathogenic pathways relevant to progressive pulmonary fibrosis in SSc-related ILD: macrophage emigration and activation, and up-regulated expression of TGFβ- and IFN-regulated genes.
系统性硬皮病（SSc）相关的间质性肺病（ILD）是导致死亡的主要原因之一。我们进行了这项研究，以分析一组前瞻性 SSc 相关 ILD 患者的肺组织基因表达，并将其与对照组肺组织的表达以及 2 个前瞻性临床参数进行比较，以了解与进行性肺病相关的分子途径。
对 28 例 SSc 相关 ILD 患者和 4 例对照者进行开胸肺活检，以获取肺组织。基于肺组织学分类，在治疗前后 2-3 年进行高分辨率计算机断层扫描（HRCT）和肺功能检测（PFT）。进行微阵列分析，并将结果与 HRCT 评分（FibMax）和 PFT 值的变化相关联。使用定量聚合酶链反应（qPCR）和免疫组织化学来证实信使 RNA 和蛋白质的差异水平。
肺微阵列数据区分了 SSc 相关 ILD 患者和健康对照者。在患有非特异性间质性肺炎（NSIP）的 SSc 相关 ILD 患者的肺中，表达的基因包括巨噬细胞标志物、趋化因子、胶原蛋白和转化生长因子β（TGFβ）和干扰素（IFN）调节基因。这些基因的表达与 FibMax 定义的进行性肺纤维化相关。免疫组织化学证实，胶原蛋白（COL1A1）、IFN（OAS1 和 IFI44）和巨噬细胞（CCL18 和 CD163）的标志物增加，并且在更大的 NSIP SSc 患者群体中，通过 qPCR 证实了与 FibMax 变化的正相关。一些基因与 FibMax 的变化（r > 0.4）和预测用力肺活量的变化（r < -0.1）相关，包括 IFN 和巨噬细胞标志物、趋化因子和热休克蛋白。
这些结果突出了 SSc 相关 ILD 进行性肺纤维化的主要致病途径：巨噬细胞迁移和激活，以及 TGFβ和 IFN 调节基因的上调表达。
