Resistin Expression Is Associated With Interstitial Lung Disease in Dermatomyositis

In the current study, we aimed to assess resistin mRNA levels in the peripheral blood mononuclear cells (PBMCs) of dermatomyositis patients with interstitial lung disease (DM-ILD) and their correlation with disease activity.

We detected resistin mRNA levels in the PBMCs of 37 DM-ILD, 8 DM patients without ILD, and 19 healthy control (HC) subjects by performing quantitative reverse transcription real-time polymerase chain reaction analysis. Associations between resistin expression levels and major clinical manifestations, laboratory examinations, and disease activity were also analyzed. In addition, resistin expression in lung specimens from patients with DM-ILD was examined via immunohistochemistry and immunofluorescence.

Resistin mRNA levels in PBMCs were significantly higher in DM-ILD than that in DM patients without ILD and HCs (p = 0.043, 0.014, respectively). Among these DM-ILD patients, the resistin levels were significantly elevated in those with rapidly progressive ILD than in those with chronic ILD (p = 0.012). The resistin mRNA levels in DM-ILD positively correlated with serum alanine aminotransferase (r = 0.476, p = 0.003), aspartate aminotransferase (r = 0.488, p = 0.002), lactate dehydrogenase (r = 0.397, p = 0.014), C-reactive protein (r = 0.423, p = 0.008), ferritin (r = 0.468, p = 0.003), carcinoembryonic antigen (r = 0.416, p = 0.011), carbohydrate antigen 125 (r = 0.332, p = 0.047), interleukin-18 (r = 0.600, p < 0.001), and lung visual analog scale values (r = 0.326, p = 0.048), but negatively correlated with the diffusing capacity of carbon monoxide (DLco)% (r = -0.447, p = 0.041). Immunohistochemical analysis of resistin showed its elevated expression in the macrophages, alveolar epithelial cells, and weak fibrotic lesions from patients with DM-ILD. Immunofluorescence staining confirmed CD68+ macrophages co-express resistin.

Resistin levels were increased in patients with DM-ILD and associated with disease activity and ILD severity. Therefore, resistin may participate in the pathogenesis of DM-ILD and may act as a useful biomarker.