Correlation research of low density granulocytes with interstitial lung disease in dermatomyositis / 中华风湿病学杂志

ABSTRACT

Objective This study aims to test the hypothesis that low density granulocytes (LDGs) is involved in the pathogenesis of DM associated-Interstitial lung disease (ILD).Methods Forty eight DM patients (28 with ILD) and 19 age-and sex-matched healthy Chinese volunteers were recruited to this study.LDGs percentage in peripheral blood mononuclear cells (PBMCs) was tested by flow cytometry.Neutrophilrelated genes (LL-37,MPO and MMP-8) expressions in PBMCs were tested by quantitative RT-PCR.Myositis disease activity assessment visual analogue scales (MYOACT) was used to assess the disease activity.Percentages of LDGs were compared in patients with ILD and without by using unpaired t test with Welch's correction,the correlations between LDGs and clinical parameters were further analyzed by linear correlation analysis.The expressions of neutrophil-related mRNA and proteins in PBMCs were compared by using MannWhitney U test.Results LDGs percentage in PBMCs was 7.1-fold higher in DM patients than healthy controls [(9.1±11.5)％ vs (1.3±0.7)％,t=4.664,P＜0.01].LDGs percentage in PBMCs was 2.7-fold higher in DM patients with ILD than DM patients without ILD [(12.3±14.1)％ vs (4.5±2.6)％,t=2.835,P=0.008 3].The mRNA expression level of LL-37,MPO and MMP-8 and LL-37 protein levels in the DM group were significantly higher than those in the control group.LDGs percentage positively correlated with MYOACT lung disease activity scores (r=0.439,P=0.010).Conclusion Percentage of LDGs in PBMCs is significantly increased in DM patients with ILD and positively correlated with MYOACT lung disease activity scores,suggesting that abnormall increasing of LDGs is a potential contributor to the pathogenesis of DM-associated ILD.