The Risk Factors Associated With The Outcome Of Clinically Amyopathic Dermatomyositis Accompanied With Acute Interstitial Lung Disease And Potential Contribution Of Circulating Neutrophils And Th17 Cells To The Pathogenesis Of Interstitial Lung Disease

Objective The aim of this study is to evaluated the risk factors associated with the outcome of clinically amyopathic dermatomyositis(CADM) accompanied with interstitial lung disease(ILD) and the potential contribution of circulating neutrophils and Th17 cells to the pathogenesis of interstitial lung diseaseMethods First, we reviewed 55 CADM with acute ILD retrospectively. There were 30 cases developed acute interstitial pneumonia(AIP) and 25 cases with acute exacerbation of non-acute interstitial pneumonia(non-AIP). The clinical features, blood tests, chest high-resolution computed tomography(HRCT) score and lung function were analyzed respectively. Second, eighteen CADM with acute ILD were enrolled to analyze variance of T helper(Th) cells, serum IL8 and m RNA expression of markers in circulating neutrophils, compared with classic dermatomyositis(DM) with acute ILD. Third, partial least squares(PLS) model was applied to assess the weight of factors to the disease activity.Results Acute interstitial pneumonia(AIP), neutrophil lymphocyte ratio(NLR),serum ferritin level, serum Lactate dehydrogenase(LDH) level,forced percentual vital capacity(FVC%), carbon monoxide diffusing capacity(DLCO%) and HRCT score were risk factors of poor outcome on univariate analysis. Multivariate analysis revealed that AIP, NLR and overall HRCT score were independently risk factors of poor outcome. Patients didn’t benefit from large corticosteroids dose. Patients with calcineurin inhibitor presented a better overall survival rate than those without calcineurin inhibitor. Early application of Basiliximab might improve the outcome of CADM patients with actue ILD. Serum IL8, m RNA levels of CD11 b, MCL1 and IL18 in circulating neutrophils and Th17 cells in CADM with ILD differed from those in DM with ILD. In remission period of CADM-ILD, serum IL8, m RNA levels of CD11 b, MCL1 and IL18 in circulating neutrophils and Th17 cells were decrease. There was positive correlation between m RNA level of CD11 b in circulating neutrophils and chest HRCT score. PLS model indicated that m RNA level of CD11 b, IL18 in circulating neutrophils and Th17 cells were major important factors according to Variable importance plot(VIP).Conclusion AIP, high HRCT score and high NLR are factors associated with the one-year mortality of acute ILD in CADM patients. Large corticosteroids dose didn’t improve the overall survival rate of all patients and that of patients with AIP. Patients who treated with calcineurin inhibitor presented a better overall survival rate than those without calcineurin inhibitor. Early application of Basiliximab might improve the outcome of CADM patients with actue ILD. The activation of circulating neutrophils and Th17 cells may be involved in the pathogenesis of interstitial lung disease.