Clinical features of patients with idiopathic inflammatory myopathy and interstitial lung disease when complicated with pulmonary infection / 中华风湿病学杂志

ABSTRACT

Objective:Toanalyze the clinical features of patients with idiopathic inflammatory myopathy (IIM) and interstitial lung disease (ILD) when complicated with pulmonary infection.Methods:Clinical data ofconsecutive IIM patients admitted to our hospital from January 2014 to December 2017 were collected. Patients were divided into two groups pure IIM-ILD and IIM-ILD with pulmonary infection, and the difference in clinical manifestations and lab test results was compared. The ROC curve was used to evaluate the predictive diagnostic value of T lymphocytes. The data was analyzed by the Chi-square test, Mann-Whitney U test and multiple logistic regression analysis. Results:Totally 153 patients were included, in which 51 cases were complicated with pulmonary infection. The incidence of myalgia, rash, cough/expectoration and fever and the levels of aspartate aminotransferase, lactate dehydrogenase (LDH), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were increased in the infection group, while the number of lymphocytes was significantly decreased ( P<0.05). Multivariate logistic regression analysis showed that myalgia, cough/expectoration, serum LDH level >350 U/L and peripheral blood lymphocyte count <0.9×10 9/L were independent risk factors for pulmonary infection in IIM-ILD patients (ORvalues 4.31, 3.81, 2.70 and 2.44, respectively, P<0.05) . Meanwhile, the number of natural killer cells as well as CD3 +, CD3 +CD4 +, CD3 +CD8 + T cells in the infection group was significantly lower than that in the pure IIM-ILD group ( Z values -2.28, -3.094, -2.918, and -2.308, respectively, P<0.05). ROC curve showed that CD3 + T cells combined with CRP improved the diagnostic sensitivity of pulmonary infection in IIM-ILD. Conclusion:IIM-ILD patients are more likely to have myalgia,cough/expectoration as well as increased LDH level when complicated with infection. The decrease in peripheral T lymphocyte numbers may indicate an increased risk of pulmonary infection in these patients.