A Retrospective Study On High-Resolution Coputed Tomography Imaging Of Interstitial Lung Disease In Rheumatoid Arthritis

Objective:To investigate the risk factors of rheumatoid arthritis(RA)complicated with interstitial lung disease(ILD).To analyze the relationship between different clinical parameters and chest high-resolution computed tomography(HRCT)manifestations,lung interstitial lesion score and the degree of involvement.In addition,the factors of chest HRCT lesion progression in patients with RA-ILD were investigated to provide reference for the treatment and prognosis of patients with RA-ILD.Methods:A retrospective analysis was performed on 461 RA patients with complete clinical data treated by HRCT from July 2020 to October 2021 in the Rheumatology and Immunology Department of the Affiliated Hospital of North Sichuan Medical College,including 273 ILD patients and 188 non-ILD patients.The clinical data of patients between the two groups were compared to analyze the correlation between age,sex,smoking,serological indicators and ILD.The differences of chest HRCT manifestations,lung interstitial lesions score and involvement degree of ILD patients with different age,gender,smoking status and serological indexes were compared.In addition,the differences of lung interstitial disease score and involvement degree between usual interstitial pneumonia(UIP)and non-UIP patients were compared.Finally,Cox regression analysis was used to discuss the correlation between different chest HRCT manifestations and ILD progression.Results:The patients in the RA-ILD group were older and more male than those in non-ILD group.The erythrocyte sedimentation rate(ESR),C-reactive protein,rheumatoid factor(RF)IgM and IgA in the RA-ILD group were higher than those in the non-ILD group(All P<0.05).The risk of ILD was greater in male patients(OR=2.916,95%CI:1.294-6.573,P=0.010)and age≥60 years(OR=6.062,95%CI:3.960-9.281,P<0.001).Women have a longer course of disease,and the ESR,C-reactive protein and RF in male patients were higher than those in female patients(All P<0.05).The ESR and RF-IgA in smoking group were higher than those in non-smoking group.The proportion of males in the UIP group was higher than that in the non-UIP group.Interlobular septal thickening was the most common HRCT manifestation in patients with RA-ILD(88.6%).The scores of lung interstitial lesions and lung involvement in male patients with RA-ILD were higher than those in female patients.The proportion of male patients with honeycomb shadow,pleural involvement,emphysema was higher than that of female patients(All P<0.05).The degree of lung involvement in the smoking group was higher than that in the non-smoking group.The risk of emphysema was significantly higher in the smoking group than that in the non-smoking group(All P<0.05).The proportion of interlobular septal thickening,emphysema and pleural involvement in patients with≥60 years old was higher than that in patients with<60 years old(All P<0.05).Scores of interstitial lung lesions in RA-ILD patients with interstitial emphysema were higher than those in patients without emphysema(P<0.05).The lung interstitial lesion score and lung involvement degree in UIP group were higher than those in non-UIP group(All P<0.05).100 patients with RA-ILD underwent multiple HRCT reexamination:54 patients showed no significant changes in lung interstitial lesions,26 patients had disease progression,and 20 patients had improved absorption of lesions,mainly manifested as changes in ground glass shadow and plaque shadow.Univariate Cox regression analysis showed that the risk of lung interstitial disease progression in patients with ground glass shadow was 2.653 times higher than that in patients without ground glass shadow(HR=2.653,95%CI:1.212-5.809,P=0.015).After adjustments for age,gender,smoking and image classification as UIP type,multivariate Cox regression analysis showed that the risk of lung interstitial disease progression in RA-ILD patients with ground glass shadow was 2.661 times higher than that in patients without ground glass shadow(HR=2.661,95%CI:1.191-5.945,P=0.017).In addition,after adjustments for age,gender,smoking,lung interstitial involvement,multiple imaging signs and image classification as UIP type,the risk of lung interstitial disease progression in RA-ILD patients with a course of disease of 5 to 10 years was 3.172 times higher than that in patients with a course of disease of less than or equal to 5 years(HR=3.172,95%CI:1.045-9.624,P=0.042).And the risk was 3.196 times higher in patients with pleural involvement than that in patients without pleural involvement(HR=3.196,95%CI:1.021-10.005,P=0.046).Conclusion:Male and over 60 years old patients with RA are more likely to have ILD.Male,smoking,combined with interstitial emphysema may be the risk factors of poor prognosis in ILD patients,such patients should focus on the detection of lung lesions in clinical diagnosis and treatment,early intervention treatment.Ground glass shadow is a risk factor for the progression of interstitial lung disease,so ILD patients with ground glass shadow should be focused on detection and timely treatment to improve the condition and prognosis.