A Study Of Risk Factors For Progressive Fibrosis In CTD-ILD

Objective(s):By analyzing the clinical data of patients with Connective tissue disease-related interstitial lung disease(CTD-ILD).To investigate the clinical characteristics of the development of progressive pulmonary fibrosis,to find the risk factors associated with the development of CTD-ILD,and to provide a theoretical basis for the early prediction of progressive pulmonary fibrosis.We also analyzed the clinical data of patients with progressive pulmonary fibrosis who received antifibrotic therapy to evaluate the efficacy of antifibrotic drugs in patients with progressive fibrosing interstitial lung diseases(PF-ILD)and to provide a reference for optimizing the treatment of CTD-ILD.Methods:Retrospective analysis of clinical data of all patients diagnosed with CTD-ILD who were hospitalized and treated at the First People’s Hospital of Kunming between August 2015 and December 2022.The CTD-ILD group was divided into a progressive fibrosis group with connective tissue disease-associated interstitial lung disease(PF-CTD-ILD)and a non-progressive fibrosis group with connective tissue disease-associated interstitial lung disease(NPF-CTD-ILD)according to the diagnostic criteria of PF-ILD,and the demographics,primary morbidity,laboratory findings,and comorbidities of the two groups were compared and analyzed.The neutrophil-to-lymphocyte ratio(NLR)and C-reactive protein-to-albumin ratio(CAR)were calculated,and the optimal threshold values of NLR and CAR were determined using ROC curves,logistic regression analysis was performed to identify risk factors for the development of progressive fibrosis in patients with CTD-ILD.The PF-CTD-ILD group was also divided into antifibrotic group and non-antifibrotic group according to whether antifibrotic drugs were used or not,and the clinical characteristics,laboratory test results,high resolution CT(HRCT)and pulmonary function test of the chest were compared and analyzed between the two groups.Results:PF-CTD-ILD group and NPF-CTD-ILD group:1.A total of 103 patients with CTD-ILD were included according to the inclusion criteria,45 in the PF-CTD-ILD group and 58 in the NPF-CTD-ILD group,and the incidence of progressive pulmonary fibrosis was 43.7%.Compared with patients in the NPF-CTD-ILD group,patients in the PF-CTD-ILD group were more likely to develop progressive fibrosis at an older age(P < 0.05),whereas there was no significant difference in gender,smoking history and BMI between the two groups.(P > 0.05).2.The types of progressive pulmonary fibrosis that occurred in CTD-ILD patients included polymyositis/dermatomyositis in 4 cases(57.1%),dry syndrome in 10 cases(50.0%),rheumatoid arthritis in 8 cases(32.0%),ANCA-associated vasculitis in 6cases(50.0%),undifferentiated connective tissue disease in 14 cases(45.2%),and overlap syndrome in 3 cases(50.0%).3.patients in the PF-CTD-ILD group had significantly higher interleukin-6,procalcitonin,C-reactive protein,hematocrit,fibrinogen,and D-dimer than those in the NPF-CTD-ILD group(P < 0.05)and significantly lower lymphocyte counts than those in the NPF-CTD-ILD group(P < 0.05).Patients in the PF-CTD-ILD group with high NLR or high CAR were more likely to develop progressive pulmonary fibrosis(P < 0.05).4.Patients with CTD-ILD combined with hypertension and diabetes were more likely to develop progressive pulmonary fibrosis than those with CTD-ILD without hypertension and diabetes(P < 0.05).In contrast,there was no significant difference in the development of progressive pulmonary fibrosis between patients with CTD-ILD combined with pulmonary hypertension and those without CTD-ILD combined with pulmonary hypertension(P > 0.05).5.Logistic regression analysis showed that CAR>1.39 and combined hypertension were independent risk factors for the development of progressive pulmonary fibrosis in patients with CTD-ILD.Antifibrotic group and non-antifibrotic group:1.Among 45 patients with PF-ILD,20 patients were in the antifibrotic group and25 patients in the No-anti-fibrotic group.Among the 20 patients in the antifibrotic group,there were 8 male patients(40.0%)and 12 female patients(60.0%)with a mean age(70.20±10.28)and a mean BMI(22.46±3.51)Kg/m2.And among 25 patients in the non-antifibrotic group,12(48.0%)were male and 13(52.0%)were female,with a mean age(78.48±8.37)years and a mean BMI(21.32±3.78)Kg/m2.2.Patients in the antifibrotic group had a significantly lower rate of shortness of breath and chest tightness than those in the non-antifibrotic group(P < 0.05),while there was no significant difference in the comparison of cough,pestle finger and Velcro rales between the groups(P > 0.05).3.Interleukin-6,D-dimer,NLR,and CAR were significantly lower in the antifibrotic group than in the non-antifibrotic group(P < 0.05);There was no significant difference in procalcitonin,C-reactive protein between the two groups(P >0.05).4.The antifibrotic group showed fewer ground glass and foveal shadows on HRCT than the non-antifibrotic group,and the difference was statistically significant(P < 0.05).In contrast,there was no significant difference between the two groups in the imaging features such as grid-like shadow,thickened lobular septa and distended bronchus on HRCT(P > 0.05)5.The FVC%,FVC% change,DLCO% change,and FEV1% change were significantly higher in the antifibrotic group than in the non-antifibrotic group(P <0.05);the DLCO%,FEV1%,FEV1/FVC% change,and PEF% change between the two groups were not There was no significant difference in DLCO%,FEV1%,FEV1/FVC% change and PEF% change between the two groups(P>0.05).Conclusion(s):1.In patients with CTD-ILD,older age,elevated C-reactive protein,fibrinogen,D-dimer,NLR >3.57,CAR >1.39,combined with hypertension and diabetes mellitus may have a higher risk of PF-ILD and need to be alert for the development of PF-ILD.CAR >1.39 and combined hypertension are independent risk factors for the development of PF-ILD in patients with CTD-ILD.2.Antifibrotic drugs can improve respiratory symptoms,HRCT performance and reduce inflammation levels in patients with PF-ILD,while slowing down the decline in lung function,and additional anti-fibrotic therapy should be considered after the diagnosis of PF-ILD.