A Comparative Study On Idiopathic Interstitial Pneumonia And Connective Tissue Disease-associated Interstitial Lung Diseases

Objective: To analyze and compare the clinical manifestations, laboratory findings, high- resolution computed tomography(HRCT) findings and treatment of idiopathic interstitial pneumonia(IIP) with connective tissue disease-associated interstitial lung diseases(CTD-ILD),the ultimate goal is to give some evidence for distinguishing the two different diseases.Methods: Patients with IIP or CTD-ILD from respiratory department in the eastern district of the Second Hospital of He Bei Medical University, from February, 2013 to December, 2014 were selected in this study. The clinical features, laboratory findings, HRCT findings and treatment were analyzed and compared between the two groups.Results: A total of 87 patients with complete data were included in this study, with 58 IIP cases and 29 CTD-ILD cases. CTD-ILD is common in many of these diffuse connective tissue diseases, including Rheumatoid Arthritis(RA), Systemic Lupus Erythematosus(SLE), Sjogren’s syndrome(SS), Systemic sclerosis(SSc),Polymyositis and Dermatomyositis(PM/DM). IIP group: 32 males and 26 female, had an average age of(70.0±10.8)years, there were 30 smokers. CTD-ILD group: 10 males and 19 female, had an average age of(60.1±12.0)years, there were 7 smokers. Age, gender, smoking history showed significantly difference between IIP and CTD-ILD group(P<0.05). Clinical Manifestations: main symptoms were cough, sputum production, chest discomfort, dyspnea, and cracks, which more IIP patients suffers. While chest discomfort, dyspnea, finger clubbing and symotoms related to CTD such as skin rash, arthralgia, Raynaud’s phenomenon and so on, showed significant differences between IIP and CTD-ILD(P<0.05). Serologic tests: Significant difference in serologic tests between CTD-ILD group and IIP group was seen in autoantibodies series(ANA, RNP, Anti-Smith, Anti-SSA, Anti-SSB, Anti-Scl-70, Anti-Jo-1, r RNP, Anti-ds-DNA),RF, Anti-CCP,ANCA, Ig M,C3,C4(P<0.05). There are no significant differences of the infection rate of Gram negative bacteria,Gram positive bacteria and Fungi between the two groups(P>0.05).HRCT Findings:The percentage of presence of consolidation in CTD-ILD patients was lower than IIP patients(P<0.05), while the presence of ground glass opacities in CTD-ILD patients was more common than IIP patients(P<0.05). Pulmonary Arterial Hypertension(PAH) showed more severe in CTD-ILD than IIP(P<0.05),Emphysema showed more severe in IIP than CTD-ILD(P<0.05). Treatment: IIP patients were often treated by corticosteroids, while corticosteroids and immunosuppressant for CTD-ILD(P<0.05). Prognosis: And the main results of death were the respiratory failure related diseases. during the study, there were 16 deaths,the causes of death were severe infection, cute exacerbation, lung cancer metastasis, pulmonary embolism, heart failure, sudden deaths. Respiratory failure accounted for 70% of the deaths in the IIP group, while 66.7% in the CTD-UIP group. There were no significant difference between the proportional mortality rate of the two groups.Conclusions:1 The age of CTD-ILD suffers is younger than that of IIP suffers. Females are more likely to be attacked, while male, over 50, with smoking habit are the predilection of IIP.2 The symptoms suggestive of a connective tissue disease including arthralgia, dry eyes/dry mouth, Raynaud’s phenomenon, proximal muscle weakness, and muscle pain less occured to IIP, while were more common in CTD-ILD. CTD-ILD patients less appear Chest discomfort and the symptom of dyspnea than IIP. IIP patients were more likely to have the finger clubbing.3 ANA and RF were also found in IIP patients, Diagnosis of connective tissue diseases also needs to be combined with other autoantibodiesindex.4 30 bacteria strains were isolated.Gramnegative bacteria was 60%,compared two groups of patients Gram-negative bacteria, Gram-positive bacteria and fungal infection were not significantly different.5 HRCT image characteristics of IIP and CTD-ILD patients were differences. The percentage of presence of consolidation in CTD-ILD patients was lower than IIP patients,while the presence of ground glass opacities in CTD-ILD patients was more common than IIP patients.6 The emphysema showed more severe in IIP than CTD-ILD,PAH showed more severe in CTD-ILD than IIP(P<0.05).7 A lot of IIP patients were often treated by corticosteroids, while corticosteroids and immunosuppressant for CTD-ILD.8 There were no significant differences between the proportional mortality rate of the two groups. And the main results of death were the respiratory failure diseases.