Clinical Characteristics Of Interstitial Pneumonia With Autoimmune Features

Objectives:To explore the clinical characteristics of patients with interstitial pneumonia with autoimmune features(IPAF),compare the clinical differences between IPAF and non-IPAF-IIP(idiopathic interstitial pneumonia)and IPF(idiopathic pulmonary fibrosis),and find out the risk factors affecting IPAF death.Methods:A retrospective analysis was made on 130 IIP patients that hospitalized in Department of Respiratory Medicine and Department of Rheumatology and Immunology of the Second Affiliated Hospital of Kunming Medical University from January 2014 to December 2019.The diagnostic criteria ofⅡP were based on the diagnostic and classification criteria proposed by American Thoracic Society(ATS)and European Respiratory Society(ERS)in 2013.All patients were diagnosed with pulmonary interstitial diseases by HRCT and had complete medical records.Patients who met the diagnostic criteria of interstitial pneumonia with autoimmune features(IPAF)[2](see Table 1-1)of American Thoracic Society(ATS)and European Respiratory Society(ERS)in 2015 were selected as IPAF group.The patients who could not be diagnosed as IPAF were non-IPAF-ⅡP group,and those who met the diagnostic criteria for idiopathic pulmonary fibrosis published by European Respiratory Society(ERS),Japanese Respiratory Society(JRS),American Thoracic Society(ATS)and Latin American Thoracic Society(ALAT)in 2018 were IPF group.Collect the basic information,clinical manifestation,serological antibody,blood routine,biochemical test,acute infection,erythrocyte sedimentation rate,pulmonary function,blood gas analysis,artery pressure by echocardiographic pulmonary,HRCT manifestation,clinical treatment plan,outpatient records and telephone follow-up survival time of the above patients,discuss the clinical characteristics of IPAF patients,compare the differences of the above clinical data with non-IPAF-IIP and IPF patients,and further discuss the diagnostic criteria and differential diagnosis of IPAF Survival analysis was used to further explore the risk factors that may affect the death of patients with IPAF.Results:1.Comparison of general data and treatment schemes between IPAF group,non-IPAF-IIP group and IPF group respectively.Compared with non-IPAF-IIP group and IPF group in general information and treatments,there was no significant difference in age,nationality,past medical history(hypertension,diabetes,coronary heart disease,after cholecystectomy and appendectomy)and treatments(using antibiotics,proton pump inhibitors,steroids and low molecular heparin)(P>0.05).The number of female patients in IPAF group was more than that in non-IPAF-IIP group(47%vs 29.7%,p=0.043)and IPF group(47%vs 26.2%,P=0.031).Patients with hypertension in IPAF group were less than those in IPF group(28.8%vs 47.6%,p=0.047).Compared with non-IPAF-iip group(65.2%vs 45.3%,p=0.023)and IPF group(65.2%vs 40.5%,p=0.012),the difference was statistically significant(p<0.05).2.Comparison of clinical data between IPAF group and non-IPAF-IIP group and IPF group respectively.In the comparison of clinical examination data between IPAF group,non-IPAF-IIP group and IPF group,there was no significant difference in white blood cells,neutrophils,lymphocytes,red blood cells,hemoglobin,eosinophils,platelets,albumin,creatinine,urea,interleukin-6,high-sensitivity C-reactive protein,ESR,respiratory failure,positive bronchodilation test,ventilation dysfunction,DLCO,pulmonary artery pressure,thyroid dysfunction,HRCT manifestation etc(P>0.05).The PCT in IPAF group was significantly lower than that in non-IPAF-IIP group(0.057 0,068 vs 0.077 0.10,p=0.023)and IPF group(0.057±0.068 vs 0.083±0.12,p=0.008),(p<0.05).3.Characteristics of IPAF patients in IPAF diagnostic criteria in 2015.The positive rate of 66 patients with IPAF was 27.3%in clinical field,81.8%in serology and 93.9%in morphology.Compared with the diagnostic criteria of IPAF,inflammatory arthritis or morning stiffness of multiple joints and unexplained finger swelling were the main clinical areas in this study,and no telangiectasia of palm or finger abdomen and unexplained fixed rash of finger extension side were found.ANA,RF>2 times normal upper limit and anti-riboprotein are the main serological fields.In morphological field(confirmed by HRCT),NSIP,multiple thoracic involvement and UIP are common.4,Survival analysis.During the follow-up,12 patients(18.2%)died in IPAF group,13 patients(20.3%)died in non-IPAF-IIP group and 12 patients(28.6%)died in IPF group.There was no statistical difference in survival rate among the three groups(P>0.05).5.Risk factor analysis.66 patients with IPAF were analyzed by univariate COX regressio,.after adjustment of variables,it was found that age(HR 1.152,95%CI(1.026-1.293),p=0.017)and pulmonary artery pressure(HR 1.058 95%CI(1.006-1.112),p=0.029)were risk factors for increased mortality,the difference was statistically significant(p<0.05).6.Comparison between IPAF(UIP-IPAF)group whose HRCT phenotype is UIP mode and IPF groupTwenty-two patients with UIP mode in HRCT phenotype in IPAF were redefineted as UIP-IPAF group.Compared with IPF group,there was no significant difference in age,race,complication,treatments,blood routine,biochemical test,ESR,PCT,IL-6,pulmonary functionb,blood gas analysis,pulmonary artery pressure and thyroid function between the two groups(P>0.05)Compared with IPF group,UIP-IPAF group has more women,including 12 women(54.5%)in UIP-IPAF group and 11 women(26.2%)in IPF group.Hs-CRP in IPF was significantly higher than that in UIP-IPAF.The above differences were significant(P<0.05).After continuing the survival analysis of UIP-IPAF and IPF,it was found that there was no significant difference of them(P>0.05).Conclusion(s):1.IPAF is more common in female patients.2.NSIP is the main type of HRCT of IPAF,and ANA is the main type of serology.3.The treatment of IPAF is mainly hormone,and significantly higher than that of non-IPAF-IIP and IPF.4.Compared with non-IPAF-IIP and IPF,the infection index PCT of IPAF is lower,that is,IPAF patients may be less likely to be infected at the initial stage of the disease.5.OLd age and higher pulmonary artery pressure may be risk factors affecting the prognosis of patients with IPAF.