Clinical And Prognostic Studies Of Interstitial Pneumonia

Background:Some of the patients with idiopathic interstitial pneumonia(IIP)present with features of connective tissue disease(CTD)while lacking findings diagnostic of any specific CTD.Those patients may have different clinical manifestation,pathologic findings and prognosis compared with IIP patients.Thus ATS/ERS proposed a classification criteria of interstitial pneumonia with autoimmune features(IPAF).The aim of this study is to investigate the development from IIP and IPAF to CTD-ILD,compare clinical features,survival and relapse amone the three groups and finally validate the predictor of survival and relapseMethod:Retrospectively analysis was performed among consecutive patients with interstitial pneumonia visiting Peking Union Medical College Hospital from March 2006 to March 2016.All the patients confirmed to have ILD by high resolution computed tomography(HRCT)or surgical lung biopsy were identified.Patients were excluded if they had ILD from other causes,was not treated with systemic corticosteroid,or did not undergo the baseline test of CT or pulmonary function test.We applied IPAF criteria to these patients and divided them into 3 groups:connective tissue disease associated interstitial lung disease(CTD-ILD),IPAF and IIP.The data of clinical manifestation,pulmonary function test,CT and pathological findings were extracted from the medical record.Using survival time and time to relapse as the endpoints,we then compared the clinical features,prognosis and relapse among these three group,and validated the predictor of survival and relapse.Result:1.274 patients with interstitial lung disease(ILD)were included among which there were 93 patients in CTD-ILD group,119 patients in IPAF group and 62 patients in IIP group.During a median follow-up period of 36.3 months,there were 17 deaths,4 loss to follow up and 104 relapse.7 in IPAF group and 4 in IIP group were diagnosed as CTD-ILD during follow up.2.The extrapulmoary manifestations such as mechanic's hands and Gottron sign were more common in IPAF group than those in CTD-ILD group and IIP group(p<0.05).ANA was less common in ?P group than that in IPAF group and CTD-ILD group(p<0.05).There were significantly more CT pattern of nonspecific interstitial pneumonia(NSIP)and more patients with improvement of CT findings in IPAF group compared with other two groups(p<0.05).FEV1%and FVC%in IPAF group was significantly lower than that of IIP group(p<0.05),and no significant difference of improvement of pulmonary function test were found among the three groups.3.No significance was found in survival and relapse among the three groups,while regrouping after follow up demonstrated different survival(p=0.051)and relapse rate(p=0.025)among the three groups.4.UIP as CT pattern was associated with increased mortality in ILD patients(p<0.001),as well as in CTD-ILD patients(p<0.001),IPAF patients(p=0.031)and IIP patients(p=0.003).5.Jo-1 was an independent predictor associated with increased relapse rate(p=0.020).Improvement of DLCO(p=0.022)and improvement of CT findings(p=0.003)was an independent predictor associated with decreased relapse rate.Conclusion:1.The classification criteria of IPAF identifies the patients with different clinical manifestation,baseline pulmonary function test,CT pattern,improvement in CT.2.During follow-up,some of IPAF patients and ?P patients will be diagnosed with some certain CTD-ILD,thus the confirmed diagnosis of IPAF and ?P requied follow up.3.UIP as CT pattern is assoctiated with increased mortality in ILD patients,as well as in CTD-ILD patients,IPAF patients and IIP patients.4 After regrouping,?P shows lower risk of relapse than IPAF and CTD-ILD.Jo-1 were independent predictors associated with increased relapse rate.