ObjectivePulmonary infection is commonly seen in patients with rheumatic autoimmune disease (RAD).Sometimes bronchoscopy is used to obtain microorganisms.In order to improve diagnostic yield, the factors affecting diagnostic yield of bronchoscopy in obtaining microorganisms in RAD patients with pulmonary abnormality were analyzed retrospectively. MethodsA retrospective study was performed in RAD patients with lung infiltrates who received bronchoscopy for obtaining microorganisms at the Department of Rheumatology,Peking Union Medical College Hospital from January 2009 to June 2013.Patients characteristics,clinical symptoms,medication history,laboratory parameters,radiographic findings and locations where microorganisms were obtained were recorded. Results87 patients received 91 bronchoscopic exams,including 72 bronchoalveolar lavages,21 bronchial aspirates,and 72 bronchial brushes.The total diagnostic yield was 52.7%.The diagnostic yield was 71.4% with bronchoalveolar lavage,38.9% with bronchial aspirate,and 18.1% with bronchial brush.Diagnostic yield was significantly higher in the patients with clinical symptoms of fever,cough or expectoration compared with the patients without either symptoms (60.0%% vs.34.6%,P=0.028).The patients with CT finding of nodular,massive or consolidation had a higher diagnostic yield compared with those with CT findings of reticular,linear or ground glass opacity (61.8% vs.26.1%,P=0.003).Diagnostic yield was not affected by location of bronchoalveolar lavage (P=0.691). ConclusionRAD patients with fever,cough or sputum,and CT findings of nodular,massive or consolidation would get a higher diagnostic yield by bronchoscopy.