{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T01:37:10Z","timestamp":1776217030068,"version":"3.50.1"},"reference-count":19,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2021,8,12]],"date-time":"2021-08-12T00:00:00Z","timestamp":1628726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Japan College of Rheumatology","award":["None"],"award-info":[{"award-number":["None"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>The relationship between microorganisms present in the lower respiratory tract and the subsequent incidence of pneumonia in patients with rheumatoid arthritis is unclear. A retrospective cohort study was designed to include a total of 121 patients with rheumatoid arthritis who underwent bronchoscopy at three hospitals between January 2008 and December 2017. Data on patient characteristics, microorganisms detected by bronchoscopy, and subsequent incidences of pneumonia were obtained from electronic medical records. Patients were divided into groups based on the microorganisms isolated from the lower respiratory tract. The cumulative incidence of pneumonia was assessed using the Kaplan\u2013Meier method, and decision tree analysis was performed to analyze the relation between the presence of microorganisms and the occurrence of pneumonia. The most frequently isolated microbes were Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae. Patients whose samples tested negative for bacteria or positive for normal oral flora were included in the control group. The rate of the subsequent incidence of pneumonia was higher in the P. aeruginosa group than in the control group (p = 0.026), and decision tree analysis suggested that P. aeruginosa and patient performance status were two important factors for predicting the incidence of pneumonia. In patients with rheumatoid arthritis, the presence of P. aeruginosa in the lower respiratory tract was associated with the subsequent incidence of pneumonia.<\/jats:p>","DOI":"10.3390\/jcm10163552","type":"journal-article","created":{"date-parts":[[2021,8,12]],"date-time":"2021-08-12T10:54:41Z","timestamp":1628765681000},"page":"3552","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Infectious Pneumonia and Lower Airway Microorganisms in Patients with Rheumatoid Arthritis"],"prefix":"10.3390","volume":"10","author":[{"given":"Shuhei","family":"Ideguchi","sequence":"first","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan"},{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1357-1676","authenticated-orcid":false,"given":"Kazuko","family":"Yamamoto","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"},{"name":"Department of Infection Control and Education Center, Nagasaki University Hospital, Nagasaki 852-8102, Japan"},{"name":"Clinical Research Center, National Hospital Organization Nagasaki Medical Center, Omura 856-0835, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3266-6726","authenticated-orcid":false,"given":"Masahiro","family":"Tahara","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, University of Occupational and Environmental Health Japan, Kitakyushu 807-8555, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tomohiro","family":"Koga","sequence":"additional","affiliation":[{"name":"Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shotaro","family":"Ide","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Isahaya General Hospital, Isahaya 854-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tatsuro","family":"Hirayama","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0696-5386","authenticated-orcid":false,"given":"Takahiro","family":"Takazono","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoshifumi","family":"Imamura","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0962-5758","authenticated-orcid":false,"given":"Taiga","family":"Miyazaki","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7577-476X","authenticated-orcid":false,"given":"Noriho","family":"Sakamoto","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shimpei","family":"Morimoto","sequence":"additional","affiliation":[{"name":"Innovation Platform & Office for Precision Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Koichi","family":"Izumikawa","sequence":"additional","affiliation":[{"name":"Department of Infection Control and Education Center, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katsunori","family":"Yanagihara","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6726-1297","authenticated-orcid":false,"given":"Kazuto","family":"Ashizawa","sequence":"additional","affiliation":[{"name":"Department of Clinical Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takatoshi","family":"Aoki","sequence":"additional","affiliation":[{"name":"Department of Radiology, University of Occupational and Environmental Health Japan, Kitakyushu 807-8555, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atsushi","family":"Kawakami","sequence":"additional","affiliation":[{"name":"Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2955-4432","authenticated-orcid":false,"given":"Kazuhiro","family":"Yatera","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, University of Occupational and Environmental Health Japan, Kitakyushu 807-8555, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hiroshi","family":"Mukae","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan"},{"name":"Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki 852-8102, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wakabayashi, A., Ishiguro, T., Takaku, Y., Miyahara, Y., Kagiyama, N., and Takayanagi, N. 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