title: Pulmonary tuberculosis and disease-related pulmonary apical fibrosis in ankylosing spondylitis.
abstract: OBJECTIVE
  We investigated the etiological association and clinical characteristics of apical pulmonary fibrosis in ankylosing spondylitis (AS).
  
  
  METHODS
  We reviewed medical records of 2136 consecutive patients diagnosed with AS at a tertiary medical center. Clinical and radiographic characteristics were analyzed for evidence of apical lung fibrosis on chest radiographs.
  
  
  RESULTS
  Of 2136 patients with AS, 63 (2.9%) developed apical lung fibrosis, of which chronic infections were the cause in 41 and AS inflammation predisposed the fibrosis in 22 patients. Tuberculosis (TB) infection was considered to be the cause of apical lung fibrosis in 40 patients (63.5%) including 19 with bacteriologically-proven TB and 21 with chest radiographs suggestive of TB. Two were identified as having non-TB mycobacterial infection and one as Aspergillus infection. Lung cavity lesion appeared to be a crucial differentiator (p = 0.009, odds ratio 7.4, 95% CI 1.5-36.0) between TB infection and AS inflammation-induced apical fibrosis.
  
  
  CONCLUSIONS
  Our study suggests that TB, instead of Aspergillus, is the most common pulmonary infection in patients with AS presenting with apical lung fibrosis. AS-associated apical lung fibrosis may mimic pulmonary TB infection. Thus, bacteriological survey and serial radiological followup of lung fibrocavitary lesions are critical for accurate diagnosis and treatment.
authors.affiliation: Department of Medicine, Division of Allergy, Immunology and Rheumatology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, No. 5, Fu-Shin St. Kuei-Shan, Tao-Yuan, Taiwan, Republic of China.
authors.forename: Huei-Huang
authors.initials: HH
authors.lastname: Ho
authors.forename: Meng-Chih
authors.initials: MC
authors.lastname: Lin
authors.forename: Kuang-Hui
authors.initials: KH
authors.lastname: Yu
authors.forename: Chin-Man
authors.initials: CM
authors.lastname: Wang
authors.forename: Yeong-Jian Jan
authors.initials: YJ
authors.lastname: Wu
authors.forename: Ji-Yih
authors.initials: JY
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000995:Antitubercular Agents / Q000627:therapeutic use; D015897:Comorbidity; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis; D015995:Prevalence; D055732:Pulmonary Aspergillosis / Q000453:epidemiology; D011658:Pulmonary Fibrosis / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D011859:Radiography / Q000379:methods; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology; D013167:Spondylitis, Ankylosing / Q000453:epidemiology*; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000473:pathology; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents