title: Nodular bronchiectatic Mycobacterium avium complex pulmonary disease. Natural course on serial computed tomographic scans.
abstract: BACKGROUND
  Existing literature is inconclusive regarding how the nodular bronchiectatic form of Mycobacterium avium complex (MAC) disease will progress without treatment and when treatment initiation should be considered.
  
  
  OBJECTIVE
  To assess the natural course of MAC pulmonary disease by serial thin-section computed tomography (CT).
  
  
  METHODS
  Of 339 patients with nodular bronchiectatic form of MAC disease, we selected 265 untreated patients who had serial CTs (mean observation period, 32 ± 21 mo). Two independent chest radiologists reviewed retrospectively all CT scans for the presence and extent of lung abnormalities (maximal total score, 30).
  
  
  RESULTS
  Of 265 patients, 126 patients (48%) had disease that had progressed and that needed treatment owing to radiologic deterioration or worsening symptoms, and the remaining 139 patients (52%) did not. On multivariate analysis, the presence of cavity (adjusted hazard ratio, 2.06; P = 0.004) and consolidation (adjusted hazard ratio, 1.55; P = 0.019) at initial CT remained as independent factors associated with disease progression and treatment requirement. The presence of cavitary lesions demonstrated the highest positive predictive value (61%) and significant correlation (P = 0.005) with smear positivity. Differences in the extent of each pattern and total CT score in the serial studies were significantly larger (P < 0.05) in patients requiring treatment. The total CT score increased by 2.41 in the treatment-requiring group compared with 0.25 in the group that did not receive treatment.
  
  
  CONCLUSIONS
  Without treatment, about half of patients demonstrate progressive disease on serial CT over a mean follow-up period of 32 months and, thus, required treatment. Patients showing cavities or consolidation on initial CT are more likely to have progressive disease and thus to require treatment eventually.
authors: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Geewon
authors: G
authors: Lee
authors: Kyung Soo
authors: KS
authors: Lee
authors: Jung Won
authors: JW
authors: Moon
authors: Won-Jung
authors: WJ
authors: Koh
authors: Byeong-Ho
authors: BH
authors: Jeong
authors: Yeon Joo
authors: YJ
authors: Jeong
authors: Hak Jin
authors: HJ
authors: Kim
authors: Sookyoung
authors: S
authors: Woo
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use; D001987:Bronchiectasis / Q000000981:diagnostic imaging*; D017291:Clarithromycin / Q000627:therapeutic use; D018450:Disease Progression; D004359:Drug Therapy, Combination; D004977:Ethambutol / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D055613:Multiple Pulmonary Nodules / Q000000981:diagnostic imaging*; D015999:Multivariate Analysis; D015269:Mycobacterium avium Complex / Q000302:isolation & purification; D015270:Mycobacterium avium-intracellulare Infection / Q000000981:diagnostic imaging* / Q000188:drug therapy; D018410:Pneumonia, Bacterial / Q000000981:diagnostic imaging*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012293:Rifampin / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin; D004977:Ethambutol; D017291:Clarithromycin; D012293:Rifampin