title: Clinical symptoms and survival in non-smoking and smoking HIV-negative patients with non-tuberculous mycobacterial isolation.
abstract: BACKGROUND
  Non-tuberculous mycobacteria (NTM) cause infections in patients with smoking-related chronic lung diseases and also in non-smoking healthy elderly women. We analyzed the clinical symptoms, underlying diseases and mortality in patients with NTM culture findings, with special emphasis on smoking status.
  
  
  METHODS
  A total of 120 consecutive adult HIV-negative patients with NTM isolation were followed between 1990 and 1998 by retrieving data from their medical records for a period of at least 4 y, until 8 June 2006. Their clinical pictures and outcomes were analysed according to smoking status.
  
  
  RESULTS
  In this study, 42% of the patients had never smoked. Females accounted for 72% of non-smokers, but only 30% of smokers (p < 0.001). Mycobacterium avium complex (MAC) accounted for 72% of all isolates in non-smokers and 41% in smokers (p = 0.001). Furthermore, 28% of non-smokers and 19% of smokers had no previous pulmonary diseases (p = 0.223). In nearly half of all patients (48%), symptoms of NTM infection started within a year prior to NTM isolation. Smokers had a higher risk of mortality compared to non-smokers (hazard ratio 1.64, p = 0.049), though this was not found after adjusting for underlying diseases. No fatal underlying diseases were found for 82% of non-smokers and 59% of smokers (p < 0.01).
  
  
  CONCLUSIONS
  Non-smokers with NTM isolates had fewer previous lung diseases but had a higher incidence of MAC and bronchiectasis. Time from symptoms to NTM isolation was shorter than previously reported.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Aurora Hospital, Helsinki, Finland. hannele.kotilainen@hus.fi
authors.forename: Hannele
authors.initials: H
authors.lastname: Kotilainen
authors.forename: Ville
authors.initials: V
authors.lastname: Valtonen
authors.forename: Pentti
authors.initials: P
authors.lastname: Tukiainen
authors.forename: Tuija
authors.initials: T
authors.lastname: Poussa
authors.forename: Jussi
authors.initials: J
authors.lastname: Eskola
authors.forename: Asko
authors.initials: A
authors.lastname: Järvinen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000453:epidemiology / Q000401:mortality* / Q000473:pathology*; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification*; D012907:Smoking / Q000009:adverse effects*; D016019:Survival Analysis