title: Chlamydophila (Chlamydia) pneumoniae serology and asthma in adults: a longitudinal analysis.
abstract: BACKGROUND
  Many cross-sectional studies have found an association between Chlamydophila pneumoniae infection and asthma, and a possible causative role of C pneumoniae infection in asthma pathogenesis has been proposed. No longitudinal studies have been undertaken to estimate the effect on asthma incidence of previous or chronic infection.
  
  
  OBJECTIVE
  We evaluated whether serological findings suggestive for recent or chronic C pneumoniae infection affect asthma risk or lung function during follow-up.
  
  
  METHODS
  We followed a population-based adult cohort for 15 years and made a clinical evaluation of persons with new persistent asthma (n = 83) and matched controls (n = 162). Serological testing was performed by microimmunofluorescence and enzyme immunoassay from both baseline and follow-up samples.
  
  
  RESULTS
  Subjects with serologically diagnosed recent or chronic C pneumoniae infection did not run a higher risk of new asthma. An increased risk was found in subjects with allergic rhinitis, low lung function, history of smoking, and positive family background of asthma or allergy. However, chronic C pneumoniae infection was found to accelerate the loss of lung function significantly in subjects who contracted new nonatopic asthma (median change in FEV(1), 89.6 vs 55.9 mL/y; P = .032).
  
  
  CONCLUSIONS
  Chronic C pneumoniae infection promotes the development of airflow limitation in adults with nonatopic asthma. However, our results indicate that at the population level, any possible effect of C pneumoniae infection on asthma incidence is of minor significance.
authors.affiliation: Department of Dermatology and Venereology, University of Tampere, Medical School, FIN-33014 University of Tampere, Finland.
authors.forename: Rafael
authors.initials: R
authors.lastname: Pasternack
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.forename: Jussi
authors.initials: J
authors.lastname: Karjalainen
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000209:etiology; D001249:Asthma / Q000235:genetics / Q000382:microbiology* / Q000503:physiopathology; D016022:Case-Control Studies; D023521:Chlamydophila Infections / Q000150:complications* / Q000175:diagnosis*; D016993:Chlamydophila pneumoniae; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000235:genetics; D008137:Longitudinal Studies; D008168:Lung / Q000503:physiopathology; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D012220:Rhinitis / Q000150:complications / Q000209:etiology; D018570:Risk Assessment; D012698:Serologic Tests; D012907:Smoking / Q000009:adverse effects