title: Respiratory symptoms, asthma, atopy and Chlamydia pneumoniae IgG antibodies in a general population sample of young adults.
abstract: BACKGROUND
  This study was designed to test the association of Chlamydia pneumoniae infection with respiratory symptoms and atopy.
  
  
  METHODS
  A general population sample of 369 young adults (aged 20-44 years) completed a questionnaire on respiratory symptoms and underwent skin prick testing. C. pneumoniae IgG and IgM serum titers were measured by microimmunofluorescence. Prior infection was defined by titers of IgG > or = 1:32, acute infection by titers of IgG > or = 1:512 and/or IgM > or = 1:16.
  
  
  RESULTS
  The prevalence of cough and phlegm was higher in subjects with (19.0%) than in those without (11.4%) prior C. pneumoniae infection (p = 0.01). A similar difference was found for wheezing (14.3% vs 8.0%; p = 0.05), whereas the percentage of asthmatics was equally distributed between seropositive and seronegative subjects. IgG titers > or = 1:128 were found more frequently in atopic subjects (p = 0.04). After adjusting for any confounding factors, cough and phlegm (but not wheezing) were found significantly associated with C. pneumoniae positivity, both for 1:32 (OR 1.80; 95% CI: 1.01-3.36; p = 0.05) and for 1:128 titers (OR 2.31; 95% CI: 1.20-4.42; p = 0.01). A significant association was also found for atopy, for titers > or = 1:128 (OR 1.73; 95% CI: 1.01-3.20, p = 0.05). Acute infection was not associated with respiratory symptoms or asthma.
  
  
  CONCLUSIONS
  We conclude that C. pneumoniae infection is associated with cough and phlegm and may have a role in the pathogenesis of chronic respiratory diseases. Moreover, our results indicate a relationship between atopy and C. pneumoniae infection.
authors.affiliation: Dept. of Science and Surgery, Policlinico Borgo Roma, Verona, Italy. ferrari@medicinad.univr.it
authors.forename: M
authors.initials: M
authors.lastname: Ferrari
authors.forename: A
authors.initials: A
authors.lastname: Poli
authors.forename: M
authors.initials: M
authors.lastname: Olivieri
authors.forename: G
authors.initials: G
authors.lastname: Verlato
authors.forename: S
authors.initials: S
authors.lastname: Tardivo
authors.forename: M
authors.initials: M
authors.lastname: Nicolis
authors.forename: C
authors.initials: C
authors.lastname: Campello
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D001249:Asthma / Q000209:etiology / Q000276:immunology*; D023521:Chlamydophila Infections / Q000150:complications / Q000276:immunology* / Q000473:pathology; D016993:Chlamydophila pneumoniae / Q000276:immunology* / Q000472:pathogenicity*; D003371:Cough / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis*; D008297:Male; D018410:Pneumonia, Bacterial / Q000150:complications / Q000276:immunology* / Q000473:pathology; D015995:Prevalence; D012135:Respiratory Sounds
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G