title: Chlamydia pneumoniae-specific cell-mediated and humoral immunity in healthy people.
abstract: In this work, cell-mediated immunity to Chlamydia pneumoniae was studied in 157 healthy individuals using lymphoproliferative assay and serum antibodies were analysed by microimmunofluorescence techniques. The C. pneumoniae-specific IgG antibodies were elevated more frequently and the geometric mean titres for IgG (67.5 versus 44.1; P = 0.05) and IgA (14.9 versus 11.3; P = 0.025) antibodies were significantly higher in males than in females. However, no gender-dependent differences were observed in cellular reactivity to C. pneumoniae, since the median cellular responses were similar (stimulation indices 7.5) in men and women. Although the cell-mediated and humoral responses to C. pneumoniae did not correlate clearly, elevated IgG antibodies were associated with slightly higher lymphocyte proliferation in comparison to all subjects (15.5 versus 7.5) and significantly stronger in comparison to those with persistently elevated IgA (> 80) antibodies (15.5 versus 3.5; P = 0.023). Further studies are needed to evaluate a possible role of reduced cellular reactivity in the cause of chronic C. pneumoniae infection.
authors.affiliation: National Public Health Institute, Department of Medical Microbiology, University of Oulu, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Halme
authors.forename: L
authors.initials: L
authors.lastname: von Hertzen
authors.forename: A
authors.initials: A
authors.lastname: Bloigu
authors.forename: J
authors.initials: J
authors.lastname: Kaprio
authors.forename: M
authors.initials: M
authors.lastname: Koskenvuo
authors.forename: M
authors.initials: M
authors.lastname: Leinonen
authors.forename: P
authors.initials: P
authors.lastname: Saikku
authors.forename: H M
authors.initials: HM
authors.lastname: Surcel
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology*; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000494:pharmacology; D002690:Chlamydia Infections / Q000453:epidemiology; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors; D017186:Titrimetry
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G