title: Asthma and antibodies to pneumococcal virulence proteins.
abstract: OBJECTIVE
  We previously reported that asthmatics had lower anti-serotype-specific pneumococcal polysaccharide antibody levels than non-asthmatics, and the T-helper 2 (Th2) immune profile was associated with suboptimal pneumococcal polysaccharide antibody. Our objective was to determine the influence of asthma status on anti-pneumococcal protein antigen antibody levels.
  
  
  METHODS
  We conducted a cross-sectional study, which enrolled 16 children and adults with asthma and 14 subjects without asthma. Asthma was ascertained by predetermined criteria. Serum IgG antibody levels to pneumococcal surface protein A (PspA), pneumococcal surface protein C (PspC), pneumococcal choline-binding protein A (PcpA), and pneumolysin (PLY) were measured by enzyme-linked immunosorbent assays (ELISA). These antibody levels were compared between asthmatics and non-asthmatics. The Th2 immune profile was determined by IL-5 secretion from PBMCs cultured with house dust mite (HDM) and staphylococcal enterotoxin B (SEB) at day 7. The correlation between the anti-pneumococcal antibody levels and the Th2-HDM and SEB-responsive immune profile was assessed.
  
  
  RESULTS
  Of the 30 subjects, 16 (53%) were male and the median age was 26 years. There were no significant differences in anti-PspA, anti-PspC, anti-PcpA, and anti-PLY antibody levels between asthmatics and non-asthmatics. The Th2 immune profile was inversely correlated with the anti-PspC antibody levels (r = -0.53, p = 0.003). This correlation was significantly modified by asthma status (r = -0.74, p = 0.001 for asthmatics vs. r = -0.06, p = 0.83 for non-asthmatics). Other pneumococcal protein antibodies were not correlated with the Th2 immune profile.
  
  
  CONCLUSIONS
  No significant differences in the anti-pneumococcal protein antigen antibody levels between asthmatics and non-asthmatics were found. Asthma status is an important effect modifier determining the negative influence of the Th2 immune profile on anti-PspC antibody levels.
authors.affiliation: Division of Community Pediatric and Adolescent Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, 200 First Street, SW, Rochester, MN, 55905, USA.
authors.forename: H
authors.initials: H
authors.lastname: Zhao
authors.forename: J A
authors.initials: JA
authors.lastname: Jung
authors.forename: D E
authors.initials: DE
authors.lastname: Briles
authors.forename: H
authors.initials: H
authors.lastname: Kita
authors.forename: C
authors.initials: C
authors.lastname: Tsigrelis
authors.forename: Y J
authors.initials: YJ
authors.lastname: Juhn
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001249:Asthma / Q000276:immunology* / Q000382:microbiology; D001426:Bacterial Proteins / Q000276:immunology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D015848:Interleukin-5 / Q000097:blood; D007963:Leukocytes, Mononuclear; D008297:Male; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013301:Streptolysins / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C508599:IL5 protein, human; D007074:Immunoglobulin G; D015848:Interleukin-5; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae