title: Age-specific immunoglobulin g (IgG) and IgA to pneumococcal protein antigens in a population in coastal kenya.
abstract: Streptococcus pneumoniae is the primary etiological agent of community-acquired pneumonia and a major cause of meningitis and bacteremia. Three conserved pneumococcal proteins-pneumolysin, pneumococcal surface adhesin A (PsaA), and pneumococcal surface protein A (PspA)-are currently being investigated as vaccine candidates. Such protein-based vaccines, if proven effective, could provide a cheaper alternative to conjugate vaccine formulae. Few data from sub-Saharan Africa exist concerning the development of natural antibody to these antigens, however. To investigate the age-specific development of antiprotein immunoglobulin G (IgG) and IgA antibody responses, the sera of 220 persons 2 weeks to 84 years of age from coastal Kenya were assayed using enzyme-linked immunosorbent assays. IgG and IgA antibody responses to each antigen were observed in all age groups. Serum concentrations of IgG and IgA antibody responses to PspA and PdB (a recombinant toxoid derivative of pneumolysin), but not to PsaA, increased significantly with age (P < 0.001). No decline was observed in the sera of the elderly. Anti-protein IgG concentrations were only weakly correlated (0.30 < r < 0.56; P < 0.0001), as were IgA concentrations (0.24 < r < 0.54; P < 0.0001).
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts 02115, USA. claine@hsph.harvard.edu
authors.forename: Catherine
authors.initials: C
authors.lastname: Laine
authors.forename: Tabitha
authors.initials: T
authors.lastname: Mwangi
authors.forename: Claudette M
authors.initials: CM
authors.lastname: Thompson
authors.forename: Jacktone
authors.initials: J
authors.lastname: Obiero
authors.forename: Marc
authors.initials: M
authors.lastname: Lipsitch
authors.forename: J Anthony G
authors.initials: JA
authors.lastname: Scott
mesh_terms: D018829:Adhesins, Bacterial; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology; D002352:Carrier Proteins / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D007630:Kenya / Q000453:epidemiology; D008074:Lipoproteins / Q000276:immunology; D008297:Male; D026901:Membrane Transport Proteins; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control; D011018:Pneumonia, Pneumococcal / Q000276:immunology / Q000517:prevention & control; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013301:Streptolysins / Q000276:immunology
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008074:Lipoproteins; D026901:Membrane Transport Proteins; C085000:PsaA protein, Streptococcus; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae; C051592:pneumococcal surface protein A