title: Host-pathogen interaction during pneumococcal infection in patients with chronic obstructive pulmonary disease.
abstract: Acute exacerbation is a frequent complication of chronic obstructive pulmonary disease (COPD). Recent studies suggested a role for bacteria such as Streptococcus pneumoniae in the development of acute exacerbation. For this study, we investigated the following in COPD patients: (i) the epidemiology of pneumococcal colonization and infection, (ii) the effect of pneumococcal colonization on the development of exacerbation, and (iii) the immunological response against S. pneumoniae. We cultured sputa of 269 COPD patients during a stable state and during exacerbation of COPD and characterized 115 pneumococcal isolates by use of serotyping. Moreover, we studied serum immunoglobulin G (IgG) antibody titers, antibody avidities, and functional antibody titers against the seven conjugate vaccine serotypes in these patients. Colonization with only pneumococci (monocultures) increased the risk of exacerbation, with a hazard ratio of 2.93 (95% confidence interval, 1.41 to 6.07). The most prevalent pneumococcal serotypes found were serotypes 19F, 3, 14, 9L/N/V, 23A/B, and 11. We calculated the theoretical coverage for the 7- and 11-valent pneumococcal vaccines to be 60 and 73%, respectively. All patients had detectable IgG levels against the seven conjugate vaccine serotypes. These antibody titers were significantly lower than those in vaccinated healthy adults. Finally, on average, a 2.5-fold rise in serotype-specific and functional antibodies in S. pneumoniae-positive sputum cultures was observed during exacerbation. Our data indicate that pneumococcal colonization in COPD patients is frequently caused by vaccine serotype strains. Moreover, pneumococcal colonization is a risk factor for exacerbation of COPD. Finally, our findings demonstrate that COPD patients are able to mount a significant immune response to pneumococcal infection. COPD patients may therefore benefit from pneumococcal vaccination.
authors.affiliation: Department of Pediatrics, Erasmus MC-Sophia, Rotterdam, The Netherlands.
authors.forename: Debby
authors.initials: D
authors.lastname: Bogaert
authors.forename: Paul
authors.initials: P
authors.lastname: van der Valk
authors.forename: Reshmi
authors.initials: R
authors.lastname: Ramdin
authors.forename: Marcel
authors.initials: M
authors.lastname: Sluijter
authors.forename: Evelyn
authors.initials: E
authors.lastname: Monninkhof
authors.forename: Ron
authors.initials: R
authors.lastname: Hendrix
authors.forename: Ronald
authors.initials: R
authors.lastname: de Groot
authors.forename: Peter W M
authors.initials: PW
authors.lastname: Hermans
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000276:immunology*; D022242:Pneumococcal Vaccines / Q000276:immunology; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology*; D012703:Serotyping; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate