title: Systemic and mucosal antibody response to Moraxella catarrhalis after exacerbations of chronic obstructive pulmonary disease.
abstract: To characterize the immune response to Moraxella catarrhalis after exacerbations of chronic obstructive pulmonary disease (COPD), pre- and postexacerbation serum and sputum supernatant samples obtained during 21 exacerbations in 18 patients were studied, using the homologous infecting isolates. New serum immunoglobulin G (IgG) detected by whole-cell enzyme-linked immunosorbent assay developed after 12 (57.1%) of 21 exacerbations. Analysis of serum samples with flow cytometry, which detects antibodies that are exclusive to epitopes on the bacterial surface, revealed that 5 (23.8%) of the 21 exacerbations were associated with the development of new serum IgG to surface epitopes. Three of these serum samples and 2 other serum samples contained new IgG directed at lipooligosaccharide. Flow cytometry revealed that new mucosal IgA to surface-exposed epitopes of the infecting isolate developed in sputum supernatants after 42% of exacerbations. Therefore, adults with COPD develop variable humoral immune responses to M. catarrhalis after exacerbations, including new serum IgG and new mucosal IgA to epitopes on the bacterial surface.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA.
authors.forename: Faris
authors.initials: F
authors.lastname: Bakri
authors.forename: Aimee L
authors.initials: AL
authors.lastname: Brauer
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sethi
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Murphy
mesh_terms: D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D016905:Gram-Negative Bacterial Infections / Q000276:immunology* / Q000382:microbiology; D006801:Humans; D015151:Immunoblotting; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D001936:Moraxella catarrhalis / Q000276:immunology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000276:immunology; D013183:Sputum / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007071:Immunoglobulin A, Secretory