title: Differential switching to IgG and IgA in active smoking COPD patients and healthy controls.
abstract: Several studies have demonstrated the presence of B-cell follicles and autoantibodies in chronic obstructive pulmonary disease (COPD). It is unclear against which antigens this B-cell response is directed and whether it contributes to development or worsening of disease. We assessed different B-cell subsets in blood and lung tissue from COPD patients and controls, and compared differences in B-cell responsiveness to stimulation with lung-specific antigens. Active smoking induced an adaptive immune response with relatively high levels of (class-switched) memory B-cells in blood and immunoglobulin (Ig)G memory B-cells in the lung. COPD smokers showed more switching to IgG, whereas healthy smokers switched more to IgA. COPD patients had higher levels of memory B-cells in the lung and stimulation with lung-specific antigens induced higher numbers of anti-decorin antibody-producing cells in COPD patients compared with healthy controls. Differential switching to IgG and IgA indicates that the adaptive immune response to smoke differs between COPD patients and healthy controls. A higher level of memory B-cells in the lungs of COPD patients may reflect an antigen-specific immune response, which could be directed against decorin, as suggested by the induction of anti-decorin antibody-producing cells in response to antigen-specific stimulation in COPD patients.
authors.affiliation: Dept of Pathology and Medical Biology, University Medical Center Groningen and University of Groningen, P.O. box 30.001, 9700 RB, Groningen, The Netherlands. c.a.brandsma@umcg.nl
authors.forename: Corry-Anke
authors.initials: CA
authors.lastname: Brandsma
authors.forename: Huib A M
authors.initials: HA
authors.lastname: Kerstjens
authors.forename: Wouter H
authors.initials: WH
authors.lastname: van Geffen
authors.forename: Marie
authors.initials: M
authors.lastname: Geerlings
authors.forename: Dirkje S
authors.initials: DS
authors.lastname: Postma
authors.forename: Machteld N
authors.initials: MN
authors.lastname: Hylkema
authors.forename: Wim
authors.initials: W
authors.lastname: Timens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000276:immunology*; D016022:Case-Control Studies; D058575:Decorin / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007107:Immune System; D007070:Immunoglobulin A / Q000737:chemistry*; D017578:Immunoglobulin Class Switching; D007074:Immunoglobulin G / Q000737:chemistry*; D007962:Leukocytes / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology; D008168:Lung / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology* / Q000378:metabolism; D012907:Smoking / Q000276:immunology* / Q000378:metabolism
chemical_list: D058575:Decorin; D007070:Immunoglobulin A; D007074:Immunoglobulin G