title: Decreased serum antibody responses to recombinant pneumocystis antigens in HIV-infected and uninfected current smokers.
abstract: Serologic studies can provide important insights into the epidemiology and transmission of Pneumocystis jirovecii. Exposure to P. jirovecii can be assessed by serum antibody responses to recombinant antigens from the major surface glycoprotein (MsgC), although factors that influence the magnitude of the antibody response are incompletely understood. We determined the magnitudes of antibody responses to P. jirovecii in comparison to adenovirus and respiratory syncytial virus (RSV) in HIV-infected and uninfected patients and identified predictors associated with the magnitude of the response. We performed a cross-sectional analysis using serum samples and data from 153 HIV-positive and 92 HIV-negative subjects enrolled in a feasibility study of the Veterans Aging Cohort 5 Site Study (VACS 5). Antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). Independent predictors of antibody responses were determined using multivariate Tobit regression models. The results showed that serum antibody responses to P. jirovecii MsgC fragments were significantly and independently decreased in current smokers. Antibodies to P. jirovecii also tended to be lower with chronic obstructive pulmonary disease (COPD), hazardous alcohol use, injection drug use, and HIV infection, although these results were not statistically significant. These results were specific to P. jirovecii and did not correlate with adenovirus. Antibody responses to RSV were in the inverse direction. Thus, current smoking was independently associated with decreased P. jirovecii antibody responses. Whether smoking exerts an immunosuppressive effect that affects the P. jirovecii antibody response, colonization, or subsequent risk for disease is unclear; prospective, longitudinal studies are needed to evaluate these findings further.
authors.affiliation: University of Washington School of Medicine, Department of Medicine, Division of Pulmonary and Critical Care Medicine, Harborview Medical Center, 325 Ninth Avenue, Box 359762, Seattle, WA 98104, USA. crothk@uw.edu
authors.forename: Kristina
authors.initials: K
authors.lastname: Crothers
authors.forename: Kieran R
authors.initials: KR
authors.lastname: Daly
authors.forename: David
authors.initials: D
authors.lastname: Rimland
authors.forename: Matthew Bidwell
authors.initials: MB
authors.lastname: Goetz
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Gibert
authors.forename: Adeel A
authors.initials: AA
authors.lastname: Butt
authors.forename: Amy C
authors.initials: AC
authors.lastname: Justice
authors.forename: Kpandja
authors.initials: K
authors.lastname: Djawe
authors.forename: Linda
authors.initials: L
authors.lastname: Levin
authors.forename: Peter D
authors.initials: PD
authors.lastname: Walzer
mesh_terms: D000256:Adenoviridae / Q000276:immunology; D000328:Adult; D000908:Antibodies, Fungal / Q000097:blood*; D000914:Antibodies, Viral / Q000097:blood; D000946:Antigens, Fungal / Q000276:immunology*; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D045363:Pneumocystis carinii / Q000276:immunology*; D012136:Respiratory Syncytial Viruses / Q000276:immunology; D012907:Smoking / Q000276:immunology*
chemical_list: D000908:Antibodies, Fungal; D000914:Antibodies, Viral; D000946:Antigens, Fungal