title: Psychological distress and salivary secretory immunity.
abstract: Stress-induced impairments of mucosal immunity may increase susceptibility to infectious diseases. The present study investigated the association of perceived stress, depressive symptoms, and loneliness with salivary levels of secretory immunoglobulin A (S-IgA), the subclasses S-IgA1, S-IgA2, and their transporter molecule Secretory Component (SC). S-IgA/SC, IgA1/SC and IgA2/SC ratios were calculated to assess the differential effects of stress on immunoglobulin transport versus availability. This study involved 113 university students, in part selected on high scores on the UCLA Loneliness Scale and/or the Beck Depression Inventory. Stress levels were assessed using the Perceived Stress Scale. Unstimulated saliva was collected and analysed for total S-IgA and its subclasses, as well as SC and total salivary protein. Multiple linear regression analyses, adjusted for gender, age, health behaviours, and concentration effects (total protein) revealed that higher perceived stress was associated with lower levels of IgA1 but not IgA2. Perceived stress, loneliness and depressive symptoms were all associated with lower IgA1/SC ratios. Surprisingly, higher SC levels were associated with loneliness and depressive symptoms, indicative of enhanced transport activity, which explained a lower IgA1/SC ratio (loneliness and depression) and IgA2/SC ratio (depression). This is the first study to investigate the effects of protracted psychological stress across S-IgA subclasses and its transporter SC. Psychological stress was negatively associated with secretory immunity, specifically IgA1. The lower immunoglobulin/transporter ratio that was associated with higher loneliness and depression suggested a relative immunoglobulin depletion, whereby availability was not keeping up with enhanced transport demand.
authors: Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, USA; College of Nursing, The Pennsylvania State University, University Park, PA, USA; Center for Wound Healing and Tissue Regeneration, University of Illinois at Chicago, Chicago, IL, USA. Electronic address: cge2@psu.edu.
authors: C G
authors: CG
authors: Engeland
authors: Department of Social and Preventive Dentistry, College of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors: F N
authors: FN
authors: Hugo
authors: Department of Social and Preventive Dentistry, College of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors: J B
authors: JB
authors: Hilgert
authors: Post-graduate Program in Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil.
authors: G G
authors: GG
authors: Nascimento
authors: Department of Social and Preventive Dentistry, College of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; Institute of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors: R
authors: R
authors: Junges
authors: Department of Orthodontics, School of Dentistry, Chonnam National University, Dental Science Research Institute, Gwangju, South Korea.
authors: H-J
authors: HJ
authors: Lim
authors: Center for Wound Healing and Tissue Regeneration, University of Illinois at Chicago, Chicago, IL, USA; School of Dentistry, Oregon Health and Science University, Portland, OR, USA.
authors: P T
authors: PT
authors: Marucha
authors: Department of Clinical Psychology, University of Amsterdam, Amsterdam, The Netherlands; Mannheim Institute of Public Health, Social and Preventive Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. Electronic address: j.a.bosch@uva.nl.
authors: J A
authors: JA
authors: Bosch
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D018928:Immunity, Mucosal / Q000276:immunology; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D007239:Infections / Q000276:immunology; D008297:Male; D012463:Saliva / Q000276:immunology; D012635:Secretory Component / Q000378:metabolism; D013315:Stress, Psychological / Q000276:immunology*; D055815:Young Adult
chemical_list: D007071:Immunoglobulin A, Secretory; D012635:Secretory Component
keywords: Depression; IgA1; IgA2; Immunoglobulin A; Immunoglobulin subclass; Loneliness; Saliva; Secretory Component; Stress