title: Environmental triggers of autoimmunity in anti-synthetase syndrome: the lungs under the spot light.
abstract: The prevalence of interstitial lung involvement in anti-synthetase syndrome (anti-SS) may be as high as 70% and is a major contributor to morbidity and mortality. Histidyl-tRNA synthetase (Jo-1) is the most common autoantigenic target among the aminoacyl-tRNA synthetases. We report two well documented anti-SS cases where it was observed significant exposure to a known inhaled offending antigen, development of a lymphocytic interstitial lung disease (ILD) and negative auto-antibodies, interpreted at first as hypersensitivity pneumonitis. Only after 14 and 30 months, respectively, the development of systemic symptoms compatible with anti-SS and anti-Jo-1 was observed. A growing body of evidence suggests that the lungs are the environment in which Jo-1 autoimmunity may be initiated and propagated. The description of the clinical and laboratorial evolution of these patients together with accumulated evidence of biological plausibility support the hypothesis that anti-SS can follow an episode of lung inflammation secondary to inhaled antigen exposure.
authors.affiliation: Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas, University of São Paulo Medical School, São Paulo, Brazil. leticiakawano@gmail.com.
authors.forename: Leticia
authors.initials: L
authors.lastname: Kawano-Dourado
authors.forename: Andre N
authors.initials: AN
authors.lastname: Costa
authors.forename: Carlos R R
authors.initials: CR
authors.lastname: Carvalho
authors.forename: Ronaldo A
authors.initials: RA
authors.lastname: Kairalla
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood; D000941:Antigens; D015551:Autoimmunity; D030161:Avian Proteins / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D001716:Bird Fancier's Lung / Q000097:blood / Q000188:drug therapy / Q000276:immunology; D004359:Drug Therapy, Combination; D004781:Environmental Exposure; D005260:Female; D005658:Fungi / Q000276:immunology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008168:Lung / Q000000981:diagnostic imaging / Q000276:immunology*; D017563:Lung Diseases, Interstitial / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology*; D008875:Middle Aged; D009220:Myositis / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology*; D011237:Predictive Value of Tests; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000974:Antibodies, Antinuclear; D000941:Antigens; D030161:Avian Proteins; D015415:Biomarkers; D007166:Immunosuppressive Agents; C046750:Jo-1 antibody