title: Immunoglobulin A in serum: an old acquaintance as a new prognostic biomarker in idiopathic pulmonary fibrosis.
abstract: Immunoglobulin (Ig)A is an important immunoglobulin in mucosal immunity and protects the lungs against invading pathogens. The production of IgA is regulated by transforming growth factor (TGF)-β, a versatile cytokine and key player in the pathogenesis of pulmonary fibrosis. TGF-β is up-regulated in patients with idiopathic pulmonary fibrosis (IPF), but difficult to use as a biomarker. The aim of this study was to evaluate the prognostic value of IgA in serum in patients with IPF. We examined IgA levels at time of diagnosis in 86 patients diagnosed with IPF. Mean serum IgA level in IPF is 3·22 g/l and regression analyses showed a significant association with mortality (hazard ratio = 1·445, P = 0·002). A significantly worse survival was found in patients with IgA serum levels > 2·85 g/l compared to patients with lower IgA serum levels (P = 0·003). These findings were confirmed in a duplication cohort. In conclusion, the level of IgA in blood is a promising prognostic marker in IPF and can be implemented easily in the hospital setting. Future studies are warranted to investigate if repeated measurements of serum IgA can further improve the performance of serum IgA as a prognostic marker.
authors.affiliation: Centre of Interstitial Lung Diseases, Department of Pulmonology, St Antonius Hospital, Nieuwegein.
authors.forename: L
authors.initials: L
authors.lastname: Ten Klooster
authors.affiliation: Centre of Interstitial Lung Diseases, Department of Pulmonology, St Antonius Hospital, Nieuwegein.|Division of Heart and Lungs, Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht.
authors.forename: C H M
authors.initials: CH
authors.lastname: van Moorsel
authors.affiliation: Division of Heart and Lungs, Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht.
authors.forename: J M
authors.initials: JM
authors.lastname: Kwakkel-van Erp
authors.affiliation: Department of Medical Microbiology and Immunology, St Antonius Hospital, Nieuwegein, the Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: van Velzen-Blad
authors.affiliation: Centre of Interstitial Lung Diseases, Department of Pulmonology, St Antonius Hospital, Nieuwegein.|Division of Heart and Lungs, Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht.
authors.forename: J C
authors.initials: JC
authors.lastname: Grutters
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000097:blood* / Q000276:immunology / Q000401:mortality / Q000473:pathology; D018928:Immunity, Mucosal; D007070:Immunoglobulin A / Q000097:blood*; D008168:Lung / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016019:Survival Analysis; D016212:Transforming Growth Factor beta / Q000097:blood
chemical_list: D015415:Biomarkers; D007070:Immunoglobulin A; D016212:Transforming Growth Factor beta
keywords: fibroblasts; human; lung; transplantation
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