title: IgG4-Related Lung Disease Associated with Usual Interstitial Pneumonia.
abstract: We report a case of immunoglobulin(Ig)G4-related disease with the radiologic and histopathological manifestations resembling usual interstitial pneumonia (UIP). The patient was a 62-year-old man who presented with progressive dyspnea of insidious onset. High resolution computed tomography of the chest showed lower-lobe predominant peripheral reticulation and traction bronchiectasis but no honeycomb change. Microscopic examination of the surgical lung biopsy showed characteristic features of UIP including architectural distortion by fibrosis with peripheral and paraseptal accentuation, scattered fibroblast foci and microscopic honeycomb change. In addition there were prominent multifocal lymphoplasmacytic infiltrates with a marked increase of IgG4-positive plasma cells (79 per high power field in hot spots) and high IgG4/IgG ratio (up to 67%). The serum IgG4 level was elevated at 760 mg/dl (reference range 9-89), with normal levels for the other IgG subclasses and negative serologic markers for autoimmune diseases. The patient's symptoms improved significantly with oral corticosteroid treatment.
authors.affiliation: Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Schneider
authors.affiliation: Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Veraldi
authors.affiliation: Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Levesque
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Colby
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Eunhee
authors.initials: E
authors.lastname: S Yi
keywords: Autoimmune disease; IgG4-related disease; fibrosis; interstitial lung disease; usual interstitial pneumonia