title: IgG4-related lung and pleural disease: a clinicopathologic study of 21 cases.
abstract: Immunoglobulin G4 (IgG4)-related disorders can occur in the respiratory system. However, the clinicopathologic characteristics have not been well clarified. In this study, we examined clinical and pathologic features of, and follow-up data on, IgG4-related lung and pleural lesions. The patients group consisted of 17 males and 4 females with an average age of 69 years (range: 42 to 76). Pulmonary lesions in 16 patients and pleural lesions in 5 patients were examined. Histologically, all lesions showed diffuse lymphoplasmacytic infiltration. Irregular fibrosis and obliterative vascular changes were more common in solid areas. Nine cases (43%) had eosinophilic infiltration with more than 5 cells per high-power field. Immunostaining revealed numerous IgG4-positive plasma cells in inflamed areas. Sclerosing inflammation was distributed with intrapulmonary connective tissue. Pulmonary lesions showed a variety of morphologic changes according to the predominant area of inflammation. Serum IgG4 concentrations were elevated in 9 of 11 patients tested (average 6.9 g/L; range 0.3 to 18.0 g/L; normal range <1.35 g/L). Extra-pulmonary and extra-pleural IgG4-related lesions were identified in 9 patients (43%), and developed simultaneously or asynchronously during follow up. All patients treated with steroids responded, but some radiologic abnormalities remained in 3 patients. Interestingly, 1 patient was found to have a primary adenocarcinoma against a background of IgG4-related lung disease during follow up. In conclusion, IgG4-related diseases show a greater variety of pulmonary and pleural lesions than previously thought. It is important, therefore, to know the morphologic variety and clinicopathologic characteristics of this disorder.
authors.affiliation: Institute of Liver Studies, King's College Hospital, London, UK. yoh.zen@kcl.ac.uk
authors.forename: Yoh
authors.initials: Y
authors.lastname: Zen
authors.forename: Dai
authors.initials: D
authors.lastname: Inoue
authors.forename: Azusa
authors.initials: A
authors.lastname: Kitao
authors.forename: Manabu
authors.initials: M
authors.lastname: Onodera
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Abo
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyayama
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Gabata
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsui
authors.forename: Yasuni
authors.initials: Y
authors.lastname: Nakanuma
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000097:blood; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008168:Lung / Q000276:immunology* / Q000473:pathology; D008171:Lung Diseases / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010994:Pleura / Q000276:immunology* / Q000473:pathology; D010995:Pleural Diseases / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D013256:Steroids / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G; D013256:Steroids