IgG4-related interstitial lung disease: a new and evolving concept.
OBJECTIVE
This review examines recent advances in our knowledge of the clinical, pathological, diagnostic, and therapeutic aspects of IgG4-related interstitial lung disease (ILD).


RESULTS
A recent case series of ILD with IgG4-positive plasma cells suggested grade 1 lymphomatoid granulomatosis. The presence of the IgG4-positive plasma cells with the lack of atypical cells favored IgG4-related ILD as a diagnosis. In another case study, four out of 30 patients with autoimmune pancreatitis developed pulmonary involvement during follow-up. Elevations of IgG4 and Krebs von den Lungen-6 levels were associated and thought to be predictive of the development of IgG4-related lung disease. A retrospective analysis investigating radiological/pathologic correlation in IgG4 lung disease identified computed tomographic features pathologically corresponding to IgG4-related sclerosing inflammation in the pulmonary interstitium.


CONCLUSIONS
IgG4-related ILD is a new and evolving entity. It can occur with or without systemic involvement. Larger studies are necessary to elucidate the exact mechanism and clinical characteristics of this disorder.
Shigemitsu
Hidenobu
H
Division of Pulmonary and Critical Care Medicine, University of Southern California Keck School of Medicine, Los Angeles, California 90033, USA. hshigemi@usc.edu
Koss
Michael N
MN
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D003937:Diagnosis, Differential; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology* / Q000378:metabolism; D017563:Lung Diseases, Interstitial / Q000175:diagnosis / Q000276:immunology* / Q000378:metabolism
D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G