A Case of IgG4-Related Lung Disease Mimicking Non-Specific Interstitial Pneumonia / 대한내과학회지

ABSTRACT

Immunoglobulin (Ig) G4-related disease is a recently described systemic inflammatory disease characterized by high serum IgG4 concentrations and sclerosing inflammation of numerous IgG4-positive plasma cells that responds favorably to steroid treatment. Although initial description of this disorder focused on its pancreatic presentation, it has become apparent that it is a systemic disease. In this report, we describe a case of IgG4-related lung disease presenting as non-specific interstitial pneumonia in a 78-year-old male with interstitial lung disease. Pathological examination through video-assisted thoracic surgery showed a non-specific interstitial pneumonia pattern and numerous (> 50/high-power field) infiltrating IgG4-positive plasma cells. Laboratory tests also revealed a high serum IgG4 concentration. Prednisolone therapy was initiated and his symptoms and reticular opacity improved after two months of treatment.