Clinical characteristics of immunoglobulin G

Immunoglobulin G4-related disease is a systemic disease characterised by tumefactive lesions with abundant IgG4-positive plasma cells and elevated serum IgG4 concentrations [1–4]. We previously assessed IgG4-related respiratory disease (IgG4-RRD) with extrathoracic manifestations [5]. IgG4-RRD develops through the lymphatic routes in the lungs and responds well to corticosteroid therapy with a benign prognosis [5–7]. However, whether interstitial pneumonia (IP) with IgG4-positive plasma cell infiltration in the lungs without the extrathoracic lesions of IgG4-related disease could be considered a type of IgG4-RRD is controversial.
This study suggests that IgG4+ IP with abundant IgG4+ cells and elevated serum IgG4 levels could be treated differently from IgG4-related respiratory disease due to potential differences in disease behaviour and response to corticosteroid therapy https://bit.ly/3dUo2cu