Clinical characteristics of IgG4-related lung disease: a single-center based experience

IgG4-related lung disease (IgG4-RLD) is a rare autoimmune condition. This study aims to systematically analyze the clinical characteristics of IgG4-RLD to enhance clinicians' awareness and improve patient outcomes.

This retrospective analysis investigates the clinical data of 20 patients diagnosed with IgG4-RLD at the Yichang Central People's Hospital between January 2019 and April 2025.

The mean age at diagnosis among the 20 patients with IgG4-RLD was 60.10 ± 10.34 years, with a male-to-female ratio of 3:1. The most frequent clinical manifestations were hemoptysis and abnormalities in pulmonary imaging. Eight patients (40.00%) presented with isolated pulmonary involvement, while 12 patients (60.00%) exhibited extra-pulmonary organ involvement, with lymph node involvement being the most prevalent. The pulmonary imaging characteristics primarily included solid nodular patterns in 10 patients (50.00%) and round ground-glass opacity (GGO) patterns in 9 patients (45.00%). Patients with round GGO patterns exhibited a higher incidence of hemoptysis and predominantly had a history of respiratory conditions (P < 0.05). Patients with solid nodular patterns exhibited significantly higher percentages of eosinophils and lymphocytes, as well as elevated serum IgG levels, compared to those with round GGO patterns (P < 0.05). By contrast, patients with round GGO patterns demonstrated significantly higher percentages of neutrophils and a markedly increased neutrophil-to-lymphocyte ratio (NLR) compared to those with solid nodular patterns (P < 0.05).

The clinical manifestations of IgG4-RLD are complex and heterogeneous. Clinicians need to acquire a thorough understanding of these features in order to develop personalized diagnostic and therapeutic approaches, thereby enhancing patient outcomes. Key Points • The pulmonary imaging characteristics of IgG4-RLD were primarily manifested as solid nodular patterns and round GGO patterns. • Patients with round GGO patterns were more likely to experience hemoptysis, and the majority of these patients presented with a history of respiratory conditions. • Patients with solid nodular patterns demonstrated significantly higher percentages of eosinophils, lymphocytes, and serum IgG levels compared to those with round GGO patterns. • Patients with round GGO patterns demonstrated significantly higher percentages of neutrophils and a markedly increased NLR compared to those with solid nodular patterns.