First-Year IgG Dynamics in IgG4-Related Disease: A Critical Window for Predicting Long-Term Outcomes

Area of Science:

• Immunology
• Rheumatology
• Internal Medicine

Background:

• Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by elevated serum IgG4 levels.
• Understanding the longitudinal dynamics of serum IgG and its prognostic value is crucial for managing IgG4-RD patients.

Purpose of the Study:

• To investigate the changes in serum IgG levels over time in patients with IgG4-RD following treatment.
• To evaluate the predictive value of these IgG dynamics for disease relapse.

Main Methods:

• Retrospective analysis of 274 newly treated IgG4-RD patients, stratified by baseline IgG levels.
• Longitudinal IgG trends and relapse risk were assessed using Kaplan-Meier curves and Cox regression analysis.
• Covariance analysis adjusted for baseline IgG was used to evaluate treatment responses.

Main Results:

• Elevated baseline IgG was linked to more severe IgG4-RD phenotypes.
• Achieving IgG normalization within 12 months of treatment was strongly associated with a reduced risk of relapse and improved relapse-free survival.
• Glucocorticoid-based regimens demonstrated higher IgG normalization rates compared to GC-sparing therapies.

Conclusions:

• Baseline IgG elevation indicates a more severe IgG4-RD phenotype.
• IgG normalization within the first year of treatment serves as a critical prognostic biomarker for relapse.
• Longitudinal IgG monitoring aids in risk stratification and optimizing treatment strategies for IgG4-RD.