Validation of the Diagnostic Criteria for IgG4-Related Periaortitis/Periarteritis and Retroperitoneal Fibrosis...

Area of Science:

• Rheumatology and Immunology
• Vascular Medicine
• Diagnostic Criteria Development

Background:

• Established in 2018, diagnostic criteria for IgG4-related periaortitis/periarteritis and retroperitoneal fibrosis (PA/RPF) require assessment and refinement.
• IgG4-related disease (IgG4-RD) can involve cardiovascular and retroperitoneal structures, necessitating accurate diagnostic tools.

Purpose of the Study:

• To evaluate the diagnostic performance of the 2018 criteria for IgG4-related cardiovascular/retroperitoneal disease.
• To develop and validate an improved set of diagnostic criteria for IgG4-related PA/RPF.

Main Methods:

• Retrospective analysis of 110 Japanese patients with IgG4-related cardiovascular/retroperitoneal manifestations and 73 non-IgG4-RD 'mimickers'.
• Stratification into derivation (n=88) and validation (n=95) cohorts.
• Comparison of the 2018 criteria and revised versions, using expert diagnosis as the gold standard for sensitivity and specificity calculations.

Main Results:

• In the derivation group, the 2018 criteria yielded 58.5% sensitivity and 100% specificity.
• A revised version incorporating radiologic findings of pericarditis, specific pathological features, and extra-PA/RPF lesions improved sensitivity to 69.8% (100% specificity).
• In the validation group, the revised criteria achieved 77.2% sensitivity and 94.7% specificity, compared to 68.4% sensitivity and 97.4% specificity for the original criteria.

Conclusions:

• The proposed 2023 revised criteria for IgG4-related cardiovascular/retroperitoneal disease demonstrate significantly enhanced sensitivity.
• High specificity is preserved in the revised criteria.
• Improvements are attributed to the inclusion of new radiologic, pathological, and extra-organ findings.