IgG4-related disease: a rheumatologist's perspective

Area of Science:

• Rheumatology
• Immunology
• Internal Medicine

Background:

• Immunoglobulin G4-related disease (IgG4-RD) often presents with symptoms overlapping those of various autoimmune disorders.
• Distinguishing IgG4-RD from other rheumatologic conditions can be challenging, potentially leading to diagnostic delays.

Purpose of the Study:

• To identify distinguishing clinical features of IgG4-related diseases (IgG4-RD) within a rheumatology clinic population.
• To aid in differentiating IgG4-RD from other autoimmune conditions managed by rheumatologists.

Main Methods:

• Retrospective review of medical records for patients meeting diagnostic criteria for IgG4-RD.
• Analysis of presenting features, comorbidities, laboratory, radiologic, and histologic findings.
• Documentation of treatment response and patient outcomes.

Main Results:

• Eleven cases of IgG4-RD were identified, including autoimmune pancreatitis, retroperitoneal fibrosis/periaortitis, sialadenitis, and interstitial nephritis.
• Five patients had prior diagnoses of autoimmune diseases (rheumatoid arthritis, Sjogren's syndrome, antiphospholipid syndrome).
• Elevated CRP in autoimmune pancreatitis, constitutional symptoms in retroperitoneal fibrosis, and Sjogren's-like features in sialadenitis were noted. Most patients responded well to steroids.

Conclusions:

• Common presentations of IgG4-RD in rheumatology clinics were identified.
• Increased clinical awareness of these presentations can help avoid diagnostic delays for IgG4-RD.