High IgG4 serum concentration is associated with active Graves orbitopathy

Area of Science:

• Ophthalmology
• Immunology
• Endocrinology

Background:

• Graves orbitopathy (GO) is an autoimmune condition affecting the eyes.
• Immunoglobulin G4 (IgG4)-related disease is an emerging condition with diverse manifestations.
• The role of IgG4 in GO activity and clinical presentation requires further elucidation.

Purpose of the Study:

• To compare clinical, laboratory, and ophthalmological features of patients with high IgG4 GO versus normal IgG4 GO.
• To determine if elevated IgG4 levels correlate with disease activity in Graves orbitopathy.

Main Methods:

• Prospective observational study of 60 adult patients with Graves orbitopathy.
• Assessment included ophthalmological evaluation, orbital MRI, and serum IgG4 measurement.
• High IgG4 GO defined as IgG4 > 135 mg/dl; active GO defined by MRI.

Main Results:

• 15% of GO patients had elevated IgG4 levels.
• High IgG4 GO group showed higher prevalence of active disease (100% vs. 64.44%) and increased eosinophils.
• Elevated IgG4 levels were associated with active GO (AUC 0.848, sensitivity 79.5%, specificity 87.5%).

Conclusions:

• Immunoglobulin G4 (IgG4) serves as a marker for Graves orbitopathy (GO) activity.
• Distinct clinical profiles observed in high IgG4 GO patients warrant further investigation.
• High IgG4 GO may represent a distinct clinical entity or a more active form of GO.