Management of Severe Hypersensitivity Reaction to Rituximab with Obinutuzumab in Patients with IgG4-Related Ophthalmic Disease

By
Üçler Can Ateş
Semih Gülle
September 22, 2026

Clinical Rheumatology

Background

IgG4-related disease can lead to significant morbidity, particularly in cases involving the eyes. Rituximab is commonly used for treatment, but hypersensitivity reactions can limit its use. Obinutuzumab, a newer monoclonal antibody, may be considered for patients intolerant to rituximab.

Data Highlights

No numerical data or trial data provided in the source material.

Key Findings

A 40-year-old man with IgG4-related ophthalmic disease experienced a severe hypersensitivity reaction to rituximab.
Initial treatment with glucocorticoids and mycophenolate mofetil resulted in only a partial response.
Obinutuzumab was administered without any infusion reactions, leading to clinical improvement.
Serum IgG4 levels decreased from 861 mg/dL to 49.1 mg/dL after treatment with obinutuzumab.
Repeat imaging showed reduction in lacrimal gland enlargement.
This case suggests obinutuzumab may be an option for patients with rituximab intolerance in IgG4-related disease.

Clinical Implications

Monitoring for clinical response and potential side effects remains essential.

Conclusion

Further studies are needed to confirm the safety and efficacy of obinutuzumab in patients with IgG4-related ophthalmic disease who cannot tolerate rituximab.