American Board of Internal Medicine (ABIM) Certification Practice Exam

Which treatment option is emerging for severe cases of IgG4-related disease?

1. Azathioprine

2. Rituximab

3. Mycophenolate mofetil

4. NSAIDs

The correct answer is: Rituximab

Rituximab has emerged as a significant treatment option for severe cases of IgG4-related disease due to its mechanism of targeting CD20 positive B cells, which play a crucial role in the pathogenesis of this condition. IgG4-related disease is characterized by an infiltration of IgG4-positive plasma cells and often presents with symptoms related to inflammation and fibrosis of various organs. The use of rituximab has been supported by studies that demonstrate its efficacy in reducing serum IgG4 levels and improving clinical symptoms, particularly in cases that are refractory to standard glucocorticoid therapy or in situations where patients cannot tolerate corticosteroids. In contrast to other treatment options like azathioprine or mycophenolate mofetil, which are also immunosuppressive but might have slower onset and less targeted action in this specific disease, rituximab offers a more immediate and effective approach in managing severe manifestations. Furthermore, NSAIDs are typically used for symptomatic relief in inflammatory conditions but do not directly address the underlying immune dysregulation seen in IgG4-related disease. This targeted approach aligns well with the current understanding of the disease's immunological basis, making rituximab a prominent choice in the management of severe cases.