American Board of Internal Medicine (ABIM) Certification Practice Exam

Which is a common glucocorticoid-sparing agent used in IgG4-related disease?

1. Azathioprine

2. Leflunomide

3. Cyclophosphamide

4. Rituximab

The correct answer is: Azathioprine

Azathioprine is a common glucocorticoid-sparing agent used in the management of IgG4-related disease due to its immunosuppressive properties that help reduce the dependence on glucocorticoids. In this condition, glucocorticoids are often used as the first-line treatment to manage inflammation and symptoms. However, long-term glucocorticoid use can lead to significant side effects; therefore, glucocorticoid-sparing agents like azathioprine are introduced. Azathioprine works by inhibiting purine synthesis, which effectively dampens the immune response. By using azathioprine, clinicians aim to achieve disease control with lower doses of glucocorticoids, thereby minimizing the adverse effects associated with prolonged steroid use while still managing the patient's symptoms adequately. Other agents listed, such as leflunomide and cyclophosphamide, may also be used in various autoimmune or inflammatory diseases, but they are not as commonly used specifically for IgG4-related disease compared to azathioprine. Rituximab is a monoclonal antibody targeting CD20 on B cells and can be effective in certain cases of IgG4-related disease but is generally considered when there is a