American Board of Surgery Qualifying Exam (ABS QE) Practice Test

In the context of immunosuppressive therapy, Mycophenolate mofetil is often preferred due to its impact on which cellular process?

1. Cellular respiration

2. DNA synthesis

3. Protein synthesis

4. Mitochondrial function

The correct answer is: DNA synthesis

Mycophenolate mofetil is highly regarded in immunosuppressive therapy primarily because of its mechanism of action, specifically in inhibiting DNA synthesis. This drug selectively targets and inhibits inosine monophosphate dehydrogenase (IMPDH), an enzyme crucial in the de novo synthesis pathway of purine nucleotides. This pathway is particularly important in lymphocytes, as they rely heavily on it for proliferation and function. By disrupting DNA synthesis, Mycophenolate mofetil effectively suppresses the growth and activation of rapidly dividing immune cells, such as T and B lymphocytes, which are key players in the immune response. This targeted inhibition leads to reduced immune-mediated responses, making it an effective agent in preventing transplant rejection and treating autoimmune diseases. In contrast, the other processes listed have different implications and roles that are not as directly influenced by Mycophenolate mofetil. Protein synthesis and mitochondrial function are crucial for cell survival and function but are not specifically the target of this drug. Cellular respiration, while essential for energy production, is also not directly affected by Mycophenolate mofetil in the context of its immunosuppressive effects. By focusing on DNA synthesis, Mycophenolate mofetil demonstrates a