IBD IBD Pharmacotherapy 3

Question 1

Therapeutic drug monitoring (TDM) of infliximab targets which minimum trough level for maintaining remission in IBD?

Accepted Answer

3–7 µg/mL

Answer

Infliximab trough levels of 3–7 µg/mL are associated with maintained mucosal healing and clinical remission, with levels below 3 µg/mL predicting loss of response.

Question 2

Which new IL-23 p19 specific inhibitor was FDA-approved for Crohn's disease, offering more selectivity than ustekinumab?

Accepted Answer

Risankizumab (Skyrizi)

Answer

Risankizumab selectively inhibits IL-23 via the p19 subunit without blocking IL-12, potentially preserving Th1 immune responses while reducing Th17-driven inflammation.

Question 3

Fecal microbiota transplantation (FMT) has shown the most promising evidence for treating which IBD-related condition?

Accepted Answer

Recurrent C. difficile infection in IBD patients

Answer

FMT is most established for recurrent C. difficile infection, including in IBD patients, with high cure rates; evidence for primary UC or Crohn's remains investigational.

Question 4

Cyclosporine IV is used as rescue therapy in severe acute UC refractory to IV corticosteroids. What is its primary mechanism?

Accepted Answer

Calcineurin inhibition → reduced IL-2 → T-cell suppression

Answer

Cyclosporine inhibits calcineurin, preventing nuclear translocation of NFAT and reducing IL-2 transcription, thereby suppressing T-lymphocyte activation in acute UC.

Question 5

Ozanimod, approved for UC, works through which novel mechanism?

Accepted Answer

Sphingosine-1-phosphate (S1P) receptor modulation, sequestering lymphocytes in lymph nodes

Answer

Ozanimod activates S1P receptors 1 and 5, preventing lymphocytes from egressing lymph nodes and reducing circulating lymphocytes available to inflame the colon.

IBD - Inflammatory Bowel Disease Practice Test

IBD - Inflammatory Bowel Disease Practice Test

IBD IBD Pharmacotherapy 3