Ustekinumab, used in moderate-to-severe plaque psoriasis, exerts its therapeutic effect through which mechanism?

• A Binding the shared p40 subunit of IL-12 and IL-23 ✓
• B Binding the p19 subunit of IL-23
• C Inhibiting phosphodiesterase 4
• D Blocking TNF-alpha binding to its receptor

Explanation

Ustekinumab is a human monoclonal antibody against the p40 subunit shared by IL-12 and IL-23, thereby blocking signaling through both the Th1 and Th17 pathways central to psoriasis. Agents binding only the p19 subunit of IL-23 include guselkumab and risankizumab. Apremilast is the phosphodiesterase 4 inhibitor, and etanercept, infliximab, and adalimumab are the TNF-alpha blockers. Recognizing the p40 target distinguishes ustekinumab from both newer IL-23-specific agents and anti-TNF drugs.

Reference: Fitzpatrick's Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.