A new drug — rituximab — has been approved as first-line therapy for moderate-to-severe pemphigus vulgaris. The mechanism by which rituximab achieves remission in pemphigus is:
- A Inhibition of T helper cell activation
- B Blockade of IL-4 and IL-13 signalling
- C Depletion of CD20+ B cells, reducing anti-desmoglein antibody production ✓
- D Inhibition of complement C5 component
Explanation
Rituximab is a chimeric monoclonal antibody targeting CD20 on B lymphocytes. It causes profound B cell depletion via complement-dependent cytotoxicity, antibody-dependent cellular cytotoxicity, and direct apoptosis induction. Since pemphigus pathogenesis depends on B cells producing IgG autoantibodies against Dsg1 and Dsg3, rituximab reduces antibody titres and induces long-term remission. The Ritux 3 RCT demonstrated superior remission rates vs. corticosteroid monotherapy. Two IV infusions of 1000 mg two weeks apart (RA regimen) or 500 mg x2 (lymphoma-based) are used.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.