A patient with pustular psoriasis of von Zumbusch type fails methotrexate. Biologics are considered. Secukinumab, an anti-IL-17A monoclonal antibody, is to be initiated. IL-17A is secreted primarily by which cell type that acts as the key effector in psoriasis pathogenesis?
- A Th17 cells ✓
- B Th1 cells
- C Regulatory T cells
- D NK cells
Correct answer: A. Th17 cells
Explanation
The IL-23/Th17 axis is the predominant immunopathological pathway in psoriasis. Dendritic cells produce IL-23 which drives naive T cells toward the Th17 phenotype; Th17 cells secrete IL-17A, IL-17F, and IL-22, driving keratinocyte hyperproliferation and neutrophil recruitment. Biologics targeting this axis include: anti-IL-17A (secukinumab, ixekizumab), anti-IL-17RA (brodalumab), anti-IL-23p19 (guselkumab, risankizumab). Anti-TNF agents (adalimumab, infliximab) are also used.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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