tsDMARDs are exemplified by which class of agents?

• A. JAK inhibitors
• B. Anti-TNF monoclonal antibodies
• C. Calcineurin inhibitors
• D. PDE-5 inhibitors

Answer: (A)

Targeted synthetic DMARDs are small-molecule agents that inhibit intracellular signaling pathways to dampen immune activation. JAK inhibitors exemplify this approach because they block the JAK-STAT signaling cascade inside immune cells, reducing the downstream effects of multiple cytokines. This intrace llular targeting differentiates tsDMARDs from biologic DMARDs, which are large protein molecules (such as monoclonal antibodies) that neutralize extracellular cytokines like TNF. The other options represent different mechanisms: anti-TNF monoclonal antibodies are biologics, not tsDMARDs; calcineurin inhibitors suppress the calcineurin–NFAT pathway as immunosuppressants rather than targeting intracellular cytokine signaling in the same way; PDE-5 inhibitors affect cyclic GMP signaling and are not DMARDs.