tsDMARDs are small molecule inhibitors targeting intracellular signaling such as JAK-STAT.

• A. They are small molecule inhibitors targeting intracellular signaling pathways such as JAK-STAT
• B. They are monoclonal antibodies that neutralize TNF-alpha
• C. They are vaccines
• D. They are antibiotics

Answer: (A)

Targeted synthetic DMARDs are small-molecule inhibitors that block intracellular signaling pathways such as JAK-STAT, dampening cytokine signaling and inflammation. They work inside cells by inhibiting JAK enzymes (JAK1, JAK2, JAK3, TYK2), which stops the phosphorylation and activation of STAT transcription factors, leading to reduced expression of inflammatory genes. This mechanism directly contrasts with monoclonal antibodies that neutralize extracellular cytokines like TNF-α, vaccines that prime the immune system, and antibiotics that target bacteria. Examples of these agents include JAK inhibitors such as tofacitinib, baricitinib, and upadacitinib.