If a patient exhibits persistent inflammation despite immunosuppressant treatment, which mechanism likely indicates a failure in peripheral immune tolerance involving regulatory T cells?

💡 Explanation

Defective Treg suppression allows autoreactive T cells to proliferate and cause inflammation because functional regulatory T cells are essential for maintaining peripheral tolerance and suppressing self-reactive lymphocytes. Therefore, Treg dysfunction explains persistent inflammation, rather than Th17 differentiation, MHC II expression, or complement activation directly.

• If a dorsal horn neuron is continuously bombarded by substance P from C-fiber nociceptors, which consequence affecting descending modulation is most probable?
• If a pharmaceutical company aims to reduce chronic neuropathic pain by enhancing descending modulation, which consequence follows from stimulating the periaqueductal gray (PAG) region?
• Why does skeletal fragility increase post-menopause even with adequate dietary calcium?
• If a collegiate soccer player sustains a concussion during a game, and a stepwise return-to-play protocol is initiated, why does prematurely advancing through stages likely exacerbate their condition?
• Why does bone density adaptation (Wolff's Law) following femur fracture repair prioritize new bone deposition along stress lines, rather than uniform callus distribution?
• Which failure mode becomes likely when regulatory T cell function decreases within pancreatic islets during autoimmune attack?