Promising novel mechanisms of action always create excitement, but the immune checkpoint PD-1 has cemented itself in the news far more than most. This fame is primarily from therapeutic inhibition in cancer and rheumatological inflammatory sequelae that emerge, but invoking the inverse and using PD-1 agonism to treat classical autoimmunity has subsequently been making its own mark. Given the evident plausibility, how do we feel about invoking

Ankylosing spondylitis (AS) is a burden on the bones—both literally and diagnostically. The disease’s dual nature, marked by chronic inflammation and abnormal new bone formation, complicates the assessment of bone health. While inflammation erodes trabecular bone, syndesmophytes and ligamentous calcifications can falsely elevate spine bone mineral density (BMD) readings on standard dual-energy X-ray absorptiometry (DXA).