SYSTEMIC INFLAMMATORY BURDEN AND MULTIORGAN INVOLVEMENT IN ANKYLOSING SPONDYLITIS: CLINICAL PATTERNS, DETERMINANTS, AND THERAPEUTIC IMPLICATIONS

Ankylosing spondylitis (AS) is a prototypical form of axial spondyloarthritis characterized by chronic inflammation of the sacroiliac joints and spine, progressive structural damage, and functional impairment. Historically regarded as a disease confined to the axial skeleton, AS is now understood as a systemic inflammatory disorder with diverse clinical expressions. The pathogenesis of AS involves complex interactions between genetic predisposition, immune dysregulation, and environmental triggers. The strongest genetic association is linked to the HLA-B27 antigen, which plays a critical role in antigen presentation and immune activation. Although HLA-B27 positivity is present in the majority of AS patients, its exact pathogenic contribution remains incompletely elucidated.