Innate immunity-related Gene Expression Profiling Reveals Two Distinct Endotypes in PFAPA Syndrome

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in children. Elevated serum proinflammatory cytokine levels imply dysregulation of innate immunity in the pathogenesis of PFAPA. However, it remains unclear what types of innate immunity molecules/pathways are actually involved. Most PFAPA patients develop tonsillitis during febrile episodes, and tonsillectomy promptly and completely resolves the periodic fever. That fact suggests that the tonsils are the primary site of immune dysregulation in PFAPA.