Human pathological findings in Kawasaki disease: a narrative review of autopsy and biopsy evidence.

Background: Kawasaki disease (KD) is an acute systemic vasculitis affecting children under five years of age and a leading cause of acquired heart disease in developed countries. Although autopsy and biopsy studies provide important insights into disease progression, integrated summaries combining classical histopathology with modern molecular findings remain limited. Methods: This narrative review searched PubMed and Web of Science from January 1, 1974 to December 31, 2025 for human autopsy and biopsy studies on KD. Findings were synthesized to characterize pathological features across cardiovascular and extracardiac systems, focusing on vascular progression based on the three-process model, multisystem involvement, and underlying molecular and genetic mechanisms. Results: Coronary artery involvement follows a three-process model, including necrotizing arteritis, subacute/chronic vasculitis, and luminal myofibroblastic proliferation, which drives progressive luminal stenosis. The myocardium, pericardium, and cardiac valves are also frequently affected. Extracardiac tissues show intracytoplasmic inclusion bodies and IgA plasma cell infiltration, suggesting a potential infection-triggered mechanism. Key signaling pathways, including TLRs/NF-κB, NLRP3/IL-1β, Ca² Conclusion: KD is a systemic vasculitis primarily targeting the coronary arteries, with a dynamic pathological progression from acute inflammation to chronic vascular remodeling. Future research should focus on prospective pathology studies, long-term vascular remodeling, and underlying molecular mechanisms.