A mice-model of Kawasaki disease based on Lactobacillus casei cell wall extract injection: focus on echocardiographic findings

Kawasaki disease is a leading cause of pediatric cardiac issues, associated with the risk of coronary artery complications, myocardial infarction, and untreated fatal outcomes. Approximately10% of patients do not respond to initial high-dose intravenous immunoglobulin treatment. This study utilized a novel model to explore the use of high-resolution small-animal ultrasound for coronary imaging and its correlation with histopathology and clinical progression. Eighteen BALB/c mice were divided into Kawasaki disease and control groups. Kawasaki disease was induced through a single intraperitoneal injection of Lactobacillus casei cell wall extract. High-resolution small-animal ultrasound was employed to monitor coronary changes on multiple days, and histopathological analysis was performed on various organs. Significant changes in coronary artery diameter were observed, with both the left and right coronary arteries showing marked expansion during the experiment. By day 21, the model group exhibited pronounced coronary artery dilation. Ejection fraction and fractional shortening declined significantly by day 14 compared to baseline. Histopathological analysis provided a detailed timeline of cardiac involvement. This model uniquely demonstrates coronary arteritis and cardiac lesions in Kawasaki disease mice, highlighting progressive coronary dilation, particularly by day 21. Correlation with histopathology validates these findings, offering insights into disease progression in this mouse model. The results suggest a delayed course compared to human Kawasaki disease, with potential for severe myocarditis.