Urinary exosomal microRNAs in Kawasaki disease and their changes after treatment.

BACKGROUND: Kawasaki disease (KD) is an acute systemic vasculitis of childhood characterized by intense inflammatory responses. Although circulating microRNAs have been investigated in KD, urinary exosomal microRNAs (miRNAs) and their dynamic changes following treatment remain poorly defined. METHODS: Urinary exosomes were isolated from children with KD and febrile control (FC) subjects. MicroRNA expression profiles were analyzed using TaqMan® human microRNA low-density arrays. Differentially expressed miRNAs were further evaluated in paired urine samples collected before and after intravenous immunoglobulin (IVIG) and aspirin treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to explore potential biological functions. RESULTS: Distinct urinary exosomal microRNA expression patterns were observed in the KD subjects compared to the FC subjects. Several miRNAs, including let-7g-5p, miR-26b-5p, miR-125b-5p, and miR-200b-3p, showed differential expression and changes following IVIG and aspirin treatment. Enrichment analyses indicated involvement of intracellular signaling pathways, including MAPK, PI3K-Akt, Ras, and Rap1 signaling pathways. CONCLUSIONS: Urinary exosomal miRNAs differ in children with KD and exhibit changes following IVIG and aspirin treatment, suggesting potential involvement in inflammatory signaling during the acute phase of KD. IMPACT: Urinary exosomal microRNA profiles differ between children with Kawasaki disease (KD) and febrile controls. Several urinary exosomal microRNAs show changes following IVIG and aspirin treatment. Urinary exosomal microRNAs may reflect inflammatory signaling in acute KD.