Acute Kawasaki disease is characterized by substantial BCR repertoire remodeling, marked by selective IgM clonal expansion, repertoire convergence, and CAL-associated IgA-biased remodeling.
Kawasaki disease patients had reduced overall BCR repertoire diversity compared with healthy controls, with a significant decrease in IgM diversity.
The KD repertoire showed increased contributions of high-frequency and hyperexpanded clonotypes, most pronounced in patients with CAL.
IgM showed the strongest clonal remodeling in KD, with fewer low-frequency clonotypes and more highly abundant clonotypes.
KD was associated with selective alterations in IGHV gene usage and V-J gene pairing.
CAL was associated with increased IGHA usage and changes in CDR3 amino acid composition.
Substantial inter-individual CDR3 sharing was observed among KD patients, and 20 recurrent clonotypes absent from healthy controls were identified as candidate KD-associated sequences.
Cross-isotype CDR3 sharing tended to be higher in KD, particularly among patients with CAL.
This study looked at the antibody-producing immune cells (B cells) of children with Kawasaki disease, an acute inflammatory illness of blood vessels in children that can damage the heart's coronary arteries. The researchers sequenced the genes that determine the antibody-binding regions in 22 children: 9 healthy, 9 with Kawasaki disease but no coronary damage, and 4 with Kawasaki disease and coronary damage. Children with Kawasaki disease had a less diverse B-cell repertoire, especially for IgM antibodies, with certain B-cell clones expanded and dominating. These changes were strongest in children with coronary artery damage, who also showed a shift toward IgA antibodies and changes in the amino acid makeup of the antibody-binding regions. Different patients also shared some of the same antibody sequences, and 20 of these were never seen in healthy children, suggesting a possible common immune response. This research suggests that B-cell responses are substantially reshaped during acute Kawasaki disease and may relate to coronary involvement. However, the study is small, especially the group with coronary damage (4 children), so the findings are preliminary. The candidate sequences would need further study before their role in disease or any use as markers could be understood.
Xu Y, Lin X, Chen Y, Zhang X, Ma L, Yao X, et al.. (2026). B-cell receptor repertoire remodeling in Kawasaki disease is associated with clonal expansion and distinct repertoire features in coronary artery lesions.. Frontiers in immunology. https://doi.org/10.3389/fimmu.2026.1994376