Increased production of serum IgA-class antibody to lipid A in Kawasaki disease

• Published in: Pediatrics international Vol. 44; no. 1; pp. 5 - 11
• Main Authors: Takeshita, Seiichiro, Kawase, Hiroko, Shimizu, Tooru, Yoshida, Maki, Sekine, Isao
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science, Ltd 01.02.2002
• Subjects: anti-lipid A IgA; Antigens, Bacterial - immunology; Child; Child, Preschool; Female; Humans; Immunity, Mucosal; Immunoglobulin A - blood; Immunoglobulin M - blood; Infant; Kawasaki disease; Lipid A - immunology; lipopolysaccharide; Lipopolysaccharides; Male; Mucocutaneous Lymph Node Syndrome - immunology
• ISSN: 1328-8067; 1442-200X
• DOI: 10.1046/j.1442-200X.2002.01506.x

Background : The etiology of Kawasaki disease (KD) remains unknown. To investigate whether a conventional bacterial antigen is involved in the pathogenesis of KD, we studied the serum response to lipopolysaccharide (LPS). Methods : We measured the serum levels of IgG‐, IgM‐ and IgA‐class antibodies (Ab) to lipid A, a toxic site of LPS, using enzyme‐linked immunosorbent assay in 20 patients with KD, 11 patients with Gram‐negative bacterial infection (GNBI), 27 healthy children and 12 healthy adults. Results : The serum levels of anti‐lipid A IgG, IgM and IgA tended to increase with advancing age in healthy children older than 6 months of age. The mean level of anti‐lipid A IgM in the acute phase of GNBI and the mean levels of anti‐lipid A IgM and IgA in the acute phase of KD were found to increase significantly, in comparison to the age‐matched controls. Furthermore, the mean level of anti‐lipid A IgA also showed a significant increase from the acute to the subacute phases of KD. Regarding the IgA‐subclass response, higher titers of anti‐lipid A specific Ab were seen in the IgA2 subclass than in the IgA1 subclass. Conclusion : These findings indicate that KD patients demonstrate an intense response to lipid A in the IgA, especially IgA2‐subclass, thus suggesting that an unusual activation of the mucosal immune response to a ubiquitous antigen derived from Gram‐negative bacteria may be involved in the pathogenesis of KD.