Polymorphisms in the mannose-binding lectin gene as determinants of age-defined risk of coronary artery lesions in Kawasaki disease.

Objective: To evaluate the relationship between polymorphisms in the gene coding for mannose-binding lectin (MBL) and the occurrence of coronary artery lesions (CALs) among different age groups of patients with Kawasaki disease.
Methods: The frequencies of the genotypes, defined as mutations in codons 52, 54, and 57, and the functional promoter variants of the MBL2 gene were determined in 88 patients with acute Kawasaki disease (median age at onset 1.9 years). The possible influence of the MBL2 genotype on the development and progression of CALs in Kawasaki disease was assessed according to age categories and MBL genotypes in univariate and multivariate analyses.
Results: In patients younger than age 1 year, we found an increased risk of developing CALs in the presence of a variant MBL2 genotype (P = 0.008). In contrast, in patients older than age 1 year, we found an increased risk of CALs in those patients with the wild-type genotype (P = 0.005).
Conclusion: Our findings indicate that MBL has an ambiguous role in Kawasaki disease and contributes differently to the pathophysiologic development of CALs, being protective in infants but potentially harmful in patients of older age. The data also imply that the standard treatment of intravenous immunoglobulins to reduce the development of lesions may not be as effective in the very young as it is in the older patients. For the very young, alternative or adjuvant treatment may be indicated, particularly in infants who are MBL-deficient.