ABSTRACT
OBJECTIVES: To investigate whether superantigens (SAgs) are involved in the development of Kawasaki disease (KD) by examining SAg genes in the stool of patients with KD. STUDY DESIGN: Stool specimens were obtained from 60 patients with KD and 62 age-matched children (36 children with acute illness and 26 healthy children). Total DNA was extracted from these stool samples. Using polymerase chain reaction, we examined genes of 5 SAgs: streptococcal pyrogenic exotoxin-A (SPE-A), SPE-C, SPE-G, SPE-J, and toxic shock syndrome toxin-1. RESULTS: At least 1 of the 5 SAg genes was detected in 42 (70%) specimens from patients with KD, 14 (38.9%) from the febrile group, and 7 (26.9%) from the healthy group. The detection rate between subjects with and without KD was of at least 1 of the 5 SAg genes (P < .001), and more than 2 SAg genes were significantly different (P = .002). CONCLUSIONS: SAg may be involved in the development of KD; data suggest that multiple SAgs may trigger KD.
Subject(s)
Bacterial Proteins/genetics , Bacterial Toxins/genetics , Enterotoxins/genetics , Exotoxins/genetics , Feces/chemistry , Membrane Proteins/genetics , Mucocutaneous Lymph Node Syndrome/immunology , Superantigens/genetics , Case-Control Studies , Child, Preschool , DNA, Bacterial/isolation & purification , Female , Humans , Male , Mucocutaneous Lymph Node Syndrome/genetics , Polymerase Chain ReactionABSTRACT
OBJECTIVE: To investigate whether reduced levels of plasma platelet-activating factor acetylhydrolase (PAF-AH) as a result of a genetic polymorphism are involved in the pathogenesis of Kawasaki disease (KD). STUDY DESIGN: The frequency of a V279F polymorphism (G/T transversion) in the PAF-AH gene was quantified in 76 Japanese children with KD and 112 healthy Japanese adults using the allele-specific polymerase chain reaction (PCR). Associations between genotype, clinical features, and resistance to intravenous immunoglobulin (IVIG) were investigated in the patients with KD. Plasma PAF-AH activity was measured by using [3H]-acetyl-PAF. RESULTS: There were no significant differences in genotype frequency between patients and controls (P = .51). Compared with the GG (normal genotype) group, significantly more patients in the GT (heterozygous) +TT (homozygous deficient) group required additional IVIG (52% vs 14%, P = .001). The duration of fever and maximum serum C-reactive protein (CRP) levels also were significantly increased in the GT+TT group (P = .012 and .036, respectively), whereas plasma PAF-AH activity was significantly lower (P <.0001). CONCLUSION: We conclude that the V279F polymorphism in the plasma PAF-AH gene and consequent enzymatic deficiency is one of the factors for IVIG nonresponse in Japanese patients with acute KD.