Superantigen involvement and susceptibility factors in Kawasaki disease: profiles of TCR Vβ2+ T cells and HLA-DRB1, TNF-α and ITPKC genes among Filipino patients

Abstract

Superantigens and genetic factors may play roles in the etiology and susceptibility to Kawasaki disease (KD). To investigate these roles, percentages of TCR-Vβ2+ T cells were compared by flow cytometry using anti-Vβ2 monoclonal antibodies and genotyping was done on HLA-DRB1 exon 2, the -308 site of the TNF-α promoter region, and ITPKC SNP rs28493229 by polymerase chain reaction followed by direct sequencing. There were higher percentages of Vβ2+ T-cells in KD patients (9.5 ± 2.15%) compared to healthy controls (7.25 ± 1.48%) (P<0.05, Student's t-test, n=6-8/group). However, no polymorphisms were observed in exon 2 of HLA-DRB1 and in the -308 region of the TNF-α promoter. The ITPKC SNP rs28493229 G/C polymorphism was observed in 1 KD patient and 4 healthy controls. This study suggests that KD etiology may be associated with a superantigen and that HLA-DRB1 exon2, TNF-α -308 region and ITPKC SNP rs28493229 may not be associated with KD. This is the first study investigating Vβ2+ T cells and candidate genes involvement among Filipino KD patients.

Keywords: HLA-DRB1; ITPKC; Kawasaki disease; Superantigens; TNF-α.