T cell Vβ repertoires in childhood vasculitides

Abstract

Summary Superantigens (SAgs) are potent stimulators of T cells bearing specific Vβ T cell receptors (TCR) and may play a role in the aetiopathogenesis of systemic vasculitis, although this remains contentious. To investigate the possible aetiological role of SAgs, this study examined peripheral blood T cell Vβ repertoires in children with systemic vasculitis. FACS analysis of 17 different peripheral blood T cell Vβ families was performed in 20 healthy control children, 27 disease control children with nonvasculitic inflammatory disease, 25 children with primary systemic vasculitis, six patients with Kawasaki disease (KD) and six patients with Henoch–Schönlein purpura (HSP). There was a significantly increased variance of CD4 Vβ12 and Vβ17, and CD8 Vβ1 in the primary systemic vasculitis group compared to control and disease controls. Moreover, 80% of the primary systemic vasculitis children had one or more CD4 Vβ expansions or deletions, compared with 30% of controls (P < 0·002), and 37% of the disease controls (P < 0·002). In the KD group, the mean percentage of CD4 Vβ2 T cells was higher than in controls or disease controls. In the HSP group, there was no consistent skewing of the T cell Vβ repertoire. We have observed changes in the T cell Vβ repertoire in children with vasculitis over and above those observed in disease controls. While these data provide impetus for further research into this contentious field, they do not resolve unequivocally the question of the role of SAgs in childhood vasculitic syndromes.