Immune mechanisms can precipitate cerebrovascular thrombosis and hemorrhage, but the involvement of immunologic tolerance mechanisms in suppressing local vessel activation and prevention of stroke has been unclear. In September 3 Stroke, Hidetaka Takeda and colleagues at the National Institutes of Health, Bethesda, USA, show that induction of mucosal tolerance to E-selectin prevents ischaemic and hemorrhagic stroke in a rat model of stroke (Stroke 2002, 33:2156–2164).

Takeda et al. used spontaneously hypertensive rats, genetically prone to stroke and observed that nasal instillation of E-selectin — specifically expressed on activated endothelium — potently inhibited the development of ischaemic and hemorrhagic strokes in rats with untreated hypertension. In addition, they showed that intranasal exposure to E-selectin induced immunologic tolerance, which reduced endothelial activation and immune responses following intravenous lipopolysaccharide challenge.

These data suggest that immunologic tolerance may be further developed as a novel stroke prevention strategy in susceptible individuals,...