Stroke induced lateralization of delayed-type hypersensitivity in the early and chronic phase of the disease: a prospective study.

The impact of the acute and chronic phase of stroke on in vivo mediated immune functions was prospectively analysed in patients with mono- and multifocal brain lesions. The cutaneous delayed-type hypersensitivity (DTH) reaction to purified protein derivate was used as an in vivo measure of antigen specific T cell reactivity. Stroke patients have been tested prospectively for DTH reactivity at two separate occasions, 6-12 months apart. Both sides of the body were tested at each occasion. The DTH response on the paretic side changed significantly with time, from being smaller on the paretic side as compared with the contralateral one early after the onset of stroke, to become significantly larger (p = 0.017) in the chronic phase of the disease. In addition, stroke patients showed a significantly larger (p = 0.001) DTH reactivity bilaterally in the chronic phase of the stroke than in the early phase. When patients with single brain lesion and multiple brain lesions were analyzed separately, the increase of DTH reactivity on the paretic side between the 2 challenges was significant (p = 0.016) only in patients with the monofocal disease. We conclude that stroke induces i. an inhibition of DTH reactivity on the paretic side as compared with the non-paretic one in the acute phase but a lateralized enhancement of the DTH reactivity in the chronic phase of the disease, ii. a systemic increase of DTH reactivity in the chronic phase of the disease. Clinical factors positively correlated with these aberrations are: i. right sided, subcortical brain lesion, ii. paresis associated with impaired sensitivity, iii. minor stroke.