Presence of heat shock protein 70 in secondary lymphoid tissue correlates with stroke prognosis.

Heat shock protein 70 (Hsp-70) can act as a danger signal and activate immune responses. We studied the presence of Hsp-70 in lymphoid tissue and plasma of acute stroke patients and asymptomatic controls free of neurological disease. Immunofluorescence, Western blotting, qRT-PCR and flow cytometry studies were performed. Plasma Hsp-70 concentration at day 7 was similar in patients and controls, whereas patients disclosed stronger immunoreactivity to Hsp-70 in lymphoid tissue than controls. Most Hsp-70+ cells were antigen presenting cells located in T cell zones. Stronger immunoreactivity to Hsp-70 was associated with smaller infarctions and better functional outcome.