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

•Hsp-70 immunoreactivity was higher in lymphoid tissue of patients than controls•Plasma Hsp-70 concentration at day 7 was similar in patients and controls.•Hsp-70 cells expressed antigen presenting cell markers in T cells areas.•Stronger lymphoid tissue Hsp-70 was related to smaller infarctions and good outcome.

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.