Correlation of lymphocyte heat shock protein 70 levels with neurologic deficits in elderly patients with cerebral infarction

Purpose To assess the association between heat shock protein 70 (HSP70) levels and the severity of ischemic stroke in elderly patients. Methods We conducted a case-control study to investigate the changes in lymphocyte HSP70 levels by immunoblot in 65 elderly patients with mild (n = 22), intermediate (n = 21), or severe (n = 22) stroke, and in 34 healthy controls. We analyzed correlations between HSP70 levels and neurologic deficit scores on days 1, 15, and 30 after the onset of stroke. Results Mean (± SD) HSP70 levels were higher in all stroke patients compared with controls (mild stroke: 709 ± 194 units; intermediate: 585 ± 165 units; severe: 421 ± 124 units; controls: 86 ± 34 units on day 1). Patients with mild stroke had higher levels at day 1 and 15 than did patients with severe stroke. HSP70 levels decreased rapidly from days 1 to 30 in all patients, except in patients with severe stroke, in whom levels decreased slowly between days 15 and 30. There were significant negative correlations between HSP70 levels and neurologic deficit scores in patients on days 1 (r = −0.53, P<0.001) and 15 (r = −0.54, P <0.001), but a positive correlation on day 30 (r = 0.49, P<0.001). Conclusion These data suggest that HSP70 may be a marker for neuroprotection in the early stage of ischemic stroke and a marker for a crisis in the later stages of severe cerebral infarction. Further studies on the use of lymphocyte HSP70 levels in predicting clinical outcomes and underlying mechanisms in cerebral infarction are warranted.