Heat shock protein (HSP70) expression in septic patients.

ABSTRACT

PURPOSE: This study investigates heat shock protein 70 (HSP70) expression by peripheral blood mononuclear cells (PBMCs) of septic patients admitted to an intensive care unit and examines the possibility of a correlation between HSP70 levels and plasma tumor necrosis factor alpha (TNF-alpha) concentrations. Additionally, we evaluated whether the HSP70 production could be regarded as a prognostic factor for the development of septic shock as well as for patient survival. MATERIALS AND METHODS: Blood samples of 29 patients were taken 24 hours after the diagnosis of sepsis. HSP70 expression and TNF-alpha level were measured using indirect immunofluorescent analysis and a commercially available enzyme-linked immunosorbent assay method, respectively. RESULTS: PBMCs expressed significantly high levels of HSP70 (11.9 +/- 5.6 [sd]) compared with those of the healthy control group (3.2 +/- 2.1% positive cells). Such enhanced levels were correlated to plasma TNF-alpha concentrations (r = .99, P < .01). This study failed to demonstrate a relationship between HSP70 production and clinical outcome. CONCLUSION: These findings give further evidence that also in humans, heat shock response is activated during sepsis. The correlation observed between HSP70 overproduction and TNF-alpha plasma concentrations suggests that HSP70 exerts a possible protective effect against TNF-alpha cytotoxicity. Such hypothesis has not been confirmed by our clinical data.