Myocardial ischaemia and the inflammatory response: release of heat shock protein 70 after myocardial infarction

Objectives: To test the hypothesis that heat shock protein (Hsp) 70 may be released into the circulation after acute myocardial infarction ( AMI) by exploring the kinetics of Hsp70 release and the relations between Hsp70 and markers of inflammation and myocardial damage in AMI. Design: Blood samples from 24 patients were prospectively collected through to the first day after AMI. Hsp70, interleukin ( IL) 6, IL- 8, and IL- 10 in serum were measured by enzyme linked immunosorbent assay ( ELISA). Results: Median Hsp70 concentrations in AMI patients measured at arrival, six hours thereafter, and the following morning were 686, 868, and 607 pg/ml, respectively. These concentrations were all significantly different from those of the control patients with angina with a median serum Hsp70 concentration of 306 pg/ml. Peak Hsp70 correlated with creatine kinase ( CK) MB ( r = 0.62, p< 0.01) and cardiac troponin T ( r = 0.58, p< 0.01). Furthermore, serum Hsp70 correlated with IL- 6 and IL- 8 at six hours ( r = 0.60, p< 0.01 and r = 0.59, p< 0.01, respectively). Conclusions: In this study, Hsp70 was rapidly released into the circulation after AMI. Circulating Hsp70 is suggested as a marker of myocardial damage. In addition, Hsp70 may have a role in the inflammatory response after AMI.