Background: Increased expression of heat shock proteins (HSPs) was assumed during cardiac allograft rejection. To find evidence for this in man, we quantified HSP27 and HSP72 in cardiac allograft biopsies.
Methods: In parallel to histological assessment of rejection, HSP27 was quantified by Western blotting in a total of 43 biopsies sampled from 3 patients. HSP72 was analyzed in parallel in 30 of the 43 cases. For comparison, HSPs were analyzed in myocardium.
Results: HSP27 was significantly higher in rejecting cardiac allografts than in non-rejecting allografts and non-failing myocardium (1.52 +/- 0.25 vs. 0.83 +/- 0.11 vs. 0.50 +/- 0.05 microg/mg protein). Similarity for HSP72 (6.27 +/- 1.54 vs. 4.06 +/- 1.03 vs. 6.27 +/- 0.76 microg/mg protein) was not found.
Conclusion: For the first time in humans with cardiac allograft rejection, increased expression of HSP27, which could be important for cardiac self-protection, was demonstrated. For the lack of increased HSP72 expression, the influence of the cyclosporine A treatment was discussed.