Increased level of HSP27 but not of HSP72 in human heart allografts in relation to acute rejection

Background Increased expression of heat shock proteins (HSPs) was assumed d uring cardiac allograft rejection. To find evidence for this in man, we qua ntified HSP27 and HSP72 in cardiac allograft biopsies. Methods. In parallel to histological assessment of rejection, HSP27 was qua ntified by Western blotting in a total of 43 biopsies sampled from 3 patien ts. HSP72 was analyzed in parallel in 30 of the 43 cases. For comparison, H SPs were analyzed in myocardium. Results. HSP27 was significantly higher in rejecting cardiac allografts tha n in non-rejecting allografts and non-failing myocardium (1.52+/-0.25 vs. 0 .83+/-0.11 vs. 0.50+/-0.05 mug/mg protein). Similarity for HSP72 (6.27+/-1. 54 vs. 4.06+/-1.03 vs. 6.27+/-0.76 mug/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-pr otection, was demonstrated. For the lack of increased HSP72 expression, the influence of the cyclosporine A treatment was discussed.