Abstract
Objectives:
Previously, we reported a change in phenotype of myocardial mast cells during LVAD-support. Such altered mast cells had modulating effects on collagen production in a co-culture system with fibroblasts. To support our findings, we determined the HSP-47 expression in the myocardium, a specific molecular chaperone for procollagen.
Material and Methods:
HSP-47 staining was performed on matched tissue slides from 10 patients with DCM at the time of LVAD implantation and of transplantation following LVAD support. Tissue slides from 5 donor hearts not used for transplantation served as a control group.
Results:
While slides of normal myocardium presented almost no staining for HSP-47 (1 positive cell per microscopy field), there was a highly significant increase in HSP-47 positive cells in the pre-LVAD DCM-tissue (34 positive cells per microscopy field) (p<0.01). Interestingly, the post-LVAD myocardium showed a significant decrease in HSP-47 positive cells (8 positive cells per microscopy fields) (p<0.01). All Hsp-47 positive cells stained also positive for the fibroblast marker vimentin.
Conclusions:
There was a decrease of HSP-47 positive cells following LVAD support compared to pre-LVAD DCM myocardium. This may confirm results of our previous study showing mast cells isolated from post-LVAD myocardium having an inhibiting effect on the fibroblastic protein production in vitro.