Activation of endothelial cells lining the blood vessels

1. Conditioning regiment

2. Cytokines produced by injured tissues

3. Microbial tanslocation through mucosal barriers

4. Engrafment process

5. Intense and sustained activation of endothelial cells leads to cellular damage

6. Alloreactivity (the immune response in reaction to the transplanted stem cells) has been postulated to play a role in this damage and activation. This explains the greater incidence of certain complications (e.g. GvHD) after allogeneic transplantation