Reducing macrophages to improve bone marrow stromal cell survival in the contused spinal cord.

We tested whether reducing macrophage infiltration would improve the survival of allogeneic bone marrow stromal cells (BMSC) transplanted in the contused adult rat thoracic spinal cord. Treatment with cyclosporine, minocycline, or methylprednisolone all resulted in a significant decrease in macrophage infiltration at 3 days postinjury. However, when BMSC were injected at that time point, survival 7 days later was similar between treatment groups and saline-injected controls. In fact, we found that the presence of BMSC resulted in a significant increase in macrophage infiltration into the contusion.