GVHD in bone marrow transplant

[Danh Tran-Thanh]

I am interested in bone marrow transplantation and have recently read that graft-versus-host disease (GVHD) is one of the major 
complications of the procedure.  
Does anyone have any idea on where I can find some more info on GVHD?
Is it a mainly a T-cell mediated disease or a macrophage mediated inflammatory response?
And what are current therapies to treat GVHD in patients undergoing BM transplant?

Thanks