Method of prevention of GVHD in bone marrow transplantation is?
Treatments used to prevent GVHD include
1) Prior immunosuppression

Ciclosporin is used most commonly. This drug works by reducing the number of T cells in donated marrow or stem cells. Started a couple of days before transplant and continued for about 6 months after the transplant.
Other drugs used are- MMF, tacrolimus, sirolimus

2) T cell depletion from the marrow or stem cells

Removal of T cells from donor's bone marrow after it has been donated, or during the donation of stem cells. This method is not commonly used.

3) Treatment after transplant

Low doses of the chemotherapy drug methotrexate to suppress your immune system. This helps to keep the t cells down and so stops them attacking body cells. Cyclophosphamide is also used.
T-cell removal
Prior immune suppression
Post procedure immune suppression
All of the above