Understanding Graft Versus Host Disease and Its Treatments
Graft Versus Host Disease (GVHD) is a complex condition that can occur following an allogeneic stem cell or bone marrow transplant. This occurs when the donated immune cells, or graft, recognize the recipient's body tissues as foreign and mount an immune response against them. GVHD is categorized into acute and chronic forms, with each type affecting the body differently and requiring tailored treatment strategies. Acute GVHD typically develops within the first 100 days post-transplant, primarily affecting the skin, liver, and gastrointestinal tract. Chronic GVHD can appear later and may involve multiple organs, often resembling autoimmune disorders.
The first line of defense against GVHD involves prevention through careful donor selection and the use of immunosuppressive medications. Human leukocyte antigen (HLA) matching between donor and recipient significantly reduces the risk of GVHD. Prophylactic immunosuppressive drugs, such as calcineurin inhibitors (e.g., cyclosporine or tacrolimus), are commonly administered to prevent the donor’s immune cells from attacking the host tissues. These medications are often combined with corticosteroids to provide additional immune suppression during the critical period following transplantation.
When GVHD develops despite preventive measures, treatment focuses on controlling the immune response while preserving the beneficial graft-versus-leukemia effect. Corticosteroids, particularly prednisone, remain the cornerstone of initial treatment. They help reduce inflammation and tissue damage by suppressing overactive immune cells. However, long-term steroid use carries risks, including increased susceptibility to infections, osteoporosis, and metabolic complications.