Graft-Versus-Host Disease

Graft-versus-host disease (GVHD) is a systemic disorder occurring when immune cells from transplanted tissue recognize the recipient's body as foreign and attack its cells. In this context, graft refers to transplanted or donated tissue, while host refers to the recipient's tissues. GVHD is a common complication following allogeneic hematopoietic stem cell transplant.

GVHD has traditionally been categorized based on the timing of presentation into acute and chronic, with a cutoff of 100 days post-transplant. These classifications have been further refined based on clinical manifestations accepted by the National Institutes of Health (NIH):

1. Acute classic GVHD presents within 100 days of transplantation with typical clinical features of acute GVHD.

2. Persistent, recurrent, or late-onset acute GVHD manifests with clinical features of classic acute GVHD but after 100 days of transplantation.

3. Classic chronic GVHD presents after 100 days of transplant with classic clinical features of chronic GVHD.

4. Overlap syndrome may occur at any time posttransplant with features of both acute and chronic GVHD.