What is graft-versus-host disease?
Graft-versus-host disease (GVHD) is a serious and frequent complication of allogeneic haematopoietic stem cell transplantation that occurs partly due to the alloreactive activity of donor T-cells. Traditionally GVHD was labelled as chronic GVHD (cGVHD) when it occurred 100 or more days after the initial transplant operation; and as acute GVHD (aGVHD) when it occurred less than 100 days after transplant. More recently cGVHD and aGVHD are both diagnosed based on clinical signs and symptoms and further tests, and the National Institutes of Health classification also includes late-onset aGVHD and an overlap syndrome with features of both acute and chronic GVHD.
Acute graft-versus-host disease
Symptoms of aGVHD can range from mild to severe. The first sign of aGVHD is typically a skin rash that appears on the palms of the hands and soles of the feet. Patients may complain of severe itching or tenderness in affected areas, and rash onset frequently correlates with engraftment of donor cells. The other two areas that are typically affected by aGVHD are the gastrointestinal (GI) tract and the liver. The severity of aGVHD is determined by the extent of involvement of the skin, GI tract and liver; and the disease can be graded (from I to IV) depending on severity. Steroids are the first-line treatment for aGVHD, but photopheresis has also been shown to be useful as an adjunctive therapy in refractory disease.
Chronic graft-versus-host disease
Chronic GVHD may start as aGVHD, which then transitions into cGVHD. Chronic GVHD may also occur after aGVHD has resolved, or as de novo disease. The greatest risk factors for cGVHD are age, and a history of aGVHD.
Chronic GVHD can range from mild to severe and commonly affects the skin, mouth, eyes and vaginal mucosa. Chronic GVHD can also affect the gut, nails, hair, liver, lungs, kidneys and heart, and may persist even when skin changes have resolved. First-line therapy for cGVHD involves treatment with steroids and immunosuppressive drugs such as calcineurin inhibitors. Photopheresis has also been shown to be a useful adjunctive therapy for cGVHD.