Graft versus host disease (GVHD) is an excessive inflammatory response mediated by donor-derived immunoreactive cells in vivo that attack host cells and organs. GVHD is clinically referred to as acute GVHD when it occurs within 100 days of transplantation and as chronic GVHD after 100 days, depending on the time of onset.
Acute GVHD
Acute GVHD is one of the major barriers to successful allogeneic bone marrow transplantation and is primarily caused by donor-derived T lymphocytes attacking recipient tissue. Organs affected by acute GVHD typically include the skin, intestine, and liver.
- Skin lesions: often appear within 2 to 6 weeks after transplantation, with a peak onset around 30 days. The initial symptoms are pruritic or painful skin, followed by a rapid onset of diffuse symmetric maculopapular rash resembling measles, mostly on the back and neck, but also palmoplantar erythema, periauricular purple changes, and facial and neck involvement, with perifollicular papules as the perifollicular papules are the hallmark manifestations. In severe cases, the epidermis may become necrotic and loose, with diffuse erythema with macules and desquamation.
- Gastrointestinal damage: Symptoms are mainly nausea, vomiting, anorexia, diarrhea, and in severe cases, malabsorption, abdominal pain, even intestinal obstruction, ascites, etc. The degree of diarrhea is one of the important evaluation indicators of GVHD.
- Liver damage: The main characteristic manifestations are elevated levels of liver enzymes and conjugated bilirubin, and signs such as hepatomegaly and jaundice may also be present.
Chronic GVHD
It can develop from acute GVHD or occur de novo, and it involves a wider range of organ systems, but the disease progresses relatively slowly, with the main clinical symptoms:
- Skin involvement
- Dermal involvement begins about 4 months after transplantation: e.g., scleroderma, dry syndrome, vitiligo, scarring alopecia, hyperkeratosis, skin contractures, abnormal nail bed development;
- Mucous membranes: lichen planus, dry mouth, non-infectious ulcers, corneal erosions, non-infectious conjunctivitis;
- Digestive tract: loss of appetite, dyspepsia, weight loss, diarrhea, esophageal stricture, steatorrhea;
- Liver: hypertransaminase hepatitis, cholangitis, hyperbilirubinemia;
- Genitourinary tract: non-infectious vaginitis, vaginal atrophy or stenosis;
- Muscle, bone, and plasma membranes: nonspecific arthritis, myositis, muscle weakness, plasmacytosis, contracture fixation;
- Hematologic: thrombocytopenia, eosinophilia, autoimmune hematocrit;
- Lung: occlusive fine bronchitis, interstitial pneumonia.
GVHD prevention and care
GVHD prevention
Prevention of GVHD is important, and the main preventive measures include careful monitoring of the histocompatibility system of the donor-recipient, aseptic environment and gastrointestinal debridement, prophylactic medications (cyclosporine, methotrexate, primaquine, etc.), and removal of donor T cells. The prophylactic dosing usually starts at the pretreatment stage and is adjusted during treatment according to the relevant drug concentrations, etc. to prevent GVHD.
Immunosuppression should be administered as prescribed to suppress excessive immune responses. In the event of acute GVHD, additional measures such as high-dose methylprednisolone, FK506, sulforaphane (CD25 monoclonal antibody), and anti-thymocyte globulin ATG should be added to the original prophylaxis regimen.
GVHD care
Parents caring for their post-transplant child should be aware of whether the child is exhibiting any of the symptoms described above and seek prompt medical attention. While taking immunosuppressant medications as prescribed by the physician, care should also be given to lifestyle care, mainly in the areas of keeping clean and preventing infection:
- Provide a clean, low bacterial diet, fasting in the presence of severe diarrhea, total parenteral hypernutrition after consultation, and accurate documentation of changes in stool frequency, color, and volume.
- Learn to wash hands properly, bathe daily, keep the skin intact and dry, and pay attention to changing the child’s underwear.
- When the skin is damaged and thin and bleeds easily, to protect the skin from further damage after flaking, apply tetracycline ointment or paraffin oil evenly after washing with warm water daily to keep the skin moist and use a brace quilt if necessary to prevent the quilt from touching the skin directly and causing breakout infection due to damage from friction.
- Get good eye and oral care and develop good oral cleaning habits.
- Rationalize vaccination schedule after transplantation to avoid infection due to contact as much as possible.
- We should also pay attention to the negative psychological state of the children due to their condition and their own influence, and communicate reasonably to enhance their confidence to fight the disease and cooperate with the treatment and care with a positive attitude.