Acute Graft Versus Host Disease, often abbreviated as GVHD, is a serious and life-threatening non-infectious complication associated with an allogeneic stem cell transplantation (allogeneic SCT), meaning a bone marrow or stem cell transplant in which the cells or marrow in question come from a donor. Such transplants are somewhat common yet very serious treatment options for patients with many different subtypes of lymphoma.
GVHD can occur either as an acute disease, or as a chronic disease. Doctors generally take preventive measures against GVHD, but they do not always prove effective.
What is Acute Graft Versus Host Disease
In transplant medicine, the biggest concern is organ rejection. For example, a donated kidney is transplanted into a patient desperately needing a kidney. Once the procedure is done, doctors must do all they can to prevent the patient's immune system from seeing the new kidney as a foreign—and unwelcomed—intruder in the body, because when this happens, the immune system attacks the new kidney with the purpose of killing it.
However, in an allogeneic stem cell transplantation, the opposite occurs. Because allogeneic SCT patients have had their immune systems destroyed by preparative chemotherapy and radiation, they don't have an immune system of their own to attack the new cells or marrow introduced into their bodies. In fact, the point, or the job, or the donor marrow or cells is to rebuild the patient's immune system, and to do it free of cancer.
The problem is that sometimes, the donor marrow (referred to as the 'Graft') begins to systematically attack the organs of the patient (referred to as the 'Host'). It does this because one of the blood cells it makes is the lymphocyte, whose job it is to attack foreign bodies. When this happens, the patient is diagnosed as suffering from Acute Graft Versus Host Disease.
Incidence and organ involvement in graft versus host disease
GVHD incidence is alarmingly high—it occurs in at least half of all allogeneic SCT patients. When it does occur, the organs most frequently involved are, in order of frequency:
-- Organs in the GI tract
Staging and grading of Acute Graft Versus Host Disease
Like the cancer the transplant is intended to treat, GVHD has a staging system. However, it is done a little differently: Staging is done first, according to the organ involvement, then all those values are added up to create a single 'grade' for acute graft versus host disease.
GVHD staging for the skin
Stage I: Rash on less than 25 percent of the skin
Stage II: Rash on 25-50 percent of the skin
Stage III: Generalized erythroderma (describes a skin condition covering at least 90 percent of the body)
Stage IV: Bullae (meaning that blisters larger than 1 cm in diameter begin to develop)
GVHD staging for the liver measures the total amount of bilirubin
Stage I: 2-3 mg/dl
Stage II: 3.1-6 mg/dl
Stage III: 6.1-15 mg/dl
Stage IV: 15 mg/dl or higher
GVHD staging for the organs of the GI tract
Stage I: Diarrhea amounting to at least 500 mL per day
Stage II: Diarrhea amounting to at least 1000 mL per day
Stage III: Diarrhea amounting to at least 1500 mL per day
Stage IV: Severe abdominal pain and bleeding
Overall Grade scale for GVHD
Grade I: Skin 1-2, liver 0 and GI tract 0
Grade II: Skin 1-3, liver 1 and/or GI tract 1
Grade III: Skin 2-3, liver 2-4 and/or GI tract 2-3
Grade IV: Skin 2-4, liver 2-4 and/or GI tract 2-4
Boyiadzis, Michael M. et al. Hematology-Oncology Therapy. 2007. New York: McGraw Hill, Medical Publishing Division, Ch. 50, "Complications and Follow-Up after Hematopoietic Stem Cell Transplantation."
The National Marrow Donor Program