Immunologically competent donor T lymphocytes mount an immune response against the recipient's lymphoid tissue
Can develop 2 days to 6 weeks after the transfusion
Typical symptoms include fever, erythematous maculopapular rash, which can progress to generalised erythroderma, toxic epidermal necrolysis in extreme cases, hepatomegaly, cough, abdominal pain, vomiting, and profuse diarrhea (up to 8 liters/day)
Laboratory findings include pancytopenia, marrow aplasia, abnormal liver enzymes, and electrolyte imbalance (when diarrhea is present)
TA-GvHD can be suspected from a biopsy of the affected skin or liver and established by HLA analysis of the circulating lymphocytes
Prevention includes gamma irradiation of the lymphocyte-containing blood components such as red blood cells, platelets and granulocytes
Dose of 2500 cGy is required to completely inactivate T cells
