When to suspect this adverse reaction
TA-GVHD is extremely rare and transfused patients present with fever, rash and diarrhoea commencing 1-2 weeks post-transfusion.
Laboratory findings include pancytopenia and liver function abnormalities.
TA-GVHD leads to profound marrow aplasia with a mortality rate >90%.
Death typically occurs within one to three weeks of first symptoms, most commonly due to overwhelming infections.
This normally happens to immunodeficient recipients whose immune system is unable to recognise the transfused T lymphocytes as foreign.
These lymphocytes engraft in the recipient and react against the host.
The three primary risk factors for developing TA-GVHD are:
- degree of immunodeficiency of the recipient.
- number of viable T lymphocytes transfused (affected by the age of the blood transfused, degree of leucodepletion and irradiation status), and
- genetic diversity between donor and recipient. Greatest risks are donations from blood relatives and with HLA-matched blood products.
Diagnosis is normally made on skin biopsy and occasionally on liver or bone marrow biopsies.
What to do
Treatment is supportive and often, corticosteroids and cytotoxic agents are used, but are largely ineffective which means prevention is crucial.
For patients at risk, it’s critical to provide irradiated cellular blood components.
Leucocyte depletion is not sufficient to prevent TA-GVHD.