Optimal approach to assessing T-cell function in haematopoietic cell transplant recipients

Standardised approaches to functional immune assessment after haematopoietic cell transplantation (HCT) are lacking. A 12-year-old girl with relapsed acute myelogenous leukaemia, 2 years post-unrelated HCT, underwent immunological evaluation prior to receiving live vaccinations. Assessment of standard immune parameters and T-cell proliferation to phytohaemagglutinin was reassuring. She was given Varicella vaccination based on usual post-transplant protocols but was hospitalised 10 days later with localised Varicella infection (vaccine strain). Following recovery, she underwent further assessment that showed reduced T-cell proliferation to an anti-CD3 stimulation panel (anti-CD3 alone, soluble anti-CD3⁺ anti-CD28 and soluble anti-CD3⁺ plus exogenous IL-2). On reassessment, 7 months later, T-cell responses to anti-CD3 stimulation were normal and she was revaccinated without further incident. Measurement of T-cell proliferation to anti-CD3 stimulants likely yields more useful information about global T-cell function and should be strongly considered prior to live vaccine administration post-allogeneic haematopoietic transplant.