Reference intervals for functional lymphocyte proliferation studies using 3H thymidine uptake in adults

Although there has been a recent move to implement non-radioactive methods for functional cellular immunity, ³H thymidine uptake continues to be utilized in many diagnostic laboratories because of excellent sensitivity. Robust vaccine-induced cellular responses in immunodeficient patients may inform clinical decisions such as using live attenuated viral vaccines. Similarly, markedly impaired responses to phytohemagglutinin A (PHA), in the appropriate clinical context, supports a diagnosis of Severe Combined Immunodeficiency (SCID) and the need for urgent hematopoietic stem cell transplantation (HSCT). The reference intervals established by this audit will assist other diagnostic laboratories using this platform.