June 19, 2023—Qiagen announced the publication of a study that aimed to compare and analyze the difference in interferon-gamma (IFN-γ) production between QuantiFeron-TB Gold Plus TB1 and TB2 blood collection tubes in general and specific populations (Darmawan G, et al. Clin Chem Lab Med. Published online May 25, 2023. doi:10.1515/cclm-2023-0293). TB1 is designed to target cell-mediated responses from CD4 T cells while TB2 stimulates CD4 and CD8 T cells. The systematic review, based on 17 studies and including 4,050 subjects, showed a higher level of IFN-γ production in the TB2 tube than in the TB1 tube, confirming the important role of CD8 T cells for a broad immune assessment of TB infection.
Subgroup analysis in specific populations revealed that the difference of IFN-γ production between the TB2 and TB1 tubes was significantly higher in active TB disease subjects than in those with latent TB. The study also highlighted the potential benefit of the TB2 tube for CD8 detection in certain high-risk populations, such as immunocompromised patients and those who have a CD4 T cell deficiency.