Clinical immune monitoring: Impact of in vitro PBMC expansion on quantity and quality of HBV-specific CD4 and CD8 T cells

In vitro expansion of PBMC is commonly used prior to a T-cell monitoring to increase low number of peripheral HBV-specific T cells. However, whether in vitro expansion changes functional composition of T-cell responses detectable directly ex vivo has not yet been investigated in detail. We compared quantity and functionality of HBV surface- (HBs) and core- (HBc) specific CD4/CD8 T cells ex vivo and after 10-days in vitro expansion in 41 individuals with different HBV status (acute self-limiting, chronic or resolved infection). T-cell reactivity was analyzed by intracellular cytokine staining (IL-2, IFN-γ, TNF-α)…