The establishment of a cytomegalovirus -specific CD8(+) T-cell threshold by kinetic modeling for the prediction of post-hemopoietic stem cell transplant reactivation

The dynamic interaction between the CMV virus and host immune response remains obscure, thus hindering the diagnosis and therapeutic management of patients with HSCT. The current diagnosis of CMV viremia depends on viral load estimation. Medical intervention based on viral load, can be unnecessary or poorly timed for many patients. Here we examined the clinical features and blood samples of patients with HSCT and assessed the CMV reactivation kinetics and corresponding CMV antigen-specific T-cell response in individual patients based on a peptide pool stimulation T-cell assay, which showed that CMV-specific CD8(+) T cells were more suitable to be a diagnosis indicator for suppressing CMV reactivation. Using ROC analysis, we defined and verified a CMV-specific CD8(+) T-cell counts threshold (925 cells/10(6) PBMCs) as an indicator of CMV reactivation post-HSCT, and suggested that use of this threshold would provide more accurate guidance for prompt medication and better management of CMV infection post-HSCT.