Infectious complications after hematopoietic stem cell transplantation: current status and future perspectives in Korea

Cho, Sung-Yeon; Lee, Hyeon-Jeong; Lee, Dong-Gun

In Korea, which has a high CMV-seropositive rate (95% to 100%) in adults, most donors and recipients are seropositive (D+/R+) and the frequency of CMV infection after transplantation is up to 50% [76] . In addition, owing to active CMV monitoring and pre-emptive therapy, there has been a decrease in the incidence of CMV infection immediately after transplantation. However, late CMV infection (> 3 months after transplantation) is increasing, especially if CMV-specific T-cell function has not been restored due to chronic GVHD. Therefore, immune monitoring is required in patients with high-risk of CMV disease. CMV-specific immune recovery has been studied in kidney transplantation (KT) and HSCT recipients [86] [87] [88] [89] [90] [91] . CMV-specific cytotoxic T lymphocytes (CTLs) play an important role in the reconstitution of CMV-specific immunity in immunocompromised patients. The methods used to evaluate CMV-specific immunity include tetramer assay, intracellular cytokine analysis by flow cytometry, measurement of interferon-γ secretion by CMV-specific CD8 T-cells, and enzyme-linked immunospot assay using IE-1 and pp65 peptide pools [92] . Quantification of CMV-specific T-cell immunity after HSCT facilitates the identification of patients at risk of CMV-related complications [87, 88] .