1. ¹Department of Medical Oncology, National Cancer Center Hospital, Tokyo, Japan
2. ²Department of Hematology and Oncology, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
3. ³Cellular Immunology Section, SRL Inc., Hachioji-city, Tokyo, Japan

Correspondence: Dr Y Takaue, Director, Department of Medical Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. E-mail: ytakaue@ncc.go.jp

Received 7 August 2007; Revised 10 October 2007; Accepted 15 October 2007; Published online 19 November 2007.

Abstract

In order to evaluate whether we could predict reactivation of CMV by monitoring the number of CMV-specific cytotoxic T-lymphocytes (CTL), tetramer analysis was performed in 37 patients who underwent hematopoietic stem cell transplantation (HSCT). The results disclosed that the mean number of CMV-specific CTL at day 30 did not differ among patients who developed CMV antigenemia (22/l) and those who did not (12/l). Serial tetramer analysis showed that 21% of the patients had >10/l CMV-specific CTL at the first detection of CMV antigenemia and 67% of the patients had more than 10/l CMV-specific CTL at the onset of CMV disease. Intracellular staining upon stimulation by CMV lysates and peptide in patients with CMV colitis revealed that both IFN- producing CD4+ and CD8+ lymphocytes were suppressed at the onset of CMV colitis (1.6 and 8/l), which increased with recovery of the disease (19 and 47/l). These data suggest that it is difficult to predict CMV reactivation solely by the number of CMV-specific CTL. We suggest that additional functional analysis by intracellular cytokine assay may be useful for immunomonitoring against CMV.