Department of Pediatrics, Nagoya University Graduate School of Medicine, Japan.
J Clin Virol. 2011 Mar;50(3):244-6. doi: 10.1016/j.jcv.2010.11.017. Epub 2010 Dec 24.
During the convalescent phase of acute infectious mononucleosis (AIM), Epstein-Barr virus (EBV) load shrinks rapidly in association with a rapid decline in the number of EBV-specific CD8(+) T cells. The actual contribution of EBV-specific CD8(+) T cells in reducing EBV load, however, is not known.
To clarify the impact of EBV-specific CD8(+) T cells on the contraction of EBV load in AIM, we estimated half-lives of both EBV load and EBV-specific CD8(+) T cells.
Blood was serially taken from five pediatric patients with AIM during the convalescent period, including the very early phase, and both EBV load and EBV-specific CD8(+) T cell numbers were assayed.
EBV load declined rapidly (half-life 1.5 d) during the first 2 weeks after onset of symptoms. This half-life was seven-fold shorter than that reported for CD27(+) memory B cells. Subsequently, the EBV load declined much more slowly, with a half-life of 38.7 d. EBV-specific CD8(+) T cell numbers also declined concomitantly with the decrease in EBV load. The half-life of EBV-specific CD8(+) T cells during first 2 weeks was 2.9 d. The number of EBV-specific CD8(+) T cells and the rate of change of viral load correlated significantly (R(2) ≥ 0.8; p ≤ 0.02).
The short half-life of EBV load, together with the strong correlation between the number of EBV-specific CD8(+) T cells and the rate of change of viral load indicates an active role for EBV-specific CD8(+) T cells in elimination of EBV in AIM.
在急性传染性单核细胞增多症（AIM）的恢复期，EB 病毒（EBV）载量迅速下降，同时 EBV 特异性 CD8+T 细胞数量迅速减少。然而，EBV 特异性 CD8+T 细胞在降低 EBV 载量方面的实际贡献尚不清楚。
为了阐明 EBV 特异性 CD8+T 细胞在 AIM 中减少 EBV 载量中的作用，我们估计了 EBV 载量和 EBV 特异性 CD8+T 细胞的半衰期。
从 5 例儿科 AIM 患者的恢复期连续采集血液，包括早期阶段，并检测 EBV 载量和 EBV 特异性 CD8+T 细胞数量。
症状出现后前 2 周 EBV 载量迅速下降（半衰期 1.5 d）。该半衰期是 CD27+记忆 B 细胞半衰期的七倍。随后，EBV 载量下降速度明显减慢，半衰期为 38.7 d。EBV 特异性 CD8+T 细胞数量也随着 EBV 载量的减少而相应下降。前 2 周 EBV 特异性 CD8+T 细胞的半衰期为 2.9 d。EBV 特异性 CD8+T 细胞数量与病毒载量变化率呈显著相关（R2≥0.8；p≤0.02）。
EBV 载量的半衰期较短，以及 EBV 特异性 CD8+T 细胞数量与病毒载量变化率之间的强相关性表明 EBV 特异性 CD8+T 细胞在 AIM 中消除 EBV 中发挥积极作用。
