Kumagai Takuji, Yoshikawa Tetsushi, Yoshida Mariko, Okui Toyo, Ihira Masaru, Nagata Nobuo, Yano Shoki, Shiraki Kimiyasu, Yamada Masao, Ichihara Kiyoshi, Asano Yoshizo
Pediatric Allergy and Infectious Diseases Society of Sapporo, Kumagai Pediatric Clinic, Sapporo, Hokkaido, Japan.
J Med Virol. 2006 Jun;78(6):792-9. doi: 10.1002/jmv.20625.
The time-course of cell-mediated immunity in exanthema subitum is not well documented. The lymphoproliferative response to purified human herpesvirus 6 (HHV-6) antigen and to phytohemagglutinin was measured and natural killer (NK) cell activities determined in three consecutive specimens obtained biweekly from 18 young children and infants with exanthema subitum. Virus isolation and PCR detection of virus DNA and determination of neutralization antibody to HHV-6 and -7 were also carried out. The magnitude of the HHV-6 specific lymphoproliferative response varied; however, in most cases the time course kinetics revealed a low response in the acute phase with a subsequent gradual increase. In contrast, NK cell activities were high in the acute phase and declined gradually during convalescence. The lymphoproliferative response to phytohemagglutinin did not show a consistent trend in kinetics of time; however, dynamic changes in activity were observed in patients during the acute and convalescent periods. The results suggest that NK cells play a major role in resolving acute phase infection while specific lymphocyte activity develops later. The cause of the delayed development of HHV-6 specific lymphoproliferative response is unknown. The lymphoproliferative response to phytohemagglutinin ratios implied that HHV-6 infection has some impact on host T-cell immunity during the course of exanthema subitum.
幼儿急疹中细胞介导免疫的时间进程尚无充分记录。对18名患幼儿急疹的年幼儿童和婴儿每两周连续采集三份标本，检测其对纯化人疱疹病毒6型（HHV-6）抗原和植物血凝素的淋巴细胞增殖反应，并测定自然杀伤（NK）细胞活性。还进行了病毒分离、病毒DNA的PCR检测以及对HHV-6和-7的中和抗体测定。HHV-6特异性淋巴细胞增殖反应的幅度各不相同；然而，在大多数情况下，时间进程动力学显示急性期反应较低，随后逐渐增加。相比之下，NK细胞活性在急性期较高，在恢复期逐渐下降。对植物血凝素的淋巴细胞增殖反应在时间动力学上未显示出一致趋势；然而，在急性期和恢复期患者中观察到活性的动态变化。结果表明，NK细胞在解决急性期感染中起主要作用，而特异性淋巴细胞活性随后发展。HHV-6特异性淋巴细胞增殖反应延迟发展的原因尚不清楚。对植物血凝素的淋巴细胞增殖反应比率表明，HHV-6感染在幼儿急疹病程中对宿主T细胞免疫有一定影响。
