心脏移植并发疱疹病毒6型感染

Heart transplantation complicated with human herpesvirus 6 infection

从１３例心脏移植病人的外周血淋巴细胞中分离出２株疱疹病毒６型（ＨＨＶ６），并检测了手术前后病人血清特异性抗－ＨＨＶ６ＩｇＧ抗体。这２株ＨＨＶ６可引起典型的细胞病变。分离的毒株在电镜下可见疱疹类病毒样颗粒。经特异性抗体和ＤＮＡ杂交试验证明，这两株病毒均属于ＨＨＶ６Ｂ组。病人血清中特异性抗－ＨＨＶ６ＩｇＧ抗体出现４倍或４倍以上增长的有５例（３９％），其中包括２例病毒分离阳性的病人血清。由于病人在术前血清已是阳性和术后出现有意义效价的增长，因此试验结果提示心脏移植前后免疫抑制剂的应用可能是造成ＨＨＶ６复发感染的重要原因。

HHV 6 was isolated from peripheral blood mononuclear cells (PBMC) of heart transplanted recipients cocultured with normal cord blood lymphocytes (CBL). Two of the 13 patients were positive for HHV 6 and none were positive in the normal control group. The virus-infected cells showed a characteristically enlarged, balloon-shaped syncytial cell pathogenic effect (CPE). The positive isolates were confirmed by indirect immunofluorescence assay, electron microscopy and southern hybridization with a 6 9 kb HHV 6 (Z29) BamHI DNA probe. In addition, the positive isolates did not react with monoclonal antibodies against HSV, CMV, VZV and EBV. The two positive isolates were identified as HHV 6 B group. In this study, a series of sera were also screened for specific anti HHV 6 IgG antibody. Five of the 13 patients showed a fourfold or greater rise in HHV 6 antibody after transplantation including the two from whom viruses have been isolated. The results suggest that the HHV 6 infection was most likely due to reactivation by immunosuppressive therapy since patientss sera were already positive before transplantation. Our results confirm the report that HHV 6 might remain as a latent infection following the primary infection and also demonstrates that HHV 6 as a new member of herpesvirus family might coinfect with other viruses in post heart transplanted recipients.