人疱疹病毒6型感染与淋巴瘤关系的初步研究

目的:研究人疱疹病毒6型(HHV-6)感染与淋巴瘤的关系。方法:用间接免疫荧光法及PCR,分别检测淋巴瘤患者和对照组患者血清中抗HHV-6 IgG及外周血单个核细胞(PBMC)中HHV-6 DNA序列。用免疫组化染色法,检测淋巴瘤患者淋巴结组织标本中HHV-6抗原。结果:淋巴瘤患者血清抗HHV-6抗体的阳性率为95.5％,几何平均滴度为1:123,PBMC中HHV-6 DNA的检出率为59.1％,均明显高于对照组(P<0.05)。免疫组化染色检测的5例淋巴瘤患者淋巴结组织标本中,4例HHV-6抗原阳性。结论:HHV-6感染可能与淋巴瘤的发病有关。     

口腔鳞癌患者淋巴细胞对人疱疹病毒6型增殖应答受损

目的研究口腔鳞癌患者淋巴细胞对人疱疹病毒6型（HHV-6）特异性增殖应答,初步探讨HHV-6在口腔鳞癌发病机制中的作用。方法间接免疫荧光法（IIF）检测血浆中抗HHV-6IgG;免疫微磁珠分离CD4^＋T及CD8^＋T细胞;3H-TdR法检测CD4^＋T和CD8^＋T细胞及PBMCs的增殖水平;FACS分析CD4^＋C25^＋调节性T细胞（Treg）的比例。结果口腔鳞癌组血浆中抗HHV-6IgG阳性数为8/8,正常对照组为12例（12/20）;口腔鳞癌组PBMCs及CD4^＋T细胞对HHV-6的增殖水平显著低于HHV-6潜伏感染组与未感染组（P〈0.05）;HHV-6潜伏感染组PBMCs及CD4^＋T细胞对HHV-6的增殖水平显著低于未感染组（P〈0.05）;口腔鳞癌组外周血中CD4^＋C25^＋Treg比例明显高于HHV-6潜伏感染组与未感染组（P〈0.05）。结论口腔鳞癌患者的HHV-6特异性CD4＋T细胞增殖应答减弱,可能在口腔鳞癌的发生发展中起一定作用。     

HHV-6和VEGF-C在口腔鳞癌组织中的表达及其相关性

目的探讨人类疱疹病毒6型(HHV-6)和血管内皮生长因子-C(VEGF-C)mRNA及其蛋白表达水平与口腔鳞癌的关系,初步探讨HHV-6感染与VEGF-C表达水平的关系。方法用实时定量PCR技术和免疫组织化学方法检测口腔鳞癌组织中HHV-6和VEGF-C mRNA及其蛋白的表达水平。结果口腔鳞癌组织中HHV-6和VEGF-C mRNA及其蛋白表达水平显著高于正常口腔组织(P0.05);在相同口腔鳞癌组织中HHV-6与VEGF-C mRNA的表达水平显著正相关(P0.001);口腔鳞癌组织中HHV-6和VEGF-C的表达水平与淋巴结转移具有显著相关性(P0.05)。结论口腔鳞癌的发生与HHV-6的感染有关,其感染可能引起VEGF-C的高表达。     

人疱疹病毒6型感染与白血病关系的初步研究

白血病是来源于造血系统的一种恶性肿瘤，好发于儿童和青少年，其病因和发病机制尚不完全清楚，但病毒病因学较受重视。人疱疹病毒6型(HHV-6)是1986年发现的疱疹病毒科中的一个新成员。研究发现，HHV-6的感染与淋巴瘤的发生有一定关系，在白血病患者中具有较高的感染率。为了探讨HHV-6感染与白血病的关系，我们采用间接免疫荧光试验(IFA)和PCR，分别检测了白血病患者血清抗HHV-6 IgG和外周血单个核细胞(PBMC)中HHV-6 DNA的序列。     

口腔鳞癌组织中p15和p21的表达分析

目的 探讨p15和p21基因的蛋白产物在口腔鳞癌中的表达及意义。 方法 采用免疫组化P-V法检测108例口腔鳞癌和10例正常口腔黏膜组织中p15和p21蛋白的表达，并将结果与临床病理指标进行统计分析。 结果 口腔鳞癌组织中p15蛋白的阳性表达率低于正常口腔黏膜组织(P<0.05)，而p21蛋白的阳性表达率两组间无明显差异(P>0.05)；口腔鳞癌中，III、IV期口腔鳞癌p15蛋白的阳性表达率明显低于I、II期口腔鳞癌的表达率（P<0.01），无颈淋巴结转移组p15蛋白表达水平比有转移组高（P<0.05）；p21阳性表达率在不同性别组中的表达差异具有统计学意义(P<0.05)。 结论 p15蛋白的表达与口腔鳞癌的临床分期及淋巴结转移有关，p15蛋白表达水平可作为临床评估口腔鳞癌恶性程度、转移和预后的参考指标。     

人疱疹病毒6型感染与神经胶质瘤关系的初步研究

目的探讨人疱疹病毒6型（human herpesvirus-6,HHV-6）感染与神经胶质瘤的关系。方法将辽宁省肿瘤医院神经外科2011年6月-2013年5月收治的神经胶质瘤患者45例纳入病例组,将同期该医院收治且已排除神经胶质瘤的脑外伤患者45例作为对照组。分别采用巢式聚合酶链式反应（nested polymerase chain reaction,Nested—PCR）法检测两组研究对象人病变脑组织样本中HHV-6序列;采用免疫组化染色法检测两组研究对象人病变脑组织样本中HHV-6抗原的表达。结果病例组HHV石DNA阳性率为31．11％,对照组HHV-6DNA阳性率为6．67％（χ2=8．755,P=0．003）。病例组HHV-6早期抗原041表达阳性率为22．22％,对照组HHV-6早期抗原p41表达阳性率为0．00％（χ2=11．250,P=0．001）。病例组HHV-6DNA阳性率、HHV-6抗原阳性率均高于对照组,组间差异有统计学意义（P〈0．05）。结论神经胶质瘤患者和非神经胶质瘤脑外伤患者病变脑组织中HHV石感染率有差异,据此推断HHV-6感染在神经胶质瘤的发生和发展过程中起到一定的作用。     

血清中丙型肝炎NS3抗原ELISA检测方法的建立和初步应用

目的 评价血清中丙型肝炎病毒(HCV)游离NS3抗原的酶联免疫吸附(ELISA)检测方法的特异性和灵敏度,初步探讨该方法在临床应用中的意义.方法 对77例正常人血清标本,173例抗-HCV阳性标本和3708例抗-HCV阴性的其他类型肝炎血清标本检测HCV游离NS3抗原;对部分HCV NS3抗原阳性标本进行验证,包括HCV RNA测定、中和试验和免疫斑点试验;对11例患者的25份系列血清标本进行了HCV游离NS3抗原、HCV RNA和HCV抗体的联合检测,并结合临床资料综合分析.结果 3708例抗-HCV阴性的其他类型肝炎血清标本中有48例为HCV NS3抗原阳性,其中3030例单纯乙型肝炎和445例其他类型肝炎血清标本中分别有44例和4例为HCV NS3抗原阳性;173例HCV抗体阳性标本中有42例为HCV NS3抗原阳性;77例正常人血清标本的HCV NS3抗原检测结果均为阴性;15例HCV NS3抗原阳性标本中有9例为HCV RNA阳性;23例HCV NS3抗原阳性标本的中和率和免疫斑点试验的阳性率分别为87.0%和69.6%;25份系列血清标本的检测结果显示其HCV NS3抗原的吸光度值与时间呈负相关,并有2例HCV NS3抗原阳性标本随着血清中HCV NS3抗原的吸光度值下降,其HCV抗体转阳.结论 血清中HCV游离NS3抗原的ELISA检测方法有较好的特异性和敏感度,在发展中国家应用此方法进行HCV感染的早期诊断有一定的临床意义和推广价值.     

人类疱疹病毒6型荧光定量PCR检测方法的建立和应用

目的 建立人类疱疹病毒6型(HHV-6)荧光定量PCR检测方法,并检测临床样本.方法 根据文献合成HHV-6 U65-66基因片段的特异性引物和TaqMan探针,构建质粒制备标准品,评估该方法的特异性、灵敏度和重复性;并用该方法检测93份临床诊断为病毒性脑炎的脑脊液标本.结果 本实验检测HHV-6的灵敏度为3×10(0)拷贝/μl;标准曲线间线性关系(R2)为0.999,扩增效率为97.9％;同一样本重复检测3次,组内Ct值的变异系数最大为0.61％,组间为3.13％;特异性检测中只有HHV-6阳性标本出现扩增曲线.93份临床标本中检出HHV-6阳性2例,检出率为2.15％.结论 本实验所建立的荧光定量PCR检测HHV-6的方法特异强、灵敏高、重复性好,具有应用于临床检测的潜在价值.     

肝硬化时糖代谢紊乱与肝细胞胰岛素受体及胰腺细胞HBV DNA表达的关系

目的探讨肝硬化患者糖代谢紊乱与肝细胞胰岛素受体(IR)和酪氨酸蛋白激酶(TPK)表达,以及胰腺细胞HBV DNA阳性表达的关系。方法 应用地高辛素标记HBV DNA s 577 bp探针原位杂交技术,检测12例血清HBV标志物阳性的肝炎肝硬化患者肝、胰组织内的HBV DNA;应用图象分析系统对该12例肝细胞IR和TPK,进行抗胰岛素受体和酪氨酸蛋白激酶抗体免疫组化标记物定量测定。用免疫荧光组织化学双重染色技术,激光共聚焦扫描显微镜观察HBsAg和lR。肝、胰组织活检前,常规进行静脉葡萄糖耐量试验。结果 肝细胞HBV DNA阳性11例(11/12),糖耐量试验异常(IGT)7例中肝细胞HBV DNA均阳性(7/7),糖耐量试验正常(NGT)5例中HBV DNA阳性4例(4/5)。胰腺细胞阳性8例(8/12),IGT7例中胰腺细胞HBV DNA均阳性(7/7),NGT5例中仅1例HBV DNA阳性(1/5),IGT组与NGT组胰腺细胞检出HBV DNA差异有显著意义(P<0.05)。IGT的肝硬化患者肝细胞内IR和TPK表达较NGT的肝硬化患者差异有非常显著意义(tIR=3.617 P<0.O1,tTPK=20.143P<0.01)。肝细胞内IR与TPK表达量高度相关,r=0.82597(P<0.01)。免疫荧光组织化学双重染色显示肝细胞和胰岛细胞IR阳性处有HBsAg存在。结论HBV不仅能侵害肝细胞,也能直接侵害胰岛细胞。后者可能是HBV感染后并发类胰岛素依赖性糖尿病的直接     

抗ABCA1自身抗体在SLE患者动脉粥样硬化发病机制中的意义

检测系统性红斑狼疮(SLE)患者血清中抗三磷酸腺苷结合盒转运子(ABCA1)抗体及探讨其致SLE早发动脉粥样硬化(AS)的机制。采用免疫印迹法检测75份SLE患者血清中抗ABCA1自身抗体。75份性别年龄匹配正常人血清为对照。观察抗ABCA1抗体阳性患者血清IgG对细胞胆固醇流出的影响。结果显示,SLE患者血清中存在抗ABCA1抗体,阳性率为29.3%,正常人中无一阳性(P<0.05)。SLE有斑块组的抗ABCA1抗体阳性率高于SLE无斑块组(43.8%和16.3%,P<0.05)。纯化的抗ABCA1抗体阳性SLE患者IgG体外可抑制THP-1细胞内胆固醇的流出,抑制率最高可达28.7%,正常人IgG抑制率相比有显著性差异。实验表明,SLE患者血清中抗ABCA1抗体阳性率明显高于正常人,且纯化的抗AB-CA1抗体阳性患者IgG在体外能抑制细胞内胆固醇的流出,从而促进SLE患者早发动脉粥样硬化的发生。     

Serological examination of human herpesvirus 6 and 7 in patients with coronary artery disease

Fifty-three (96%) of 55 patients with coronary artery stenosis were positive for serum anti-HHV-6 IgG, and 50 (91%) of these patients had anti-HHV-7 IgG. The number of cases sero-positive for HHV-6 and -7 in the 54 age matched control volunteers was 52 (96%) and 53 (98%), respectively. No statistical difference in the sero-prevalence of the viruses existed between the patients and the control group. The mean geometric titer (log10) of anti-HHV-6 IgG in both the patients and controls were the same (1.4) (P = 0.845), whereas anti-HHV-7 titers were 1.4 and 1.5, respectively (P = 0.161). Ten (18%) of the 55 patients had anti-HHV-6 IgM; eight (15%) of the 54 control volunteers were also positive (P = 0.636). Three (5%) of the 55 patients had anti-HHV-7 IgM, whereas 3 (6%) of the 54 control volunteers had detectable serum antibody (P = 0.691). Forty-seven of the 55 patients were examined by follow-up angiographic evaluation to clarify the association between viral infection and restenosis following balloon angioplasty. Fifteen of these patients developed restenosis, as determined by angiography. The mean geometric titer (log10) of anti-HHV-6 IgG were 1.3 and 1.4 in patients with restenosis and those without restenosis, respectively (P = 0.724). The mean geometric titer (log10) of anti-HHV-7 IgG in patients with restenosis was not significantly higher (1.5) than in patients without restenosis (1.3) (P = 0.099). Three (20%) of the 15 patients affected by restenosis had anti-HHV-6 IgM; five (16%) of the 32 control patients also had the antibody (P = 0.965). One (7%) of the 15 patients with restenosis and 2 (6%) of the 32 patients without restenosis had anti-HHV-7 IgM (P = 0.558). The present study demonstrates that HHV-6 and -7 reactivation is not associated with the establishment of coronary artery stenosis and restenosis following balloon angioplasty.     

Reactivation of human herpesvirus 6 (HHV-6) infection in patients with connective tissue diseases

BackgroundLittle is known about the involvement of human herpesviruses 6 and 7 (HHV-6 and HHV-7) in autoimmune connective tissue diseases (ACTD).ObjectiveTo determine the prevalence of active infection with HHV-6 and HHV-7 in patients with ACTD.Study designThe presence and quantity of HHV-6 DNA was determined by quantitative real-time PCR in a cross-sectional study of serum, peripheral blood mononuclear cells, and tissues obtained from 58 ACTD patients and 38 healthy subjects (HS). Specific anti-HHV-6 antibody titer was also measured.ResultsHHV-6 serum viremia occurred in a significantly higher proportion of ACTD patients compared to HS [26/58 (44.8%) vs. 1/38 (2.6%), p = 0.001] with the highest reactivation frequency [7/10 (70%)] observed in patients with scleroderma. Moreover, HHV-6 in serum was associated with ACTD activity (22/38 vs. 4/20, p < 0.05). Higher titers of HHV-6 antibodies were found in ACTD patients than in HS, although HHV-6 seroprevalence among patients with ACTD and HS was similar. HHV-7 viremia was not detected in any patients or HS controls.ConclusionThe frequent reactivation of HHV-6 in scleroderma and other ACTD, especially when active, suggests that HHV-6 may play a role in the pathogenesis of these diseases.     

HnRNP A2/B1和P53蛋白对肺癌诊断价值的探讨

目的：采用流式细胞术检测肺癌患者支气管肺泡灌洗液（BALF）脱落细胞中HnRNP A2/B1和外周血单个核细胞中P53蛋白水平,探讨联检HnRNP A2/B1和P53蛋白在肺癌诊断中应用价值。方法：收集30例肺癌患者的支气管肺泡灌洗液（BALF）的脱落细胞和其外周血,用流式细胞术检测脱落细胞表达HnRNP A2/B1和外周血中的P53蛋白水平;同时检测30例肺部良性疾病患者为对照组。结果：肺癌患者的BALF脱落细胞表达HnRNP A2/B1的含量明显高于对照组（P〈0.01）;非小细胞肺癌患者中HnRNP A2/B1明显高于小细胞肺癌（P〈0.05）。NSCK临床TNM分期Ⅰ-Ⅱ期的患者与Ⅲ-Ⅳ期相比,HnRNP A2/B1无显著性差异（P〉0.05）。肺癌患者外周血中P53蛋白明显异于对照组（P〈0.01）;小细胞肺癌患者的P53蛋白明显高于非小细胞肺癌（P〈0.01）。结论：FCM检测肺癌患者BALF脱落细胞中HnRNP A2/B1和外周血P53,有助于肺癌的早期诊断。     

检测抗人疱疹病毒6型IgG的间接免疫荧光试验的建立及其应用

目的 :建立检测血清中人疱疹病毒 6型 (HHV 6 )IgG的间接免疫荧光试验 (IFA)。方法 :用HHV 6国内分离株感染人脐带血单个核细胞制备抗原片 ,建立检测HHV 6IgG的IFA方法 ,并用于育龄期妇女血清流行病学调查。结果 :建立的IFA具有特异性。对 116份育龄期妇女血清标本检测表明 ,HHV 6IgG的阳性率为 72 .4 % ,几何平均滴度 (GMT)为 1∶6 1;在孕妇和正常未孕妇女之间 ,以及不同孕期的孕妇之间 ,HHV 6IgG的阳性率和GMT均无差异 (P >0 .0 5 )。结论 :建立了具有特异性的IFA法 ,可用于对育龄妇女HHV 6感染率的流行病学调查     

类风湿病与人类6型疱疹病毒感染的研究

用抗补体免疫荧光法（ＡＣＩＦ）和聚合酶链反应技术（ＰＣＲ），检测了４０例类风湿病人和８０例对照外周血中人类６型疱疹病毒的抗体及ＤＮＡ。若以抗体滴度≥１：２０为阳性，对照组抗体阳性率为７２．５０％，类风湿病人抗体阳性率为９７．５０％。两组抗体阳性率有显著性差异。类风湿病人感染ＨＨＶ－６的危险度对对照人群高１４倍以上。且病例组抗体几何平均滴度显著高于对照组。当采用ＰＣＲ技术检测外周血单核细胞内ＨＨＶ－     

Avidity of IgG antibodies to human herpesvirus-6 distinguishes primary from recurrent infection in organ transplant recipients and excludes cross-reactivity with other herpesviruses

Saliva and peripheral blood mononuclear cells from three patients, two with lymphoproliferative disorders and one suffering from multiple sclerosis, were examined for the presence of human herpesvirus-6 (HHV-6) genome by using the polymerase chain reaction and Southern blot analysis. The search for anti-HHV-6 antibodies, carried out in the sera of the same cases by an immunofluorescence assay, was negative in two cases at the lowest dilution used (1:40). These three patients had a high number of HHV-6 specific sequences in uncultured peripheral blood mononuclear cells, which are thought to be a normal site of viral latency although, in healthy individuals, the infected cells are extremely rare. In order to gain some insight into the state of the viral genome in this latent HHV-6 infection, we used pulsed field gel electrophoresis to separate HHV-6 DNA directly from HHV-6 (strain GS) infected HSB-2 cells and from the peripheral blood mononuclear cells of these three patients. Our study showed the presence of intact viral genome, of the expected length of 170 kb, persisting as free extrachromosomal element in the HSB-2 cells but not in patients' peripheral blood mononuclear cells. On the other hand, in strong contrast with the results obtained in infected HSB-2 DNA, the restriction analysis of the three patients' peripheral blood mononuclear cell DNA showed fragments of molecular weight constantly higher than the 170 kb segment, indicating that the viral sequences are linked to high molecular weight cellular DNA. Our findings are consistent only with a latent infection in which HHV-6 is integrated in vivo and suggest that pulsed field gel electrophoresis analysis is well worth using to evaluate the presence of integrated, intact, or fragmented viral genomes in HHV-6 associated lymphoproliferative diseases and immune disorders. © 1993 Wiley-Liss, Inc.     

Similar humoral and cellular immunological reactivities to human herpesvirus 6 in patients with multiple sclerosis and controls.

Several studies have suggested an association between human herpesvirus 6 (HHV-6) and multiple sclerosis (MS). We have previously studied intrathecal production of antibody to lymphotropic herpesviruses in MS patients and the presence of human herpesvirus 1 to 7 DNAs in cerebrospinal fluid (CSF). In the present study anti-HHV-6 immunoglobulin M (IgM) in serum and anti-HHV-6 IgG subclasses in serum and CSF were examined and the lymphoproliferative response to HHV-6 was analyzed. The PCR examination was refined by purifying DNA from CSF and retesting the samples for HHV-6 DNA. There were no statistically significant differences between the groups concerning IgM positivity, distribution of IgG subclasses, or lymphoproliferative response to HHV-6. The purification of DNA increased the number of PCR-positive samples from 0 of 71 to 4 of 68. The study does not give additional support to the possibility that HHV-6 is a common cause of MS, but a role for the virus in a subset of patients cannot be excluded.     

Risk factors for developing human herpesvirus 6 (HHV-6) reactivation after allogeneic hematopoietic stem cell transplantation and its association with central nervous system disorders.

We prospectively evaluated the incidence of human herpesvirus 6 (HHV-6) DNAemia after allogeneic hematopoietic stem cell transplantation (HSCT) using quantitative plasma real-time polymerase chain reaction. Of 46 recipients of bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT) from related (n = 11) or unrelated donors (n = 22), and cord blood transplantation (CBT) from unrelated donors (n = 13), 22 (47.8%) developed HHV-6 DNAemia. HHV-6 DNA levels ranged from 200 to 200,000 copies/mL of plasma, and HHV-6 DNAemia was observed significantly more frequently after CBT than after BMT/PBSCT (92.3% vs 30.3%; P < .001). Multivariate analyses identified CBT (vs BMT/PBSCT), HLA mismatches between recipient and donor, and low anti-HHV-6 IgG titer before transplantation as the only risk factors for developing HHV-6 DNAemia. Three patients developed central nervous system (CNS) disorders with detectable HHV-6 DNA in the cerebrospinal fluid; all of these patients simultaneously developed HHV-6 DNAemia. These results suggest that HHV-6 DNAemia is frequently observed after allogeneic HSCT, especially in patients with the aforementioned risk factors. Thus, together with the assessment of risk factors, monitoring of HHV-6 DNAemia could be a useful asset in diagnosing HHV-6-associated CNS disorders.     

Antibodies against human herpesvirus 8 in black South African patients with cancer.

BACKGROUND: Infection with human herpesvirus 8 (HHV-8) has been consistently linked to Kaposi's sarcoma, but its mode of transmission, association with other cancers, and interaction with the human immunodeficiency virus type 1 (HIV-1) are largely unknown. METHODS: Between January 1992 and December 1997, we interviewed 3591 black patients with cancer in Johannesburg and Soweto, South Africa. Blood was tested for antibodies against HIV-1 and HHV-8 in 3344 of the patients. Antibodies against HHV-8 were detected with an indirect immunofluorescence assay. The intensity of the fluorescent signal correlated well with the titers of antibodies (P<0.001). The relations among the presence of anti-HHV-8 antibodies, sociodemographic and behavioral factors, type of cancer, and the presence or absence of coexistent HIV infection were examined with the use of unconditional logistic-regression models. RESULTS: Among the 3293 subjects with cancers other than Kaposi's sarcoma, the standardized seroprevalence of antibodies against HHV-8 was 32 percent, which did not differ significantly from the standardized seroprevalence among black blood donors. Among these 3293 patients, the prevalence of antibodies against HHV-8 increased with increasing age (P<0.001) and an increasing number of sexual partners (P=0.05) and decreased with increasing years of education (P=0.007); it was not strongly associated with HIV-1 infection. Anti-HHV-8 antibodies were more frequent among black than white blood donors (P<0.001). Among the 51 patients with Kaposi's sarcoma, the standardized seroprevalence of antibodies against HHV-8 was 83 percent, significantly higher than the prevalence among those without Kaposi's sarcoma (P<0.001). For 16 other specific types of cancer, including multiple myeloma (108 cases) and prostate cancer (202 cases), the variation in the standardized seroprevalence of antibodies against HHV-8 was not remarkable. At a given intensity of fluorescence of anti-HHV-8 antibodies, Kaposi's sarcoma was more frequent among HIV-1-positive patients than among those who were HIV-1-negative (P<0.001). CONCLUSIONS: Among black patients with cancer in South Africa, the seroprevalence of anti-HHV-8 antibodies is high and is specifically associated with Kaposi's sarcoma, particularly at high titers.     

Frequent detection of the human herpesvirus 6-specific genomes in the livers of children with various liver diseases

This study was performed to investigate the frequency of human herpesvirus 6 (HHV-6) infection of the liver in children with a variety of liver diseases and to evaluate the role of HHV-6 infection in pediatric patients with prolonged non-B non-C hepatitis. Detection of the HHV-6 genomes in liver, in peripheral blood mononuclear cells (PBMC), and in plasma was performed by PCR or by in situ hybridization. Liver biopsy materials from 48 patients, in whom HHV-6 infection was serologically confirmed, were available for PCR analysis. Sequences of the HHV-6B genome were detectable in the livers of 36 of 48 patients (75%). The presence of the genome was not associated with serum transaminase activities. The genome was detectable in PBMC of 22 of 31 (71%) patients tested. In these 31 patients HHV-6 was detected in both the livers and PBMC of 20, was detected in PBMC but not in the livers of 2, was detected in the livers but not in PBMC of 3, and was detected in neither of samples of 6. In situ hybridization of the livers of six patients showed the presence of the HHV-6B genome in the nuclei of hepatocytes. The anti-HHV-6 immunoglobulin M antibody was detectable in 2 of 9 of the non-B non-C hepatitis patients, whereas none of the 22 patients with etiology-defined liver diseases tested positive. Cell-free viral DNA was not detectable in either group of patients. Our results showed that HHV-6B is frequently present in the livers of children with a variety of liver diseases but do not support the assumption that HHV-6B infection of the liver is associated with prolonged non-B non-C hepatitis.