Elevated Epstein–Barr virus loads and lower antibody titers in competitive athletes

Epstein–Barr virus (EBV) is a persisting herpesvirus which is controlled by the adaptive immune response after primary infection and maintained in a latent state. However, reactivation or persistent replication is observed in situations where the immune response is compromised. Since intensive physical training has been reported to diminish immune function, increased EBV load may be a cause of reduced performance and decreased ability to sustain high training loads in competitive athletes. Samples drawn from 209 athletes during their regular follow‐up appointments were tested. One hundred sixty‐five individuals of similar age not active in competitive sports served as case–controls. EBV load was quantified in peripheral blood leucocytes (PBLs) by real‐time PCR, and EBV antibodies were detected in plasma by ELISA and immunoblot analysis. EBV DNA was detectable in 25 of 209 athletes and in 26 of 165 controls. Of note, the EBV load per 10⁵ PBLs was 6.44 ± 1.75 in the case and 1.67 ± 0.44 copies in the controls, yielding a high significant difference (P < 0.0001). However, EBV‐specific IgG titers were significantly lower in athletes (150.4 ± 10.73 U ml^?1 vs. 241.6 ± 18.59 U ml^?1). As monitored by immunoblotting, primary infections were detected with low prevalence, three in the case group and one in the control group. These findings demonstrate that EBV is present at higher levels in athletes, but the antibody response is lower in athletes than in the controls. J. Med. Virol. 82:446–451, 2010. © 2010 Wiley‐Liss, Inc.     

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.     

Human herpesvirus 6‐A, 6‐B,and 7 in vitreous fluid samples

Human herpesvirus 6 and 7 (HHV‐6, HHV‐7) have been associated with several neurologic syndromes and have been detected in nervous tissue from healthy persons; however, only two cases of HHV‐6A have been reported to be associated with intraocular inflammatory disease. Vitreous fluid was tested from 101 patients, including 69 samples from patients with ocular inflammation including CMV retinitis, idiopathic retinitis, iritis, and vitritis, for HHV‐6A, HHV‐6B, and HHV‐7 DNA by PCR. HHV‐6A DNA (4,950 copies per ml) was detected in vitreous fluid from one patient with CMV retinitis, HHV‐6B DNA (10,140 copies per ml) was detected in vitreous fluid from one patient with idiopathic ocular inflammation in the absence of CMV DNA, and HHV‐7 was not detected in any of the vitreous samples. HHV‐6A, HHV‐6B, and HHV‐7 DNA are detectable in less than 2% of vitreous samples in patients with ocular inflammation. J. Med. Virol. 82:996–999, 2010. © 2010 Wiley‐Liss, Inc.     

High incidence of cytomegalovirus, human herpesvirus-6, and Epstein-Barr virus reactivation in patients receiving cytotoxic chemotherapy for adult T cell leukemia

The etiology of cytomegalovirus (CMV), human herpesvirus-6 (HHV-6), and Epstein-Barr virus (EBV) reactivation and the potential for complications following cytotoxic chemotherapy in the absence of allogeneic transplantation are not clearly understood. Patients with adult T cell leukemia (ATL) are susceptible to opportunistic infections. In this study, the incidence, kinetics and clinical significance of reactivation of CMV, HHV-6, and EBV in ATL patients were investigated. Viral DNA in a total of 468 plasma samples from 34 patients was quantified using real-time PCR. The probability of CMV, HHV-6, and EBV reactivation by 100 days after the start of chemotherapy was 50.6%, 52.3%, and 21.6%, respectively. Although most CMV reactivations were self-limited, plasma CMV DNA tended to persist or increase if the CMV DNA levels in plasma reached ≥ 10(4) copies/ml. CMV reactivation was negatively associated with survival, but the P-value for this association was near the borderline of statistical significance (P=0.052). One patient developed fatal interstitial pneumonia concomitant with peak CMV DNA accumulation (1.6 × 10(6) copies/ml plasma). Most HHV-6 and EBV reactivations were self-limited, and no disease resulting from HHV-6 or EBV was confirmed. HHV-6 and EBV reactivation were not associated with reduced survival (P=0.35 and 0.11, respectively). These findings demonstrated that subclinical reactivation of CMV, HHV-6, and EBV were common in ATL patients receiving chemotherapy. There were differences in the viral reactivation patterns among the three viruses. A CMV load ≥ 10(4) copies/ml plasma was indicative of subsequent exacerbation of CMV reactivation and developing serious clinical course.     

Fatal adult case of severe lymphocytopenia associated with reactivation of human herpesvirus 6.

It has been suggested that immunosuppression associated with human herpesvirus 6 (HHV-6) infection is a result of functional impairment or direct destruction of immunological cells. The ability of the virus to infect and destroy lymphocytes may cause progressive immunodeficiency in an infant with primary HHV-6 infection. An adult patient is described who had a fatal cytomegalovirus (CMV) infection due to severe and prolonged lymphocyte depletion associated with HHV-6 reactivation. The HHV-6 antibody titers were increased significantly after reactivation, and the virus was isolated from his peripheral blood mononuclear cells. The quantity of both HHV-6 and CMV DNA was determined by using real-time PCR in plasma samples collected serially. HHV-6 DNAemia persisted for 1 month, which started just 1 week after the onset of lymphocytopenia. In contrast to HHV-6, CMV DNAemia was detected in the terminal phase of the illness. Thus, HHV-6 reactivation may have been the cause of the severe lymphocyte depletion and fatal CMV infection.     

IgG subclasses and DNA detection of HHV‐6 and HHV‐7 in healthy individuals

Human herpesvirus 6 (HHV‐6) and 7 (HHV‐7) are common opportunistic agents in immunocompromised hosts, although infection with HHV‐6 and HHV‐7 can also be observed in immunocompetent hosts. Despite similar biology and epidemiology, this study evaluated differences in the IgG subclass distribution associated with HHV‐6 and HHV‐7 in seropositive, healthy persons. The identified subclasses were also compared with the detection of HHV‐6 and HHV‐7 DNA. For these assays, sera, plasma, and saliva samples were obtained from 40 healthy blood donors in Argentina who were seropositive for both HHV‐6 and HHV‐7. HHV‐6 and HHV‐7 DNA were detected in saliva and plasma samples using nested PCR, and specific IgG subclasses were determined using immunofluorescent assays of sera samples. HHV‐7 DNA was detected in 90% of all plasma samples and in 100% of saliva samples. In contrast, HHV‐6 DNA was not detected in any of the plasma samples, and it was detected in only 6 of 40 saliva samples. Determination of IgG subclass distributions showed that HHV‐6 was restricted to IgG1, whereas HHV‐7 IgG subclasses included two groups, one restricted only to IgG1 and the other to IgG1 and IgG3. These results demonstrate the differences between HHV‐6 and HHV‐7 DNA range detection in saliva and plasma samples, as well as the IgG subclass patterns for each virus type, in healthy persons in Argentina. J. Med. Virol. 82:1679–1683, 2010. 2010 Wiley‐Liss, Inc.     

Prevalence of Epstein–Barr virus associated with nasal lymphoma in patients attending the regional hospital of Valdivia,Chile, between 1987 and 2005

Epstein–Barr virus (EBV) is a ubiquitous herpes virus with a widespread infection in the world's adult population. EBV has been associated with human malignancies, mainly the nasal type NK/T cell lymphoma. The disease is more frequent in Asian than in Western countries. However, there are few studies from Latin American countries. The aim of this study was to determine the prevalence of EBV in patients with nasal lymphomas diagnosed in the Regional Hospital of Valdivia, southern Chile, during 1987–2005. Immunohistochemistry was done on paraffin sections using anti‐CD3ε, anti‐CD20, and anti‐CD56. The presence of small ribonucleic acids (RNAs) of EBV was detected in paraffin sections by in situ hybridization using oligonucleotides targeting EBV‐encoded small RNAs. The present study revealed a prevalence of 27.7% of Hodgkin's lymphomas and 72.3% of non‐Hodgkin's lymphomas. From the latter group, there was a prevalence of 2.9% (10 cases) of nasal lymphoma. From these 10 cases, 6 (60%) were NK/T cell lymphomas, nasal type; 1 case (10%) was a T‐cell phenotype; and 3 cases (30%) were B‐cell phenotype. The prevalence was higher than reports from Western countries, but lower than the reports from Asian countries. These results agreed with previous reports suggesting that EBV is strongly associated with T lymphomas. This study contributes new epidemiological data on EBV in Chile. J. Med. Virol. 82: 825–828, 2010. © 2010 Wiley‐Liss, Inc.     

Prevalence of human papilloma virus and human herpes virus types 1–7 in human nasal polyposis

This study aimed to investigate the prevalence of human papilloma virus (HPV), herpes simplex virus‐1/‐2 (HSV‐1/‐2), varicella‐zoster virus (VZV), Epstein–Barr virus (EBV), cytomegalovirus (CMV), and human herpes virus‐6/‐7 (HHV‐6/‐7) in 23 human nasal polyps by applying PCR. Two types of control tissues were used: adjacent inferior/middle turbinates from the patients and inferior/middle turbinates from 13 patients undergoing nasal corrective surgery. EBV was the virus most frequently detected (35%), followed by HPV (13%), HSV‐1 (9%), and CMV (4%). The CMV‐positive polyp was simultaneously positive for HSV‐1. HPV was also detected in the adjacent turbinates (4%) and the adjacent middle turbinate (4%) of one of the HPV‐positive patients. EBV, HSV, and CMV were not detected in the adjacent turbinates of the EBV‐, HSV‐ or CMV‐positive patients. All mucosae were negative for the VZV, HHV‐6, and HHV‐7. This is the first study to deal with the involvement of a comparable group of viruses in human nasal polyposis. The findings support the theory that the presence of viral EBV markedly influences the pathogenesis of these benign nasal tumors. The low incidence of HPV detected confirms the hypothesis that HPV is correlated with infectious mucosal lesions to a lesser extent than it is with proliferative lesions, such as inverted papilloma. The low incidence of HSV‐1 and CMV confirms that these two herpes viruses may play a minor role in the development of nasal polyposis. Double infection with HSV‐1 and CMV may also play a minor, though causative, role in nasal polyp development. VZV and HHV‐6/‐7 do not appear to be involved in the pathogenesis of these mucosal lesions. J. Med. Virol. 81:1613–1619, 2009. © 2009 Wiley‐Liss, Inc.     

Human herpesvirus 6 variant a infects human term syncytiotrophoblasts in vitro and induces replication of human immunodeficiency virus type 1 in dually infected cells

Human herpesvirus 6 (HHV-6) and human immunodeficiency virus type 1 (HIV-1) may interact during transplacental transmission of HIV-1. The placental syncytiotrophoblast layer serves as the first line of defense of the fetus against viruses. Patterns of replication of HHV-6 variant A (HHV-6A) and HIV-1 were analyzed in singly and dually infected human term syncytiotrophoblast cells cultured in vitro. For this purpose, the GS strain of HHV-6A and the Ba-L and IIIB strains of HIV-1 were used. HHV-6A replication was restricted at the level of early gene products in singly infected syncytiotrophoblasts, whereas no viral protein expression was found in cells infected with HIV-1 alone. Coinfection of syncytiotrophoblast cells with HHV-6A and HIV-1 resulted in production of infectious HIV-1. In contrast, no enhancement of HHV-6A expression was observed in cell cultures infected with both viruses. Uninfected syncytiotrophoblast cells were found to express CXCR4 and CCR3 but not CD4 or CCR5 receptors. Infection of syncytiotrophoblasts with HHV-6A did not induce CD4 expression and had no influence on chemokine receptor expression. Activation of HIV-1 from latency in coinfected cells was mediated by the immediate-early (IE)-A and IE-B gene products of HHV-6A. Open reading frames U86 and U89 of the IE-A region were able to activate HIV-1 replication in a synergistic manner. The data suggest that in vivo double infection of syncytiotrophoblast cells with HHV-6A and HIV-1 could contribute to the transplacental transmission of HIV-1 but not HHV-6A.     

Modulation of interleukin-6 expression in Hodgkin and Reed–Sternberg cells by Epstein–Barr virus

Variable proportions of Hodgkin's disease (HD) cases are associated with the Epstein–Barr virus (EBV), but the role of EBV in HD is not entirely clear. Hodgkin and Reed–Sternberg (HRS) cells of EBV-associated HD are characterized by expression of the EBV gene product LMP1. In other cellular environments, LMP1 has been shown to induce interleukin (IL)-6. In this study, 105 HD cases were tested for differences in IL-6 expression among LMP1-positive and -negative cases. Isotopic in situ hybridization and correlation with the presence of EBV gene products revealed significantly higher proportions of cases with IL-6-expressing tumour cells in LMP1-positive (31 of 37, 84 per cent) as compared with LMP1-negative HD cases (35 of 68, 51 per cent). Thus, although not exclusive to EBV-positive HRS cells, IL-6 expression appears to be upregulated in EBV-associated HD. IL-6 receptor (CD126) expression was tested by in situ hybridization and found in a broad spectrum of cell types, regularly including HRS cells. Superinduction of IL-6 expression may be among the mechanisms by which EBV confers a growth advantage on virus-infected HRS cells and by which the virus may contribute to the morphological and clinical peculiarities of HD. © 1997 John Wiley & Sons, Ltd.     

Epstein–Barr virus induction of the Hedgehog signalling pathway imposes a stem cell phenotype on human epithelial cells

Nasopharyngeal carcinoma (NPC) is a cancer common in southern China and South East Asia that is causally linked to Epstein–Barr virus (EBV) infection. Here, we demonstrate that NPC displays frequent dysregulation of the Hedgehog (HH) pathway, a pathway implicated in the maintenance of stem cells, but whose aberrant activation in adult tissues can lead to cancer. Using authentic EBV‐positive carcinoma‐derived cell lines and nasopharyngeal epithelial cell lines latently infected with EBV as models for NPC in vitro, we show that EBV activates the HH signalling pathway through autocrine induction of SHH ligand. Moreover, we find that constitutive engagement of the HH pathway induces the expression of a number of stemness‐associated genes and imposes stem‐like characteristics on EBV‐infected epithelial cells in vitro. Using epithelial cells expressing individual EBV latent genes detected in NPC, we show that EBNA1, LMP1, and LMP2A are all capable of inducing SHH ligand and activating the HH pathway, but only LMP1 and LMP2A are able to induce expression of stemness‐associated marker genes. Our findings not only identify a role for dysregulated HH signalling in NPC oncogenesis, but also provide a novel rationale for therapeutic intervention. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Human herpesvirus 6 and human herpesvirus 7 in chronic fatigue syndrome.

We analyzed lymphocytes of patients with chronic fatigue syndrome (CFS) for the presence of human herpesvirus 6 (HHV-6) and HHV-7 DNA. HHV-7 was present in over 80% of CFS patients and healthy controls, while the prevalence of HHV-6 variant A increased significantly in CFS cases (22 versus 4%; P = 0.05).