Oropharyngeal excretion of Epstein-Barr virus by patients with lymphoproliferative disorders and by recipients of renal homografts

Epstein-Barr Virus-Encoded BILF1 Orthologues From Porcine Lymphotropic Herpesviruses Display Common Molecular Functionality

Infection of immunosuppressed transplant patients with the human γ-herpesvirus Epstein-Barr virus (EBV) is associated with post-transplant lymphoproliferative disease (PTLD), an often fatal complication. Immunosuppressed miniature pigs infected with γ-herpesvirus porcine lymphotropic herpesvirus 1 (PLHV1) develop a similar disease, identifying pigs as a potential preclinical model for PTLD in humans. BILF1 is a G protein-coupled receptor (GPCR) encoded by EBV with constitutive activity linked to tumorigenesis and immunoevasive function downregulating MHC-I. In the present study, we compared BILF1-orthologues encoded by the three known PLHVs (PLHV1-3) with EBV-BILF1 to determine pharmacological suitability of BILF1 orthologues as model system to study EBV-BILF1 druggability. Cell surface localization, constitutive internalization, and MHC-I downregulation as well as membrane proximal constitutive Gα_i signaling patterns were conserved across all BILFs. Only subtle differences between the individual BILFs were observed in downstream transcription factor activation. Using Illumina sequencing, PLHV1 was observed in lymphatic tissue from PTLD-diseased, but not non-diseased pigs. Importantly, these tissues showed enhanced expression of PLHV1-BILF1 supporting its involvement in PTLD infection.

The promise of a prophylactic Epstein-Barr virus vaccine

The worldwide burden of disease due to Epstein-Barr virus (EBV) infection is enormous. Diseases include endemic Burkitt lymphoma, infectious mononucleosis, cancers after transplantation, Hodgkin lymphoma, and nasopharyngeal carcinoma. A prophylactic EBV vaccine has the potential to significantly reduce the incidence and/or the severity of all these diseases. Infectious mononucleosis can be nasty and prolonged with a median duration of 17 days. Patients, especially children, undergoing bone marrow or solid organ transplantation may develop post-transplant lymphoproliferative disorder (PTLD). Preventing or modifying primary EBV infection could reduce the incidence PTLD, and also certain lymphomas and nasopharyngeal carcinoma. EBV is a major environmental risk factor for multiple sclerosis (MS). Contracting EBV is essential to getting MS, and having a childhood case of infectious mononucleosis increases that risk. Vaccinating against EBV could be vaccinating against MS.

EBV reactivation as a target of luteolin to repress NPC tumorigenesis

Nasopharyngeal carcinoma (NPC) is a malignancy derived from the epithelial cells of the nasopharynx. Although a combination of radiotherapy with chemotherapy is effective for therapy, relapse and metastasis after remission remain major causes of mortality. Epstein-Barr virus (EBV) is believed to be one of causes of NPC development. We demonstrated previously that EBV reactivation is important for the carcinogenesis of NPC. We sought, therefore, to determine whether EBV reactivation can be a target for retardation of relapse of NPC. After screening, we found luteolin is able to inhibit EBV reactivation. It inhibited EBV lytic protein expression and repressed the promoter activities of two major immediate-early genes, Zta and Rta. Furthermore, luteolin was shown to reduce genomic instability induced by recurrent EBV reactivation in NPC cells. EBV reactivation-induced NPC cell proliferation and migration, as well as matrigel invasiveness, were also repressed by luteolin treatment. Tumorigenicity in mice, induced by EBV reactivation, was decreased profoundly following luteolin administration. Together, these results suggest that inhibition of EBV reactivation is a novel approach to prevent the relapse of NPC.

Oral hairy leukoplakia in patients without HIV: presentation of 2 new cases

OBJECTIVE

We report 2 cases of oral hairy leukoplakia (OHL) in patients without HIV and present a comprehensive review of OHL in HIV-negative individuals.

STUDY DESIGN

Two cases of non-HIV-associated OHL are described. A PubMed search identified previously reported cases. The attributes of those cases were ascertained.

RESULTS

OHL was confirmed in both of our cases. Both patients used inhaled steroids for pulmonary disorders, and were found to have depressed levels of immunoglobulin M. Additionally, 76 cases were identified in the literature. The condition occurred in association with various medical conditions, with the majority of patients on immunosuppressant medications (67 of 76). Systemic drugs were implicated most frequently. The condition has also been reported in healthy individuals (6 of 76).

CONCLUSIONS

Although thought of as an HIV/AIDS-associated condition, OHL can develop in patients without HIV, including healthy individuals. There is a strong correlation between the use of immunosuppressants and development of OHL in these patients.

Post-transplant lymphoproliferative disorders following solid-organ transplantation

A post-transplant lymphoproliferative disorder (PTLD) is an uncommon but serious complication following solid-organ transplantation. The incidence varies, depending on the type of organ transplanted, the degree of immunosuppression, the number of episodes of acute rejection and a patient's immune status to Epstein-Barr virus. The incidence of PTLD is thought to be bimodal; cases in the first year after solid-organ transplantation are typically related to Epstein-Barr virus. A second incidence occurs more than 1 year following transplantation and is typically not related to Epstein-Barr virus. A variety of therapeutic approaches has been used for these patients, with more recent strategies including the use of rituximab, with or without combination chemotherapy. Efforts continue to be made to improve the outcome of patients with PTLD.

[Prevalence of Epstein-Barr virus in Sjögren's syndrome in Tunisia]

PURPOSE

The cause of Sjögren's syndrome is unclear. Several studies suggested the role of Epstein-Barr virus (EBV) in the pathogenesis of this syndrome, but this always remains a subject of numerous controversies. The purpose of this study was to evaluate the prevalence of EBV in Sjögren's syndrome in Tunisia.

METHODS

A series of 31 paraffin-embedded biopsies of salivary glands from patients with Sjögren's syndrome were studied in comparison with 19 control glands. EBV was investigated by PCR, EBERs in situ hybridization and by immunohistochemistry for the detection of LMP1, EBNA2 and ZEBRA.

RESULTS

EBV DNA was detected by PCR in 3 of 22 PCR beta-globin positive Sjögren's syndrome cases (13.6%) and in 2 of 17 PCR beta-globin positive control glands (11.7%); in situ hybridization positivity was noted in rare lymphocytes in the 3 EBV positive cases of Sjögren's syndrome, but not in control glands; immunohistochemical study was negative in all cases.

CONCLUSION

EBV infection does not appear to play a significant role in the pathogenesis of Sjögren's syndrome in Tunisia.

Possible involvement of IL-12 expression by Epstein-Barr virus in Sjögren syndrome

AIM

To determine the correlation between interleukin 12 (IL-12) expression and Epstein-Barr virus (EBV) in Sjögren syndrome.

METHODS

Indirect immunohistochemical technique, enzyme linked immunosorbent assay (ELISA), and immunoblot analysis were used to investigate IL-12 expression by EBV activation, using 13 surgical specimens and four B cell lines.

RESULTS

Marked expression of IL-12 was found in the epithelial cells and the infiltrating B cells of salivary gland tissues from patients with Sjögren syndrome (six of 10 cases), but not in those from normal individuals (none of three cases). A striking topographic correlation between IL-12 and EBV was found. In addition, levels of IL-12 production by B cell lines were clearly enhanced by EBV activation in vitro.

CONCLUSIONS

IL-12 expression closely reflects the intracellular event of EBV activation in Sjögren syndrome, and may contribute to the T helper cell type 1 (Th1) cytokine overexpression seen in this disease.

Effects of smokeless tobacco and tumor promoters on cell population growth and apoptosis of B lymphocytes infected with epstein-barr virus types 1 and 2

The effects of smokeless tobacco purified products 4-(N-methyl-N-nitrosamine)-1-3-pyridinyl)-1-butanone (NNK) and N-nitrosonornicotine (NNN), smokeless tobacco extracts (dry snuff, moist snuff, and loose leaf), and the tumor promoters 12-O-tetradecanoyl phorbol-13-acetate (TPA) and n-butyrate on cell population growth, cell death, and apoptosis were studied in B lymphocyte cell lines harboring Epstein-Barr virus (EBV) type 1 (Raji and X50-7) or type 2 (HR-1K and AG876) and in an EBV-uninfected control lymphocyte cell line (Ramos). Spontaneous apoptosis was present in all EBV-infected cell lines, but at varying levels. Spontaneous and induced apoptosis were generally greater by Student-Newman-Keuls tests in cells harboring EBV type 2 compared to EBV type 1. The greatest effects on cell population growth, cell death, and apoptosis on cells harboring lytic EBV type 1 (X50-7) was with each of the three smokeless tobacco extracts. The greatest effects on cells harboring EBV type 2 was with TPA and n-butyrate. There were no effects of smokeless tobacco extracts on the Raji cell line that harbors EBV type 1 incapable of lytic replication. Smokeless tobacco purified products, NNN and NNK, had no discernible effects. At the concentrations used in these experiments, there appears to be an EBV type-specific response to chemical induction, with greater susceptibility of lytic EBV type 1 to smokeless tobacco extracts and lytic EBV type 2 to TPA and n-butyrate. This EBV type-specific susceptibility to the effects of smokeless tobacco extracts is another phenotypic difference between EBV types. The use of smokeless tobacco products may affect B lymphocytes infected with replication-capable EBV in the oropharynx. The absence of significant effects with NNK and NNN suggests that these properties reside with other compounds present in tobacco extracts.

Natural history of primary Epstein-Barr virus infection in children of mothers infected with human immunodeficiency virus type 1

The natural history of Epstein-Barr virus (EBV) infection in 556 infants born to 517 human immunodeficiency virus (HIV) type 1-infected mothers was studied in a prospective, multicenter, cohort study. HIV-1-infected children had a cumulative EBV infection rate similar to HIV-1-uninfected children at age 3 years (77.8% vs. 84. 9%) but had more frequent oropharyngeal EBV shedding (50.4% vs. 28. 2%; P<.001). The probability of shedding decreased with longer time from EBV seroconversion and was similar to that of HIV-1-uninfected children 3 years after seroconversion. HIV-1-infected children identified as rapid progressors shed EBV more frequently than nonrapid progressors (69.4% vs.41.0%; P=.01). HIV-1-infected children with EBV infection had higher mean CD8 cell counts. EBV infection did not have an independent effect on mean CD4 cell counts, percent CD4, IgG levels, HIV-1 RNA levels, lymphadenopathy, hepatomegaly, or splenomegaly. Early EBV infection is common in children born to HIV-1-infected mothers. Children with rapidly progressive HIV-1 disease have more frequent EBV shedding.

Evaluation of the effect of smokeless tobacco purified products and extracts on latent Epstein-Barr virus

Numerous chemical tumor promoters induce latent Epstein Barr virus (EBV) to active replication. The effect of smokeless tobacco purified products N-nitrosonornicotine (NNN), 4-(N-methyl-N-nitrosamine)-1-3-pyridinyl)-1-butanone (NNK), benzo(a)pyrene (BaP), and smokeless tobacco extracts (dry snuff, moist snuff, and loose leaf tobacco) was tested for induction of latent EBV in Raji cells using fluorescence-activated cell sorter flow cytometry detection of the restricted component of EBV early antigen (EA-R). Concentrations of smokeless tobacco purified products or preparations were used that have carcinogenic effects in animal cell lines. There was no discernible effect for the 6-7-day duration of treatment on viability of Raji cells, or on induction of latent EBV in Raji cells. Results were comparable using paraformaldehyde- or acetone-fixed cells. There does not appear to be an in vitro effect of smokeless tobacco constituents on EBV-infected lymphocytes that may contribute to development of oral cancers.

Oral hairy leukoplakia in a patient with acute lymphocytic leukemia

The first case of oral hairy leukoplakia (OHL) in an HIV-negative 56-year-old patient with acute lymphocytic leukemia (ALL) is reported. A white plaque was observed while the patient was in complete remission which followed the chemotherapeutic scheme. The clinical and histopathologic findings were typical for OHL and the polymerase chain reaction method was positive for Epstein-Barr virus DNA. Underdiagnosis and underreporting of OHL in patients with a malignant haematological disease and the apparent different environmental factors to which these non-AIDS patients have been exposed, probably constitute some of the reasons for the very few OHL cases reported in these patients.

Infections in solid-organ transplant recipients

Solid-organ transplantation is a therapeutic option for many human diseases. Infections are a major complication of solid-organ transplantation. All candidates should undergo a thorough infectious-disease screening prior to transplantation. There are three time frames, influenced by surgical factors, the level of immunosuppression, and environmental exposures, during which infections of specific types most frequently occur posttransplantation. Most infections during the first month are related to surgical complications. Opportunistic infections typically occur from the second to the sixth month. During the late posttransplant period (beyond 6 months), transplantation recipients suffer from the same infections seen in the general community. Opportunistic bacterial infections seen in transplant recipients include those caused by Legionella spp., Nocardia spp., Salmonella spp., and Listeria monocytogenes. Cytomegalovirus is the most common cause of viral infections. Herpes simplex virus, varicella-zoster virus, Epstein-Barr virus and others are also significant pathogens. Fungal infections, caused by both yeasts and mycelial fungi, are associated with the highest mortality rates. Mycobacterial, pneumocystis, and parasitic diseases may also occur.

Detection of Epstein-Barr virus in salivary gland specimens from Sjögren's syndrome patients

The cause of Sjögren's syndrome remains unclear, but several environmental and genetic factors have been implicated. The Epstein-Barr virus (EBV), among others (e.g., cytomegalovirus, human herpesvirus 6, and retroviruses), has been widely studied in connection with Sjögren's syndrome without conclusive results. To determine the role of EBV infection in patients with Sjögren's syndrome, the presence of EBV deoxyribonucleic acid (DNA) in major and minor salivary gland biopsy specimens was investigated by means of sulfur 35 in situ hybridization and polymerase chain reaction. Additionally, the presence of latent virus proteins EBV latent membrane protein and Epstein-Barr nuclear antigen 2 was analyzed by immunohistochemical methods. Viral DNA, detected by in situ hybridization, was found in 19% of patients with a diagnosis of Sjögren's syndrome and in 3% of controls. All tissues studied were found to be negative for EBV DNA by polymerase chain reaction. EBV latent membrane protein-positive staining was seen in 17% of patients and 22% of control subjects, while Epstein-Barr-positive staining was found in 25% of patients and 39% of controls. The low frequency of EBV DNA detected in the biopsy specimens does not indicate that the virus itself is the cause of Sjögren's syndrome. However, the possibility that the virus acts as a cofactor cannot be ruled out.

Increased expression of human thioredoxin/adult T cell leukemia-derived factor in Sjögren's syndrome

OBJECTIVE

To determine the involvement of human thioredoxin/adult T cell leukemia-derived factor TRX/ADF) in Sjögren's syndrome (SS) and the correlation with Epstein-Barr virus (EBV).

METHODS

Indirect immunohistochemical techniques and reverse transcriptase polymerase chain reaction were utilized to analyze TRX/ADF expression and the presence of EBV, using 6 normal tissues and 23 surgical specimens. The kinetics of expression of TRX/ADF induced by EBV was examined in vitro with peripheral blood B cells from EBV-seronegative donors.

RESULTS

Marked expression of TRX/ADF was found in the infiltrating B cells and the epithelial cells of salivary gland tissues from patients with SS (11 of 12 cases), but not in those from patients with other salivary gland inflammatory conditions (0 of 11 cases) or those of normal individuals (0 of 6 cases). In immunohistologic analyses, a striking topographic correlation between TRX/ADF and EBV was found. The coexistence of TRX/ADF messenger RNA and EBV DNA was detected by polymerase chain reaction (r = 0.75, P < 0.01). Peripheral blood B cells from EBV-seronegative donors showed de novo synthesis of TRX/ADF following in vitro infection with EBV. EBV-infected B cell lines all expressed TRX/ADF. TRX/ADF was not detected in non-EBV-infected cells. Tumors in SCID mice reconstituted with mononuclear cells of salivary glands from SS patients, which were composed of human B cells carrying EBV DNA, were positive for TRX/ADF.

CONCLUSION

These findings suggest that TRX/ADF expression closely reflects the intracellular event of EBV reactivation in SS. This is also the first report to show the ectopic in vivo expression of TRX/ADF in human autoimmune disease.

Viral infections in the immunocompetent patient

Human herpesviruses and human papillomaviruses are ubiquitous and may cause an array of oral disease. Herpesviruses are unique because recurrent localized disease occurs after the primary infection. Human papillomaviruses are known for their ability to produce benign epithelial proliferations and increasingly are implicated in the development of oral cancer. This article reviews the pathogenesis of common oral lesions induced by these viruses.

The ecology and pathology of Epstein-Barr virus

Epstein-Barr virus achieves its ubiquitous and uniform epidemiological distribution by a dual strategy of latency to guarantee lifelong persistence and intermittent replication to guarantee transmission. These two functions appear to dictate residence in different cell types: latency in B lymphocytes and replication in epithelial cells. Both of these cell compartments are potential sites for EBV-associated malignancies.

Increased levels of Epstein-Barr virus DNA in lacrimal glands of Sjögren's syndrome patients

Many Sjögren's syndrome patients complain primarily of dry eye. Epstein-Barr virus DNA has recently been found in the lacrimal glands of Sjögren's syndrome sufferers and normal individuals, and lacrimal glands are thought to be a target organ for latent Epstein-Barr virus infection. In this study, we performed lacrimal and salivary gland biopsies on 9 Sjögren's syndrome patients. Extracted Epstein-Barr virus DNA was assayed by polymerase chain reaction and compared to that of healthy individuals. An increased level of Epstein-Barr virus DNA was observed in all of the lacrimal glands and 8 of the 9 salivary glands from the Sjögren's syndrome patients. However, the amount of genome in the lacrimal gland was more than 10 times that in the salivary glands, not only in the Sjögren's syndrome patients but also in the controls. This may explain the pathogenesis of dry eye in patients with Sjögren's syndrome, and why the lacrimal gland tends to be so prominently affected. It may also suggest a therapeutic approach for this and possibly other types of dry eye.

Viral infections in severely immunocompromised cancer patients

Immunocompromised cancer patients are susceptible to infection by many viral pathogens. The most serious morbidity results from active infection by members of the herpes virus family. Reactivation of latent virus occurs as a sequela of cytotoxic therapy and deficiency of cell-mediated immunity, especially cytotoxic responses, the major host protective defense. Herpes simplex virus and varicella zoster virus infections are problematic in patients with all types of cancer; cytomegalovirus infections cause life-threatening morbidity in bone marrow transplant patients. Several antiviral agents are highly active against these pathogens and different strategies of using them have resulted in reduced morbidity and mortality. Ultimately, the resolution of these infections is dependent on the control of the malignancy and the ability of the patient to mount an adequate immune response.

Hepatitis C infection in potential recipients with normal liver biochemistry does not preclude renal transplantation

The hepatitis C virus (HCV) may be an important cause of chronic liver disease in renal transplant recipients. We investigated retrospectively the incidence and outcome of HCV infection in long-term renal transplant recipients and patients on hemodialysis. Stored, pretransplant sera of transplant recipients with normal liver biochemistry at surgery were tested for hepatitis C by a second-generation enzyme immunoassay. Hemodialysis patients were tested by a first-generation enzyme-linked immunosorbent assay (ELISA) against c100-3. We studied 252 renal transplant recipients and 58 hemodialysis patients followed for 65 +/- 10 months and 26 +/- 6 months, respectively. Fifteen percent (38/252) of the transplant recipients were HCV positive as were 3/58 (5%) of the hemodialysis patients. Overt liver disease occurred in 22/252 (8.7%) transplant recipients and none in the hemodialysis group. Thirty-six percent (8/22) of transplant recipients with overt liver disease were HCV positive. No HCV-positive patients died of liver failure. Of six biopsies in the HCV-positive transplant group, two had histological evidence of CAH. CAH was seen in six of eight biopsies in the HCV-negative transplants and two of these latter patients progressed to cirrhosis. No hemodialysis patients had clinical or histological evidence of chronic liver disease. Two HCV-negative transplant patients died of liver failure, while no deaths related to liver disease occurred in hemodialysis patients regardless of HCV status. We conclude that hepatitis C may cause chronic hepatitis in renal transplant patients.(ABSTRACT TRUNCATED AT 250 WORDS)

A modified procedure for the propagation of wild type Epstein-Barr virus in cultures of marmoset blood cells

Productive infection of marmoset blood mononuclear cells by the Epstein-Barr virus was generally achieved by the co-cultivation method. By introducing 2 modifications, the success rate of infection was increased from 6% to 79%. The modifications consisted of the selection of human lymphocyte donors to serve as carriers of Epstein-Barr virus in cocultures, and the addition of cyclosporin A to culture media. So far, 10 of 10 wild type oropharyngeal EBV have been propagated successfully in cultures of marmoset blood mononuclear cells by the modified procedure. Fragment length polymorphism study failed to reveal any difference between viral genomes in human lymphocytes and that in marmoset blood mononuclear cells. Antigenic analysis of 8 wild strains showed that all were related to the B95-8 strain of Epstein-Barr virus by the neutralization test.

Increased expression of Epstein-Barr virus in primary biliary cirrhosis patients

Peripheral blood mononuclear cells (PBMC, n = 26), formalin-fixed paraffin-embedded liver tissues (n = 11) and saliva (n = 15) of primary biliary cirrhosis (PBC) patients were used for the detection of Epstein-Barr virus (EBV) sequences by polymerase chain reaction (PCR) assay. The semiquantitative analysis of EBV-DNA was also carried out in a reconstructive experiment using an EBV-infected cell line. The PBMCs of PBC patients showed increased levels of EBV-DNA (61%) in contrast to chronic active hepatitis patients (19%), liver cirrhosis patients (14%) and healthy individuals (11%). Furthermore, formalin-fixed paraffin-embedded liver tissues, as well as saliva from PBC patients, also demonstrated increased levels of EBV-DNA when compared to healthy individuals and those with other liver diseases. The increased levels of EBV-DNA in the PBMC, liver tissue and saliva of the PBC patients suggest that those patients may have a depressed immune function against EBV infection.

Direct detection of Epstein-Barr virus in peripheral blood and comparison of Epstein-Barr virus genotypes present in direct specimens and lymphoblastoid cell lines established from nasopharyngeal carcinoma patients and healthy carriers in Hong Kong

By means of a PCR assay, EBV was demonstrated directly in peripheral blood of previously infected individuals. The virus was detected in approximately 80% of specimens from EBV-seropositive individuals, but not in cord-blood lymphocytes by this method. When virus present in peripheral blood was compared to that observed directly in NPC biopsies or throat washings, it was distinct from that seen in biopsies in 4/15 cases (27%) and from that seen in throat washes in 1/22 cases (5%). The throat-wash virus differed from the biopsy virus in 3/20 cases (15%). The prototype F virus was found in 7/10 LCLs (70%) established from NPC patients' peripheral blood, but was only detected in 2/9 specimens (22%) directly analyzed by the PCR assay. This finding suggests selective isolation of prototype F EBV in spontaneous LCLs established from NPC patients.

Post renal transplantation non-Hodgkin's lymphoma: Local experience and review of the literature

Among a population of 600 renal transplant patients, only three cases (0.5%) have developed a non-Hodgkin's lymphoma, while in the same population, 28 cases (4.6%) have developed a Kaposi's sarcoma. The significant low incidence of lymphoma in the Saudi grafted population must be underlined, particularly because of the very high incidence of this malignancy among either the post-transplant Western population, up to 20% of the cancers, or the Saudi general population where the incidence can reach 15% of malignancies.

Lymphomas following cardiac transplantation. Case report and review of the literature

The success of allogeneic organ transplantation is in great part due to pharmacologic advances in the area of immunosuppressive therapy. However, this achievement has been attained at the price of an unexpectedly high incidence of malignancies in this transplant population. Lymphoid malignancies predominate in this and other immunodeficiency states. There is some controversy in the literature over the clonal or malignant nature of these proliferations. This paper presents a case of Burkitt-like lymphoma occurring after cardiac transplantation. The role of Epstein-Barr virus in the pathogenesis of this disorder is reviewed as are multidisciplinary approaches to its management.

Demonstration of Epstein-Barr virus in scrape material of lateral border of tongue in heart transplant patients by negative staining electron microscopy

Scrape material from the lateral border of the tongue of 50 heart transplant patients and 20 controls was studied for the presence of EBV by negative staining electron microscopy. Mild oral hairy leukoplakia was observed in two cases. Particles of the herpes virus were found in 20% of the specimens. Controls were negative for EBV. The study has shown that EBV may be expressed at the lateral border of the tongue during immunosuppression, occasionally resulting in the clinical appearance of hairy leukoplakia.

Detection of Epstein-Barr virus and human herpes virus type 6 in saliva from patients with lymphoproliferative diseases by the polymerase chain reaction

Direct detection of these viruses was made by using the PCR for amplifying viral DNA. In virtually all adults low levels of the herpesvirus can be detected. Therefore it is necessary to quantitate the amount of viral DNA, and a method to compare the plasmid containing the cloned target gene was used here. After 35 cycles of amplification, 10 copies of the viral DNA per 100 microliters saliva were detected. The PCR was used to detect increased levels of EBV and HHV-6 in saliva from patients with lymphoproliferative diseases, suggesting that these viruses may play a part in their pathogenesis. Viral detection by such highly sensitive methods as PCR may allow better monitoring of medication, as well as early detection of EBV- and HHV-6 related diseases that may arise in these patients. The great sensitivity of PCR and its ability to analyse very small samples make this technique most suitable for clinical diagnosis.

Epstein-Barr virus genotypes associated with nasopharyngeal carcinoma in southern China

We have used probes representing approximately two-thirds of the Epstein-Barr virus (EBV) genome to examine genetic polymorphism of wild-type EBV directly detected in 28 nasopharyngeal carcinoma (NPC) tissues from Southern China. In the hypervariable regions containing reiterated sequences, this analysis showed that while naturally occurring viruses are genetically diverse, only one genotype was detectable in each tumor specimen. Unique variants in NPC were detected in four regions of the EBV genome. Two of these appeared significant in their distribution. The type C variant resulting from loss of a BamHl site between the BamHl W1* and l1* regions was prevalent among isolates from Southern China, but not so common in the United States. An "f" variant having an extra BamHl site in the BamHl F region was almost exclusively detected in only Asian NPC biopsies.

Susceptibility of EBV-carrying B cell lines to infection by HIV-1: variability of production of progeny virus and expression of viral antigens

We have examined 3 different EBV-carrying B cell lines, in terms of ability to be super-infected by the human immunodeficiency virus (HIV-1), and have followed these lines, after infection by HIV-1, over a period of 3 months. We found significant variation among different HIV-1 strains in terms of the multiplicity of infection required to initiate infection in these EBV-positive cell lines. Persistent infection by HIV-1 in the absence of detectable cytopathic effects could be demonstrated, as evaluated by a variety of techniques, including reverse transcriptase assay and immunofluorescence. The results indicate also that all of these cell lines produced progeny HIV-1 intermittently, with large amounts of virus production on some days but not others. In contrast, they were all able to continuously express p24.

Possible involvement of Epstein-Barr virus (EBV) in polyclonal B-cell activation in Sjögren's syndrome

The following results suggest that EBV might be involved in the mechanism of polyclonal B-cell activation of Sjögren's syndrome (SS). (1) The levels of serum anti-VCA antibodies of both IgG and IgM class were significantly elevated in SS. (2) Excretion of EBV from the oropharynx was frequently observed in SS. (3) Spontaneously transformed B-cell lines producing a large amount of transforming EBV were established preferentially from SS. (4) An EBV-specific regulatory mechanism was impaired in SS.

Hairy leukoplakia: an AIDS-associated opportunistic infection

Hairy leukoplakia has been defined and confirmed as a specific oral mucosal marker for human immunodeficiency virus infection. Light microscopic findings include alteration of spinous layer cells, which contain nuclear chromatin abnormalities. Enlargement of spinous cells with ballooning degeneration is also characteristic. Ultrastructural morphology has defined the presence of large numbers of herpes-type virus particles within the intranuclear, cytoplasmic, and intercellular regions. Morphologically, the criteria of Epstein-Barr virus are satisfied. Southern blot analysis has confirmed the virus to be Epstein-Barr virus. Further hybridization analyses failed to show any evidence of human immunodeficiency virus or human papillomavirus in the lesions themselves. We conclude that hairy leukoplakia may represent an epithelial opportunistic Epstein-Barr virus infection. Finally, the production and shedding of Epstein-Barr virions into the oral cavity from the sites of hairy leukoplakia can occur separate from the usual tonsillar and oropharyngeal sites.

Genetic polymorphism of natural Epstein-Barr virus isolates from infectious mononucleosis patients and healthy carriers

We analyzed Epstein-Barr virus (EBV) genomes from lymphoblastoid cell lines isolated from patients with infectious mononucleosis and from healthy subjects from California, Hawaii, and Hong Kong between 1970 and 1987. Using genetic polymorphism as epidemiological markers, we found that several genotypes of EBV cocirculate in a community and that although most EBV strains isolated from California and Southern China may be differentiated genotypically, there was no specific association between genotype and disease or time of isolation.

Epstein-Barr virus and human autoimmune diseases: possibilities and pitfalls

Epidemiologic studies suggest that human autoimmune disease involves both genetic and environmental components. Although a great deal has been learned about genetic components (i.e. histocompatibility antigens), little is known about the environmental factors. Because of its ubiquitous nature and ability to stimulate lymphoid responses, Epstein-Barr virus (EBV) has been examined as a potential candidate, particularly in rheumatoid arthritis and systemic lupus erythematosus. No convincing evidence has been produced that it plays a primary etiologic role in these disorders. Nevertheless, EBV or a related herpesvirus may play an indirect role in perpetuating the disorder or in the development of extra-articular manifestations such as Sjögren's syndrome (an autoimmune disorder involving the salivary glands). Current data indicates increased EBV reactivation in some patients with autoimmune diseases, as evidenced by increased viral DNA in their saliva and increased number of circulating B-cells containing EBV in their blood. These patients also have modestly elevated anti-EBV antibody titers and altered antiviral T-cell responses, as measured by the ability to prevent outgrowth of autologous EBV infected B-cells. However, the relevance of these 'abnormalities' to pathogenesis remains unknown. It is hoped that new techniques such as polymerase chain reaction will provide new insights into these questions by allowing detection of viral DNA from tissue biopsies obtained early in the course of disease and by providing a method to identify viral isolates that do not grow well in vitro.

Possible involvement of Epstein-Barr virus in polyclonal B cell activation in Sjögren's syndrome

We sought evidence of Epstein-Barr virus (EBV) involvement in the mechanism of polyclonal B cell activation in 29 patients with Sjögren's syndrome (SS). Serum levels of anti-viral capsid antigen antibodies of both the IgG and the IgM class were significantly elevated in these patients. Excretion of EBV from the oropharynx was frequently observed, as well. Spontaneously transformed B cell lines that produced a large amount of transforming EBV were established preferentially from SS patients. We also found that an EBV-specific regulatory mechanism was impaired in these patients. Our findings thus provide evidence of the involvement of EBV in patients with SS.

Epstein-Barr virus, cytomegalovirus, and other viral infections in children after liver transplantation

We studied 51 consecutive pediatric patients for the frequency and morbidity of viral infections after liver transplantation. The incidence of primary (67%) and reactivation (48%) Epstein-Barr virus (EBV) infections and reactivation (88%) cytomegalovirus (CMV) infection was comparable to that seen in adult transplant recipients. However, fewer pediatric than adult transplant recipients experienced primary CMV infection (P less than .01). Five (38%) of 13 CMV infections were symptomatic and included hepatitis, pneumonitis, enteritis, and mononucleosis. Two of 14 patients with primary EBV infection subsequently developed, at two months and two years after initial infection, an EBV-associated lymphoproliferative syndrome, and one of 10 patients with reactivated EBV infection developed a possible EBV-associated febrile encephalopathy. Other viruses causing infection in these children included herpes simplex virus, varicella-zoster virus, adenovirus, parainfluenza virus, respiratory syncytial virus, and rotavirus.

Subclass reactivity to Epstein-Barr virus capsid antigen in primary and reactivated EBV infections

A new method for analysis of virus-specific Immunoglobulin G (IgG) subclasses was developed using indirect immunofluorescence. Three hundred thirty-three serum samples from patients with different types of Epstein-Barr virus (EBV)-associated diseases and healthy controls were examined for subclass distribution to the virus capsid antigen (EBV VCA). EBV-VCA-expressing cell preparations were incubated with patient serum followed by monoclonal antibodies to human IgG1 through IgG4 and labelled anti-mouse IgG. Virus-specific IgG1 was found to be the dominant antibody. The titers for IgG1 and total Ig to EBV VCA correlated well. EBV VCA-specific IgG2 was not found. EBV VCA-specific IgG3 in a titer of greater than or equal to 10 was found in 33% of healthy seropositive donors, in 97% of patients with suspected reactivated EBV infection, and in 100% of symptomatic patients with suspected reactivated EBV infection. EBV VCA specific IgG3 occurred in 90% of placebo-treated compared to 30% in long-term acyclovir-treated bone marrow transplant recipients, indicating more frequent reactivations in the former group. IgG4 to VCA was infrequently found in seropositive persons. In serum samples from patients with nasopharyngeal carcinoma and high EBV VCA Ig and IgA titers, IgG4 to VCA was always present. Analysis of EBV VCA specific IgG subclasses seems to be valuable for the diagnosis of reactivated EBV infection.

Increased incidence of IgA antibodies to the Epstein-Barr virus-associated viral capsid antigen and early antigens in patients with chronic lymphocytic leukemia

Antibody titers to Epstein-Barr virus (EBV)-associated early antigens (EA) and the viral capsid antigen (VCA) were determined by ELISA on 263 sera obtained from healthy donors, patients with Hodgkin's disease (HD), non-Hodgkin lymphomas (NHL), infectious mononucleosis (IM), Burkitt's lymphoma (BL), and nasopharyngeal carcinoma (NPC). As expected, most lymphoma patients showed markedly elevated anti-VCA IgG and anti-EA IgG antibody titers. Only one patient in the NHL group (n = 56) consisting of patients with lymphomas other than chronic lymphocytic leukemia (CLL) and hairy-cell leukemia (HCL), and 3 patients with HCL (n = 19) had high antibody titers of the IgA class to VCA and EA. Seventeen out of 48 patients (36%) with CLL had high IgA anti-VCA titers and 10 of these sera (21%) also contained IgA anti-EA. The geometric mean titer (GMT) of IgA anti-VCA was 2,510, the GMT of IgA anti-EA was 780. These antibody titers were about 10 times lower than the corresponding GMT of the NPC patients investigated in this study. The elevated IgG and IgA antibody titers to VCA and EA in CLL and HCL patients seem to reflect an immunodeficiency secondary to the malignant disease leading to reactivation of latent EBV infection. The possibility that at least some of these B-cell lymphomas are associated with EBV cannot be excluded.

Epstein-Barr virus serology in bone marrow transplantations: a one-year retrospective study with detection of EBV IgM-VCA-specific antibodies

The specific antibody response to Epstein-Barr virus (EBV) antigens of 41 bone marrow transplant recipients with leukemia or aplastic anemia was examined retrospectively by immunofluorescence test (IF) over 1 year. We observed high titers (greater than 640) of IgG-viral capsid antigen (VCA) with emergence of IgG-early antigen (EA) and frequent absence or low levels of Epstein-Barr nuclear antigen (EBNA) antibodies. After absorption to remove rheumatoid factor (RF), five of the 41 recipients had IgM-VCA antibody to EBV, which appeared between weeks 26 and 48 after BMT and persisted for 1-4 months. No heterophil antibodies were detected in these sera, and none of the five recipients had a history of infectious mononucleosis.