DNA-DNA dot hybridization to detect Epstein-Barr virus in throat washings

A common mechanism links Epstein-Barr virus infections and autoimmune diseases

Epstein-Barr virus (EBV) infection is associated with a variety of the autoimmune diseases. There is apparently no unified model for the role of EBV in autoimmune diseases. In this article, the development of autoimmune diseases is proposed as a simple two-step process: specific autoimmune initiators may cause irreversible changes to genetic materials that increase autoimmune risks, and autoimmune promoters promote autoimmune disease formation once cells are susceptible to autoimmunity. EBV has several types of latencies including type III latency with higher proliferation potential. EBV could serve as autoimmune initiators for some autoimmune diseases. At the same time, EBV may play a promotional role in majority of the autoimmune diseases by repeated replenishment of EBV type III latency cells and inflammatory cytokine productions in persistent stage. The type III latency cells have enhanced capacity as antigen-presenting cells that would facilitate the development of both B and T cell-mediated autoimmunity. The repeated cytokine productions are achieved by the repeated infection of naive B-lymphocytes and proliferation of type III latency cells that produce inflammatory cytokines. Presentation of viral or self-antigens by EBV type III latency B lymphocytes may promote autoreactive B cell and T cell proliferation, which can be amplified by type III latency cells-mediated cytokines productions. Different autoimmune diseases may require different kinds of pathogenic immune cells and/or specific cytokines. Frequency of the replenishment of EBV type III latency cells may determine the specific effect of the promoter functions. A specific initiator plus EBV-mediated common promoter function may lead to development of a specific autoimmune disease and link EBV-infection to a variety of autoimmunity.

Virologic Diagnosis, Viral Monitoring, and Treatment of Epstein-Barr Virus Infectious Mononucleosis

Epstein-Barr virus (EBV) is the cause of infectious mononucleosis and is associated with severe infections in immunocompromised patients. EBV is also causally linked with several human malignancies. The heterophile antibody test and EBV-specific antibody tests remain the principal means of diagnosis of initial infection in otherwise healthy patients. Enzyme-linked immunosorbent assays have replaced the traditional immunofluorescence assays for EBV-specific antibodies. Several newer molecular diagnostic tests have become available that facilitate accurate monitoring of infection. The role of these tests for patients with uncomplicated infectious mononucleosis is limited, although these tests are being increasingly used to monitor the state and level of EBV replication for severe infections and among immunocompromised patients. Antiviral therapy has a limited, short-term effect on oropharyngeal shedding but has proven ineffective for the clinical manifestations of infectious mononucleosis. Patients with selected complications frequently benefit from short-term corticosteroid therapy.

Detection and quantification of Epstein-Barr virus EBER1 in EBV-infected cells by fluorescent in situ hybridization and flow cytometry

A rapid and highly sensitive fluorescent in situ hybridization (FISH) assay was developed to detect Epstein Barr virus (EBV)-infected cells in peripheral blood. Multiple fluorescein-labeled antisense oligonucleotide probes were designed to hybridize to the EBER1 transcript, which is highly expressed in latently infected cells. After a rapid (30 min) hybridization, the cells were analyzed by flow cytometry. EBER1 was detected in several positive control cell lines that have variable numbers of EBV genome copies. No EBER1 was detected in two known EBV-negative cell lines. Northern blot analyses confirmed the presence and quantity of EBER1 transcripts in each cell line. This method was used to quantify the number of EBV-infected cells in peripheral blood from a patient with chronic mononucleosis. These results indicate that EBV-infected cells can be detected at the single cell level, and that this assay can be used to quantify the number of EBV-infected cells in clinical samples.

Pseudotumour of the tongue caused by herpes simplex virus type 2 in an HIV-1 infected immunosuppressed patient

An HIV-1 infected immunosuppressed patient (CD4+ cell counts: 382 cells/microL; viral load 94,000 copies/mL) with recurrent perianal herpes simplex virus type 2 (HSV-2) infections is described, showing an unusual exophytic tumour resembling a squamous cell carcinoma in the lateral part of the tongue. He also had persistent facial herpes infection, oral candidosis, oral hairy leukoplakia and lymphadenopathy. The presence of HSV-2 was detected by polymerase chain reaction both in smears and in a tissue biopsy taken from the involved tongue area. Treatment with brivudin, a new oral virustatic drug, led to rapid regression of the tumour.

Oral hairy leukoplakia in 71 HIV-seropositive patients: clinical symptoms, relation to immunologic status, and prognostic significance

BACKGROUND

Oral hairy leukoplakia (OHL) is a benign hyperplasia of the oral mucosa that is induced by Epstein-Barr virus. It occurs nearly exclusively in men infected with HIV. OHL is a marker of moderate to advanced immunodeficiency and disease progression in patients with HIV infection.

OBJECTIVE

We attempted to determine the clinical characteristics of OHL in a large group of patients infected with HIV and to analyze its relation to immune status and prognosis.

METHODS

A total of 456 patients with HIV-associated skin disorders were evaluated during the years 1982 through 1992. All patients had an oral examination. CD4+ cell counts were obtained within 3 months of the examination.

RESULTS

OHL was diagnosed in 15.6% of 456 patients. The median age of the patients was 35 years. OHL was found most often on the lateral aspect of the tongue; in one patient the lesion covered the entire dorsal surface of the tongue. Significant immunosuppression was present in the majority of patients at the time of OHL diagnosis (median CD4+ T-lymphocyte count, 235/microliter; median CD4+/CD8+ ratio, 0.3). The median survival time was 20 months in patients with OHL. In patients with a higher CD4 cell count (CD4+ T lymphocyte count, > or = 300/microliter) the diagnosis of OHL was associated with shorter survival times (median survival time, 25 months) compared with other patients with HIV (median survival time, 52 months).

CONCLUSION

OHL is a frequent finding in patients with HIV and indicates advanced immunosuppression. Even in patients with more than 300/microliter CD4+ T lymphocytes, OHL is associated with a poor prognosis.

Oral hairy leukoplakia in a patient with ulcerative colitis

A 30-year-old man with ulcerative colitis developed oral hairy leukoplakia (OHL). Serological examination for human immunodeficiency virus (HIV)-1 and HIV-2 infection showed no abnormalities. Biopsy specimen of the lateral tongue showed ballooned prickle cells, and electron microscopy revealed herpes-type viruses. Immunologic investigation of the patient showed a marked decrease in T-helper cells as a result of immunosuppressive regimen. The present report appears to be the first well-documented case of OHL in an HIV-negative patient with ulcerative colitis. OHL may be a marker for severe immunosuppression but is not necessarily associated with HIV infection. Patients with iatrogenic immunosuppression should be monitored for OHL. Concerning the marked decrease in T-helper cells in this case, the presence of OHL may imply the examination of T-lymphocyte subsets in patients such as HIV-infected individuals or in organ transplant recipients.

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.

Hairy leukoplakia with involvement of the buccal mucosa

Oral hairy leukoplakia occurs mainly on the tongue of human immunodeficiency virus (HIV)-infected persons. An HIV-infected patient with hairy leukoplakia involving the tongue and buccal mucosa was studied by light and electron microscopic methods, in situ hybridization, and polymerase chain reaction. Our findings indicate that hairy leukoplakia may involve the buccal mucosa and should be considered in the differential diagnosis of white oral lesions in HIV-positive patients. Epstein-Barr virus particles were found in the epithelial cells of both buccal and tongue mucosa.

Oral hairy leukoplakia

Oral hairy leukoplakia, usually observed on the lateral border of the tongue, may herald the development of symptomatic human immunodeficiency virus infection. This paper reviews the pertinent clinical features and differential diagnosis, histology, methods of establishing a definitive diagnosis, and management of the patient with this Epstein-Barr virus-associated lesion.

High levels of Epstein-Barr virus in the oropharynx: a predictor of disease progression in human immunodeficiency virus infection

The role of Epstein-Barr virus (EBV) on the progression of human immunodeficiency virus (HIV) infection is not well defined. The objective of this prospective study was to determine the prevalence of EBV excretion and the role that EBV might have on HIV disease progression. Fifty-two homosexual males were studied, all of whom had positive EBV serology. Twenty-four of the 27 HIV-seropositive and 14 of the 25 HIV-seronegative subjects had detectable levels of EBV DNA in oropharyngeal cells. In addition to a greater prevalence of detectable EBV, the level of excretion was higher among HIV-seropositives than among HIV-seronegatives, and higher among group III than among group II HIV-seropositive men. These results are consistent with earlier studies showing a relationship between immunosuppression and EBV reactivation. The EBV excretion levels in a control group of 52 age-matched heterosexual males were substantially lower than those found in the homosexual group. In a proportional hazards regression analysis EBV excretion was found to be the best single predictor of progression of HIV infection (P less than 0.001). HIV p24 core antigenemia (P = 0.048) and low EBNA (P = 0.024) were significant predictors independent of EBV excretion. Whether EV directly accelerates the time to progression or is merely a marker of underlying subclinical immunosuppression remains an open question.

Detection of porcine parvovirus using nonradioactive nucleic acid hybridization

Nonradioactive slot blot hybridization assays were established for the detection of porcine parvovirus (PPV), using either a digoxigenin-labeled DNA probe or a biotinylated RNA probe. All probes were prepared from a 3.3-kb Pst1-EcoR1 DNA fragment of the NADL8 isolate of PPV. The sensitivity and specificity of the probes in a slot blot system were evaluated in comparison with a 32P-radiolabeled RNA probe. Using an anti-digoxigenin alkaline phosphatase detection system, at least 1 ng of viral replicative form (RF) DNA, or the equivalent of 100 plaque forming units (PFU) of infectious virus, could be detected by the digoxigenin-labeled DNA probe. When the biotinylated RNA probe and a strepavidin-alkaline phosphatase detection system were employed, 0.1 ng of RF DNA, or the equivalent of 10 PFU of infectious virus, were detected, comparable to the sensitivity of the 32P-radiolabeled RNA probe. Hybridization was not observed with control DNA samples extracted from swine testicle cells, porcine kidney (PK-15) cells, uninfected mixed swine fetal tissue, or from an unrelated DNA virus (pseudorabies virus) infected PK-15 cells. Different isolates of PPV, namely NADL8, NADL2, KBSH, and Kresse, reacted on an equimolar basis in sensitivity and specificity to the biotinlyated probe. Extraction of DNA directly on the filter membrane (direct filter hybridization) was employed in an attempt to reduce processing time by eliminating DNA extraction steps. Direct filter hybridization was indeed less time consuming; it was also comparable in sensitivity and specificity to those methods employing purified DNA.

Epstein-Barr virus as a cause of autoimmune disease and other medical morbidity in patients with affective disorders

We hypothesize that psychiatric patients suffering from the major affective disorders (depression and manic-depressive illness) may commonly also suffer from a chronic active infection with the Epstein-Barr virus. This infection would be a consequence of the immune dysfunction known to be associated with these disorders of mood. According to this hypothesis, the increased medical morbidity and mortality reported in these psychiatric patients would be attributable in part to diseases in which Epstein-Barr virus is implicated or suspected as a cause.

Hairy leukoplakia: Epstein-Barr virus receptors on oral keratinocyte plasma membranes

Hairy leukoplakia (HL) is an oral white lesion associated with, and probably caused by, the Epstein-Barr virus (EBV) among persons who are seropositive for infection with human immunodeficiency virus. A unique feature of HL is its localization to the lateral portion of the tongue. To determine site differences for EBV receptors according to epithelial phenotype, these receptors were mapped in oral mucosa with the use of monoclonal antibodies HB5 and B2(specific for the Complement Fraction 3d/EBV receptor on B lymphocytes). Immunoperoxidase and immunofluorescence techniques were employed with the use of both cytologic suspensions and frozen tissue sections of oral epithelium. Pericellular plasma membrane immunoreactants were localized to upper spinous layer cells of the parakeratin phenotype; basal and parabasilar layers as well as all strata of orthokeratinized epithelia were negative. Those cells harboring EBV DNA as detected by in situ hybridization corresponded to cells with C3d/EBV receptors.

Microbial DNA diagnostic technology

The principle objectives when creating a robust DNA diagnostic assay system are sensitivity, specificity and minimal read-time. To meet these ends, depending on the specifically defined test, various aspects of molecular hybridization methodology must be optimized. In particular, among other things, attention has focused on (i) formulating highly specific probes; (ii) devising sensitive nonisotopic detection systems, (iii) minimizing the extent of preparing clinical samples for assaying, (iv) amplifying the target sequence to augment sensitivity and (v) enhancing hybridization kinetics to speed up the reaction period. In this article, some recent studies that are directed to the development of nucleic acid hybridization systems for clinical diagnosis of microorganisms are considered.

Advances in the use of nucleic acid probes in diagnosis of viral diseases of man. Brief review

A variety of methods are now available for the preparation and labelling of viral nucleic acids for use as probes in diagnostic virology. Some of these are assessed including the use of synthetic oligonucleotides in place of molecularly cloned nucleic acids, and alternatives to labelling with radioactive isotopes such as biotin, enzymes and fluorochromes. Dot blot, sandwich, indirect sandwich and in situ hybridization are covered, and examples given of the current use of nucleic acid probes in detection of human viral infections. The potential and limitations of nucleic acid hybridization are discussed in the light of these new methods.

Increased frequency of Epstein-Barr virus excretion in patients with new daily persistent headaches

In a case-control study 27 (84%) of 32 patients with new daily persistent headaches (NDPH) and 8 (25%) of 32 controls had evidence of Epstein-Barr virus (EBV) "active" infection, as demonstrated by EBV excretion and/or early antigen titre above 1:32. 20 (62%) patients and 4 (12%) controls were excreting EBV in the oropharynx, as determined by a dot hybridisation assay. The mean titre of IgG antibodies to early antigen was significantly higher in patients than controls. EBV reactivation may be important in the pathogenesis of NDPH. Alternatively, patients with NDPH may be unusually prone to EBV reactivation.