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

The Impact of Co-Infections for Human Gammaherpesvirus Infection and Associated Pathologies

The two oncogenic human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause significant disease burden, particularly in immunosuppressed individuals. Both viruses display latent and lytic phases of their life cycle with different outcomes for their associated pathologies. The high prevalence of infectious diseases in Sub-Saharan Africa (SSA), particularly HIV/AIDS, tuberculosis, malaria, and more recently, COVID-19, as well as their associated inflammatory responses, could potentially impact either virus' infectious course. However, acute or lytically active EBV and/or KSHV infections often present with symptoms mimicking these predominant diseases leading to misdiagnosis or underdiagnosis of oncogenic herpesvirus-associated pathologies. EBV and/or KSHV infections are generally acquired early in life and remain latent until lytic reactivation is triggered by various stimuli. This review summarizes known associations between infectious agents prevalent in SSA and underlying EBV and/or KSHV infection. While presenting an overview of both viruses' biphasic life cycles, this review aims to highlight the importance of co-infections in the correct identification of risk factors for and diagnoses of EBV- and/or KSHV-associated pathologies, particularly in SSA, where both oncogenic herpesviruses as well as other infectious agents are highly pervasive and can lead to substantial morbidity and mortality.

CMV and EBV Co-Infection in HIV-Infected Children: Infection Rates and Analysis of Differential Expression of Cytokines in HIV Mono- and HIV-CMV-EBV Co-Infected Groups

(1) Background: CMV and EBV co-infections can affect the HIV disease progression by modulating the immune system. The disease dynamics can differ in HIV-positive adults and children. In Pakistan, HIV is rapidly expanding, especially in children; however, the prevalence of CMV and EBV co-infection and the effect on immune modulation in HIV-positive children are not known. This study aimed to bridge this gap by estimating the rate of active CMV and EBV co-infection in HIV-positive children, followed by the analysis of differential expression of cytokines in HIV mono- and HIV/CMV/EBV co-infected children. (2) Methods: DNA samples from 319 HIV-positive children, previously recruited as part of a study to investigate the HIV outbreak in Larkana, Pakistan, in 2019, were screened for CMV and EBV through qPCR. Subsequently, differences in HIV viral loads and CD4 counts were analyzed between the HIV mono- and HIV/CMV/EBV co-infected groups. The RNA samples were used to determine the differential expression of both pro- and anti-inflammatory cytokines in the mono- and co-infected groups using RT-qPCR, while unpaired T-test and Pearson correlation test were applied to, respectively, analyze the differential cytokine expression and correlation between cytokine in the two groups. (3) Results: Of 319 samples, the rate of active EBV and CMV co-infection in HIV-positive children was observed in 79.9% and 38.9%, respectively. A significant difference was observed in HIV viral load between HIV mono- and co-infected groups. IFN-γ expression was found to be lower in the HIV mono-infected group, while higher in all other three co-infected groups. Meanwhile, mRNA expression of TGF-β1 was found to be lower in HIV mono- and HIV-CMV-EBV co-infected groups, while higher in HIV-CMV and HIV-EBV co-infected groups. IFN-γ and IL-2 exhibited a significant positive correlation in all except HIV-CMV co-infected group. (4) Conclusions: The study suggests that the presence of EBV/CMV co-infection can affect the HIV viral loads and expression of certain cytokines (IFN-γ and TGF-β1), which may affect the HIV disease dynamics in infected children.

Examining the dynamics of Epstein-Barr virus shedding in the tonsils and the impact of HIV-1 coinfection on daily saliva viral loads

Epstein-Barr virus (EBV) is transmitted by saliva and is a major cause of cancer, particularly in people living with HIV/AIDS. Here, we describe the frequency and quantity of EBV detection in the saliva of Ugandan adults with and without HIV-1 infection and use these data to develop a novel mathematical model of EBV infection in the tonsils. Eligible cohort participants were not taking antiviral medications, and those with HIV-1 infection had a CD4 count >200 cells/mm3. Over a 4-week period, participants provided daily oral swabs that we analysed for the presence and quantity of EBV. Compared with HIV-1 uninfected participants, HIV-1 coinfected participants had an increased risk of EBV detection in their saliva (IRR = 1.27, 95% CI = 1.10-1.47) and higher viral loads in positive samples. We used these data to develop a stochastic, mechanistic mathematical model that describes the dynamics of EBV, infected cells, and immune response within the tonsillar epithelium to analyse potential factors that may cause EBV infection to be more severe in HIV-1 coinfected participants. The model, fit using Approximate Bayesian Computation, showed high fidelity to daily oral shedding data and matched key summary statistics. When evaluating how model parameters differed among participants with and without HIV-1 coinfection, results suggest HIV-1 coinfected individuals have higher rates of B cell reactivation, which can seed new infection in the tonsils and lower rates of an EBV-specific immune response. Subsequently, both these traits may explain higher and more frequent EBV detection in the saliva of HIV-1 coinfected individuals.

Prevalence and anatomical sites of human papillomavirus, Epstein-Barr virus and herpes simplex virus infections in men who have sex with men, Khon Kaen, Thailand

BACKGROUND

Human papillomavirus (HPV), Epstein-Barr virus (EBV) and herpes simplex virus (HSV) cause sexually transmitted diseases (STDs) that are frequently found in men who have sex with men (MSM) with human immunodeficiency viral (HIV) infection.

METHODS

This study investigated the prevalence of infection and anatomical site distribution of these viruses in asymptomatic MSM. DNA, extracted from cells collected from the anorectum, oropharynx and urethra of 346 participants, was investigated for the presence of EBV, HPV and HSV using real-time PCR. Demographic data from the participants were analyzed.

RESULTS

All three viruses were found in all sampled sites. EBV was the commonest virus, being detected in the anorectum (47.7% of participants), oropharynx (50.6%) and urethra (45.6%). HPV and HSV were found in 43.9% and 2.9% of anorectum samples, 13.8% and 3.8% of oropharynx samples and 25.7% and 2% of urethra samples, respectively. HPV infection of the anorectum was significantly associated with age groups 21-30 (odds = 3.043, 95% CI = 1.643-5.638 and P = 0.001) and 46-60 years (odds = 2.679, 95% CI = 1.406-5.101 and P = 0.03). EBV infection of the urethra was significantly correlated with age group 21-30 years (odds = 1.790, 95% CI = 1.010-3.173 and P = 0.046). EBV/HPV co-infection of the anorectum (odds = 3.211, 95% CI = 1.271-8.110, P = 0.014) and urethra (odds = 2.816, 95% CI = 1.024-7.740, P = 0.045) was also associated with this age group. Among HIV-positive MSM, there was a significant association between age-group (odds = 21.000, 95% CI = 1.777-248.103, P = 0.016) in HPV infection of the anorectum. A failure to use condoms was significantly associated with HPV infection of the anorectum (odds = 4.095, 95% CI = 1.404-11.943, P = 0.010) and urethra (odds = 7.187, 95% CI = 1.385-37.306, P = 0.019). Similarly, lack of condom use was significantly associated with EBV infection of the urethra (odds = 7.368, 95% CI = 1.580-34.371, P = 0.011).

CONCLUSION

These results indicate that asymptomatic MSM in Northeast Thailand form a potential reservoir for transmission of STDs, and in particular for these viruses.

Clinical and virologic manifestations of primary Epstein-Barr virus (EBV) infection in Kenyan infants born to HIV-infected women

BACKGROUND

Human immunodeficiency virus (HIV) infection is a risk factor for Epstein-Barr virus (EBV)-associated lymphomas. Characterizing primary infection may elucidate risk factors for malignancy.

METHODS

To describe clinical and virologic manifestations of primary EBV infection among infants born to HIV-infected women, specimens were utilized from a cohort study conducted in Nairobi, Kenya. HIV and EBV viral loads were measured serially in plasma. EBV serology was performed on EBV DNA-negative infants. Monthly clinical examinations were performed by pediatricians.

RESULTS

The probability of EBV infection by 1 year of age was .78 (95% CI, .67-.88) in HIV-infected and .49 (95% CI, .35-.65) in HIV-uninfected infants (P < .0001). At 2 years, probability of EBV infection was .96 (95% CI, .89-.99) in HIV-infected infants. Peak EBV loads were higher in HIV-infected versus HIV-uninfected infants (median 2.6 vs 2.1 log10 copies/mL; P < .0001). The majority of HIV-infected infants had detectable EBV DNA for >3 months (79%). Primary EBV infection was associated with cough, fever, otitis media, pneumonia, hepatomegaly, splenomegaly, and hospitalization in HIV-infected infants; conjunctivitis and rhinorrhea in HIV-uninfected infants.

CONCLUSIONS

EBV infection occurs early in infants born to HIV-infected women. HIV infection was associated with more frequent and higher quantity EBV DNA detection.

Oral Hairy Leukoplakia in HIV-Negative Patients: Report of 10 Cases

Ten cases of oral hairy leukoplakia (OHL) in HIV- negative patients are presented. Eight of the 10 patients were on steroid treatment for chronic obstructive pulmonary disease, 1 patient was on prednisone as part of a therapeutic regimen for gastrointestinal stromal tumor, and 1 patient did not have any history of immunosuppression. There were 5 men and 5 women, ages 32-79, with mean age being 61.8 years. Nine out of 10 lesions were located unilaterally on the tongue, whereas 1 lesion was located at the junction of the hard and soft palate. All lesions were described as painless, corrugated, nonremovable white plaques (leukoplakias). Histologic features were consistent with Epstein—Barr virus—associated hyperkeratosis suggestive of OHL, and confirmatory in situ hybridization was performed in all cases. Candida hyphae and spores were present in 8 cases. Pathologists should be aware of OHL presenting not only in HIV-positive and HIV-negative organ transplant recipients but also in patients receiving steroid treatment, and more important, certain histologic features should raise suspicion for such diagnosis without prior knowledge of immunosuppression.

Epstein-Barr virus DNA loads in adult human immunodeficiency virus type 1-infected patients receiving highly active antiretroviral therapy

Patients with human immunodeficiency virus type 1 (HIV-1) infection are at high risk of developing Epstein-Barr virus (EBV)-associated lymphoma. However, little is known of the EBV DNA loads in patients receiving highly active antiretroviral therapy (HAART). Using a real-time quantitative polymerase chain reaction assay, we demonstrated that significantly more HIV-1-infected patients receiving HAART than HIV-1-uninfected volunteers had detectable EBV DNA in blood (57 [81%] of 70 vs. 11 [16%] of 68 patients; P=.001) and saliva (55 [79%] of 68 vs. 37 [54%] of 68 patients; P=.002). The mean EBV loads in blood and saliva samples were also higher in HIV-1-infected patients than in HIV-1-uninfected volunteers (P=.001). The frequency of EBV detection in blood was associated with lower CD4+ cell counts (P=.03) among HIV-1-infected individuals, although no differences were observed in the EBV DNA loads in blood or saliva samples in the HIV-1-infected group. Additional studies are needed to determine whether EBV-specific CD4+ and CD8+ cells play a role in the pathogenesis of EBV in HIV-1-infected patients receiving HAART.

Detection of human viruses in patients with chronic periodontitis and the relationship between viruses and clinical parameters

BACKGROUND

Recent studies have demonstrated that various human viruses, especially cytomegalovirus (HCMV), Epstein-Barr virus type-1 (EBV-1), and herpes simplex virus (HSV), seem to play a part in the pathogenesis of human periodontitis. Little information is available on the relationship between these viruses and clinical periodontal parameters in patients with chronic periodontitis. This study examined the occurrence of HCMV, EBV-1, and HSV in patients with chronic periodontitis and the relationship between these viruses and clinical parameters.

METHODS

A nested polymerase chain reaction (PCR) method determined the presence of HCMV, EBV-1, and HSV. Subgingival plaque samples from 30 patients with chronic periodontitis and 21 randomly selected healthy controls were collected by paper points, and clinical measurements were recorded from both sampling sites and entire dentition. The following indices were measured: plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment loss (CAL).

RESULTS

HCMV was detected in 44.3% of chronic periodontitis patients and 14.3% of healthy persons (P < 0.05); EBV-1 in 16.7% of chronic periodontitis patients and 14.3% of healthy persons (P = 1.00); and HSV in 6.7% of chronic periodontitis patients and in no healthy persons. HCMV and EBV-1 detected and undetected sites in patients with periodontitis showed statistically significant differences in sampling clinical depth (SPD) and sampling clinical attachment loss (SCAL). Differences in the measurements of PI of entire dentition and GI of entire dentition between HSV detected and undetected sites were statistically significant.

CONCLUSIONS

Findings of the present study confirm the frequent presence of HCMV in crevicular samples of chronic periodontitis lesions, and suggest a strong relationship between the presence of HCMV and EBV-1 in subgingival areas and the measurements of probing depth and probing attachment loss.

Epstein-Barr virus reactivation after superinfection of the BJAB-B1 and P3HR-1 cell lines with cytomegalovirus

BACKGROUND

Studies examining herpesvirus-herpesvirus (cytomegalovirus (CMV)-Epstein-Barr virus (EBV)) interactions are limited, and many of the studies have been clinical observations suggesting such an interaction exists. This report aims to examine the in vitro susceptibilities of BJAB-B1 and P3HR-1 cells (EBV positive Burkitt's lymphoma B-cell lines) to a CMV superinfection; and show that EBV reactivation occurs after CMV superinfects these cell lines.

RESULTS

The BJAB-B1 and P3HR-1 cells were observed to be susceptible to a CMV superinfection by detecting the major immediate early (MIE) viral transcript and protein (p52) expression. The BZLF1 transcript was observed in both cell lines superinfected with CMV, indicating EBV reactivation. BZLF1 protein was observed in the BJAB-B1 cells. Antigen detection was not performed in the P3HR-1 cells.

CONCLUSION

The results from the in vitro superinfections support the in vivo studies suggesting a CMV infection is related to an EBV reactivation and suggests that CMV may be important as a co-factor in EBV pathogenesis in the immunocompromised patient.

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.

Detection of Epstein-Barr virus (EBV) DNA and antigens in oral mucosa of renal transplant patients without clinical evidence of oral hairy leukoplakia (OHL)

The use of the polymerase chain reaction (PCR) to detect the presence of Epstein-Barr virus (EBV) DNA in oral mucosa in the absence of specific lesions gives rise to the problem of identifying the real viral replication sites. To verify whether the detection of EBV is due to salivary contamination or its true replicative capacity in oral mucosa, saliva samples and exfoliated cells from four different oral mucosa sites were taken from 40 renal transplant patients and 20 normal subjects for examination by PCR using two pairs of primers specific for the BamHI-L and BamHI-K genomic regions. EBV-specific sequences were detected in one or more of the oral mucosa samples from 29 transplant patients (72.5%) and six healthy controls (30%), and in the saliva samples of 16 transplant patients (40%) and three healthy controls (15%). A total of 89 oral mucosa smears from 29 transplant patients, and 13 from healthy subjects, were EBV-positive. The positive samples were also investigated by means of in situ hybridization in order to confirm the intracellular presence of the viral genome, and by means of immunofluorescence testing with monoclonal antibodies to assess the possible expression of viral antigens. Hybridization with the EBV-specific probe was observed in 40/ 89 and 2/13 samples, respectively. Latent antigens (with or without lytic antigens) were detected in only 23 of the 40 samples (collected from eight different transplant patients) that were positive by in situ hybridization. Our data show that EBV is more frequently present in the oral mucosa of immunodeficient patients (where it can efficiently replicate) than in normal subjects.

Isolation of intertypic recombinants of Epstein-Barr virus from T-cell-immunocompromised individuals

All wild-type isolates of Epstein-Barr virus (EBV) analyzed to date for allelic polymorphisms of the nuclear antigen EBNA2 gene (in the BamHI YH region of the genome) and of the EBNA3A,-3B, -3C genes (tandemly arranged in the BamHI E region) have proved either uniformly type 1 or uniformly type 2 at all four loci. The absence of detectable intertypic recombination in the wild probably reflects the rarity with which individual carriers, and certainly individual target cells, become coinfected with both virus types. Studying a group of human immunodeficiency virus-positive T-cell-immunocompromised patients known to be at enhanced risk of multiple EBV infections, we have isolated intertypic EBV recombinants from 2 of 40 patients analyzed. These recombinants, whose in vitro transforming capacity appeared at least equal to that of type 1 strains, carried a type 1 EBNA2 allele and type 2 EBNA3A,-3B, and -3C alleles. This was clearly demonstrable at the DNA level by PCR amplification using type-specific primer-probe combinations and was confirmed at the protein level (for EBNA2 and EBNA3C) by immunoblotting with type-specific antibodies. In one patient, the recombinant appeared to be the predominant strain, being the virus most commonly rescued by in vitro transformation both from the blood and from the throat washings on two separate occasions 20 months apart. A regular type 1 virus strain was also present in this individual, but this was not related to the recombinant since the two viruses carried type 1 EBNA2 genes with different patterns of variance from the B95.8 prototype sequence. In the other patient, recombinants were isolated on one occasion from the blood and on a separate occasion, 21 months later, from the throat; these recombinants were almost certainly related, being identical at several genomic polymorphisms and differing only in one facet of the "EBNAprint," the size of the EBNA1 protein. Three different type 1 viruses were also isolated from this patient, two of which carried EBNA2 genes with the same pattern of sequence variation from B95.8 as the recombinant; however, since this is a fairly common pattern of variance, the relationship of these viruses to the recombinant remains an open question. We infer that intertypic recombinants of EBV are not uncommon in HIV-positive T-cell-immunocompromised patients, that they arise in such individuals as a consequence of their increased frequency of mixed-type infections, and that they will prove capable of efficient transmission in the human population.

Epstein-Barr virus (EBV) DNA in saliva and EBV serology of HIV-1-infected persons with and without hairy leukoplakia

Secretion of Epstein-Barr virus (EBV) in saliva, as well as serum antibody titres against various EBV antigens, were analyzed in respect of (1) 15 HIV-1-infected patients with oral hairy leukoplakia proven to contain EBV by in situ hybridization, (2) 45 HIV-1 infected patients without hairy leukoplakia, (3) 10 HIV-1 infected patients treated with acyclovir or foscarnet and (4) 21 healthy controls. The numbers of CD4+ cells in the peripheral blood were also recorded. The HIV-1 infected patients were at various stages of HIV-1-associated disease. Excretion of EBV DNA in the saliva was determined by means of the polymerase chain reaction (PCR) while the amount of EBV DNA in positive samples was estimated by repeated titrations. The frequency of shedding of EBV DNA increased from 33% in healthy controls to 78% in asymptomatic HIV-1 infected persons, but did not increase significantly with progression of HIV-1-associated disease. The titres of EBV DNA in saliva correlated inversely and significantly with the number of CD4+ cells in the peripheral blood. All patients with hairy leukoplakia shed by EBV DNA in their saliva but the titres were not significantly higher than those of other HIV-1 infected persons. The serum titres of antibodies against EBV nuclear antigen 1 (EBNA-1) correlated positively and significantly with the CD4+ cell count in the peripheral blood. EBNA-1 IgG antibody in the serum was also significantly lower in symptomatic than in asymptomatic HIV-1 infected persons. There were, however, no significant differences in serum antibodies to various EBV antigens between patients with and without hairy leukoplakia.

Expression of IL-10, IL-4 and interferon-gamma in unstimulated and mitogen-stimulated peripheral blood lymphocytes from HIV-seropositive patients

Infection of immune cells with HIV induces dysregulation of cytokines which may play a vital role in HIV pathogenesis. We analysed the expression of T helper type 1 (Th1) (interferon-gamma (IFN-gamma)) and Th2 (IL-4, IL-10) type cytokines in peripheral blood lymphocytes (PBL) from HIV+ patients. The semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that IFN-gamma mRNA in unstimulated PBL was significantly decreased and IL-10 mRNA was significantly upregulated in patients with < 400 CD4+ T cells/mm3 (n = 30) as compared to patients with > 400 CD4+ T cells/mm3 (n = 6) and normal controls (n = 16). In addition, IL-10 mRNA levels were inversely associated with IFN-gamma expression. Similar results were obtained by measuring IL-10 production in the supernatants of PBL cultured in vitro without stimulation by employing an enzyme immunosorbent assay (ELISA). However, the levels of IL-4 and IFN-gamma produced by unstimulated PBL were undetectable by ELISA. Mitogen stimulation of PBL revealed two groups of HIV+ individuals based on IL-10 production. PBL from one set of individuals produced low levels of IL-10 (low IL-10 producers) whereas the other group produced IL-10 comparable to that of normal controls (IL-10 producers). Production of IL-4 was significantly reduced in HIV+ individuals with < 400 CD4+ T cells/mm3 as compared to the normal controls. However, ability to produce IFN-gamma by mitogen-stimulated total PBL and CD4+ purified cells was not impaired in HIV+ individuals. These results suggest that unstimulated and mitogen-stimulated PBL of HIV+ individuals exhibit dysregulation of Th2 type cytokines which may play a role in HIV immunopathogenesis.

Detection of Epstein-Barr virus DNA in tongue tissues from AIDS autopsies without clinical evidence of oral hairy leukoplakia

Epstein-Barr virus (EBV) DNA was detected by in situ hybridization at 3 sites of 30 samples taken from clinically normal lateral border of tongue mucosa from 15 AIDS autopsies and in none of 20 samples from 10 controls. The first positive case showed a thin layer of parakeratosis correlated with positive signals for EBV in one area and an adjacent area without obvious parakeratosis was also positive for EBV. These findings were present on both sides of the tongue. The second case was unilaterally positive for EBV and parakeratosis was absent. The hybridization signals were localised to koilocyte-like cells in the stratum spinosum, as in oral hairy leukoplakia (OHL). These observations suggest that the in situ hybridization technique can detect very early or subclinical OHL, and supports the role of EBV in the pathogenesis of this lesion.

Epstein-Barr virus in lingual epithelium of liver transplant patients

Thirty-three liver transplant patients and 20 controls were examined for the presence of EBV in epithelium of the lateral border of the tongue by negative staining electron microscopy. Five of the specimens (15%) showed particles typical of the herpes virus family, while all controls were negative for EBV. In 3 of the 5 patients moderate oral hairy leukoplakia was observed clinically. Our results indicate that EBV may be expressed at the lateral border of the tongue of liver transplant patients, who in some cases show oral hairy leukoplakia clinically.

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.

Epstein-Barr virus latent and replicative gene expression in oral hairy leukoplakia

Oral hairy leukoplakia is an epithelial lesion of the tongue associated with productive infection by Epstein-Barr virus (EBV). However, no data concerning the pattern of EBV latent gene expression have been reported, and it remains unresolved whether true latent infection occurs in basal cell layers of oral hairy leukoplakia. We have studied six cases of oral hairy leukoplakia using monoclonal antibody immunohistology for EBV latent--EB nuclear antigen (EBNA) 1, EBNA 2 and latent membrane protein 1 (LMP 1); immediate-early (BZLF1); and replicative (EA, VCA, MA) proteins, and for the EBV-receptor (CD21 antigen). EBV DNA was demonstrated by nucleic acid in situ hybridization. Mid- to upper-zone keratinocytes contained EBV DNA and co-expressed EBNA 1, EBNA 2 (5 of 6 cases), LMP 1, BZLF1 protein, EA, VCA and MA. No EBV genome or gene expression could be demonstrated in basal or parabasal cells. Spinous keratinocytes were labelled by anti-CD21 antibodies HB5 and B2, but did not express the EBV-receptor as defined by reactivity with OKB7. The co-expression of latent and replicative infection-associated antigens is striking, indicating possible functional roles for latent proteins during the productive cycle. Our results suggest that oral hairy leukoplakia is caused by repeated direct infection of upper epithelial cells with virus from saliva or adjacent replicatively infected cells, rather than by a latent EBV infection of basal epithelial cells with a differentiation-dependent switch to productive infection as previously proposed.

HIV-related infections of the oral cavity

Oral infections are among the first manifestations of infection by the human immunodeficiency virus (HIV). They include fungal, viral, and bacterial infections and range from being essentially trivial, through troublesome to life threatening. Although some infections are due to overproliferation of the normal oral flora, others are due to organisms that normally are not found in the mouth. The clinical features of many of these infections have now been characterized, and clinical trials have indicated the optimal management. However, for many infections, the underlying processes are still not clear, and improvements in treatment are necessary.

Prevalence of Epstein-Barr virus and human papillomavirus in oral mucosa of HIV-infected patients

Epstein-Barr virus (EBV) has been implicated in the genesis of oral hairy leukoplakia (OHL). Initially, OHL was also associated with human papillomavirus (HPV) as evidenced by staining with antiserum to papillomavirus common structural antigens and reports of two HPV-positive OHL as detected by in situ DNA hybridization. The aims of this study were to determine the prevalence of EBV and HPV DNA in OHL and normal oral mucosa and to explain the basis for the staining of OHL tissues with antibodies to papillomavirus common structural antigens. EBV DNA was detected by in situ hybridization in 47 of 47 cases of OHL from human immunodeficiency virus (HIV)-seropositive individuals and in 1 of 10 biopsies of clinically normal buccal mucosa from the same group of individuals. Twenty-five of 35 OHL specimens stained with antibody to papillomavirus common structural antigens. There was no staining of two EBV-containing lymphoblastoid lines, indicating that the staining with anti-papillomavirus antibody was not due to antigenic cross-reactivity with EBV antigens. HPV DNA was detected by polymerase chain reaction amplification in 10 of 18 OHL specimens and in 6 of 10 normal buccal mucosa specimens. Our results indicate that EBV and HPV are present frequently in OHL and that HPV can be found regularly in histologically normal mucosa.

Immunocytochemical detection of herpes viruses in oral smears of HIV-infected patients

Cytologic smears (CS) were taken from the lateral border of the tongue of HIV-seropositive patients (HIV+) (n = 39) and of seronegative controls (HIV-) (n = 19) and examined by immunocytochemistry (APAAP) and in situ hybridization (ISH) (biotinylated DNA probes) for the presence of viral antigens/DNA of EBV and CMV. While none of the HIV controls showed positive results for EBV antigen, 61% (APAAP) resp. 79% (ISH) of oral epithelial cells in the group of HIV+ patients were EBV-positive. While all CS taken from areas with the clinical diagnosis of hairy leukoplakia (HL) were EBV positive (APAAP and/or ISH), the detection of EBV in CS from uninvolved oral mucosa seemed to be associated with the later development of HL. In the group of HIV+ patients the detection rate for CMV was about five times (APAAP) resp. three times (ISH) higher than in HIV- persons. This non-invasive technique seems to be a valuable tool to screen for viral antigens/genomes.

Antibodies to Epstein-Barr virus and cytomegalovirus in relation to CD4 cell number in human immunodeficiency virus 1 infection

Interaction between herpesviruses and human immunodeficiency virus (HIV)1 is postulated in the progression of HIV disease. In order to evaluate the specific antibody responses directed to Epstein-Barr virus (EBV) and cytomegalovirus (CMV) and to provide serological evidence suggesting reactivation of these viruses able to accelerate the immunodeficiency, we studied IgA and IgG titres to EBV and CMV in the serum of HIV positive patients in relation to the CD4 cell number. The titres of IgG antibodies to EBV and the prevalence of IgG to CMV were significantly higher in HIV positive patients compared to control high risk HIV negative subjects. In HIV infected patients, anti-VCA IgG antibodies increased and anti-EBNA IgG antibodies decreased progressively in relation to the decline of CD4 cell number whereas anti-CMV IgG antibodies did not varied significantly at the same time. Anti-VCA IgA and anti-EA IgG antibodies were found uncommonly and with low titres. IgA antibodies to EA and CMV were not detected in any patient. The variations in EBV antibody response that we describe in HIV infection were previously reported in other immunodeficiency states and could be distinctive of these diseases.

Application of molecular techniques in the rapid diagnosis of EBV-associated oral hairy leukoplakia

A rapid method for the detection of EBV-DNA in paraffin sections of lesions of oral hairy leukoplakia (OHL) is described. The method makes use of advances in molecular technology, including the use of synthetic oligonucleotides with digoxigenin labelling in an in situ hybridisation (ISH) reaction, which can be completed in 24 h. Using this method, sections from 15 of 17 patients clinically diagnosed as having OHL contained readily detectable EBV-DNA in small foci along the upper layers of the stratum spinosum. The sections examined from the two remaining patients appeared to be EBV-DNA negative but both patients were on AZT therapy and one was in addition receiving acyclovir.

Reactivation of Epstein-Barr virus during early infection with human immunodeficiency virus

Reactivation of Epstein-Barr virus (EBV) in early human immunodeficiency virus (HIV) infection was investigated in 49 homosexual men who seroconverted to HIV (cases) as compared with 49 matched controls who remained seronegative to HIV during a longitudinal study. EBV infection was reactivated in cases 6 months, but not 12 months, prior to HIV seroconversion as compared with controls and remained reactivated during 18 months of follow-up after HIV seroconversion, as shown by increases in immunoglobulin (Ig) G antibody titers to EBV early antigen. Antibody titers to EBV viral capsid antigen did not differ between cases and controls prior to the time of seroconversion to HIV but were significantly increased among cases by the first seropositive study visit and remained elevated during the 18 months after HIV seroconversion. Total serum IgG levels were increased in cases at the visit of seroconversion, and during 18 months of follow-up, but did not correlate with enhanced IgG production specific for EBV antigens. Significant decreases in numbers of CD4+ cells and increases in numbers of CD8+ cells during this early phase of HIV infection were not associated with changes in patterns of EBV antibody responses. Reactivation of EBV beginning 6 months before HIV seroconversion may have implications regarding the role of this herpesvirus in the pathogenesis of HIV.