Quantitative analysis of Epstein-Barr virus load by using a real-time PCR assay

Human herpesvirus 8 DNA load in the leukocytes correlates with the platelet counts in HIV type 1-infected individuals

Abstract Human herpes virus 8 (HHV-8) is known to be reactivated in immunocompromised situations and it is associated with Kaposi's sarcoma (KS) and some hematological diseases. The aim of this study was to analyze the effect of HHV-8 on HIV-1 infection, especially on thrombocytopenia complicated with HIV infection. The HHV-8 DNA load was determined by a quantitative real-time PCR, using leukocytes from 125 HIV-1-infected individuals. HHV-8 DNA was detected in 37 individuals. The increased HIV-1 load and reduced percentage of CD4-positive T cells were significantly associated with the presence of HHV-8. The prevalence and load for HHV-8 are higher in patients with KS than in patients without KS, but the difference is not significant. The increased HHV-8 DNA load was significantly correlated with thrombocytopenia, and platelet counts were significantly lower in individuals with HHV-8 than in individuals without HHV-8. We also obtained the negative correlations between changes in platelet counts and changes in HHV-8 DNA loads. The association between thrombocytopenia and HHV-8 has never been reported previously, apart from some case reports of Castleman's disease and KS. Various cytokines or chemokines are produced by HHV-8-infected cells, some of which have been reported to inhibit hematopoiesis. This may be one of the mechanisms by which HHV-8 infection induces thrombocytopenia. These results indicate that HHV-8 DNA in leukocytes may provide useful information for the assessment of the clinical appearance of HIV-1 infection.

Quantitative PCR for the detection of genomic DNA of Epstein-Barr virus in ocular fluids of patients with uveitis

PURPOSE

To measure the genomic DNA from Epstein-Barr virus (EBV) in ocular fluids and to analyze the clinical relevance of EBV in uveitis.

METHODS

Intraocular fluids (30 aqueous humor and 30 vitreous fluid samples) were taken from 55 patients with uveitis after informed consent was obtained. Samples were assayed for EBV DNA using qualitative multiplex polymerase chain reaction (PCR) and quantitative real-time PCR. Antibodies to EBV were examined using a complement fixation test.

RESULTS

EBV DNA was detected in 17 of 60 samples (28%) and 16 of 55 patients (29%) using multiplex PCR. However, only three of the 17 samples showed significantly high copy numbers of EBV DNA with real-time PCR. EBV DNA was not detected in the serum of all patients. EBV-specific antibodies were positive in the serum of all patients, but not in the vitreous fluid. Vitreous anti-EBV antibodies were positive only in patients displaying genomic DNA of EBV in the vitreous samples.

CONCLUSIONS

EBV DNA was detected by qualitative PCR in ocular fluids of many uveitis patients, but only a small proportion of patients showed high viral loads on quantitative real-time PCR, indicating that replication of the virus takes place only in a few patients.

Measuring Epstein-Barr virus (EBV) load: the significance and application for each EBV-associated disease

Because Epstein-Barr virus (EBV) is ubiquitous and persists latently in lymphocytes, simply detecting EBV is insufficient to diagnose EBV-associated diseases. Therefore, measuring the EBV load is necessary to diagnose EBV-associated diseases and to explore EBV pathogenesis. Due to the diverse biology of EBV, the significance of measuring EBV DNA and the optimal type of specimen differ among EBV-associated diseases. Recent advances in molecular technology have enabled the EBV genome to be quantitated rapidly and accurately. Real-time polymerase chain reaction (PCR) is a rapid and reliable method to quantify DNA and is widely used not only as a diagnostic tool, but also as a management tool for EBV-associated diseases. However, each laboratory currently measures EBV load with its own "homebrew" system, and there is no consensus on sample type, sample preparation protocol, or assay units. The EBV real-time PCR assay system must be standardised for large-scale studies and international comparisons.

A new humanized mouse model of Epstein-Barr virus infection that reproduces persistent infection, lymphoproliferative disorder, and cell-mediated and humoral immune responses

The functional human immune system, including T, B, and natural killer lymphocytes, is reconstituted in NOD/Shi-scid/IL-2Rgamma(null) (NOG) mice that receive hematopoietic stem cell transplants. Here, we show that these humanized mice can recapitulate key aspects of Epstein-Barr virus (EBV) infection in humans. Inoculation with approximately 1 x 10(3) TD(50) (50% transforming dose) of EBV caused B cell lymphoproliferative disorder, with histopathological findings and latent EBV gene expression remarkably similar to that in immunocompromised patients. Inoculation with a low dose of virus (<or=1 x 10(1) TD(50)), in contrast, resulted in apparently asymptomatic persistent infection. Levels of activated CD8(+) T cells increased dramatically in the peripheral blood of infected mice, and enzyme-linked immunospot assay and flow cytometry demonstrated an EBV-specific T cell response. Immunoglobulin M antibody specific to the EBV-encoded protein BFRF3 was detected in serum from infected mice. The NOG mouse is the most comprehensive small-animal model of EBV infection described to date and should facilitate studies of the pathogenesis, prevention, and treatment of EBV infection.

Allogeneic hematopoietic stem cell transplantation for Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disease in Japan

Epstein-Barr virus (EBV)-associated T/NK-cell lymphoproliferative disease (LPD) has been linked to several different disorders. Its prognosis is generally poor and a treatment strategy has yet to be established. There are reports, however, that hematopoietic stem cell transplantation (HSCT) can cure this disease. To clarify the current situation regarding allogeneic hematopoietic stem cell transplantation (allo-HSCT) for EBV-associated T/NK-LPD, a nationwide survey was performed in Japan. Data for 74 patients were collected. There were 42 cases of chronic active EBV infection (CAEBV), 10 cases of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), and 22 cases of EBV-associated lymphoma/leukemia (EBV-lymphoma/leukemia). Of those with CAEBV, 54% had the EBV-infected T-cell type and 59% with EBV-lymphoma/leukemia had the EBV-infected NK-cell type. Most patients with EBV-HLH and EBV-lymphoma/leukemia received allo-HSCT within 1 year after onset compared to only 14% of patients with CAEBV. The event-free survival (EFS) rate following allo-HSCT was 0.561 +/- 0.086 for CAEBV, 0.614 +/- 0.186 for EBV-HLH, and 0.309 +/- 0.107 for EBV-lymphoma/leukemia. The EFS of allo-HSCT with conventional conditioning was 0.488 +/- 0.074 and with reduced-intensity conditioning was 0.563 +/- 0.124. Thus, in a substantial number of cases, EBV-associated T/NK-LPD can be cured by either allogeneic conventional stem cell transplantation or reduced-intensity stem cell transplantation.

Oral mucosal reactivation rates of herpesviruses among HIV-1 seropositive persons

Herpes simplex virus, cytomegalovirus and Epstein-Barr virus infections are prevalent among HIV-1 infected persons. The relationships between salivary shedding of these herpesviruses have not been characterized. Salivary samples were collected on a median of 61 consecutive days from 41 HIV-1 seropositive persons and tested for HSV-1, HSV-2, CMV and EBV. HSV was detected on 5%, CMV on 19% and EBV on 71% of the days of sampling. HSV shedding was not related to CMV or EBV shedding rates. Persons with EBV shedding rates >40% had CMV DNA detected in their saliva significantly more often than those with EBV shedding rates <or=40% (P=0.008). The odds of detecting CMV were greater on days with HSV (OR 2.5, 95% CI 1.4, 4.4) or EBV (OR 3.8, 95% CI 1.9, 7.9) shedding. No significant associations between HSV shedding rates and CD4 count, plasma HIV-1 RNA or HAART were observed. Increasing plasma HIV-1 RNA was associated with greater frequency (P=0.01) and quantity (P<0.001) of EBV shedding. Among persons not receiving HAART, CD4 counts >200 cells/mm(3) were associated with lower frequency (P=0.02) and quantity (P=0.03) of CMV compared with CD4 counts <or=200 cells/mm(3). These data suggest that separate factors influence mucosal shedding of each of the three classes of herpesviruses but that virological interactions between the pathogens also exist.

Multicenter comparison of PCR assays for detection of human herpesvirus 6 DNA in serum

Human herpesvirus 6 (HHV-6) is a ubiquitous virus with which infections have been associated with pathologies ranging from delayed bone marrow engraftment to a variety of neurological diseases. The lack of a standardized assay that can be used to detect and estimate HHV-6 DNA contents in various clinical specimens can lead and has led to discordant results among investigators and on the potential association of HHV-6 to diseases. To identify the most reliable and sensitive assays, an identical set of 11 coded serum samples spiked with various quantities of the HHV-6A variant (range, 4 to 400,000 genome copies/ml) was sent to eight independent laboratories around the world. Each laboratory was asked to estimate the HHV-6 DNA content by use of its own protocols and assays. Among the various assays, three TaqMan-based real-time PCR assays yielded quantities that were closest to the quantity of HHV-6 that had been spiked. To provide better homogeneity between the results from the different laboratories working on HHV-6, we propose that investigators interested in quantifying HHV-6 in clinical samples adopt one of these assays.

Two cases of chronic active Epstein-Barr virus infection in which EBV-specific cytotoxic T lymphocyte was induced after allogeneic bone marrow transplantation

CAEBV is a high mortality and morbidity disease with life-threatening complications. Nevertheless, the treatment regimens for CAEBV have not yet been established. Although some reports have described CAEBV therapy involving treatments such as antiviral drugs, immunomodulatory agents, and immunochemotherapy, none of these treatments have been demonstrated to be effective. The only treatment reported to be effective is allogeneic SCT. However, the complications of SCT are severe, so treatment results have been poor. Recently, immunotherapy has been devised, but this is still in the developmental stage. In this report, two cases of CAEBV in which allogeneic SCT was performed soon after diagnosis are reported. In both cases, a high EBV genome titer in the peripheral blood was detected at onset. After SCT, the EBV genome titer decreased as CTL activity gradually increased. This fact suggested that not only high-dose chemotherapy as a preconditioning treatment of SCT but also increased CTL activity which could eliminate virus-infected cells might be effective, although additional cases should be studied in order to establish effective treatments.

Combined automated cell and flow cytometric analysis enables recognition of persistent polyclonal B-cell lymphocytosis (PPBL), a study of 25 patients

Persistent polyclonal B-cell lymphocytosis (PPBL) is an extremely rare disorder, which occurs almost exclusively in smoking women and is characterized by a lymphocytosis with circulating binucleated lymphocytes. We analyzed 25 PPBL patients with respect to immunophenotype and by adaptive cluster analysis system (ACAS). Furthermore, HLA type, presence of Epstein-Barr virus (EBV) DNA in B cells, and clinical data were evaluated. Overall, the median percentages of B cells in PPBL patients with expression of CD5(dim), CD23(dim), CD25, CD27, and FMC7 were 21%, 38%, 16%, 74%, and 93%. Compared to normal controls, ACAS revealed a subset of nucleic-acid-rich lymphocytes located between the regular lymphocyte and regular monocyte region. Sixteen (64%) of 25 patients carried a HLA DR7 phenotype. Quantitative real-time polymerase chain reaction analysis did not detect relevant amounts of EBV DNA in circulating B cells of any patient. During a median follow-up of 5 years, a single patient developed lymphoplasmacytic lymphoma. The abnormal morphology and frequent, albeit dim, expression of CD5 and CD23 in PPBL may result in erratic diagnostic assignment of this benign disorder. However, incorporation of immunophenotyping and ACAS into the diagnostic algorithm allows recognition of PPBL in routine analysis and its differentiation from malignant B cell lymphoproliferative diseases. We found that an infection of a significant percentage of PPBL cells by EBV is unlikely. The observation of malignant lymphoma in a single patient implicates that evolution into a clonal malignant transformation may occasionally occur in PPBL.

Screening for PTLD in lung and heart-lung transplant recipients by measuring EBV DNA load in bronchoalveolar lavage fluid using real time PCR

Pediatric L-HLTx recipients are at risk for developing PTLD with the lung being a primary site of disease. We hypothesized that BALF is a better sample than peripheral blood for measuring EBV DNA load in this high-risk population. Archived BALF specimens from pediatric L-HLTx recipients with and without PTLD were assayed for EBV DNA load using a quantitative real time TaqMan PCR assay. These values were compared with values determined in peripheral blood by a competitive PCR assay. Fifty-five BALF specimens from 16 L-HLTx patients were evaluated. Three patients with PTLD had mean BALF EBV DNA load values almost 50-fold higher than subjects without PTLD (4.6 x 10(5) copies/mL vs. 1.0 x 10(4) copies/mL). Patients who were EBV seronegative pretransplantation (i.e., high risk for PTLD) had elevated EBV DNA load values vs. patients who were EBV seropositive pretransplantation, regardless of the diagnosis of PTLD (mean values of 3.2 x 10(5) copies/mL vs. 1.1 x 10(4) copies/mL). Lastly, BALF analysis identified all subjects with PTLD, whereas peripheral blood analysis identified only one of these cases. Therefore, it can be concluded that monitoring EBV DNA load in BALF following L-HLTx facilitates detection of PTLD in high-risk patients and may be superior to peripheral blood assays.

Clinical and virological characteristics of 15 patients with chronic active Epstein-Barr virus infection treated with hematopoietic stem cell transplantation

BACKGROUND

Chronic active Epstein-Barr virus (EBV) infection is characterized by recurrent infectious mononucleosis-like symptoms, and infected patients have high viral loads in their peripheral blood. Standard therapy for the disease has not yet been established. Recently, hematopoietic stem cell transplantation (HSCT) has been introduced and has the potential to become a standard treatment, although guidelines for HSCT to treat chronic active EBV infection have not yet been proposed.

METHODS

Fifteen patients were retrospectively analyzed, both clinically and virologically, to investigate the factors associated with prognosis of chronic active EBV infection treated with HSCT.

RESULTS

After HSCT, 7 patients died after survival periods that ranged from 1 to 16 months (mean duration of survival after HSCT, 5 months). Three patients were considered to have died of transplantation-related complications. The duration between infection onset and diagnosis was significantly longer in patients who died than in those who survived. Five of the 7 patients who died experienced > or =3 life-threatening complications. The plasma concentrations of interferon-gamma, interleukin-10, thrombomodulin, and soluble E-selectin did not differ significantly between the groups of patients. With regard to sequence variations in the EBV latent membrane protein 1 gene, no specific patterns were found in the patients who died. Importantly, the plasma EBV load at diagnosis was significantly higher in patients who died than in living patients. Moreover, plasma viral load was shown to be an important factor to monitor during follow-up for patients after HSCT.

CONCLUSIONS

The number of life-threatening complications and plasma viral load are indicative of the stage of disease progression and may be useful factors for predicting the outcome of HSCT.

Multiplex real-time PCR for the detection and quantification of latent and persistent viral genomes in cellular or plasma blood fractions

In common with latent viruses such as herpesviruses, parvovirus B19, HBV and GBV-C are contained successfully by the immune response and persist in the host. When immune control breaks down, reactivation of both latent and persistent viruses occurs. Two multiplex assays were developed (B19, HBV, HHV-8), (EBV, CMV, VZV) for blood screening, and tested on blood donor samples from Ghana to determine baseline prevalence of viraemia in immunocompetent persons. Single-virus real-time quantitative PCR (qPCR) assays were optimised for viral load determination of positive initial screening. The qPCR method utilised was absolute quantification with external standards. Multiplex and single-virus qPCR assays had similar sensitivity, except for the B19 assay in which sensitivity was 100-fold lower. Assays were optimised for reproducibility and repeatability, with R(2) of 0.9 being obtained for most assays. With the exception of B19 and CMV, assays had 100% detection limit ranging between 10(1) and 10(2) copies, IU or arbitrary units under single-virus and multiplex assay conditions. The prevalence of viraemia was 1.6% HBV (0.8% DNA+/HBsAg-, 0.8% DNA+/HBsAg+), 0.8% parvovirus B19, and 3.3% GBV-C viraemia in the plasma fraction. The prevalence of four herpesviruses was 1.0% HHV-8, 0.85% CMV, and 8.3% EBV, and no detectable VZV viraemia.

Herpesvirus prevalence and viral load in healthy blood donors by quantitative real-time polymerase chain reaction

BACKGROUND

After primary infection, human herpesviruses (HHVs) maintain long-term latent persistence, often punctuated years later by sporadic episodes of symptomatic lytic activation. Also, blood-borne herpesvirus from healthy persistently infected blood donors can lead to active primary infection of immunocompromised transfusion recipients.

STUDY DESIGN AND METHODS

Utilizing a set of newly developed real-time polymerase chain reaction assays for detection and quantification of all eight human herpesviruses, the prevalence and viral DNA load of white cell-enriched blood from 100 randomly selected blood donors from the southeast Texas region are reported.

RESULTS

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), and HHV-8 DNA were not detected in any donor sample. In contrast, Epstein-Barr virus (EBV) (72%) and HHV-7 (65%) were commonly detected, HHV-6 (30%) was often detected (Type B only), and cytomegalovirus (CMV; 1%) was rarely detected. Median viral loads of positive samples (per milliliter of blood) ranged from 4278 for HHV-6 to less than 46 for EBV.

CONCLUSIONS

These results suggest that the potential for transfusion-mediated transmission of herpesviruses from healthy adult blood donors is high for EBV and HHV-7; moderately high for HHV-6; uncommon for CMV; and rare for HSV-1, HSV-2, VZV, and HHV-8. Perhaps the most remarkable finding in this study was the detection of a single donor sample with greater than 6.1 x 10(7) HHV-6 Type B genome equivalents per mL blood. Given that this extraordinarily high level of HHV-6 DNA was obtained from a healthy adult blood donor, this phenomenon is likely unrelated to active infection or immunodeficiency.

Induction of apoptosis in Epstein-Barr virus-infected B-lymphocytes by the NF-kappaB inhibitor DHMEQ

Epstein-Barr virus (EBV) causes EBV-associated lymphoproliferative diseases in patients with profound immune suppression. Most of these diseases are life-threatening and the prognosis of AIDS-associated lymphomas is extremely unfavorable. Polyclonal expansion of virus infected B-cell predisposes them to transformation. We investigated the possibility of nuclear factor kappa B (NF-kappaB) inhibition by dehydroxymethylepoxyquinomicin (DHMEQ) for the treatment and prevention of EBV-associated lymphoproliferative diseases. We examined the effect of DHMEQ on apoptosis induction in four EBV-transformed lymphoblastoid cell lines as well as peripheral blood mononuclear cells infected with EBV under immunosuppressed condition. DHMEQ inhibits NF-kappaB activation in EBV-transformed lymphoblastoid cell lines and induces apoptosis by activation of mitochondrial and membranous pathways. Using an in vivo NOD/SCIDgammac mouse model, we showed that DHMEQ has a potent inhibitory effect on the growth of lymphoblastoid cells. In addition, DHMEQ selectively purges EBV-infected cells expressing latent membrane protein (LMP) 1 from peripheral blood mononuclear cells and inhibits the outgrowth of lymphoblastoid cells. These results suggest that NF-kappaB is a molecular target for the treatment and prevention of EBV-associated lymphoproliferative diseases. As a potent NF-kappaB inhibitor, DHMEQ is a potential compound for applying this strategy in clinical medicine.

Use of multiplex PCR and real-time PCR to detect human herpes virus genome in ocular fluids of patients with uveitis

AIM

To measure the genomic DNA of human herpes viruses (HHV) in the ocular fluids and to analyse the clinical relevance of HHV in uveitis.

METHODS

After informed consent was obtained, a total of 111 ocular fluid samples (68 aqueous humour and 43 vitreous fluid samples) were collected from 100 patients with uveitis. The samples were assayed for HHV-DNA (HHV1-8) by using two different polymerase chain reaction (PCR) assays, qualitative PCR (multiplex PCR) and quantitative PCR (real-time PCR).

RESULTS

In all of the patients with acute retinal necrosis (n = 16) that were tested, either the HSV1 (n = 2), HSV2 (n = 3), or VZV (n = 11) genome was detected. In all patients, high copy numbers of the viral DNA were also noted, indicating the presence of viral replication. In another 10 patients with anterior uveitis with iris atrophy, the VZV genome was detected. When using multiplex PCR, EBV-DNA was detected in 19 of 111 samples (17%). However, real-time PCR analysis of EBV-DNA indicated that there were only six of the 19 samples that had significantly high copy numbers. The cytomegalovirus (CMV) genome was detected in three patients with anterior uveitis of immunocompetent patients and in one immunocompromised CMV retinitis patient. In addition, one patient with severe unilateral panuveitis had a high copy number of HHV6-DNA. There was no HHV7- or HHV8-DNA detected in any of the samples.

CONCLUSIONS

A qualitative multiplex PCR is useful in the screening of viral infections. However, the clinical relevance of the virus infection needs to be evaluated by quantitative real-time PCR.

Development of Langerhans cell histiocytosis associated with chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus (CAEBV) infection is characterized by a status of lymphoproliferative disease of EBV-infected cells, resulting in chronic or recurrent infectious mononucleosis-like symptoms. CAEBV is always accompanied by life-threatening complications. We report the case of a 2-year-old female patient with CAEBV who subsequently developed Langerhans cell histiocytosis (LCH) presenting with bilateral exophthalmos, bone, and skin involvement. In situ hybridization for EBER revealed EBV-infected B-cells present in lesional tissue implying that interactions between EBV-infected B-cells and lesional Langerhans cells may be associated with the development of LCH.

A new animal model for primary and persistent Epstein-Barr virus infection: human EBV-infected rabbit characteristics determined using sequential imaging and pathological analysis

Most adults have persistent Epstein-Barr virus (EBV)-infection. Adolescents and young adults with primary EBV-infection frequently develop infectious mononucleosis. Latent EBV-infection is associated with various diseases, neoplasms, and hematological disorders. In vivo animal models of human EBV infection, such as non-human primates, have had limited success. A new rabbit model for primary human EBV-infection is described in this study. Seven male rabbits inoculated intravenously with EBV were sequentially imaged by ultrasonography and computed tomography, and examined for anti-EBV-VCA titer and EBV-DNA levels in blood. Six rabbits demonstrated transient splenomegaly, increased anti-EBV-VCA titers and/or EBV-DNA in blood. Transient infiltration of some EBER1-positive lymphocytes was observed in biopsied liver tissues. After splenomegaly, two rabbits tested continuously negative, two alternatively positive and negative, and one consistently positive EBV detection in blood for 470 days. One tested negative for both EBV DNA and splenomegaly. On the 14th day, mild to moderate numbers of EBER1-positive lymphocytes expressing LMP1, EBNA2, or ZEBRA infiltrated mainly in enlarged white pulps of two splenectomized materials. These cells included both B and T cells. EBV clonality analysis revealed an oligoclonal pattern. These indicate that EBV-inoculated rabbits exhibiting heterogenous host reactions are a good model for primary and persistent human EBV infection.

Allogeneic stem cell transplantation in children with leukemia using human leukocyte antigen-mismatched unrelated donors

Allogeneic HSCT is a curative treatment, when chemotherapy fails, for certain malignant diseases. In Europe, only 15% of the indicated children have an HLA-matched sibling available; in 65-70% of others, HLA allele-matched (9-10/10) UDs can be identified. For the rest, it is necessary to identify other alternative donors (HLA-mismatched family or unrelated cord blood). We present our data of HSCT using HLA partially allele-mismatched (7-8/10) UDs in 24 children with leukemia. Uniform GvHD prophylaxis was used (rATG, CsA and MTX). Acute GvHD grade II was diagnosed in 70.8% of the patients and grade III-IV in 12.5%. Overall incidence of chronic GvHD was 38.7% (extensive in 30%). The probability of EFS was 60.3% (95% CI 35.5-78.1) and OS was 74.9 (95% CI 49.1-88.9). No difference in survival between PBSC and BM recipients was observed. TRM at day + 100 was 4%, and overall was 12.5%. We conclude that used combination of drugs for GvHD prophylaxis is efficient even for patients transplanted with grafts from a HLA-mismatched UDs. It enables stable engraftment, good control of GvHD, full reconstitution of immunity, and is not connected with unacceptable transplant-related mortality.

Human herpesvirus 6 infection in adult living related liver transplant recipients

To analyze human herpesvirus 6 (HHV-6) infection in adult living related liver transplantation, we performed a virological analysis, including viral isolation, serological assay, and real-time polymerase chain reaction, of serially collected blood samples from 67 recipients. In addition, cytokine levels were measured to determine their role in viral reactivation. HHV-6 was isolated from only 4 recipients (6.0%), and viral DNA was detected in 15 (22.4%) of the 67 recipients. A significant increase in HHV-6 immunoglobulin G antibody titers was observed in 19 (28.4%) of the 67 recipients. Finally, 26 recipients (38.8%) had HHV-6 reactivation 2-6 weeks after transplantation. HHV-6 associated clinical features were analyzed in the 17 recipients presenting with either viremia or DNAemia. Two recipients with viremia and 3 recipients with DNAemia had unexplained fever at the time of viral infection. An increase in aminotransferase levels was observed in 2 recipients with viremia and 3 recipients with DNAemia. Recipients with liver cirrhosis caused by hepatitis B virus or hepatitis C virus infection as the underlying disease were more likely to have HHV-6 infection (P = 0.025). Mortality at the last follow-up in recipients with HHV-6 reactivation was significantly higher than in those without viral reactivation (P = 0.0118). Plasma interleukin-6 levels were significantly higher in the recipients with HHV-6 viremia than in the recipients without viremia at 4 weeks post-transplant (P = 0.0411). Moreover, tumor necrosis factor alpha levels were also higher in recipients with HHV-6 viremia (P < 0.0001) or reactivation (P = 0.0011) than in recipients without viremia or reactivation 4 weeks post-transplant.

One-step multiplex real-time PCR assay to analyse the latency patterns of Epstein-Barr virus infection

Epstein-Barr virus (EBV) establishes a latent infection with three types of viral gene expression. These latency types can be distinguished by the expression patterns of EBV nuclear antigen (EBNA)1, EBNA2, latent membrane protein (LMP)1, and LMP2. The EBV lytic cycle is initiated by the transcription of the EBV immediate early BZLF1 gene, which can be used to distinguish between a latent and a lytic infection. In this study, a one-step multiplex real-time PCR assay was developed to quantify the EBNA1, EBNA2, LMP1, LMP2, and BZLF1 expression levels simultaneously by relative quantification. To validate this assay, the quantitation of viral gene transcription was performed in EBV-positive B, T, and natural killer cell lines. Because of its rapidity, sensitivity, and specificity, this new assay can be used for quantitative analyses of the latency patterns of EBV infection and the switch from latency to lytic viral replication.

Systemic type Epstein-Barr virus-related lymphoproliferative diseases in children and young adults: challenges for pediatric hemato-oncologists and infectious disease specialists

Involvement of Epstein-Barr virus (EBV) has long been known in the development of various tumor-forming proliferating diseases, such as nasopharyngeal carcinoma in adults. However, in children and young adults more attention should be focused on systemic, severe type EBV-related diseases, such as fatal infectious mononucleosis, hemophagocytic syndrome, or chronic active EBV infection (CAEBV). These disorders show the typical clinical features of hemophagocytic lymphohistiocytosis (HLH). Although viral infectious diseases are mostly taken care of by infectious disease specialists, pediatric hemato-oncologists need to intervene in the treatment of this kind of disease because of their clonal and neoplastic disease characteristics and of their hematologically problematic, rapid, and life-threatening clinical courses.

The Epstein Barr virus DNA levels as a tumor marker in EBV-associated cancers

The Epstein Barr virus (EBV) is causally associated to several tumors of epithelial and lymphoid origin. The cancerogenic role in other than B cells has not been proven. This virus has been considered as a target in the effective diagnosis of EBV-associated tumors. For this purpose, molecular biology methods to measure EBV DNA load in the circulation of patients suffering from EBV-related cancers have been recently developed. In this review, we discuss the role of EBV DNA determination, the technical limitations of molecular assays measuring viral load and their impact on the clinical management of patients with EBV-associated tumors arising in the immunocompetent host. Several studies have recently clarified the biological and clinical characteristics of herpesvirus-associated tumors. However, some additional issues must be clarified before introducing viral load determinations into clinical practice. Firstly, since the various EBV-related tumors have different etiopathological and clinical characteristics, the most appropriate biological samples and analytical cut off values must be clearly defined in each group of patients. Secondly, a standardization of the assay, including the definition of the gene segment to be amplified, the use of an international reference for the standard curve and disease-related cut-off values, is strongly required. Thirdly, the interpretation of laboratory data may benefit from an improved design of the studies and obtaining an aggregate of patients from different institutions, pooling these together, in order to have a sample size that is adequate to reinforce the statistical power of the studies.

Advanced therapeutic and prophylactic strategies for Epstein-Barr virus infection in immunocompromised patients

Epstein-Barr virus (EBV) is an ubiquitous human herpesvirus. Primary infection is generally subclinical but in certain circumstances, such as in patients with either hereditary or secondary immunodeficiency, EBV infection may cause overt disease that is often lethal. Strategies for the prophylaxis and treatment of these potentially life-threatening complications of EBV infection have advanced dramatically. They include immunological-based approaches targeted at EBV-infected cells, as well as improvement in the treatment of the underlying and predisposing disease. This review will discuss EBV biology and immune events that occur in both immunocompetent and immunocompromised individuals and introduce the novel prophylactic and therapeutic strategies for EBV-associated life-threatening diseases.

Long-term treatment with methotrexate or tumor necrosis factor alpha inhibitors does not increase epstein-barr virus load in patients with rheumatoid arthritis

OBJECTIVE

We previously demonstrated that patients with rheumatoid arthritis (RA) have a 10-fold systemic Epstein-Barr virus (EBV) overload, very similar to that observed in healthy organ transplant recipients. Our objective was to monitor EBV load over time in patients with RA receiving methotrexate, infliximab, or etanercept to detect possible immunosuppression-associated EBV dysregulation, as described in posttransplant lymphoproliferative disease.

METHODS

The EBV load in the peripheral blood mononuclear cells (PBMCs) from 19 patients receiving methotrexate, 68 patients receiving infliximab, and 48 patients receiving etanercept was monitored for durations ranging from 6 months to 5 years using a real-time polymerase chain reaction assay previously developed for that purpose. The effect of treatment duration on EBV load and the link between the Disease Activity Score in 28 joints and EBV load were analyzed by generalized estimating equations.

RESULTS

Methotrexate tended to decrease EBV load over time, but this did not reach significance. Tumor necrosis factor alpha (TNFalpha) inhibitors did not significantly modify EBV load over time. Finally, high disease activity was significantly associated with high EBV load.

CONCLUSION

Long-term usage of methotrexate or TNFalpha inhibitors in patients with RA does not significantly influence EBV load in PBMCs.

Immunodominance of lytic cycle antigens in Epstein-Barr virus-specific CD4+ T cell preparations for therapy

BACKGROUND

Epstein-Barr virus (EBV) is associated with a number of human malignancies. EBV-positive post-transplant lymphoproliferative disease in solid organ and hematopoietic stem cell transplant recipients has been successfully treated by the adoptive transfer of polyclonal EBV-specific T cell lines containing CD4+ and CD8+ T cell components. Although patients receiving T cell preparations with a higher CD4+ T cell proportion show better clinical responses, the specificity of the infused CD4+ component has remained completely unknown.

METHODOLOGY/PRINCIPAL FINDINGS

We generated LCL-stimulated T cell lines from 21 donors according to clinical protocols, and analyzed the antigen specificity of the CD4+ component in EBV-specific T cell preparations using a genetically engineered EBV mutant that is unable to enter the lytic cycle, and recombinantly expressed and purified EBV proteins. Surprisingly, CD4+ T cell lines from acutely and persistently EBV-infected donors consistently responded against EBV lytic cycle antigens and autoantigens, but barely against latent cycle antigens of EBV hitherto considered principal immunotherapeutic targets. Lytic cycle antigens were predominantly derived from structural proteins of the virus presented on MHC II via receptor-mediated uptake of released viral particles, but also included abundant infected cell proteins whose presentation involved intercellular protein transfer. Importantly, presentation of virion antigens was severely impaired by acyclovir treatment of stimulator cells, as currently performed in most clinical protocols.

CONCLUSIONS/SIGNIFICANCE

These results indicate that structural antigens of EBV are the immunodominant targets of CD4+ T cells in LCL-stimulated T cell preparations. These findings add to our understanding of the immune response against this human tumor-virus and have important implications for the improvement of immunotherapeutic strategies against EBV.

Real-Time PCR: Revolutionizing Detection and Expression Analysis of Genes

Invention of polymerase chain reaction (PCR) technology by Kary Mullis in 1984 gave birth to real-time PCR. Real-time PCR - detection and expression analysis of gene(s) in real-time - has revolutionized the 21(st) century biological science due to its tremendous application in quantitative genotyping, genetic variation of inter and intra organisms, early diagnosis of disease, forensic, to name a few. We comprehensively review various aspects of real-time PCR, including technological refinement and application in all scientific fields ranging from medical to environmental issues, and to plant.

Chronic herpesvirus reactivation occurs in aging

The aged immune system is characterized by clonal expansions of CD8+ T cells of which a substantial portion are directed against Epstein-Barr virus (EBV) and cytomegalovirus (CMV). It is unknown if these expansions represent increased viral reactivation or simply reflect an accumulation over time. We investigated herpesvirus reactivation in young and old subjects co-infected with CMV and EBV. Using molecular and serological techniques, we found significant increases in both the frequency and magnitude of EBV and CMV reactivation in elderly subjects. CMV DNA was frequently detected in the urine of elderly subjects; EBV load in peripheral blood was also significantly increased. Notably, EBV DNA in plasma was detected in a majority of the elderly subjects which was supported by frequent transcription of late structural genes. Furthermore, CD8+ T cells specific for EBV structural antigens were detected in samples from the elderly. Samples from our younger control group were negative for EBV DNA in plasma, CMV DNA in urine, expression of structural transcripts, and lacked CD8+ T cells specific for EBV structural antigens. These findings indicate that the aged immune system is no longer able to control EBV and CMV reactivation that could now be characterized as chronic instead of latent.

Immune system changes during simulated planetary exploration on Devon Island, high arctic

Background

Dysregulation of the immune system has been shown to occur during spaceflight, although the detailed nature of the phenomenon and the clinical risks for exploration class missions have yet to be established. Also, the growing clinical significance of immune system evaluation combined with epidemic infectious disease rates in third world countries provides a strong rationale for the development of field-compatible clinical immunology techniques and equipment. In July 2002 NASA performed a comprehensive immune assessment on field team members participating in the Haughton-Mars Project (HMP) on Devon Island in the high Canadian Arctic. The purpose of the study was to evaluate the effect of mission-associated stressors on the human immune system. To perform the study, the development of techniques for processing immune samples in remote field locations was required. Ten HMP-2002 participants volunteered for the study. A field protocol was developed at NASA-JSC for performing sample collection, blood staining/processing for immunophenotype analysis, whole-blood mitogenic culture for functional assessments and cell-sample preservation on-location at Devon Island. Specific assays included peripheral leukocyte distribution; constitutively activated T cells, intracellular cytokine profiles, plasma cortisol and EBV viral antibody levels. Study timepoints were 30 days prior to mission start, mid-mission and 60 days after mission completion.

Results

The protocol developed for immune sample processing in remote field locations functioned properly. Samples were processed on Devon Island, and stabilized for subsequent analysis at the Johnson Space Center in Houston. The data indicated that some phenotype, immune function and stress hormone changes occurred in the HMP field participants that were largely distinct from pre-mission baseline and post-mission recovery data. These immune changes appear similar to those observed in astronauts following spaceflight.

Conclusion

The immune system changes described during the HMP field deployment validate the use of the HMP as a ground-based spaceflight/planetary exploration analog for some aspects of human physiology. The sample processing protocol developed for this study may have applications for immune studies in remote terrestrial field locations. Elements of this protocol could possibly be adapted for future in-flight immunology studies conducted during space missions.

Comparison of various blood compartments and reporting units for the detection and quantification of Epstein-Barr virus in peripheral blood

Epstein-Barr virus (EBV) infection is associated with a broad spectrum of disease. While quantification of EBV nucleic acid in the peripheral blood has been demonstrated to be useful for diagnosis and patient care, the optimal sample type and reporting format for such testing remain uncertain. Using quantitative real-time PCR (QRT-PCR), we evaluated EBV in whole blood (WB), peripheral blood mononuclear cells (PBMC), and plasma in 249 samples from 122 patients. In WB and PBMC, results were reported both in viral copies/ml and in copies/microg of total DNA. Trendings of quantitative values over time among the different sample types were compared. The sensitivities of QRT-PCR using WB and that using PBMC did not differ significantly (P = 0.33), and both were more sensitive than plasma alone (P < 0.0001). EBV viral load results from WB and PBMC paired sample types also showed a significant correlation (P < 0.05), as did results reported in copies/ml and copies/microg DNA for both WB and PBMC (R2 > 0.93). EBV viral loads detected using WB and PBMC trended very closely for the few patients who had multiple positive samples available for analysis. WB and PBMC show comparable sensitivities and a close quantitative correlation when assayed for EBV by QRT-PCR. The close correlation between copies/ml and copies/microg DNA also suggests that normalization to cell number or genomic DNA in cellular specimens may not be necessary.

Epstein-Barr virus-positive blastoid variant of mantle cell lymphoma in an adult with recurrent infectious mononucleosis-like symptoms: a case report

Epstein-Barr virus (EBV) is closely associated with several lymphomas, such as Burkitt lymphoma, natural killer/T-cell lymphoma, peripheral T-cell lymphoma, and Hodgkin's lymphoma; however, whether EBV is implicated in mantle cell lymphoma (MCL) has not been established. We report the case of an adult with recurrent infectious mononucleosis (IM)-like symptoms who developed an EBV-positive blastoid variant of MCL. A 54-year-old Japanese man presented with fever, swelling of the oral mucosa and tongue, dispersed pulmonary infiltrations, systemic lymphadenopathy, and splenomegaly. He had a history of recurrent IM-like symptoms (prolonged fever and cervical lymphadenopathy) for at least 1 year. MCL was diagnosed by biopsy of the cervical lymph node. The anti-EBV antibody titer indicated a reactivation of chronic infection with this virus. EBV was detected in most of the lymphoma cells and in the peripheral blood. EBV might have played some role in the tumorigenesis of blastoid MCL.

Comparison of commercial and in-house Real-time PCR assays for quantification of Epstein-Barr virus (EBV) DNA in plasma

Background

Epstein-Barr virus (EBV) DNA load monitoring is known to be useful for the diagnosis and monitoring of EBV-associated diseases. The aim of this study is to compare the performance of two real-time PCR assays for EBV DNA: a commercial kit as the Q-EBV Real-Time System (Q-EBV PCR, Amplimedical, Turin, Italy) and an in-house assay (EBV RQ-PCR).

Results

The range of linearity and the degree of precision of the two assays were similar. The clinical sensitivity of Q-EBV PCR was higher for reference samples containing less than 1,000 EBV DNA copies/ml. The absolute quantitative results of the two methods were statistically correlated (R² = 0.7789; p < 0.0001), with the systematic overestimation by EBV RQ-PCR possibly linked to different amplification efficiency in calibration standards.

Conclusion

Both the commercial and the in-house assay may be appropriate for clinical use, but common standards are advisable for comparable absolute values, as these would improve the clinical utility of EBV DNA load measurement.

Epstein-Barr virus early-antigen antibodies before allogeneic haematopoietic stem cell transplantation as a marker of risk of post-transplant lymphoproliferative disorders

The occurrence of post-transplant lymphoproliferative disorders (PTLDs) after allogeneic haematopoietic stem cell transplantation (allo-HSCT) represents a clinical problem. Pretransplant Epstein-Barr virus serological status and viral load was determined in 21 recipients and 28 control transplanted patients, with (+) and without (-) PTLD, respectively. Early-antigen immunoglobulin G (EA-IgG) was detected in 12/21 PTLD+ patients, but only 2/28 PTLD patients (P = 0.00023, Odds ratio = 17.42). High viral load was detected in peripheral blood mononuclear cells at PTLD diagnosis, independently of deleted LMP1. Detection of EA-IgG in allo-HSCT recipients pretransplantation might be considered as risk factor for PTLD development.

Presentation and early detection of post-transplant lymphoproliferative disorder after solid organ transplantation

Post-transplant lymphoproliferative disorder (PTLD) is a serious and still frequently observed complication of solid organ transplantation. Despite the recent introduction of anti B-cell monoclonal antibody therapy (rituximab) for treatment of PTLD, mortality rates remain high. Because PTLD often presents in a nonspecific way in clinically unsuspected patients, it is a major challenge to diagnose PTLD at an early stage. Epstein-Barr virus (EBV)-DNA load monitoring is a promising tool for the identification of patients at risk for PTLD development. However, there are some limitations of this method, and not all patients at risk for PTLD can be identified by EBV-DNA measurements alone. Therefore, it is of major importance to recognize early clinical signs and symptoms of PTLD. In this review, risk factors for PTLD development, disease presentation, and methods for early detection will be discussed. Special attention is given to allograft and digestive tract localization and the relation with time of onset of PTLD. The value and pitfalls of EBV-DNA load monitoring are discussed. In addition, because fluorodeoxyglucose (FDG)-positron emission tomography (PET) has shown to be a powerful tool for staging and response evaluation of malignant lymphoma, the role of FDG-PET for early diagnosis and staging of PTLD is addressed.

Simultaneous quantification of Epstein-Barr virus, cytomegalovirus, and human herpesvirus 6 DNA in samples from transplant recipients by multiplex real-time PCR assay

We developed a multiplex real-time PCR assay using 6-carboxyfluorescein, 6-carboxy-4',5'-dichloro-2',7'-dimethoxyfluorescein, and carbocyanine 5-labeled probes to simultaneously quantify Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpesvirus 6 (HHV-6) DNA. When previously tested and stored DNA samples were examined, results of the multiplex real-time PCR assay were as sensitive and specific as those of a single real-time PCR assay. The multiplex assay was used to quantify the EBV, CMV, and HHV-6 DNA in 46 transplant recipients. A total of 303 whole-blood and plasma specimens were collected and analyzed. According to the results of the multiplex assay, the detection rates for viral DNA in whole blood and plasma were 23.8% and 5.9% for EBV, 11.2% and 5.3% for CMV, and 12.5% and 2.0% for HHV-6, respectively. All forms of viral DNA were detected more frequently in whole blood than in plasma. During the symptomatic period, EBV DNA was detected in all whole-blood specimens but not in all plasma specimens. Furthermore, the EBV DNA load in whole blood was higher during the symptomatic period than during the asymptomatic period, whereas the EBV DNA load in plasma was similar for both periods. These results demonstrate that whole blood is more suitable for the quantification of EBV DNA in transplant patients. However, a cutoff value with clinical relevance still needs to be determined.

Autologous transplantation of CD133 selected hematopoietic progenitor cells for treatment of relapsed acute lymphoblastic leukemia

A 21-year-old white male with relapsed acute lymphoblastic leukemia (ALL) developed an invasive Zygomycosis infection 3 weeks after beginning re-induction chemotherapy. Because of the high risk of fatal recurrence of the fungal infection, neither long-term maintenance chemotherapy nor allogeneic hematopoietic stem cell transplant (HSCT) was considered appropriate. Because his ALL blasts expressed CD34 but lacked CD133, he received a CD133 selected autologous graft following high-dose consolidation chemotherapy. The patient survives in remission 19 months after HSCT.

A novel, noninvasive diagnostic probe for hydroa vacciniforme and related disorders

OBJECTIVE

To establish a new diagnostic method for Epstein-Barr virus (EBV)-associated cutaneous disorders.

DESIGN

Skin biopsy is usually required to confirm the latent EBV infections in cutaneous lesions of EBV-associated NK/T-cell lymphoproliferative disorders, including hydroa vacciniforme (HV) and hypersensitivity to mosquito bites (HMB). We have devised a novel, noninvasive method to detect EBV-encoded small RNA (EBER), BamHI A rightward transcripts (BARTs) in the skin crusts and scales of such patients.

PATIENTS

Six patients with EBV-associated cutaneous lesions were enrolled in the present study, including three patients with HV, one with HV-like eruptions and chronic active EBV infection, and two with EBV-associated cutaneous lymphoma.

MAIN OUTCOME MEASURES

RNA was extracted from the crusts obtained from the cutaneous lesions by forceps, converted to cDNA, and processed for polymerase chain reaction (PCR) amplification with a specific set of primers. The PCR products were assayed by a DNA sequencer.

RESULTS

Intact RNAs were successfully extracted from the crusts as well as control materials. EBER1 and BARTs RNAs were detected in all 7 crusts, and in 6 of 7 crusts of EBV-associated cutaneous diseases, respectively. One of 23 crusts from non EBV-associated diseases was positive for EBER1 RNA. The sensitivity and specificity of our assay for latent EBV infection were 100% and 95.8% for EBER1 RNA, and 85.7% and 100% for BARTs mRNA, respectively. The correct DNA sequence for EBER1 and BARTs was confirmed in the PCR products by a direct sequencing method.

CONCLUSIONS

Our procedure may be of use as a biomarker for EBV-associated cutaneous lesions, including HV, HMB, and NK/T-cell lymphomas.

Development of a multiple internal control for clinical diagnostic real-time amplification assays

A major pitfall in most published genomic amplification methods for the detection and identification of human pathogens is that they do not include an internal amplification control in order to achieve an acceptable level of confidence for the absence of false-negative results. By applying composite primer technology, a single multiple internal amplification control DNA molecule was constructed to detect and quantify the hepatitis B virus, human polyomavirus, Epstein-Barr virus, Toxoplasma gondii and cytomegalovirus using real-time PCR. The multiple internal amplification control contains all forward and reverse primer binding regions targeted in the five distinct duplex PCRs, but with a unique probe hybridization site. Multiple internal amplification control detection sensitivity, assessed by Probit analysis, was 58 copies per PCR, associated with an extremely wide dynamic range (8 log(10) units). Moreover, in testing 614 patient samples, PCR inhibition occurred at a frequency of 0-8.8%. Similar multiple internal amplification controls for quantitative PCR-based assays could be designed to accommodate any infectious profiles in a particular institution as they are easy to make and inexpensive.

Cross-reaction between tyrosinase peptides and cytomegalovirus antigen by T cells from patients with Vogt-Koyanagi-Harada disease

AIM

To determine whether T lymphocytes of patients with Vogt-Koyanagi-Harada (VKH) disease cross-react with peptides of melanocytes and with exogenous antigens.

METHODS

Cross-reactivity with melanocyte peptides, tyrosinase (tyrosinase(450-462): SYLQDSDPDSFQD) and the mimic virus peptide, i.e., cytomegalovirus envelope glycoprotein H (CMV-egH(290-302): SYLKDSDFLDAAL) was examined by a lymphocyte proliferation assay or cytokine production. The seroprevalence of various viruses was examined by a complement fixation test. To examine if the virus infections in VKH patients were latent, we measured genomic DNA of the virus using real-time polymerase chain reaction (PCR).

RESULT

Some of the T cells established from VKH recognized melanocyte peptides including the tyrosinase peptide as well as the CMV-egH(290-302) peptide, which had a high amino acid homology to the tyrosinase peptide. Cytomegalovirus (CMV) peptide-specific T cells showed a significant proliferation not only to CMV-egH(290-302) but also to tyrosinase(450-462). The seroprevalence of CMV was significantly higher in VKH patients. In addition, all tested samples of VKH patients were negative for CMV-DNA.

CONCLUSIONS

These results indicate that CMV infection may stimulate the production of T cells that cross-react with tyrosinase by a mechanism of molecular mimicry. These events may be responsible for the onset of VKH disease.

Analysis of close proximity quenching of phosphorescent metalloporphyrin labels in oligonucleotide structures

Quenching of phosphorescent platinum(II) and palladium(II) coproporphyrin (MeCP) labelled oligonucleotides was investigated. Strong hybridization-specific quenching was observed in duplex DNA structures with a variety of quenchers and with two identical porphyrin labels when in close proximity. Classical resonance energy transfer mechanism was ruled out, since quenching did not correlate with spectral overlaps and lifetime changes were insignificant. Quenching of MeCP by the free quenchers in solution revealed that porphyrin-porphyrin quenching is predominantly static while other dyes quench dynamically. The results suggest that the quenching in DNA duplex proceeds via direct contact.

High prevalence of multiple human herpesviruses in saliva from human immunodeficiency virus-infected persons in the era of highly active antiretroviral therapy

Human immunodeficiency virus (HIV) infection is associated with an increased risk for human herpesviruses (HHVs) and their related diseases. Methods for limiting the transmission of HHVs require a better understanding of the prevalence and infectiousness of oral HHVs in HIV-infected patients. We performed quantitative PCR to investigate the prevalence, quantity, risk, and correlates of salivary HHVs from 58 HIV-seropositive individuals in a case control study. HHVs were significantly more prevalent in the salivas of HIV-seropositive persons than in those of the controls (odds ratios [ORs], 4.2 to 26.2; P<or=0.008). In HIV-infected patients, Epstein-Barr virus (EBV), human herpesvirus 8 (HHV-8), cytomegalovirus (CMV), and herpes simplex virus type 1 (HSV-1) were detected in 90%, 57%, 31% and 16% of samples, respectively, compared with 48%, 24%, 2%, and 2%, respectively, of samples from controls. Multiple HHVs were observed in 71% of HIV-seropositive persons and only 16% of controls (OR, 13.0; 95% confidence interval, 5.29 to 32.56). HIV-positive patients had significantly higher EBV loads than HIV-negative persons (P<0.0001). HIV-infected patients with CD4 counts above 200 cells/microl had increased probability for having HHV-8 in saliva (P=0.009) compared with patients whose counts were less than 200. In contrast, HSV-1, EBV, and CMV were detected more often when CD4 counts were low. High salivary HHV loads were detected for those (n=7) with oral lesions. These findings suggest that saliva is a potential risk factor for the acquisition of multiple HHVs, and several host factors may function to accelerate HHV reactivation or replication in patients with HIV infection.