Epstein-Barr virus (EBV) replicative gene expression in tumour cells of AIDS-related non-Hodgkin's lymphoma in relation to CD4 cell number and antibody titres to EBV

Lytic EBV infection investigated by detection of Soluble Epstein-Barr virus ZEBRA in the serum of patients with PTLD

The ZEBRA protein (encoded by the BZLF1 gene), is the major transcription factor of EBV, expressed upon EBV lytic cycle activation. Several studies highlighted the critical role of EBV lytic infection as a risk factor for lymphoproliferative disorders like post-transplant lymphoproliferative disease (PTLD). Here, we use an antigen-capture ELISA assay specifically designed to detecting the circulating soluble ZEBRA (sZEBRA) in serum samples (threshold value determined at 40ng/mL). We retrospectively investigated a population of 66 transplanted patients comprising 35 PTLD. All the samples from a control population (30 EBV-seronegative subjects and 25 immunocompetent individuals with EBV serological reactivation), classified as sZEBRA < 40ng/mL were assigned as negative. At PTLD diagnosis, EBV genome (quantified by qPCR with EBV DNA>200 copies/mL) and sZEBRA were detectable in 51% and 60% of cases, respectively. In the patients who developed a pathologically-confirmed PTLD, the mean sZEBRA value in cases, was 399 ng/mL +/− 141 versus 53ng/mL +/− 7 in patients who did not (p  < 0,001). This is the first report relating to the detection of the circulating ZEBRA in serum specimens, as well as the first analysis dealing with the lytic cycle of EBV in PTLD patients with this new biomarker.

Analyses of the prognostic significance of the Epstein-Barr virus transactivator ZEBRA protein and diagnostic value of its two synthetic peptides in nasopharyngeal carcinoma

BACKGROUND

Although numerous serological studies have determined the diagnostic and prognostic values of Epstein-Barr virus (EBV) antibodies in adult patients with nasopharyngeal carcinoma (NPC), little data about the anti-EBV immune response in children with NPC is available.

OBJECTIVES

To examine the diagnostic value of IgG antibodies against BamHI Z Epstein-Barr replication activator (ZEBRA) protein and two related synthetic peptides (Zp125 and Zp130). To compare the prognostic value of IgA antibodies against early antigens (EA) and viral capsid antigen (VCA), and IgG antibodies against ZEBRA protein, of Moroccan children treated for NPC with their prognostic value for young and adult NPC patients.

STUDY DESIGN

Sera were collected from 255 newly diagnosed Moroccan NPC patients and 226 healthy donors. IgA antibody against VCA and EA was measured by immunofluorescence assays. IgG antibody against ZEBRA, Zp125, and Zp130 was measured by ELISA.

RESULTS

No significant difference in the detection of IgG-Zp125 and Zp130 antibodies was observed in children with NPC. IgG-Zp130 were detected less frequently than IgG-Zp125 in young and adult patients, as compared to children. High specificity of IgG-Zp125 and -Zp130 antibodies was found in the three age groups. A decrease in IgG-ZEBRA was observed in patients with NPC in clinical remission, whereas patients with NPC who died or developed metastases maintained or had an increase in these titers.

CONCLUSION

IgG-ZEBRA is a better diagnostic and post-therapeutic prognostic marker in children with NPC, who showed very low titers of IgA -VCA and -EA.

Clinical usefulness of serum EBV DNA levels of BamHI W and LMP1 for Nasal NK/T-cell lymphoma

Quantitative real-time polymerase chain reaction (PCR) was utilized to measure serum EBV DNA levels of BamHI W fragment and latent membrane protein 1 (LMP1) in 20 nasal natural killer (NK)/T-cell lymphoma patients. Both serum EBV DNAs were detected at high levels in all patients, but the levels were below the limit of detection in all healthy controls. The BamHI Z fragment, Epstein-Barr-replication activator (ZEBRA) expression was detected in a small proportion (0.1-3%) of lymphoma cells from 10 (50%) of the patients. Patients with ZEBRA expression showed significantly higher DNA levels of BamHI W and LMP1 (P = 0.0081, P = 0.004), suggesting that EBV DNA may be caused by EBV replication from lymphoma cells. Kaplan-Meier and univariate analyses revealed that high DNA levels of BamHI W and LMP1 at pre-treatment and high BamHI W DNA level at post-treatment were associated with short disease-free survival and overall survival (P < 0.05, each). Although the DNA levels of BamHI W and LMP1 correlated significantly, their dynamics were not always parallel. Patients with low pre-treatment level of both EBV DNAs showed a favorable course, in contrast to patients with high pre-treatment level of both EBV DNAs who showed an aggressive course (P = 0.0085). More importantly, the high pre-treatment level of both EBV DNAs was determined as the only independent prognostic factor among various prognostic factors. These data suggest that simultaneous measurement of serum levels of both BamHI W and LMP1 DNAs may be useful for diagnosis, disease monitoring, and prediction of prognosis for nasal NK/T-cell lymphoma patients.

A longitudinal and prospective study of Epstein-Barr virus load in AIDS-related non-Hodgkin lymphoma

BACKGROUND

Epstein-Barr virus (EBV) may be causally associated with non-Hodgkin Lymphoma (NHL) in HIV-infected patients.

OBJECTIVES

To compare EBV load in whole blood in AIDS-NHL patients, HIV non-AIDS patients and non-HIV-infected persons, and to prospectively measure EBV load in whole blood in AIDS-NHL patients.

STUDY DESIGN

Longitudinal and prospective study.

RESULTS

We observed no statistical difference in EBV load between AIDS-NHL (3.69log(10) copies/mL [interquartile range (IQR): 2.89-4.27]) and HIV non-AIDS patients (3.08log(10) copies/mL [IQR: 1.29-3.57]) but AIDS-NHL patients had significantly higher EBV loads than HIV-negative controls (1.19log(10) copies/mL [IQR: 0.00-3.29]). We noticed an inverse correlation between CD4+ lymphocytes count and EBV load in patients with AIDS-NHL (r(2)=0.41, P=0.01). In the longitudinal study, the mean EBV load three months after NHL diagnosis decreased significantly (mean difference=-1.69log(10) copies/mL [95% confidence interval: -0.32; -3.04]; P=0.03) under chemotherapy but was still elevated in patients with relapses or no response to chemotherapy.

CONCLUSION

Although EBV load seems a suboptimal marker for the diagnosis of AIDS-NHL, we observed a significant decrease of EBV load in patients treated with chemotherapy and a strong association between NHL outcome and EBV load in whole blood.

High Epstein-Barr virus (EBV) DNA loads in HIV-infected patients: correlation with antiretroviral therapy and quantitative EBV serology

OBJECTIVE

To study Epstein-Barr virus (EBV) DNA loads in peripheral blood of HIV carriers to determine base-line values and diagnostic relevance of viral load in relation to quantitative serology; to compare EBV presence in parallel plasma and unfractionated whole blood samples; and to correlate EBV DNA load to HIV, CD4 T-cell counts and HAART.

DESIGN

One-hundred and nine random patients receiving highly active antiretroviral therapy (HAART) during 1999 and 99 patients on anti-HIV monotherapy during 1993-1996 were included.

METHODS

EBV DNA load was determined by quantitative competitive PCR. EBV serology was determined by immunoblot profile and quantitative enzyme-linked immunosorbent assay for responses against VCA-p18 and EBNA-1.

RESULTS

Twenty-two out of 109 patients receiving HAART and 28 out of 99 of patients on anti-HIV monotherapy showed elevated EBV DNA loads in whole blood (> 2000 copies/ml), without elevated loads in parallel plasma. EBV DNA load distribution did not differ between the two groups (P = 0.78) and did not correlate with HIV or CD4 T-cell count. In three patients with high EBV DNA loads EBV RNA was virtually absent. Patients with high EBV DNA loads (3610-89 400 copies/ml) had higher anti-VCA-p18 IgG levels than patients with undetectable EBV DNA (P < 0.0001) but lower anti-EBNA-1 IgG levels (P = 0.005).

CONCLUSION

Absolute values of EBV DNA load may have poor diagnostic value for defining HIV patients at risk for developing EBV-associated disease. Elevated EBV DNA loads are cell-associated and are not influenced by HAART. Increased anti-p18-VCA and decreased anti-EBNA-1 IgG levels in patients with high EBV loads indicate impaired latency control and increased lytic replication suggesting disturbed overall immunosurveillance against EBV.

Oligo-monoclonal immunoglobulins frequently develop during concurrent cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections in patients after renal transplantation

In the present study we report that the appearance of oligo-monoclonal immunoglobulins (oligoM-Igs) in the sera of transplanted individuals is concurrent with the detection of coincident active CMV infection and EBV replication. Eighty-four renal allograft patients were monitored with respect to CMV isolation, to CMV conventional serology and humoral response against the EBV trans-activator ZEBRA (an immediate-early antigen also called BZLF1). Titration of anti-ZEBRA antibodies (IgG and IgM) and amount of EBV DNA in serum were evaluated. Using the combination of four techniques (agarose gel electrophoresis, analytical isoelectric focusing, high resolution immunoelectrophoresis, immunofixation electrophoresis), oligoM-Igs were found in 25% of patients after allografting and significantly associated with rejection episodes (P < 0.001). Twenty out of 23 (86%) concurrent CMV/EBV infections were associated with serum oligoM-Igs (P < 0.001). One can thus reasonably assume that a sustained EBV replication following iatrogenic immunosuppression can promote the immunoglobulin heavy chain expression in EBV-infected B lymphocytes. The proliferation of immunoglobulin-secreting clones might occur after active CMV infection, through a transient over-immunosuppression or via immune subversion.

High Epstein-Barr virus serum load and elevated titers of anti-ZEBRA antibodies in patients with EBV-harboring tumor cells of Hodgkin's disease

Hodgkin's disease is commonly associated with EBV latent infection. The incidence of EBV reactivation (active infection or EBV infection with replicative cycle) was evaluated in a series of 30 patients with untreated Hodgkin's disease (except for one case with chronic lymphocytic leukemia) by quantitation of EBV DNA and titration of anti-ZEBRA antibodies in serum samples. DNA was detected in serum (>2.5 x 10(2) genomes/ml) in 15 of 30 patients and was more frequent in Hodgkin's disease with EBV-positive Reed-Sternberg cells (10/12) than in EBV-negative cases (5/18), (P< 0.01). Of interest was the demonstration that viremia correlated well with increased titers of anti-ZEBRA IgG and/or standard serological profiles of EBV reactivation (12/15), (P < 0.05). However the lack of EBV replicative cycle in Reed-Sternberg cells (negative for ZEBRA antigen and early antigen BHLF1) suggests that the viral replication occurs in a nonneoplastic cell compartment rather than in tumor cells. The measurement of EBV DNA loads and the titration of anti-ZEBRA antibodies shed new lights on the link between activation of EBV replication and Hodgkin's disease: these serological markers together with the determination of the EBV status of the tumor suggest that replication of the viral genome occurs with a decreased efficiency of the immune system, thus allowing progression of the tumor.

Molecular Profile of Epstein-Barr Virus in Human Immunodeficiency Virus Type 1–Related Lymphadenopathies and Lymphomas

Human immunodeficiency virus type 1 (HIV-1)–infected patients develop a spectrum of lymphoproliferative disorders ranging from nonneoplastic lymphadenopathies to B-cell lymphomas. Although evidence suggests that Epstein-Barr virus (EBV) might be involved, its molecular profile and expression pattern in HIV-1–related lymphoproliferations remain to be defined. Using polymerase chain reaction–based techniques, we studied EBV types and variants in 28 lymphadenopathy lesions and in 20 lymphomas (15 large cell and 5 Burkitt-like). EBV was detected in 89% of lymphadenopathies and in 80% of lymphomas; viral DNA content was significantly higher in the latter. EBNA2 and LMP1 gene analysis indicated that half of the EBV+ lymphadenopathies were coinfected with both EBV type 1 and 2 strains and/or multiple type 1 variants. Conversely, all but one lymphoma carried a single viral variant, consistently type 1 in large cell lymphomas, and type 2 in Burkitt-like tumors. Most lymphomas, but no lymphadenopathies, showed monoclonal Ig heavy-chain rearrangement. Analysis of 5 large cell lymphomas and 9 lymphadenopathies for EBV transcripts identified LMP1 mRNA in most samples, and the EBNA2 transcript in all tumors. These findings provide evidence of a heterogeneous EBV population in lymphadenopathy lesions, strengthen the notion that lymphomas arise from clonal expansion of EBV+ cells, and suggest different roles for EBV types 1 and 2 in HIV-1–related lymphoproliferations.

Molecular Profile of Epstein-Barr Virus in Human Immunodeficiency Virus Type 1–Related Lymphadenopathies and Lymphomas

Human immunodeficiency virus type 1 (HIV-1)–infected patients develop a spectrum of lymphoproliferative disorders ranging from nonneoplastic lymphadenopathies to B-cell lymphomas. Although evidence suggests that Epstein-Barr virus (EBV) might be involved, its molecular profile and expression pattern in HIV-1–related lymphoproliferations remain to be defined. Using polymerase chain reaction–based techniques, we studied EBV types and variants in 28 lymphadenopathy lesions and in 20 lymphomas (15 large cell and 5 Burkitt-like). EBV was detected in 89% of lymphadenopathies and in 80% of lymphomas; viral DNA content was significantly higher in the latter. EBNA2 and LMP1 gene analysis indicated that half of the EBV+ lymphadenopathies were coinfected with both EBV type 1 and 2 strains and/or multiple type 1 variants. Conversely, all but one lymphoma carried a single viral variant, consistently type 1 in large cell lymphomas, and type 2 in Burkitt-like tumors. Most lymphomas, but no lymphadenopathies, showed monoclonal Ig heavy-chain rearrangement. Analysis of 5 large cell lymphomas and 9 lymphadenopathies for EBV transcripts identified LMP1 mRNA in most samples, and the EBNA2 transcript in all tumors. These findings provide evidence of a heterogeneous EBV population in lymphadenopathy lesions, strengthen the notion that lymphomas arise from clonal expansion of EBV+ cells, and suggest different roles for EBV types 1 and 2 in HIV-1–related lymphoproliferations.

Characterization of Epstein-Barr virus-infected cells in benign lymphadenopathy of patients seropositive for human immunodeficiency virus

The authors investigated 25 benign lymph nodes in patients infected with the human immunodeficiency virus (HIV) by in situ hybridization (ISH) and immunohistochemistry (IHC) to detect and characterize the Epstein-Barr virus (EBV)-infected cells. After ISH, 22 lymph nodes were found to contain various numbers of Epstein-Barr-encoded RNA (EBER)-positive cells. Most of these cells were B cells. In six lymph nodes with numerous EBV-infected cells, EBNA2-positive/LMP1-positive lymphoblastoid cells were detected by IHC. Exceptional cells (in two specimens) were positively labeled with antigen-Z Epstein-Barr replicative activator (ZEBRA) antibody or BamHI Left Frame 1/Not I (BHLF1/Not I) probes, indicating that EBV replication is not enhanced in the lymphocytes. In normal conditions (healthy individuals), small lymphocytes that express a restricted pattern of viral genes do escape immune response, whereas lymphoblastoid cells do not. Thus, impaired immune system may account for the late proliferation of lymphoblastoid cells (Epstein-Barr nuclear antigen [EBNA]2positive/latent membrane protein [LMP]1 positive) in HIV-infected patients, and could explain why EBV-driven, acquired immunodeficiency syndrome (AIDS)-related, non-Hodgkin's lymphoma occur more frequently in patients with low CD4-positive T cells.

Grafting peptides onto polystyrene microplates for ELISA

Three peptides corresponding respectively to two Epstein-Barr viral epitopes and to the c-erbB-2 oncogene product were synthesized with the aim of developing an immunoenzymatic assay. Preliminary experiments indicated that the efficiency of the assay was profoundly affected by the nature of the solid phase for each peptide. In order to optimize the assay the three peptides were covalently coupled to functionalized polystyrene microplates which were used to immobilize both haptens and nucleic acids in a previous study. The results obtained indicate that the use of the carboxylated surfaces permits the linking strategy to be adapted to each peptide. Moreover, high sensitivities (5 x 10(-10)-1 x 10(-13) M) were obtained using amounts of the peptides much lower than those used in the standard system.