Epstein-Barr virus and malignant lymphoepithelial lesions of the salivary gland.

This report describes the results of histopathologic and virologic studies in six patients with undifferentiated carcinoma (malignant lymphoepithelial lesions) of the salivary glands. Epstein-Barr virus (EBV) was detected in tumors from all six patients by DNA hybridization, while adjacent non-tumorous salivary gland tissue was negative for EBV in two patients tested for DNA and in three patients tested for Epstein-Barr nuclear antigen (EBNA). These findings add more evidence that these unusual salivary gland tumors are EBV-associated, and that EBV is specific to the tumor.

Epstein-Barr virus (EBV) antigen-specific leukocyte migration inhibition in infectious mononucleosis. II. Kinetics of sensitization against five EBV-encoded nuclear proteins and the latent membrane protein.

The T cell-mediated immune response of infectious mononucleosis (IM) patients to five Epstein-Barr virus (EBV)-determined nuclear antigens, EBNAs, and to the membrane antigen associated with growth-transformed cells (latent membrane protein, LMP) was measured by the leukocyte migration inhibition (LMI) assay. Two different antigen sources were used: extracts from cells that only expressed EBNA-1, EBNA-2, or LMP after transfection with the corresponding EBV-DNA fragment, and synthetic peptides deduced from the corresponding genes. Patients in the acute phase of the disease failed to respond to EBNA-1, -5, -6, and LMP, but became responsive during convalescence. The majority of the patients responded to EBNA-2 and/or EBNA-3 in the acute phase (9/15 and 12/15, respectively). The response to EBNA-2 and/or EBNA-3 in the acute phase (9/15 and 12/15, respectively). The response to EBNA-3 disappeared more often in convalescence than the response to EBNA-2: 6 of 15 patients were negative to EBNA-2 and 12 of 15 to EBNA-3 during recovery. In addition to its value in the assessment of host sensitization to virus EBV antigens, these studies and the derived hypotheses also provide certain predictions about the predominant antigen expression in the EBV-infected host under normal and pathological conditions that can be subjected to direct experimental tests.

Relationship between clinical stage, histopathology and antibody titers against the second Epstein-Barr virus nuclear antigen (EBNA-2) in non-Hodgkin's lymphoma patients.

Non-Hodgkin lymphoma (NHL) patients with centroblastic (Cb) or centroblastic-centrocytic (Cb/Cc)-diffuse lymphomas, immunocytoma (IC) and chronic lymphocytic leukemia (CLL) in clinical stages III-IV and with active disease (highly malignant group) were compared to NHL patients with CLL, IC, and centrocytic (Cc) or centroblastic-centrocytic (Cb-Cc)-diffuse/follicular lymphomas, in clinical stages I-II and with inactive disease (low malignant group) based on the presence of antibodies to Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) and 2 (EBNA-2). In the highly malignant group, anti-EBNA-1 geometric mean titers (GMT) were 13.2 (range less than 2-80) and anti-EBNA-2 60.6 (range: 20-320). The ratio between the logarithms of anti-EBNA-1 and anti-EBNA-2 antibody titers was less than 1.0 (mean: 0.32) in all the patients examined. In 6 out of 8 patients of the low malignant group, anti-EBNA-1 titers were higher (mean: 30.1; range 10-160) than anti-EBNA-2 titers (mean: 4.3; range less than 2-80) and the EBNA 1/2 ratio was greater than 1.0. In healthy EBV-seropositive individuals, anti-EBNA-1 GMT were 49 (range: 10-320) and only 5 out of 17 individuals had detectable anti-EBNA-2 titers (GMT: 3; range less than 5-20). The EBNA-1/2 ratio was in all cases greater than 1. Among patients of the highly and low malignant groups, patients with follicular-cell-derived lymphomas had elevated antibody titers against the restricted component of early antigens (EA-R), whereas all patients with IC and 2 out of 4 CLL patients had elevated antibody titers against the diffuse component of early antigens (EA-D). The results indicate that the ratio between anti-EBNA-1 and anti-EBNA-2 antibody titers may be of diagnostic importance in patients with immunodeficiencies.

Severe thrombocytopenia in Epstein-Barr virus-induced mononucleosis.

Severe thrombocytopenia is a rare complication of Epstein-Barr virus-induced infectious mononucleosis. We evaluated the clinical and laboratory data from seven patients seen between 1976 and 1985 whose lowest platelet counts varied from 3 to 25 x 10(9) per liter. Five of the seven patients were initially thought to have either acute leukemia or idiopathic thrombocytopenic purpura; eventually, however, primary Epstein-Barr virus infections were confirmed in all patients. Two of six patients tested had antiplatelet antibodies during the acute phase of their illnesses. Eight additional patients with acute disease who had only mild thrombocytopenia (94 to 144 x 10(9) per liter) were also tested for platelet antibodies with negative results. Steroid therapy was administered to three patients and platelet transfusions to one. All seven patients recovered with no serious hemorrhagic sequelae.

Acyclovir treatment of the chronic fatigue syndrome. Lack of efficacy in a placebo-controlled trial.

Twenty-seven adults with a diagnosis of the chronic fatigue syndrome were enrolled in a double-blind, placebo-controlled study of acyclovir therapy. The patients had had debilitating fatigue for an average of 6.8 years, accompanied by persisting antibodies to Epstein-Barr virus early antigens (titers greater than or equal to 1:40) or undetectable levels of antibodies to Epstein-Barr virus nuclear antigens (titers less than 1:2) or both. Each course of treatment consisted of intravenous placebo or acyclovir (500 mg per square meter of body-surface area) administered every eight hours for seven days. The same drug was then given orally for 30 days (acyclovir, 800 mg four times daily). There were six-week observation periods before, between, and after the treatments. Three patients had acyclovir-induced nephrotoxicity and were withdrawn from the study. Of the 24 patients who completed the trial, similar numbers improved with acyclovir therapy and with placebo (11 and 10, respectively). Neither acyclovir treatment nor clinical improvement correlated with alterations in laboratory findings, including titers of antibody to Epstein-Barr virus or levels of circulating immune complexes or of leukocyte 2',5'-oligoadenylate synthetase. Subjective improvement correlated with various measures of mood. We conclude that acyclovir, as used in this study, does not ameliorate the chronic fatigue syndrome. We believe that the clinical improvement observed in most patients reflected either spontaneous remission of the syndrome or a placebo effect.

Heterophil-negative mononucleosis-like illnesses with atypical lymphocytosis in patients undergoing seroconversions to the human immunodeficiency virus.

The authors present data from four patients with acute heterophil-negative mononucleosis-like illnesses who were initially thought to have primary Epstein-Barr virus (EBV) infections but eventually were shown to be seroconverting to the human immunodeficiency virus (HIV). Widespread lymphadenopathy and blood smears indistinguishable from those typically encountered in the acute phase of infectious mononucleosis were present in all cases. There were also varying combinations of fever, sore throat, and malaise, as well as mild abnormalities of hepatic function and elevated cold agglutinins (anti-I). Anti-HIV was detected by both enzyme-linked immunosorbent assay and Western blot techniques in all cases, with increasing titers noted in two of three serially studied cases. In one patient, a dual infection with the hepatitis B virus was also documented. Diagnostic possibilities in patients with acute mononucleosis-like illnesses dominated by prominent lymphadenopathy should include primary seroconversions to HIV.

Cellular and humoral immune responses to synthetic peptides deduced from the amino-acid sequences of Epstein-Barr virus-encoded proteins in EBV-transformed cells.

Ten synthetic peptides containing 18-22 residues deduced from the amino-acid sequences of the EBV-encoded latent-infection-associated membrane protein (LMP) and the 2 principal nuclear antigens, EBNA-1 and EBNA-2, were tested for their ability to induce lymphokine release from sensitized T-cells of EBV-seropositive donors, as measured by the leukocyte migration inhibition assay (LMI). Only one of the 10 free peptides induced EBV-specific LMI. After Sepharose-coupling, 4 additional peptides were regularly active. In parallel, the sera of the same and other donors were screened for synthetic peptide-binding antibodies, as measured by an ELISA assay. Antibodies to 9 of the 10 peptides were detected in 25-80% of EBV-antibody-positive, but not in EBV-antibody-negative sera. A comparison of the two responses indicates that the humoral immune system tends to react with more epitopes on a given protein than the cellular immune system. Furthermore, the antibody reactivity pattern to different epitopes is more variable from individual to individual than the T-cell response. Also, the epitopes detected by antibodies and sensitized T-cells are often not identical.

Selected aspects of acute and chronic infectious mononucleosis and mononucleosis-like illnesses for the practicing allergist.

The diagnosis of EBV-IM or a heterophil-negative mononucleosis-like syndrome is best approached by combining morphologic and serologic data. The minimal hematologic criteria should always be searched for before accepting a case as IM or an IM-like illness. If minimal morphologic data are not rigidly adhered to, the number of heterophil-negative cases included under the umbrella of IM or an IM-like illness will swell and include a variety of other illnesses where early diagnosis may be important for treatment purposes. When EBV studies are indicated, the entire profile (VCA-IgM, VCA-IgG, and anti-EBNA) should be performed. Anti-VCA-IgG titers alone, for example, are of very limited usefulness unless they are negative (less than 1:10), in which case the diagnosis of EBV-IM is excluded. The main problems connected with the diagnosis of the CMS center about the nonspecificity of both clinical and EBV serologic data. Thus, a significant effort must be made to rule out underlying disease, especially those chronic illnesses with immunosuppressive effects that are capable of reactivating the EBV latency state and producing EBV serology similar to that seen in CMS. Other dilemmas relate to diagnostic cut-off levels for particular EBV-related tests, including antibodies to EA and the relative unavailability of several tests for detection of subtle immunodeficiency or T-cell dysfunction in individual patients with suspected CMS. Future efforts will be directed to the diagnostic usefulness of antibody responses to well-defined recombinant fragments of the EBV genome (ie, anti-EBNA1 vs. -EBNA2 titers).

Stable transfection of a human lymphoma line by sub-genomic fragments of Epstein-Barr virus DNA to measure humoral and cellular immunity to the corresponding proteins.

An Epstein-Barr virus (EBV)-negative human lymphoid B-cell line, DG75, was stably transfected with recombinant selection vectors that carry a subfragment of the BamHI WYH region (nucleotides 44664 to 50628), the BamHI K fragment, or a subfragment of the EcoRI D region (nucleotides 166614 to 170149) of B95-8 EBV DNA. These fragments contain the coding exons for the EBV-determined nuclear antigens EBNA2 and EBNA1, and the membrane antigen LMP, respectively. Antigen expression of the cells was detected by immunofluorescence. EBNA2 was expressed in 80-100% of the transfected cells, in contrast to EBNA1 which was expressed in only 25%, and LMP in only about 5% of the cells. Humoral antibody responses were measured by immunofluorescence and compared to cellular immunity as determined by the leukocyte migration inhibition (LMI) technique. Extracts from transfected cell lines expressing EBNA1, EBNA2 or LMP elicited an LMI response with cells from healthy EBV-seropositive individuals whereas the extract from the parental DG75 cell line did not. The results demonstrate the value of stably transfected cell lines expressing a defined EBV antigen for the monospecific analysis of host responses to the EBV-encoded antigen complex in growth-transformed cells.

Selective lack of antibody to a component of EB nuclear antigen in patients with chronic active Epstein-Barr virus infection.

The sera of 12 patients with presumed chronic active Epstein-Barr virus (EBV) infection lacked antibody to a component of the Epstein-Barr nuclear antigen (EBNA) complex encoded by the BamHI K fragment of viral DNA. This anomaly, detected in approximately 18% of sera obtained from patients with a diagnosis of "chronic mononucleosis," was more often found in patients with severe disease (approximately 32%) who had objective clinical findings and markedly elevated antibody titers to EBV replicative antigens than in those patients with the "fatigue syndrome" (10%). The lack of antibody to the K nuclear antigen is specific because most of those who did not have antibody to the K antigen made antibody to other latent nuclear (EBNA 2) antigens or nuclear early antigens. Such patients are thus able to lyse immortalized cells, release nuclear products, and present them to the immune system. Three hypotheses are suggested to explain the lack of antibody to the K antigen: a viral mutation, a failure of immune recognition, or lack of in vivo expression of the antigen due to extensive viral replication. Lack of antibody to one component of EBNA may serve as an objective serological marker for certain patients with chronic EBV infection.

Nuclear DNA-binding proteins determined by the Epstein-Barr virus-related simian lymphotropic herpesviruses H. gorilla, H. pan, H. pongo and H. papio.

Nuclear DNA-binding proteins were extracted from lymphoblastoid cell lines transformed with Epstein-Barr virus (EBV) or with the related lymphotropic herpesviruses of gorilla (Herpesvirus gorilla), chimpanzee (H. pan), baboon (H. papio) or orang-utan (H. pongo). They were immunoblotted with the sera of all four simian species in comparison with EBV antibody-positive human sera. Eight nuclear proteins were identified, and were designated GONA-1 and GONA-2 for H. gorilla-determined nuclear antigens, PANA-1A, PANA-1B and PANA-2 for H. pan, PONA-2 for H. pongo and HUPNA-1 and HUPNA-2 for H. papio-determined nuclear antigens. One of two tested HUPNA-2-positive baboon sera and one PONA-2-positive orang-utan serum also reacted with EBNA-2 in EBV-transformed cells. A human serum that contained antibodies to all five EBNA proteins cross-reacted only with PANA-2 and PONA-2. Monospecific anti-peptide antibodies against EBNA-2, type A, also reacted with PONA-2, but not with the other simian nuclear antigens. The data provide evidence that EBV-like simian lymphotropic herpesviruses induce EBNA-like nuclear antigens and that EBNA-2 and some simian EBNA-related proteins contain an epitope that has been conserved during the evolution of the EBV family of viruses.

Marked hyperbilirubinemia in infectious mononucleosis. Analysis of laboratory data in seven patients.

While mild to moderate hepatic dysfunction is commonly encountered in infectious mononucleosis induced by Epstein-Barr virus (EBV), clinical jaundice with high bilirubin levels (greater than or equal to 6.0 mg/dL [greater than or equal to 103 mumol/L] is only occasionally encountered. In this study, seven patients with primary EBV infections had peak bilirubin levels of 10.2 to 23.0 mg/dL (174 to 393 mumol/L) and, for the most part, presented initial diagnostic problems. Complications included the virus-associated hemophagocytic syndrome and acute respiratory distress syndrome in one patient and transient renal failure in another. The laboratory data suggested that a combination of hemolysis and viral-induced cholestasis was responsible for the intense hyperbilirubinemia in at least five patients. Physicians should be aware that marked hyperbilirubinemia can occur with EBV-induced infectious mononucleosis and, thereby, obviate the need for costly diagnostic laboratory tests and, occasionally, invasive procedures.

Effects of human immunodeficiency virus on the cellular immune response to Epstein-Barr virus in homosexual men: characterization of the cytotoxic response and lymphokine production.

We investigated Epstein-Barr virus (EBV)-specific T cell responses in homosexual men with, and at risk for, AIDS. We studied healthy laboratory workers, healthy homosexual men, and patients with AIDS-related complex or AIDS. The cytotoxic activity, absolute number of T4 lymphocytes, and interleukin-2 (IL-2) production decreased, whereas the relative number of Ia+ lymphocytes increased with the extent of infection with the human immunodeficiency virus (HIV). Cytotoxic activity correlated positively with the number of T4 lymphocytes (r = .56, P less than .001) and the amount of IL-2 produced (r = .47, P less than .01) but not with interferon production. Recombinant IL-2, but not gamma interferon, could restore cytotoxic T cell activity to control levels in patients with early HIV infection. EBV-specific serological studies paralleled the T lymphocyte investigations. The increased EBV activity observed in progressive HIV infection may be related to a diminution in the auto-reactive population of the T4 lymphocyte subset and may be amenable to IL-2 reconstitution.

Analysis of Epstein-Barr virus-specific and non-specific immune functions in a patient during the development of a non-Hodgkin's lymphoma.

A 57-year-old woman who presented with a reactive non-malignant lymphadenopathy was observed subsequently during the development of a nodular centroblastic non-Hodgkin's B-cell lymphoma. The Epstein-Barr virus (EBV)-specific antibody profile and EBV-specific and non-specific cell-mediated immune functions were determined at first presentation, and at various times during progression, in order to determine whether EBV was causally involved in the lymphoma and to assess in general the patient's cell-mediated immune function. At presentation, an immunodeficient status was suggested by an EBV-specific antibody profile indicative of an activated persistent infection; high antibody titers to viral capsid antigen (VCA) and early antigens (EA), but a low level of antibodies to EBV nuclear antigen (EBNA) confirmed by lack of leukocyte migration inhibition in response to EBNA (LMI-EBNA). The number of positive cells reactive with OKIa1 monoclonal antibody was significantly depressed, as was also the natural and interferon-activated killing (NK-IAK). After emergence of the lymphoma, NK-IAK reactivity and spontaneous lymphocyte DNA synthesis augmented in parallel with an increase in the frequency of Leu-7+ blood lymphocytes. The EBV-specific cell-mediated response, reflected by the outgrowth inhibition (OI) test was abolished in parallel with a decrease in the frequency of OKT3- and OKT4-positive lymphocytes.

Characterization of EBV-carrying B-cell populations in healthy seropositive individuals with regard to density, release of transforming virus and spontaneous outgrowth.

Peripheral or tonsil lymphocyte populations of EBV-seropositive donors give rise to EBV-carrying LCLs upon in vitro explantation. Such lines can arise either by a 2-step mechanism, namely release of virus from some of the explanted cells followed by infection of previously uninfected B cells, or by direct outgrowth of virus-harboring B cells (Rickinson et al., 1974; Dalens et al., 1975; Hinuma and Katsuki 1978; Katsuki et al., 1979). We observed that cells responsible for both the 2-step mechanism and for direct outgrowth are found in the purified B-cell compartment. Virus release was more frequent than direct outgrowth. The majority of virus-releasing cells were found in the low-density fraction that contains large, activated B blasts. Cells that were capable of spontaneous outgrowth in the presence of the viral inhibitor PFA and of virus-neutralizing antibody gave rise to cell lines that carried the sex chromosome marker of the original donor, rather than that of admixed cord blood lymphocyte of the opposite sex. Such cells were found in both the low- and the high-density fractions. The majority of the EBV-carrying B cells in vivo are thus low-density blasts. Rare small B cells of high density harboring EBV were capable of spontaneous outgrowth. This may be indicative of a host control mechanism that is removed upon cultivation in vitro.

Acyclovir treatment in infectious mononucleosis: a clinical and virological study.

Fifty-six patients with a clinical and laboratory diagnosis of infectious mononucleosis who had not been ill for more than seven days, were randomised for peroral treatment with acyclovir (800 mg five times daily) or placebo for seven days in a double blind trial. Clinical, virological and immunological parameters were monitored in each patient for six months. During treatment, shedding of Epstein-Barr virus' as assessed in 36 patients, was significantly reduced (p less than 0.001). However, virus production in the oropharynx returned to pre-treatment levels one week after the cessation of therapy. Virus was detected in 35 patients at enrollment and in 28 of 36 patients at the six-month control. No effect on the clinical course of the disease was noticed. The virus-specific antibody response was also unaffected. A significant reduction in spontaneous outgrowth of in vivo Epstein-Barr virus-infected B-lymphocytes was found at 180 days after treatment in four acyclovir-treated patients compared to six controls (p less than 0.001). In another three patients with over-whelming clinical symptoms causing airway obstruction and/or disseminated intravascular coagulopathy, treatment with intravenous acyclovir (10 mg/kg three times daily) was combined with prednisolone (0.7 mg/kg daily) for ten days. Virus shedding ceased transiently during treatment, but returned to initial levels within one week. A dramatic clinical effect on the pharyngeal oedema and general health of the two patients with airway obstruction was noticed, but was much less evident in a patient with intravascular coagulopathy.

Antibody responses to Epstein-Barr virus-determined nuclear antigen (EBNA)-1 and EBNA-2 in acute and chronic Epstein-Barr virus infection.

Five distinct Epstein-Barr virus (EBV)-determined nuclear antigens (EBNA-1 to EBNA-5) were recently identified. Antibody responses to these antigens could conceivably differ, and thus prove of serodiagnostic value, in EBV-associated disease processes. As a first step, murine or human cell lines transfected with appropriate EBV DNA fragments and stably expressing either EBNA-1 or EBNA-2 were used to determine the frequency and time of emergence of antibodies to these two antigens in the course of acute and chronic infectious mononucleosis (IM) and to assess their titers in so-called chronic active EBV infections. Following IM, antibodies to EBNA-2 arose first and, after reaching peak titers, declined again in time to lower persistent or even nondetectable levels. Antibodies to EBNA-1 emerged several weeks or months after anti-EBNA-2 and gradually attained the titers at which they persisted indefinitely. The ratios between the anti-EBNA-1 and anti-EBNA-2 titers therefore were generally well below 1.0 during the first 6-12 months after IM and turned to well above 1.0 during the second year. In clear cases of chronic IM, the inversion of this ratio was delayed or prevented. In the less well-defined chronic EBV infections, low ratios were observed in only some of the patients. Because many of these illnesses were not ushered in by a proven IM and often showed EBV-specific antibody profiles within the normally expected range, a causal role of the virus in these cases remains doubtful.

Serum antibodies to Epstein-Barr virus in patients with major depressive disorder.

To determine whether major depressive disorder might be associated with serologic evidence for a chronic active Epstein-Barr virus infection, viral-specific antibodies were measured in two separate groups of depressed patients (N=43) and in 46 appropriately matched healthy volunteers. No evidence that depression affects cellular immunity to the point that a persistent Epstein-Barr virus carrier state becomes activated was found. There was also no evidence that depression results from an unrecognized chronic active Epstein-Barr virus infection. The authors conclude that the routine clinical determination of expensive commercial Epstein-Barr virus antibody profiles is not indicated in most patients with major depressive disorder in the absence of other signs of chronic active Epstein-Barr viral infection.