Epstein-Barr virus DNA in cerebrospinal fluid from patients with AIDS-related primary lymphoma of the central nervous system

Detection of Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus DNA in CSF from persons infected with HIV who had neurological disease

OBJECTIVES

To determine the frequency and clinical relevance of Epstein-Barr virus (EBV) and Kaposi's sarcoma associated herpesvirus (KSHV) DNA detection in the CSF from patients infected with HIV.

METHODS

Cerebrospinal fluid was obtained prospectively from 115 consecutive patients infected with HIV undergoing diagnostic lumbar puncture for investigation of neurological disease. Amplification of DNA was performed using a nested polymerase chain reaction (PCR) for detection of EBV internal repeat and KSHV minor capsid sequences.

RESULTS

EBV DNA was detected in the CSF supernatant of 18 patients. This included all patients with primary CNS lymphoma (seven patients) or a combination of systemic and CNS lymphoma (two patients). By contrast EBV DNA was not detected in the CSF supernatant of any patient with systemic, but not CNS, lymphoma (10 patients). EBV DNA was also detected in the supernatant of nine further patients without a diagnosis of lymphoma at the time of lumbar puncture, two of whom subsequently developed CNS lymphoma. No EBV DNA was detected in CSF supernatant from the remaining 87 samples (two of these patients subsequently developed lymphoma). KSHV DNA was detected in the CSF of two patients, one had systemic (but not CNS) lymphoma and the other did not have lymphoma.

CONCLUSION

A diagnosis of CNS lymphoma is strongly associated with the presence of EBV DNA in CSF. In the absence of clinical and radiological features of CNS lymphoma, the presence of detectable CSF EBV DNA may predict subsequent tumour development. KSHV DNA is rarely detected in CSF in this patient group and shows no correlation with lymphoma or other neurological disease.

Changing disease patterns in focal brain lesion-causing disorders in AIDS

OBJECTIVES

To assess temporal trends of the different disorders causing focal brain lesions (FBL) in HIV-infected patients and to examine the reliability of the U.S. Centers for Disease Control and Prevention (CDC) criteria for presumptive diagnosis of toxoplasmic encephalitis (TE) for the years 1991 to 1996.

DESIGN/METHODS

A prospective, monocenter study. Percentages of occurrence of the different FBL-causing disorders for each year were calculated. Temporal trends were analyzed by chi2 test for linear trend and multivariate polytomous nonordinal logistic regression. The positive predictive value (PPV) of the CDC's presumptive criteria for the diagnosis of TE (recent onset of a focal neurologic abnormality consistent in intracranial disease or a reduced level of consciousness, evidence on brain imaging of a lesion having mass effect or the radiographic appearance of which is enhanced by injection of contrast medium, and serum antibody to toxoplasmosis) was calculated using contingency tables for each calendar year.

RESULTS

A highly significant decline of the risk of TE and an increase of the probability of patients to take anti-Toxoplasma prophylaxis were observed. A threefold but statistically not significant augmented risk of diagnosing both primary central nervous system lymphoma (PCNSL) and progressive multifocal leucoencephalopathy (PML) has been registered for 1996 compared with 1991. Among FBL showing contrast enhancement, the increased finding of PCNSL over the years studied was significant. The probability of other FBL-causing disorders, such as focal viral encephalitis sustained by cytomegalovirus or herpes simplex virus, increased significantly over the years studied. Multivariate analysis confirmed that the year of diagnosis of FBL had a significant effect on the risk reduction of TE. The PPV of the CDC's criteria for the presumptive diagnosis of TE dropped from 100% for the year 1991 to 39% in the year 1996. A similar result was obtained in calculating the PPV of presumptive criteria only among patients without previous primary prophylaxis.

CONCLUSIONS

Because of the significant decrease of TE and the increase of PCNSL empiric anti-Toxoplasma therapy no longer seems appropriate as a first-line approach to all HIV-positive patients with FBL. Especially in the case of a finding of FBL by contrast enhancement, new diagnostic strategies should be employed to identify the underlying disorder rapidly and accurately.

Detection of feline immunodeficiency proviral sequences in lymphoid tissues and the central nervous system by in situ gene amplification

The availability of sensitive methods for detecting and localising the feline immunodeficiency virus (FIV) may help shed light on its role in generating tissue damage observed during infection. As immunohistochemical and in situ hybridisation techniques might not be sufficiently sensitive for this type of study, we adapted to FIV PCR-in situ hybridisation (PCR-ISH) that combine the extreme sensitivity of PCR with the precise localisation provided by ISH. The steps important for the success of PCR-ISH, such as sample preparation, permeabilisation, amplification profile, type of labels, and hybridisation conditions were optimised using paraformaldehyde-fixed and formalin-fixed paraffin-embedded sections of cells infected in vitro with FIV. As controls for amplification, the feline tumor necrosis factor-alpha gene (TNF-alpha) and the non-related EBNA-1 gene of the human Epstein-Barr virus were used. Once the method proved sufficiently sensitive and specific with these cells, the PCR-ISH assay was applied to paraffin sections of the lymph nodes, spleen and central nervous system of a 2-year FIV infected cat that, at the time of challenge, harboured low copy numbers of proviral genomes. Comparison of the results of PCR-ISH, competitive PCR and immunohistochemical analysis are described.

Automated in situ hybridization: diagnostic and research applications

Although in situ hybridization has been in use for almost 30 years, its technically demanding nature, the requirements for optimal tissue fixation and preservation, and the turnaround time for the experiments have prevented this technique from becoming widely used in the surgical pathology setting. The use of nonisotopic reporter molecules, the possibility of performing hybridization on archival material, and very recently, automation of the procedure have brought in situ hybridization to the forefront of diagnostic and experimental pathology. We describe our experience with nonradioactive, automated in situ hybridization, compare the technique with traditional manual procedures, and briefly outline its potential applications in diagnostic pathology and in the research setting.

The application of the polymerase chain reaction of cerebrospinal fluid in the clinical management of AIDS-related CNS disorders

In AIDS patients central nervous system (CNS) illness may be caused by HIV disease itself or by opportunistic agents, resulting in serious morbidity such as behavioral and motor disturbances, meningitis or encephalitis, among other disorders. Early diagnosis can allow specific treatment (e.g., antimicrobial treatment) that may prevent, ameliorate, or slow the catastrophic sequelae of infection, as well as reduce the need for expensive diagnostic procedures. Conventional microbiology techniques have proven inadequate for the diagnosis of most AIDS-related CNS diseases. However, the development in the past decade of the application of polymerase chain reaction (PCR) to clinical specimens has facilitated the early diagnosis of a number of infectious diseases in these patients. The technique permits the amplification of target nucleic acids such that common laboratory methods may then be used for diagnosis. The application of PCR to cerebrospinal fluid for early diagnosis of AIDS-related neurologic complications has been an impressive example of the application of PCR and may form the basis of new algorithms for diagnosis and possibly the evaluation of treatment protocols.

In situ amplification of the Epstein-Barr virus genome in cell suspensions

Epstein-Barr virus (EBV) is distributed widely throughout the world. Apart from a association with two geographically-restricted malignancies (Burkitt's lymphoma and nasopharyngeal carcinoma), EBV is thought to be implicated in the etiology of B-cell lymphoma in immunocompromised individuals. In these patients, monitoring the viral load in serum can provide useful information on the timing of the instigation of antiviral therapy, i.e. as soon as a rise is detected. PCR technology, owing to its high sensitivity, is used frequently in such situations. In order to gain further insight into the nature of the peripheral blood cells carrying the viral genome on a cell-by-cell basis, an in situ amplification technique was developed as a model using two cell lines growing in suspension, with the aim of distinguishing between EBV-positive and EBV-negative cells. Preliminary experiments were undertaken subsequently on clinical samples from patients with infectious mononucleosis and patients with lymphoma indicating that this technique might be useful clinically.

Diagnostic imaging of the brain in acquired immunodeficiency syndrome (AIDS)

The central nervous system is commonly involved in acquired immunodeficiency syndrome (AIDS), resulting in a variety of lesions and diseases. They can be divided into the primary effects of human immunodeficiency virus (HIV), opportunistic infections, tumors, and vascular disease. This article is a review of the major imaging findings observed in each disease, with clinical and pathological correlations relevant to the goal of differential diagnosis.

Comparative analysis of Epstein-Barr virus (EBV) detection by nested-PCR and non-isotopic in situ hybridization in nasopharyngeal carcinoma (NPC)

The aims of this study were two-fold: first, to assess the relative diagnostic performance of non-isotopic in situ hybridization (ISH) and the nested polymerase chain reaction (nested-PCR) applied to Epstein-Barr virus (EBV) detection in a series of 55 unselected nasopharyngeal carcinoma (NPC) cases and, secondly, to correlate these data with histopathological classification. Our study shows that in 76.36% of NPC cases positive nuclear signals were observed using EBV-ISH. Overall, EBV-ISH positivity varied according to histological type, in that undifferentiated carcinomas showed a higher proportion of positive cases than differentiated cell carcinomas, although ISH results do not show significant differences in relation to histological types when employing two different schemes (WHO and Micheau). However, in adequate quality DNA samples (54 NPC cases), EBV-DNA was detected in 100% of cases using a nested-PCR, supporting the previous view that all histological types of NPC are in reality variants of EBV-infected neoplasia. ISH-negative cases probably reflect a lower sensitivity than PCR, particularly when a small number of viral copies are present, as well as a variable technical effectiveness for detected EBV, independent of the NPC histological type.

Minimally invasive diagnosis of acquired immunodeficiency syndrome-related primary central nervous system lymphoma

BACKGROUND

The detection of Epstein-Barr virus (EBV)-DNA in cerebrospinal fluid (CSF) by means of the polymerase chain reaction (PCR) has been revealed, in retrospective studies, to be a good marker of primary central nervous system lymphoma (PCNSL) related to acquired immunodeficiency syndrome (AIDS); however, the technique's usefulness in the management of AIDS patients with focal brain lesions is still unknown. We studied the clinical usefulness of testing CSF obtained by lumbar puncture for the presence of EBV-DNA as a minimally invasive approach to the diagnosis of AIDS-PCNSL in patients with focal brain lesions.

METHODS

Human immunodeficiency virus (HIV)-infected patients with focal brain lesions, observed prospectively during a 30-month period, underwent lumbar puncture if not contraindicated; otherwise, ventricular CSF was obtained at brain biopsy. The presence of EBV-DNA was determined by means of PCR.

RESULTS

We evaluated 122 patients: 42 diagnosed with brain lymphoma and the remaining 80 diagnosed with other brain disorders. Cerebrospinal fluid was collected from 101 patients--by lumbar puncture in 95, including 40 patients with AIDS-PCNSL. The sensitivity and specificity of PCR for EBV-DNA detection in lumbar CSF were 80% (95% confidence interval [CI] = 60.9%-91.6%) and 100% (95% CI = 92.6%-100%), respectively. Lumbar puncture and subsequent assessment of EBV-DNA would have allowed a correct diagnosis in 63.2% (95% CI = 46.0%-77.7%) of patients with AIDS-PCNSL and excluded this diagnosis in 76.3% (95% CI = 65.2%-84.8%) of patients without lymphoma (because EBV-DNA was not detected).

CONCLUSIONS

The presence of EBV-DNA in lumbar CSF is a sensitive and highly specific diagnostic marker of AIDS-PCNSL, and EBV-DNA detection in this fluid may allow a minimally invasive diagnosis in a large percentage of patients with brain lymphomas.

Increased presence of Epstein-Barr virus DNA in ocular fluid samples from HIV negative immunocompromised patients with uveitis

AIMS

To investigate whether routine testing for Epstein-Barr virus (EBV) is necessary in the examination of a patient with uveitis.

METHODS

Intraocular EBV DNA was determined in 183 ocular fluid samples taken from patients with AIDS and uveitis, HIV negative immunocompromised uveitis, acute retinal necrosis, toxoplasma chorioretinitis, intraocular lymphoma, anterior uveitis, and miscellaneous uveitis of unknown cause. In 82 samples from this group of patients paired serum/ocular fluid analysis was performed to detect local antibody production against EBV. Controls (n = 46) included ocular fluid samples taken during surgery for diabetic retinopathy, macular pucker, or cataract.

RESULTS

Serum antibody titres to EBV capsid antigen proved to be significantly increased in HIV negative immunocompromised patients with uveitis (p < 0.01) compared with controls. Local antibody production revealed only three positive cases out of 82 patients tested, two results were borderline positive and one patient had uveitis caused by VZV. EBV DNA was detected in three out of 46 control ocular fluid samples. In the different uveitis groups EBV DNA was noted, but was not significantly higher than in the controls, except in six out of 11 HIV negative immunocompromised patients (p = 0.0008). In four out of these six cases another infectious agent (VZV, HSV, CMV, or Toxoplasma gondii) had previously been identified as the cause of the uveitis.

CONCLUSIONS

When comparing various groups of uveitis patients, EBV DNA was found more often in HIV negative immunocompromised patients with uveitis. Testing for EBV does not have to be included in the routine management of patients with uveitis, since indications for an important role of this virus were not found in the pathogenesis of intraocular inflammation.

Establishing a KSHV+ Cell Line (BCP-1) From Peripheral Blood and Characterizing Its Growth in Nod/SCID Mice

Kaposi's sarcoma-associated herpesvirus (KSHV or HHV8) sequences are present in primary effusion lymphomas (PEL). KSHV+cell lines have been established from such lymphomas. Here we report the first description of the establishment of a KSHV+, EBV− cell line (BCP-1) from the peripheral blood of a patient with PEL. Using this cell line and a KSHV+, EBV+ PEL cell line (HBL-6) previously established from ascitic fluid, we investigated whether in nonobese diabetic/severe combined immunodeficiency disease (Nod/SCID) mice tumors representing PEL can be established. When injected intravenously (IV) into Nod/SCID mice, BCP-1 and HBL-6 infiltrated organs, with only occasional macroscopic tumor formation. Intraperitoneal injections (ip) led to the development of ascites and diffuse infiltration of organs, without obviously solid lymphoma formation, resembling the diffuse nature of human PEL. To investigate a possible mechanism for the peculiar phenotype of PEL, we examine the presence of adhesion molecules and homing markers on PEL cells before and after growing in mice. Both BCP-1 and HBL-6 cells lack expression of important cytoadhesion molecules including CD11a and CD18 (LFA1 α and β chains), CD29, CD31, CD44, CD54 (ICAM-1), and CD62L and E (L and E selectins).

Establishing a KSHV+ Cell Line (BCP-1) From Peripheral Blood and Characterizing Its Growth in Nod/SCID Mice

Kaposi's sarcoma-associated herpesvirus (KSHV or HHV8) sequences are present in primary effusion lymphomas (PEL). KSHV+cell lines have been established from such lymphomas. Here we report the first description of the establishment of a KSHV+, EBV− cell line (BCP-1) from the peripheral blood of a patient with PEL. Using this cell line and a KSHV+, EBV+ PEL cell line (HBL-6) previously established from ascitic fluid, we investigated whether in nonobese diabetic/severe combined immunodeficiency disease (Nod/SCID) mice tumors representing PEL can be established. When injected intravenously (IV) into Nod/SCID mice, BCP-1 and HBL-6 infiltrated organs, with only occasional macroscopic tumor formation. Intraperitoneal injections (ip) led to the development of ascites and diffuse infiltration of organs, without obviously solid lymphoma formation, resembling the diffuse nature of human PEL. To investigate a possible mechanism for the peculiar phenotype of PEL, we examine the presence of adhesion molecules and homing markers on PEL cells before and after growing in mice. Both BCP-1 and HBL-6 cells lack expression of important cytoadhesion molecules including CD11a and CD18 (LFA1 α and β chains), CD29, CD31, CD44, CD54 (ICAM-1), and CD62L and E (L and E selectins).

Intravenous methotrexate for primary central nervous system non-Hodgkin's lymphoma in AIDS

OBJECTIVE

To evaluate high-dose intravenous methotrexate in primary central nervous system (CNS) lymphoma in HIV-infected patients.

DESIGN

An uncontrolled pilot trial.

SETTING

An infectious diseases department in Paris, France.

PATIENTS

All consecutive AIDS patients with primary CNS lymphoma attending the same unit from August 1994 to March 1996.

INTERVENTIONS

Methotrexate was intravenously administered at a dose of 3 g/m2 every 14 days with leucovorin rescue. A maximum of six cycles was planned. Steroids were given to all patients and haematological growth factors were administered as required.

MAIN OUTCOME MEASURES

Rate of response, time to response and survival.

RESULTS

Fifteen patients (10 with histological documentation) were recruited. The median time since clinical onset was 27 days (range, 7-69 days), median Karnofsky score was 51 (range, 30-70), and mean CD4+ cell count was 30 +/- 19 x 10(6)/l (range, 7-69 x 10(6)/l). Complete responses, defined as clinical improvement and disappearance of contrast-enhancing brain abnormalities on computed tomography or magnetic resonance imaging, were obtained in seven out of 15 patients (three out of 10 patients with histological diagnosis and four out of five patients without histological confirmation). The Karnofsky score of these seven patients improved to 80 +/- 10 (range, 70-100). The mean time taken to respond was 62 +/- 20 days (range, 45-90 days). One patient relapsed at 6 months. Six patients failed to respond, and two died of severe sepsis on days 15 and 45. The median survival time was 290 days (range, 11-570 days): 73 days (range, 11-570 days) in the 10 patients with histological diagnosis, and 347 days (range, 286-409 days) in the five patients without histological confirmation. Side-effects occurred in 10 patients, with gastrointestinal disorders in five, mucositis and skin rash in two, and fever in three patients; however, these events were mild and did not require cycle postponement or dose changes. No cognitive dysfunction occurred.

CONCLUSION

Methotrexate appears to be an attractive alternative to radiation therapy for primary CNS lymphoma and is associated with a far greater improvement in quality of life relative to historical series of radiation therapy.

Phenotypic and Functional Analysis of Fas (CD95) Expression in Primary Central Nervous System Lymphoma of Patients With Acquired Immunodeficiency Syndrome

The poor prognosis associated with patients afflicted with the acquired immunodeficiency syndrome and primary central nervous system lymphoma (AIDS-PCNSL) is due in part to the intrinsic resistance of this Epstein-Barr virus (EBV)-associated tumor to conventional antineoplastic therapy. Fas (CD95) is a transmembrane protein receptor that transmits an intracellular signal leading to rapid programmed cell death following ligation with its natural ligand or anti-Fas antibodies. Fas expression and function were assessed in AIDS-PCNSL biopsy samples and in EBV+ human B-cell tumors that spontaneously developed in severe combined immune deficient (SCID) mice engrafted with human lymphocytes (hu-PBL-SCID mice). All tumors samples showed high-density surface expression of Fas by flow cytometry or immunohistochemical staining. Cells from two AIDS-PCNSL biopsy samples that did not express pan B-cell markers did not express Fas antigen. All tumors examined were susceptible to Fas-mediated apoptosis, as measured by standard assays for endonucleolytic cleavage of DNA. The response to Fas-mediated apoptosis was dependent on log-fold increases in the concentration of immobilized anti-Fas antibody, but could also be induced with a mobilized anti-Fas antibody. No evidence for intrinsic resistance to Fas-mediated apoptosis (ie, secreted or truncated forms of Fas) could be shown. Radiation-induced apoptosis of neoplastic EBV+ B cells was enhanced by activation of Fas, and prolonged exposure to interleukin-2 increased both Fas expression and Fas-induced apoptosis. As the normal brain parenchyma appears to have either low-density or absent expression of Fas, and antineoplastic therapy can be selectively delivered to the CNS with little systemic toxicity, local delivery of Fas-activating molecules could prove to be a useful component in the multimodal treatment of AIDS-PCNSL.

Specific diagnostic methods for herpesvirus infections of the central nervous system: a consensus review by the European Union Concerted Action on Virus Meningitis and Encephalitis

BACKGROUND

Herpesvirus infections of the central nervous system are often severe but are fortunately rare. The incidence of these infections has however, increased in recent years as a consequence of an increase in the number of immune-compromised individuals. New diagnostic procedures have improved our ability to diagnose these infections and herpesviruses may yet be implicated as the cause of further neurological diseases with no known aetiology. Methodological standards for selection and evaluation of patient materials are essential to the provision of reliable diagnosis, yet few studies have addressed this important issue.

OBJECTIVES

To describe and define methodological standards and reference methodology for diagnosis of herpesvirus infections of the CNS.

STUDY DESIGN

Information gathered by literature review.

RESULTS

Only for herpes simplex encephalitis is there sufficient data to allow the definition of reference methodology. Good methodological standards exist but few studies have adhered to these standards. As methods for the detection of specific intrathecal antibody synthesis are well established yet under-used in diagnostic virology, the principle of these measurements is reviewed in some detail.

CONCLUSIONS

Herpesvirus infections of the CNS are of increasing importance. High quality, multi-centre studies are needed to establish the value of the new diagnostic test procedures if further improvement in the diagnostic sensitivity and specificity of these procedures is to be achieved.

Preventive effect of IgG from EBV-seropositive donors on the development of human lympho-proliferative disease in SCID mice

The effect of weekly treatments with various gammaglobulin preparations on the development of human B-cell tumors was studied in severe combined immunodeficient (SCID) mice. SCID mice were injected i.p. with human peripheral blood mononuclear cells (PBMCs) from an Epstein-Barr virus (EBV)-seropositive healthy blood donor. Repopulated SCID mice were divided into 7 treatment groups receiving either PBS, 2 commercial gammaglobulin preparations, purified IgG prepared from pooled plasma from EBV-seronegative or -seropositive blood donors, a rabbit anti-serum against EBV envelope glycoprotein gp340 or interferon (IFN)-alpha. All treatments started 1 day after injection of PBMC and continued for 8 weeks. In the PBS-treated control group, 85% of mice developed tumors in the abdominal cavity, mostly with liver metastasis within 150 days. Tumor formation was prevented by treatment with the 2 commercial gammaglobulin preparations as well as by purified IgG from EBV-seropositive donors. In contrast, purified IgG from EBV-seronegative donors, rabbit anti-gp340 anti-serum or IFN-alpha had no effect. Our results indicate that the effect of gammaglobulin is due to the presence of specific antibodies against EBV antigens. Further experiments showed that both the time of onset and the duration of treatment, as well as the dose of Ig, are important factors for prevention of tumor formation. Studies aiming at identification of target antigens for antibodies which prevent lymphoma development may be clinically relevant for prevention and possibly treatment of lympho-proliferative disease in severely immuno-compromised patients.

Absence of seven human herpesviruses, including HHV-6, by polymerase chain reaction in CSF and blood from patients with multiple sclerosis and optic neuritis

Several members of the herpesvirus family have been implicated in the pathogenesis of multiple sclerosis (MS). Recently, HHV-6 viral antigen has been demonstrated in association to MS plaques, as well as DNA from human herpesvirus 6 (HHV-6) in cerebrospinal fluid from a few MS patients by polymerase chain reaction (PCR). In the present study, CSF from patients with MS, optic neuritis and other neurological diseases, as well as consecutive CSF and serum samples from MS patients included in a clinical trial with acyclovir, were analysed by nested PCR for the presence of DNA from herpes simplex virus 1 and 2, Epstein-Barr virus, varicella zoster virus, cytomegalovirus, human herpesvirus 6 and 7. No virus DNA was found in any CSF (n = 115) or serum (n = 116) sample. These findings argue against a continuous disseminated herpesvirus infection in MS, but do not rule out a lesion-associated, low-grade herpesvirus infection within the MS brain.

Detection of Epstein-Barr viral DNA in serum using rapid-cycle PCR

Our study describes the comparison of a rapid nested PCR assay to standard serology techniques for the detection of Epstein-Barr virus (EBV) in serum. The sera of 81 patients with suspected EBV infection were analyzed; 54 were positive for one or more of the standard serology markers, i.e., IgM viral capsid antigen (VCA), IgG-VCA, Epstein-Barr nuclear antigen 1 (EBNA-1), and early antigen (EA), and 27 were negative for all serology markers. The sera from 15 normal healthy blood donors were also included. No EBV DNA was detected in any of the 15 blood donor samples or in any of the 27 samples with negative serology results. Eleven samples (20%) of the 54 with positive EBV serology results were positive for EBV DNA. Of these samples, 9 were EBV IgM-VCA positive and anti-EBNA negative, suggesting acute infection. One of the 11 samples had high titers of IgM-VCA, IgG-VCA, anti-EBNA, and anti-EA. The last of the 11 samples was from a patient with acute infectious mononucleosis without sufficient sample volume for EBV serology testing. Seventeen of the total 96 samples from the study were IgM-VCA positive and anti-EBNA negative and 9 of these 17 samples (53%) tested positive for EBV DNA. These data suggest that the detection of EBV DNA by PCR in serum may be a useful indicator of active infection rather than latent virus.

Comparison of magnetic resonance imaging with neuropathological findings in the diagnosis of HIV and CMV associated CNS disease in AIDS

OBJECTIVES

To compare the results of clinical assessment and MRI with neuropathological findings in the diagnosis of HIV and cytomegalovirus (CMV) associated CNS disease.

METHODS

A retrospective study of 35 patients infected with HIV who were examined at necropsy between four and 70 (median 20) days after neurological assessment and MRI.

RESULTS

Of the 35 patients, 19 had diffuse white matter hyperintensity on T2 weighted MRI, six of whom also had focal lesions. Nine other patients had focal white matter lesions and seven had changes in cortical atrophy only. Necropsy in the 19 with diffuse white matter hyperintensity showed HIV leukoencephalopathy (HIVLEP) with encephalitis in 10, CMV encephalitis in three, both HIVLEP/HIV encephalitis and CMV encephalitis in one, lymphoma in three, and non-specific inflammation in two. Necropsy in the 16 other patients without diffuse white matter hyperintensity showed CMV encephalitis in six, HIV encephalitis (without HIVLEP) in two, CMV encephalitis and HIVLEP/HIV encephalitis in one, non-HIV associated abnormalities in five, herpes simplex encephalitis in one, and lymphoma in one. CMV DNA was detected in CSF of five of seven patients with CMV encephalitis and in two of two with CMV associated polyradiculopathy but without CMV encephalitis. Diffuse white matter hyperintensity on MRI had a sensitivity of 100%, a specificity of 66.6%, and a positive predictive value of 58% for diagnosis of HIVLEP.

CONCLUSION

Diffuse white matter hyperintensity on MRI can be due to either HIV or CMV associated pathology or non-specific abnormalities.

Aseptic meningitis and encephalitis: the role of PCR in the diagnostic laboratory

In this study we have devised a simple and robust PCR strategy to detect a wide range of viruses, bacteria, and parasites, all of which are capable of causing aseptic meningitis and encephalitis. The techniques developed have been used in a routine diagnostic virology laboratory to test prospectively 2,233 cerebrospinal fluid specimens. A virus was detected in 147 specimens of cerebrospinal fluid from 143 patients. Four sets of primers were sufficient to detect the virus in 135 (94%) of the PCR-positive patients. We conclude that with appropriate primers, PCR can be systematically and economically applied to test for a range of organisms in a routine diagnostic laboratory. In our opinion, PCR will soon become the "gold standard" test for viral infections of the central nervous system.

Human immunodeficiency virus-associated lymphomas

Lymphomas associated with human immunodeficiency virus (HIV) will probably become an increasing problem with improved survivals of infected individuals in an immunosuppressed state because of the advances in antiretroviral treatment and the therapy of opportunistic infections. In an attempt to aid the understanding of the many aspects of the this growing problem, the current thinking about the epidemiology, pathology, biological and clinical features, and treatment of the systemic HIV-associated non-Hodgkin lymphomas is reviewed. The important features of the HIV-associated central nervous system lymphomas are also described. Finally, there is a discussion of Hodgkin's disease in HIV-infected individuals.

Diagnosis of viral infections of the central nervous system: clinical interpretation of PCR results

BACKGROUND

Standard laboratory techniques, such as viral culture and serology, provide only circumstantial or retrospective evidence of viral infections of the central nervous system (CNS). We assessed the diagnostic accuracy of PCR of cerebrospinal fluid (CSF) in the diagnosis of viral infections of the CNS.

METHODS

We examined all the CSF samples that were received at our diagnostic virology laboratory between May, 1994, and May, 1996, by nested PCR for viruses associated with CNS infections in the UK. We collected clinical and laboratory data for 410 patients from Oxford city hospitals (the Oxford cohort) whose CSF was examined between May, 1994, and May, 1995. These patients were classified according to the likelihood of a viral infection of the CNS. We used stratified logistic regression analysis to identify the clinical factors independently associated with a positive PCR result. We calculated likelihood ratios to estimate the clinical usefulness of PCR amplification of CSF.

FINDINGS

We tested 2233 consecutive CSF samples from 2162 patients. A positive PCR result was obtained in 143 patients, including 22 from the Oxford cohort. Logistic regression analysis of the Oxford cohort showed that fever, a virus-specific rash, and a CSF white-cell count of 5/microL or more were independent predictors of a positive PCR result. The likelihood ratio for a definite diagnosis of viral infection of the CNS in a patient with a positive PCR result, relative to a negative PCR result, was 88.2 (95% CI 20.6-378). The likelihood ratio for a possible diagnosis of viral infection of the CNS in a patient with a negative PCR result, relative to a positive PCR result, was 0.10 (0.03-0.39).

INTERPRETATION

A patient with a positive PCR result was 88 times as likely to have a definite diagnosis of viral infection of the CNS as a patient with a negative PCR result. A negative PCR result can be used with moderate confidence to rule out a diagnosis of viral infection of the CNS. We believe that PCR will become the first-line diagnostic test for viral meningitis and encephalitis.

Multiplex PCR for diagnosis of AIDS-related central nervous system lymphoma and toxoplasmosis

A nested multiplex PCR assay was designed for the simultaneous detection of Epstein-Barr virus and Toxoplasma gondii DNA from the cerebrospinal fluid of AIDS patients. T. gondii DNA was detected in 8 of 8 patients with Toxoplasma encephalitis and in 0 of 6 patients without toxoplasmosis, and Epstein-Barr virus DNA was found in 9 of 14 patients with central nervous system lymphoma and in 2 of 38 patients without disease.

Human T-cell lymphotropic virus tax and Epstein-Barr virus DNA in peripheral blood of multiple sclerosis patients during acute attack

OBJECTIVES

A study was performed to determine whether persistent or latent viruses are reactivated during the acute attack in relapsing remitting multiple sclerosis (MS).

MATERIAL AND METHODS

DNA of herpes simplex virus type 1 and 2 (HSV-1 and -2), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), JC virus (JCV) and HTLV-I was searched, using nested polymerase chain reaction (PCR), in peripheral blood mononuclear cells (PBMCs) collected from 14 MS patients on the first day and, twice a week, during an acute attack of the disease.

RESULTS

Viral DNA was detected, in at least one PBMC sample, in all the patients. Interestingly, EBV DNA was found in 42.8% of the patients on the first day, while a sharp increase of the HTLV tax-rex DNA frequency (35.7%) was observed on the tenth day.

CONCLUSIONS

In MS relapse EBV DNA detection is an early, frequent event, while the finding of tax-rex, but not of other HTLV-I genomic regions, is a secondary phenomenon, suggesting that these two factors could interact in the pathogenesis of MS relapses.

Viral etiology of acute childhood encephalitis in Beijing diagnosed by analysis of single samples

OBJECTIVE

To understand the viral etiology of acute childhood encephalitis in Beijing.

METHODS

Ninety-seven Chinese children (between 7 months and 13 years of age) with acute encephalitis were retrospectively investigated. They were treated in Beijing Children's Hospital between June, 1991, and October, 1994. Different serologic methods (immunofluorescence assay, enzyme-linked immunosorbent assay, solid phase reverse immunosorbent test) were used for detection of IgM antibody to enteroviruses, herpesviruses, mumps, measles, rubella and Japanese encephalitis virus. The viral DNA of six herpesviruses was detected by polymerase chain reaction.

RESULTS

Viral etiology was identified in 35 of 97 (36.0%) cases. The most frequently identified pathogens were enteroviruses (15; 15.4%), followed by mumps (7; 7.2%), rubella (6; 6.1%), Japanese encephalitis virus (5; 5.1%), human herpesvirus 6 (2; 2.0%), herpes simplex virus (2; 2.0%) and Epstein-Barr virus (1; 1.0%). IgM antibody in cerebrospinal fluid was detected for enterovirus, mumps and rubella viruses.

CONCLUSIONS

Enteroviruses were the most frequent viral pathogens of acute childhood encephalitis in Beijing. Detection of IgM in cerebrospinal fluid may be useful for diagnosis in certain cases of viral encephalitis.

Neurologic manifestations of HIV infection

A wide spectrum of central and peripheral nervous system abnormalities may be associated with HIV infection. These disorders may be caused by HIV infection, result as secondary complications related to immunosuppression, or be a neurotoxic effect of therapeutic agents. The range of neurologic disorders includes dementia, focal cerebral mass lesions, myelopathy, peripheral neuropathies, and myopathy. Early diagnosis and therapy is critical, and may result in substantial improvement in patients' quality and quantity of life. This article reviews the approach to differential diagnosis of these neurologic disorders and presents theories of pathogenesis and current approaches to treatment.

Biology and management of AIDS-associated primary CNS lymphomas

Primary central nervous system (CNS) lymphoma is the most common brain tumor in patients with AIDS and occurs in about 10% of this population. CT/MR scan usually demonstrates single or multiple contrast enhancing masses that are radiographically indistinguishable from other CNS processes such as toxoplasmosis. Brain biopsy, positive cerebrospinal fluid (CSF) cytology, or possibly the demonstration of Epstein-Barr viral DNA in the CSF can establish the diagnosis. Cranial radiotherapy (RT) has been the cornerstone of therapy and produces responses in most patients, but their median survival is still only a few months. The addition of chemotherapy to RT may prolong survival in a sub-group of patients.

Epstein-Barr virus DNA in serum after liver transplantation--surveillance of viral activity during treatment with different immunosuppressive agents

In immunocompromised HIV-infected and transplanted patients, there is a risk of developing Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPD) and lymphomas. EBV has previously been detected by the polymerase chain reaction (PCR) in cerebrospinal fluid from all AIDS patients with EBV-associated cerebral lymphomas. We therefore thought it would be of interest to determine whether transplant patients with extracerebral EBV-associated LPD have detectable EBV genomes in serum. Nested PCR (nPCR) showed that 58% (18/31) of liver transplant (LTX) patients had EBV DNA in 17% (21/125) of serum samples obtained within the first 3 months after LTX. In 39% (7/18) of the patients, the first EBV nPCR-positive sample was found within 2 weeks post-LTX. Basic immunosuppression with cyclosporin A or FK506 did not seem to influence the frequency of detectable EBV genomes in serum. In contrast, positive EBV nPCR correlated to secondary OKT3 treatment for severe acute rejection (P = 0.009). EBV-associated malignant lymphoma developed in three patients 2-6 months post-LTX. In all of them, EBV DNA was amplifiable within 12-14 days after LTX. The EBV antibody titers were not directly related to detectable EBV DNA in serum. We conclude that monitoring of LTX patients receiving increased immunosuppression by nPCR for EBV DNA in serum may help in the early identification of those at risk of developing EBV-associated LPD.

Human T-cell lymphotropic virus type-I infection in the severe combined immunodeficiency mouse

Human T-cell lymphotropic virus type-I (HTLV-I) is the etiologic agent of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia (ATL). HAM/TSP and ATL occur infrequently among HTLV-I-infected individuals, and rarely develop in the same individual. To study host and viral factors involved in the induction, tissue tropism, as well as pathogenesis of HAM/TSP, peripheral blood lymphocytes (PBL) from 14 patients with HAM/TSP and from 9 controls were introduced into severe combined immunodeficiency (SCID) mice by intraperitoneal injection. Mice were followed for up to 26 weeks. Human IgG was produced from 2 to 14 weeks after reconstitution in all animals. Thirty-two of 44 mice (72%) showed circulating human antibody against the major viral protein products of HTLV-I. Analysis of viral sequences by polymerase chain reaction (PCR) demonstrated HTLV-I sequences in 21/38 (55%) brains and in 7/17 (41%) spinal cords from HTLV-I-hu SCID mice. No animal had clinical evidence of neurological impairment or pathological findings similar to those seen in HAM/TSP. Seven mice who received PBL from Epstein Barr virus (EBV)-seropositive patients developed an intraperitoneal lymphoma. In 2 mice an infiltration of brain by a lymphoblastic tumor of B/T cell type was observed. By PCR, all the tumors were EBV-positive; HTLV-I sequences were detected in 5 of them. Our study suggests that the HTLV-I-hu-SCID mouse provides a potentially valuable system for studying the production, kinetics, and pathogenicity of anti-HTLV-I antibody, and may help clarify the interaction of EBV and retroviruses in the development of disease.

[Neuropathogenesis of HIV infection]

The spreading of human immunodeficiency virus (HIV) infection and its increasing scientific knowledge keep the medical staff involved with these patients in permanent need of updating themselves. The different neurologic manifestations caused by HIV are related to a variety of pathogenic mechanisms, as follows: immunodeficiency, autoimmunity, direct effects of the virus on the nervous system, and toxic and metabolic effects. The opportunistic infections are caused by the immunodeficiency due to the action of the virus on CD4+ T cells and on cells of the monocytic-macrophage lineage. Demyelinating polyradiculoneuropathy and polymyositis-like syndromes are related to autoimmune mechanisms involving, probably, the non-specific stimulation of T cells by viral proteins. The primary action of the virus on the nervous system brings out aseptic meningitis, cognitive dysfunction, dementia, vacuolar myelopathy and sensory polyneuropathy probably through liberation of neurotoxic products by the infected macrophages. Antiretroviral drugs and others used to treat patients with AIDS may also have neurotoxic effects. The better understanding of the neuropathogenesis of HIV infection will permit the use of new, and more specific, therapeutical options in the future as well as a more precocious control of its neurologic complications.

[Transverse myelitis as initial symptom of disseminated non-Hodgkin lymphoma and HIV-associated vacuolar myelopathy: case report]

Non-Hodgkin lymphoma is frequently seen in AIDS patients usually affecting the central nervous system (CNS), especially the leptomeninges and the cerebral hemispheres. The epidural involvement is rarely described, ranging from 3.5% to 8.3% among the CNS sites. The authors present a case of disseminated non Hodgkin lymphoma associated to vacuolar myelopathy in a 27 years-old male patient with AIDS emphasizing the importance of this differential diagnosis in the myelopathies of AIDS.

Immunohistochemical expression of Epstein-Barr virus-encoded latent membrane protein (LMP-1) in paraffin sections of EBV-associated nasopharyngeal carcinoma in Spanish patients

Nasopharyngeal carcinoma (NPC) paraffin samples, from Spanish patients, of distinct histological types, including squamous cell carcinoma (10 cases), nonkeratinising carcinoma (12 cases) and undifferentiated carcinoma (29 cases) were analysed for Epstein-Barr virus (EBV) detection and EBV-encoded latent membrane protein (LMP-1) expression using a sensitive nested-polymerase chain reaction with four oligonucleotide primers specific for EBV genome (EB-1, 2, 3, 4) and immunohistochemistry by means of CS1-4 pool monoclonal antibody. EBV genome was detected regardless of histological type in 100% of samples with sufficient DNA quality to permit viral diagnosis (50 out of 51 cases), supporting the previous view that all types of NPC are variants of an EBV-associated malignancy. However LMP-1, an EBV-encoded oncogenic protein, was detected in 40 out of 51 samples (78.4%) and LMP-1 immunohistochemical expression was not apparently influenced by histological type, primary or metastatic site, clinical stage, age or sex. This high percentage of detection of LMP-1 in our cases supports a role for EBV in the pathogenesis of different types of NPC, but the lack of constant expression of LMP-1 in NPC remains unclear and various reasons are postulated to explain the absence of this oncogenic protein in some EBV-associated NPCs.

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

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

Pathogenesis and classification of primary central nervous system lymphoma: an update

Primary central nervous system lymphoma has undergone a remarkable increase in incidence over the last decade, both in immunosuppressed and immunocompetent individuals. Its clinicopathologic evaluation requires knowledge of current hematopathologic systems for lymphoma classification, as well as specific understanding of unique central nervous system determinants. In immunocompromised individuals, the tumor has a constant association with Epstein-Barr virus. The form of Epstein-Barr virus in these tumors appears to be predominantly latent, however, the precise mechanism relating virus to tumor pathogenesis is still unclear. In immunocompetent patients, risk factors and oncogenic associations are completely unknown. Critical to the formation of these tumors is the trafficking of B-cells, whether pre- or post-transformation, across the blood-brain barrier. These B-cell migrations may require perturbations to the barrier that originate in or around neural parenchyma, such as localized injury or infection.

Lymphoma associated with human immunodeficiency virus infection

OBJECTIVE

To describe lymphoma associated with human immunodeficiency virus (HIV) infection.

DESIGN

A review of HIV-related lymphoma and its associated epidemiology, etiopathogenesis, and clinicopathologic characteristics is presented. Major studies of therapeutic regimens for HIV-related lymphoma are discussed. Factors that could contribute to a poor prognosis are summarized.

RESULTS

Malignant lymphoma that develops in patients with HIV infection fulfills diagnostic criteria for the acquired immunodeficiency syndrome (AIDS). The incidence is increasing and varies by subtype of lymphoma, age, sex, race, and risk factors. B-cell hyperactivation is thought to contribute to the development of lymphoma. The mechanisms that may show transformed cell hyperproliferation and clonal expansion are HIV itself or other viruses (for example, Epstein-Barr virus), growth factors, aberrant oncogene or tumor-suppressor gene expression, and factors that induce genetic instability or DNA damage or alter host or viral genome repair. Treatment of HIV-related lymphoma is associated with toxicity, infectious complications, low rate of complete response, and brief median survival time.

CONCLUSION

Persons with HIV-induced immune dysregulation have a high risk for the development of aggressive non-Hodgkin's lymphoma characterized by histologic evidence of a high-grade malignant process, B-cell phenotype, an unusual extranodal involvement, and a poor prognosis. The potential role of specific viruses, antiviral treatments, and other therapeutic strategies are future areas of investigation.

Detection of Epstein-Barr virus DNA in cerebrospinal fluid for diagnosis of AIDS-related central nervous system lymphoma

The diagnostic utility of Epstein-Barr virus (EBV) DNA detection in cerebrospinal fluid for the diagnosis of central nervous system lymphoma was evaluated with two different PCR assays to test a collection of cerebrospinal fluid samples from 24 AIDS patients with central nervous system disorders. A PCR assay amplifying a fragment from the BamHI-W region had the highest clinical and analytic sensitivity. The BamHI-W PCR assay detected EBV DNA in cerebrospinal fluid from 83% (5 of 6) of patients with pathologically proven primary central nervous system lymphoma and 7% (1 of 16) of controls with autopsy-proven nonlymphomatous central nervous system disorders. EBV DNA was also detected in one patient with autopsy-proven systemic lymphoma involving the central nervous system and one patient with probable primary central nervous system lymphoma. EBV DNA was detected consistently when central nervous system lymphoma involved meningeal surfaces. PCR for EBV in cerebrospinal fluid appears to be useful for diagnosis of AIDS-related central nervous system lymphoma, but additional studies are required to better define the sensitivity of the assay and to understand the significance of a positive test in the absence of lymphoma.

Measurement by the polymerase chain reaction of the Epstein-Barr virus load in infectious mononucleosis and AIDS-related non-Hodgkin's lymphomas

A polymerase chain reaction (PCR) assay for the detection of Epstein-Barr virus (EBV) sequences in various clinical samples, especially peripheral blood leukocytes (PBL) and serum, was carried out and the results obtained were compared with specific EBV serology. One hundred seventy patients were enrolled in the study: 89 healthy blood donors, 22 asymptomatic patients, 36 individuals with primary EBV infection (including 19 patients with infectious mononucleosis [IM]), 22 HIV-infected subjects (including 4 with hairy oral leukoplakia, 3 with central nervous disorders, and 15 with non-Hodgkin's lymphoma). All the serum samples from the healthy blood donors were negative. In patients with IM and in AIDS-non Hodgkin's lymphoma (ARNHL), PCR was strongly positive in leukocytes (> 2,000 genome equivalents/10(4) cells), which was correlated with detectable amounts of EBV DNA in serum. The overall positivity rate of PCR in serum was 58.8%, 68%, and 73% of cases for non-IM primary EBV infections, IM, and ARNHL, respectively. In two cases of EBV primary infection, the viral DNA was detected in serum, respectively 1 month and 2 months before IgM positivity and IgG rise. In one case of ARNHL followed up for several months, PCR (viral load of 2,000 genome equivalents/10(4) cells) became positive concurrently with appearance of lymphoma. In immunocompromised individuals, PCR EBV, if carried out in larger prospective studies, could be considered as a tumor marker, useful for predicting EBV-driven lymphoma and follow-up therapy.