Predictive Value of Polymerase Chain Reaction of Cerebrospinal Fluid for Detection of Epstein-Barr Virus to Establish the Diagnosis of HIV-Related Primary Central Nervous System Lymphoma

The IPTA Nashville Consensus Conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: III - Consensus guidelines for Epstein-Barr virus load and other biomarker monitoring

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders after solid organ transplantation in children. In this report from the Viral Load and Biomarker Monitoring Working Group, we reviewed the existing literature regarding the role of Epstein-Barr viral load and other biomarkers in peripheral blood for predicting the development of PTLD, for PTLD diagnosis, and for monitoring of response to treatment. Key recommendations from the group highlighted the strong recommendation for use of the term EBV DNAemia instead of "viremia" to describe EBV DNA levels in peripheral blood as well as concerns with comparison of EBV DNAemia measurement results performed at different institutions even when tests are calibrated using the WHO international standard. The working group concluded that either whole blood or plasma could be used as matrices for EBV DNA measurement; optimal specimen type may be clinical context dependent. Whole blood testing has some advantages for surveillance to inform pre-emptive interventions while plasma testing may be preferred in the setting of clinical symptoms and treatment monitoring. However, EBV DNAemia testing alone was not recommended for PTLD diagnosis. Quantitative EBV DNAemia surveillance to identify patients at risk for PTLD and to inform pre-emptive interventions in patients who are EBV seronegative pre-transplant was recommended. In contrast, with the exception of intestinal transplant recipients or those with recent primary EBV infection prior to SOT, surveillance was not recommended in pediatric SOT recipients EBV seropositive pre-transplant. Implications of viral load kinetic parameters including peak load and viral set point on pre-emptive PTLD prevention monitoring algorithms were discussed. Use of additional markers, including measurements of EBV specific cell mediated immunity was discussed but not recommended though the importance of obtaining additional data from prospective multicenter studies was highlighted as a key research priority.

CSF biomarkers in primary CNS lymphoma

PCNSL is a non-Hodgkin lymphoma (NHL) affecting brain, spinal cord, eyes and leptomeninges. In the past two decades, its prognosis significantly improved due to therapeutic advances but it remains a highly aggressive tumor and early diagnosis is necessary for optimal management. Diagnosis relies on the identification of lymphoma cells in brain tissue obtained by stereotactic biopsy. Alternatively, lymphoma cells may be found in CSF through lumbar puncture (LP) or by a vitrectomy. For several reasons, the diagnosis of PCNSL may be challenging. Misleading radiological presentations are frequent. Dramatic response to steroids may bias histological analysis and deep brain location or frail health status can contraindicate brain biopsy. In the follow-up of patients who have been previously treated, differential diagnosis between tumor relapse and post-treatment may be also difficult. Therefore, the development of complementary reliable diagnostic tools is needed. This review will summarize several diagnostic or prognostic CSF biomarkers which have been proposed in PCNSL, their interests and limits.

Diagnostic value of EBV-DNA in CSF for PCNSL in AIDS patients with focal brain lesions: A meta-analysis of diagnostic test

BACKGROUND

Epstein-Barr virus (EBV) infection plays a crucial role in the progression of acquired immunodeficiency syndrome related primary central nervous system lymphoma (AR-PCNSL). This study aimed at evaluating the diagnostic value of cerebrospinal spinal fluid (CSF) EBV-deoxyribonucleic acid (DNA) for PCNSL in patients with infection of human immunodeficiency (HIV) virus through a meta-analysis of diagnostic test.

METHODS

A systematic search in PubMed, Embase, Web of Science, Wanfang, Chinese Biomedical Database and Chinese National Knowledge Infrastructure was conducted before May 10, 2022. Heterogeneity among the studies was assessed using Q test and I2 statistics. Publication bias was assessed using the Deek's funnel plot asymmetry test. Statistical analyses were performed using Stata 16.0 software. The pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratios (DOR) and 95% confidence intervals (CI) were caculated to evaluate the diagnostic value. A symmetric receiver operating characteristic (SROC) curve and the area under the SROC curve (AUC) were constructed to evaluate the test-performance.

RESULTS

Twelve studies were included in the final analyses, with a total of 141 patients with AR-PCNSL and 590 controls. The pooled diagnostic values were sensitivity of 0.83 (95% CI: 0.73-0.90), specificity of 0.95 (95%CI: 0.89-0.98), PLR of 17.8 (95%CI: 6.8-46.1), NLR of 0.17 (95%CI: 0.10-0.30), DOR of 102 (95%CI: 28-379), and AUC of 0.94 (95%CI: 0.91-0.96).

CONCLUSION

In summary the overall diagnostic value of CSF EBV-DNA is very high and it can be a reliable diagnostic biomarker for AR-PCNSL.

Epstein-Barr Virus Detection in the Central Nervous System of HIV-Infected Patients

Simply detecting Epstein-Barr virus deoxyribonucleic acid (EBV-DNA) is insufficient to diagnose EBV-associated diseases. The current literature around EBV-DNA detection from cerebrospinal fluid (CSF) in human immunodeficiency virus (HIV)-positive non-lymphoma patients was systematically reviewed and a meta-analysis reporting the estimated pooled prevalence in this population when PCR methods are employed, targeting different sequence segments within the EBV genome, was conducted. Using a combination of three key concepts-Epstein-Barr virus detection, central nervous system disease, and human cerebrospinal fluid-and their MeSH terms, the PubMed database was searched. A total of 273 papers reporting the detection of EBV in CNS were screened, of which 13 met the inclusion criteria. The meta-analysis revealed a pooled prevalence of EBV-DNA in CSF of 20% (CI: 12-31%). The highest pooled prevalence was from studies conducted on the African population at 39% (CI: 27-51%). The investigation of the presence of EBV-DNA in the CSF was also very varied, with several gene targets used. While most patients from the articles included in this review and meta-analysis were symptomatic of CNS disorders, the pathogenicity of EBV in non-lymphoma HIV patients when detected in CSF has still not been determined. The presence of EBV-DNA in the CNS remains a concern, and further research is warranted to understand its significance in causing CNS disorders.

Lessons from Epstein-Barr virus DNA detection in cerebrospinal fluid as a diagnostic tool for EBV-induced central nervous system dysfunction among HIV-positive patients

Polymerase chain reaction (PCR) analysis of Epstein-Barr virus (EBV) DNA in cerebrospinal fluid (CSF) remains vital for evaluating active EBV infection involving the central nervous system (CNS). CSF EBV DNA was often found in conjunction with other microbial infection affecting the CNS among patients infected with human immunodeficiency virus (HIV). Sometimes CSF EBV DNA is detectable in patients without neurological symptoms. This review focused on the clinical and laboratory features of CNS EBV infection among patients with HIV, and discussed various types of EBV-associated CNS infections, and predominant neoplasms involving CNS such as primary central nervous system lymphoma (PCNSL), CNS-non-Hodgkin's lymphoma, smooth muscle tumors and leiomyosarcomas, EBV encephalitis or myelitis, EBV meningitis and EBV coinfection with other causative agents were also included. Furthermore, the metagenomic next-generation sequencing technique with high sensitivity for the detection of pathogenic coinfection in the CSF were also reviewed. We concluded that CSF EBV-DNA detection with high sensitivity and specificity could be a useful diagnostic tool for CNS lymphoma among HIV patients; however, it is still unknown for other CNS diseases. We further summarized and conclude that positive CSF EBV-DNA detection combined with specific brain focal lesions could be a minimally invasive method to diagnose PCNSL. The occurrence of positive CSF EBV-DNA was influenced by PCR detection limit, PCR methods, immunocompromised status, the possible influence of anti-herpetic therapy and anti-HIV therapy, and the size and location of a tumor mass. Uniform PCR methods as vital diagnostic tools and optimal EBV-DNA load threshold need to be established.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

Central Nervous System Infections in the Immunocompromised Adult Presenting to the Emergency Department

Over the past 2 decades, the population of immunocompromised patients has increased dramatically in the United States. These patients are at elevated risk for both community-acquired and opportunistic central nervous system infections. We review the most common and serious central nervous system pathogens affecting these patients and outline a diagnostic and therapeutic approach to their management in the emergency department. We recommend a broad diagnostic evaluation, including neuroimaging and cerebrospinal fluid studies where appropriate, empiric antimicrobial therapy, and early involvement of subspecialists to provide comprehensive care for these complex patients.

Presence of Epstein-Barr virus DNA in cerebrospinal fluid is associated with greater HIV RNA and inflammation

OBJECTIVE

The current study aimed to investigate whether cerebrospinal fluid (CSF) Epstein-Barr virus (EBV) or cytomegalovirus (CMV) DNA was associated with viral, inflammatory and neuronal damage biomarkers in people living with HIV (PLWH).

DESIGN

A cross-sectional diagnostic study on CSF fluid samples in patients undergoing lumbar punctures for clinical reasons, to better understand the role of EBV and CMV in the CNS on HIV RNA replication, blood-brain-barrier (BBB) damage and biomarkers of neuronal damage/inflammation.

METHODS

EBV, CMV DNA and HIV RNA were measured on CSF, through real time (RT)-PCR, from PLWHs undergoing lumbar punctures for clinical reasons (excluding oncho-haematological comorbidities). Immune-enzymatic assays evaluated blood-brain barrier inflammation and damage. Patients were stratified according to plasma HIV RNA levels in viremic (≥50 copies/ml) and aviremic (<50 copies/ml).

RESULTS

We included 297 participants. Among 167 viremic patients CSF EBV and CMV DNA were detectable in 42 (25.1%) and 10 (6.3%) participants; among 130 aviremic individuals CSF EBV and CMV DNA were detectable in 12 (9.2%) and 0 (0%) participants, respectively. In viremic group detectable CSF EBV DNA was associated with CSF pleocytosis (P < 0.001), higher CSF HIV RNA (P < 0.001) and neopterin levels (P = 0.002). In aviremic participants detectable EBV DNA was associated with pleocytosis (P = 0.056), higher neopterin (P = 0.027) and immune globulins (P = 0.016) in the CSF; CSF escape was more common in those with detectable EBV DNA (50 vs. 21.2%, P = 0.036).

CONCLUSION

EBV DNA was frequently detected in the CSF of viremic and fewer aviremic patients on antiretroviral treatment. In PLWH without clinical evidence of encephalitis CSF EBV DNA was associated with higher biomarkers levels of neuronal damage/inflammation. The role of EBV reactivation in HIV-associated central nervous system disorders warrants further studies.

Molecular Biology of EBV in Relationship to HIV/AIDS-Associated Oncogenesis

Herpesvirus-induced disease is one of the most lethal factors which leads to high mortality in HIV/AIDS patients. EBV, also known as human herpesvirus 4, can transform naive B cells into immortalized cells in vitro through the regulation of cell cycle, cell proliferation, and apoptosis. EBV infection is associated with several lymphoma and epithelial cancers in humans, which occurs at a much higher rate in immune deficient individuals than in healthy people, demonstrating that the immune system plays a vital role in inhibiting EBV activities. EBV latency infection proteins can mimic suppression cytokines or upregulate PD-1 on B cells to repress the cytotoxic T cells response. Many malignancies, including Hodgkin Lymphoma and non-Hodgkin's lymphomas occur at a much higher frequency in EBV positive individuals than in EBV negative people during the development of HIV infection. Importantly, understanding EBV pathogenesis at the molecular level will aid the development of novel therapies for EBV-induced diseases in HIV/AIDS patients.

Cerebrospinal fluid biomarkers of malignancies located in the central nervous system

CNS malignancies include primary tumors that originate within the CNS as well as secondary tumors that develop as a result of metastatic cancer. The delicate nature of the nervous systems makes tumors located in the CNS notoriously difficult to reach, which poses several problems during diagnosis and treatment. CSF can be acquired relatively easy through lumbar puncture and offers an important compartment for analysis of cells and molecules that carry information about the malignant process. Such techniques have opened up a new field of research focused on the identification of specific biomarkers for several types of CNS malignancies, which may help in diagnosis and monitoring of tumor progression or treatment response. Biomarkers are sought in DNA, (micro)RNA, proteins, exosomes and circulating tumor cells in the CSF. Techniques are rapidly progressing to assess these markers with increasing sensitivity and specificity, and correlations with clinical parameters are being investigated. It is expected that these efforts will, in the near future, yield clinically relevant markers that aid in diagnosis, monitoring and (tailored) treatment of patients bearing CNS tumors. This chapter provides a summary of the current state of affairs of the field of biomarkers of different types of CNS tumors.

Primary CNS lymphoma in HIV infection

Primary CNS lymphoma (PCNSL) has been designated an acquired immune deficiency syndrome (AIDS)-defining disease since 1983 and accounts for up to 15% of non-Hodgkin lymphomas in human immunodeficiency virus (HIV) patients. The majority of HIV patients are Epstein-Barr virus (EBV)-related. The most likely etiology is ineffective immunoregulation of EBV, inducing oncogenic protein expression, and subsequent loss of apoptosis and increased proliferation of lymphocytes. PCNSL generally presents with supratentorial, single or multiple, contrast-enhancing lesions. Neurologic symptoms can be headache, cognitive function disorders, focal neurologic, deficit and epilepsy. Differential diagnosis includes other oncologic or infectious causes, with cerebral toxoplasmosis being the most important. Magnetic resonance imaging characteristics, activity on ²⁰¹thallium single-photon emission computed tomography, presence of EBV DNA in the cerebrospinal fluid, and toxoplasmosis serology can make either PCNSL or cerebral toxoplasmosis more or less likely. However, definitive diagnosis of PCNSL relies on histopathologic confirmation. First-choice treatment is combination antiretroviral therapy in combination with high-dose methotrexate(-based) chemotherapy in patients in whom this is feasible. Combination antiretroviral therapy combined with whole-brain radiotherapy may be an alternative. Treatment of EBV with antiviral agents such as ganciclovir or zidovudine may be beneficial, but this needs further study. Prognosis of HIV-related PCNSL is poor, with median survival varying from 2 to 4 months, but patients treated with chemotherapy do better (median survival 1.5 years).

Safety and diagnostic value of brain biopsy in HIV patients: a case series and meta-analysis of 1209 patients

Early brain biopsy may be indicated in HIV patients with focal brain lesion. This study aimed to evaluate and compare the safety and diagnostic value of brain biopsy in HIV patients in the pre-highly active antiretroviral therapy (HAART) versus post-HAART era via meta-analysis. Appropriate studies were identified per search criteria. The local database was retrospectively reviewed to select a similar patient cohort. Patient demographics, brain biopsy technique, histopathology and patient outcomes were extracted from each study. Study-specific outcomes were combined per random-effects model. Outcomes were compared between the pre-HAART and post-HAART era. Correlations between outcomes and baseline characteristics were assessed via meta-regression analysis. The proportions of histopathological diagnosis were tabulated and compared between the pre- and post-HAART era. Survival analysis was performed for patients in the post-HAART era. A total of 26 studies (including the local database) with 1209 patients were included in this meta-analysis. The most common indications for brain biopsy were diagnosis unlikely to be toxoplasmosis (n=8, 42.1%), focal brain lesion (n=5, 26.3%) or both (n=3, 15.8%). The weighted proportions for diagnostic success were 92% (95% CI 90.0% to 93.8%), change in management 57.7% (45.9% to 69.1%) and clinical improvement 36.6% (26.3% to 47.5%). Morbidity and mortality were 5.7% (3.6% to 8.3%) and 0.9% (0.3% to 1.9%), respectively. Diagnostic success rate was significantly higher in the post-HAART than the pre-HAART era (97.5% vs 91.9%, p=0.047). The odds ratio (OR) for diagnostic success in patients with contrast-enhanced lesions was 2.54 ((1.25 to 5.15), p<0.01). The median survival for HIV patients who underwent biopsy in the post-HAART era was 225 days (90-2446). Brain biopsy in HIV patients is safe with high diagnostic yield. Early brain biopsy should be considered in patients without classic presentation of toxoplasmosis encephalitis.

Role of microRNAs in primary central nervous system lymphomas

Primary central nervous system lymphomas (PCNSL) are extranodal non-Hodgkin lymphomas arising exclusively inside the CNS, and account for about 3% of primary intracranial tumours. This tumour lacks systemic manifestations and prognosis of patients with PCNSL remains poor despite recent advancement of chemoradiotherapy. MicroRNAs are small non-coding RNAs that post-transcriptionally downregulate gene expression by binding to target mRNAs, inducing their degradation or translational repression. MicroRNAs play significant roles in almost all malignancy-related biological processes, including cell proliferation, differentiation, apoptosis and metabolism. Many deregulated miRNAs has been identified in PCNSL but their biological significance remains to be fully elucidated. In this review, we summarize current evidence regarding the pathogenic role of PCNSL-associated microRNAs and their potential applications for diagnosis and prognostication of this deadly disease.

Epstein-Barr virus encephalitis in a renal transplant recipient manifesting as hemorrhagic, ring-enhancing mass lesions

Epstein-Barr virus (EBV) encephalitis has been infrequently described in immunocompromised patients. Here, we report a unique case of biopsy-proven EBV encephalitis in a renal transplant recipient presenting with altered mental status, prominent visual disturbances, and hemorrhagic, ring-enhancing mass lesions on magnetic resonance imaging. The patient was successfully treated with a prolonged course of antivirals. This case illustrates the difficulty in interpretation of cerebrospinal fluid EBV polymerase chain reaction assay, given the lack of specificity in immunocompromised patients.

Molecular approaches towards characterization, monitoring and targeting of viral-associated hematological malignancies

Viral-associated malignancies usually arise in the setting of altered immunity or with declines in immune function associated with aging. The main culprits are the lymphotropic herpesvirus, including Epstein-Barr virus (EBV) and human herpesvirus-8, which are the focus of this review. Chronic persistent infection and viral reactivation are the main risk factors for development of herpesvirus-associated malignancies and have provided the rationale for intensive monitoring of viral loads in some clinical contexts. Quantitative detection of EBV levels in the post-transplant period and following treatment of EBV-associated malignancies now have a proven role in outcome prediction. Both T-cell immunotherapy and humoral immunotherapies directed against latent viral antigens represent promising interventional approaches to treatment of viral-associated malignancies.

Detection of human herpesviruses in the cerebrospinal fluid from patients diagnosed with or suspected of having progressive multifocal leukoencephalopathy

BACKGROUND

Progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease caused by JC virus (JCV), occurs mainly in immunocompromised patients. While JCV DNA is detected in the cerebrospinal fluid (CSF) from a certain proportion of patients suspected of having PML, JCV-negative patients may also develop brain lesions due to other infectious agents. This study assessed the prevalence of six herpesviruses in the CSF from patients diagnosed with or suspected of PML.

METHODS

Two hundred and ninety-nine CSF specimens and clinical data were collected from 255 patients, including 31 confirmed PML cases. Quantitative PCR assays were carried out to detect the genomic DNA of JCV, herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6).

RESULTS

Herpesvirus DNAs were detected in the CSF specimens from 29 of 255 patients (11.4%). HSV-1 and CMV were detected in JCV-negative patients, whereas VZV and EBV were detected in both CSF JCV-positive and -negative individuals. The herpesvirus-positive patients had underlying disorders that caused immunosuppression, such as HIV infection, congenital immunodeficiencies, and hematologic malignancies, and presented with neurologic symptoms and MRI lesions, mainly in the cerebral white matter. The median values of CSF cell counts and protein levels in the herpesvirus-positive patients were slightly higher than those in the PML patients.

CONCLUSIONS

The results demonstrate that herpesviruses are occasionally detected in the CSF from PML patients and immunocompromised individuals suspected of having PML. Thus, this study provides a significant basis for the diagnosis and treatment of neurological disorders in immunocompromised patients.

Determining EBV load: current best practice and future requirements

EBV, a gammaherpesvirus and the pathogenic agent for infectious mononucleosis, is also associated with a broad spectrum of lymphoid and epithelial malignancies in immunocompetent and immunosuppressed individuals. EBV-DNA-load measurement by PCR has been shown to be a potential tool for the diagnosis of these diseases, a prognostic factor of their outcome and a successful method to monitor immunosuppressed patients. Since the end of 2011, there is an international WHO standard reference for EBV quantification available; however, many questions still remain; for instance about the optimal amplified region of the EBV genome, or the best-used specimen for EBV detection. Additionally, the optimal specimen and amplified region may vary in different malignancies. In this article, the authors review the different methods to measure EBV load, focus on the best-used specimen for the different EBV-associated malignancies and discuss future requirements and opportunities for EBV-load measurement.

A systematic approach to the diagnosis of suspected central nervous system lymphoma

Central nervous system (CNS) lymphoma can present a diagnostic challenge. Currently, there is no consensus regarding what presurgical evaluation is warranted or how to proceed when lesions are not surgically accessible. We conducted a review of the literature on CNS lymphoma diagnosis (1966 to October 2011) to determine whether a common diagnostic algorithm can be generated. We extracted data regarding the usefulness of brain and body imaging, serum and cerebrospinal fluid (CSF) studies, ophthalmologic examination, and tissue biopsy in the diagnosis of CNS lymphoma. Contrast enhancement on imaging is highly sensitive at the time of diagnosis: 98.9% in immunocompetent lymphoma and 96.1% in human immunodeficiency virus-related CNS lymphoma. The sensitivity of CSF cytology is low (2%-32%) but increases when combined with flow cytometry. Cerebrospinal fluid lactate dehydrogenase isozyme 5, β2-microglobulin, and immunoglobulin heavy chain rearrangement studies have improved sensitivity over CSF cytology (58%-85%) but have only moderate specificity (85%). New techniques of proteomics and microRNA analysis have more than 95% specificity in the diagnosis of CNS lymphoma. Positive CSF cytology, vitreous biopsy, or brain/leptomeningeal biopsy remain the current standard for diagnosis. A combined stepwise systematic approach outlined here may facilitate an expeditious, comprehensive presurgical evaluation for cases of suspected CNS lymphoma.

Epstein-Barr viral load in cerebrospinal fluid as a diagnostic marker of central nervous system involvement of AIDS-related lymphoma

OBJECTIVE

AIDS-related lymphoma (ARL) often involves the central nervous system (CNS). Although the diagnostic value of Epstein-Barr virus (EBV)-DNA in cerebrospinal fluid (CSF) in detecting HIV-positive primary CNS lymphoma (PCNSL) has been established, its usefulness for identifying CNS involvement of systemic ARL remains elusive. In this study, we evaluated the utility of the EBV-DNA load in CSF in identifying CNS involvement in patients with systemic ARL.

METHODS

We retrospectively reviewed the clinical and pathological data of consecutive ARL patients managed at our clinic between January 1998 and June 2012. Sixty-two patients with ARL, including eight PCNSL patients and 52 systemic ARL patients, and 63 controls underwent CSF EBV-DNA load evaluations before receiving chemotherapy. ARL-related CNS involvement was defined as any lesion diagnosed histologically or radiologically as a lymphoma in the brain, meninges, spine, cranial nerves or oculus.

RESULTS

A cut off value of 200 copies/mL predicted the presence of CNS lesions with a sensitivity of 70% and a specificity of 85% in both the PCNSL and systemic ARL patients, while a sensitivity of 75% and a specificity of 93% were obtained for systemic ARL. A cut off value of 2,000 (3.30 log) copies/mL provided the best specificity (100%), with a sensitivity of 50%.

CONCLUSION

Our results support the clinical utility of evaluating the quantitative EBV-DNA load in the CSF for the diagnosis of CNS involvement of systemic ARL as well as PCNSL.

Successful treatment of Epstein-Barr virus encephalitis in the setting of HIV-associated neurocognitive disorder: a diagnostic and therapeutic challenge

We report a challenging case of HIV-associated neurocognitive disorder with superimposed Epstein-Barr virus (EBV) encephalitis. The patient presented with an abnormal MRI brain scan, and EBV DNA that was detected in the cerebrospinal fluid and brain biopsy, which also demonstrated histopathological findings consistent with the diagnosis. This occurred on the background of a 12-month period of gradual cognitive decrease secondary to HIV-associated dementia. Invasive testing was required to reach the diagnosis in this case, highlighting the importance of thorough investigation of neurological impairment in HIV-positive patients. Clinicopathological recovery was achieved through optimization of antiretroviral therapy and use of valganciclovir.

Evaluation of multiplex polymerase chain reaction and microarray-based assay for rapid herpesvirus diagnostics

Rapid diagnosis is critical to minimize morbidity and mortality associated with infections of the central nervous system (CNS). In this study, we evaluated the performance of a multiplex polymerase chain reaction (PCR) and microarray-based method, Prove-it™ Herpes, in a routine clinical laboratory setting for the diagnostics of 7 herpesviruses in viral CNS infections. Cerebrospinal fluid samples (n = 495), which had arrived for diagnostics in the 5 participating laboratories, were analyzed for herpesvirus DNA both by the current PCR-based method of the laboratory and by the microarray assay. The sensitivity and specificity for the microarray assay were 93% and 99%, respectively. The microarray assay was considered as a rapid and robust diagnostic platform that was easily implemented into the laboratory workflow. The broad herpesvirus coverage and the small sample volume required by the assay could benefit the diagnostics and thus the treatment of life-threatening infections of the CNS, especially among immunocompromised patients.

Current strategies in the diagnosis of diffuse large B-cell lymphoma of the central nervous system

Lymphomas can arise within the central nervous system (CNS) as primary CNS lymphoma (PCNSL) typically involving the brain and less often the leptomeninges, eyes, and spinal cord. In contrast to PCNSL, secondary CNS lymphoma (SCNSL) is considered to originate as quasi metastasis from systemic lymphoma spreading to the CNS. Both types of CNS lymphomas are predominantly tumours of the diffuse large B-cell type and represent aggressive diseases necessitating a rapid diagnosis. Following neuroimaging based on magnetic resonance imaging, stereotaxy and histopathological diagnosis of CNS lymphoma currently remain obligatory to plan treatment. However, progress in cytopathological, immunophenotypic, and molecular genetic analyses of the cerebrospinal fluid (CSF) has been achieved recently and potentially will facilitate lymphoma diagnosis in the future. This review describes the diagnostic procedures in patients with suspected CNS lymphomas, primarily PCNSL. In addition to a summary of the standard diagnostic work-up, an overview and discussion of current data on different techniques for evaluation of the CSF in CNS lymphoma are given.

EBV and HIV-Related Lymphoma

HIV-associated lymphoproliferative disorders represent a heterogeneous group of diseases, arising in the presence of HIV-associated immunodeficiency. The overall prevalence of HIV-associated lymphoma is significantly higher compared to that of the general population and it continues to be relevant even after the wide availability of highly active antiretroviral therapy (HAART) (1). Moreover, they still represent one of the most frequent cause of death in HIV-infected patients. Epstein-Barr virus (EBV), a γ-Herpesviruses, is involved in human lymphomagenesis, particularly in HIV immunocompromised patients. It has been largely implicated in the development of B-cell lymphoproliferative disorders as Burkitt lymphoma (BL), Hodgkin disease (HD), systemic non Hodgkin lymphoma (NHL), primary central nervous system lymphoma (PCNSL), nasopharyngeal carcinoma (NC). Virus-associated lymphomas are becoming of significant concern for the mortality of long-lived HIV immunocompromised patients, and therefore, research of advanced strategies for AIDS-related lymphomas is an important field in cancer chemotherapy. Detailed understanding of the EBV lifecycle and related cancers at the molecular level is required for novel strategies of molecular-targeted cancer chemotherapy The linkage of HIV-related lymphoma with EBV infection of the tumor clone has several pathogenetic, prognostic and possibly therapeutic implications which are reviewed herein.

Laboratory assays for Epstein-Barr virus-related disease

Epstein-Barr virus (EBV) infects various cell types in a wide spectrum of benign and malignant diseases. Laboratory tests for EBV have improved and are increasingly used in diagnosis, prognosis, prediction, and prevention of diseases ranging from infectious mononucleosis to selected subtypes of lymphoma, sarcoma, and carcinoma. Indeed, the presence of EBV is among the most effective tumor markers supporting clinical management of cancer patients. In biopsies, localization of EBER transcripts by in situ hybridization remains the gold standard for identifying latent infection. Other RNA- and protein-based assays detect lytic viral replication and can distinguish carcinoma-derived from lymphocyte-derived EBV in saliva or nasopharyngeal brushings. Analysis of blood using EBV viral load and serology reflects disease status and risk of progression. This review summarizes prior research in the context of basic virologic principles to provide a rational strategy for applying and interpreting EBV tests in various clinical settings. Such assays have been incorporated into standard clinical practice in selected settings such as diagnosis of primary infection and management of patients with immune dysfunction or nasopharyngeal carcinoma. As novel therapies are developed that target virus-infected cells or overcome the adverse effects of infection, laboratory testing becomes even more critical for determining when intervention is appropriate and the extent to which it has succeeded.

The predictive value of cerebrospinal fluid Epstein-Barr viral load as a marker of primary central nervous system lymphoma in HIV-infected persons

BACKGROUND

The presence of Epstein-Barr virus (EBV) DNA in cerebrospinal fluid (CSF) is used as a marker of HIV-associated primary central nervous system lymphoma (PCNSL). In our setting, EBV DNA is frequently detected in the CSF of HIV-infected patients with miscellaneous neurological diseases and thus its presence is a poor predictor of PCNSL.

OBJECTIVES

To determine whether quantification of EBV DNA in CSF improves its diagnostic specificity for PCNSL.

STUDY DESIGN

EBV viral loads were determined on CSF samples from 55 HIV-infected patients with CNS disease.

RESULTS

Twenty of the 55 patients had detectable EBV DNA in their CSF (median viral load 6120copies/ml, range 336-1,034,000copies/ml). PCNSL was confirmed in 2 patients. Their CSF EBV loads were 1,034,000 and 15,460copies/ml, respectively. Using a cut-off of 10,000copies/ml improved the specificity and positive predictive value (PPV) compared to a qualitative result for the diagnosis of PCNSL (96% vs. 66% and 50% vs. 10%, respectively).

CONCLUSION

EBV DNA is commonly detected in CSF of HIV-infected patients. Quantitative PCR improves the diagnostic specificity, however, the PPV remains too low for it to be used as an isolated marker for PCNSL.

The significance of Epstein-Barr virus detected in the cerebrospinal fluid of people with HIV infection

INTRODUCTION

Epstein-Barr virus (EBV) is detected in the cerebrospinal fluid (CSF) in people with HIV infection who develop primary cerebral lymphoma (PCL). However, EBV may also be detected in the CSF of patients without PCL, and here the significance is uncertain.

METHODS

Ninety-eight HIV-positive patients had lumbar punctures performed and polymerase chain reaction (PCR) for EBV was undertaken on the CSF. Thirty-eight patients had non-Hodgkin's lymphoma (NHL), including four with PCL. Sixty patients had a CSF examination for other indications. The clinicopathological details, symptoms, diagnosis, CSF and neuroimaging findings and therapy at time of CSF were recorded and correlated with CSF EBV PCR results.

RESULTS

EBV was detected in the CSF in three of four patients (75%) with PCL, one of three (33%) with systemic lymphoma and meningeal involvement, and four of 31 (13%) with systemic lymphoma and no meningeal disease. Seven of 60 patients (12%) without lymphoma were CSF EBV-positive. There were no differences in immunological, clinical, biochemical or radiological parameters between patients with and without EBV in the CSF. After a median follow-up time of 30 weeks (maximum 102 weeks), none of the seven CSF EBV-positive patients has developed PCL.

CONCLUSION

EBV was detected in up to 12% of patients with neurological symptoms but without lymphoma. A positive result did not correlate with more advanced immunosuppression or a particular neurological diagnosis. Patients with EBV in their CSF did not appear to be at increased risk of developing PCL in the short term.

Epstein-Barr virus–associated lymphoproliferative disorders

Epstein-Barr virus (EBV) is a member of the human herpesvirus family that was initially isolated from a cultured Burkitt lymphoma cell line by Epstein et al in 1964. Subsequent studies have proven that it is the causative agent in most cases of infectious mononucleosis. Primary infection is usually asymptomatic in childhood; but in adulthood, it is associated with a self-limiting infectious mononucleosis syndrome in approximately one third of the cases. EBV has been linked to many human neoplasms including hematopoietic, epithelial, and mesenchymal tumors. In this review, we will only discuss the EBV-associated lymphoproliferative disorders, dividing them into B-cell, T/NK-cell, and HIV-related lymphoproliferative disorders.

Remission of progressive multifocal leukoencephalopathy and primary central nervous system lymphoma in an HIV-infected patient

The coexistence of progressive multifocal leukoencephalopathy (PML) and primary central nervous system lymphoma (PCNSL) is a rare event, usually associated with a fatal outcome. We report the case of a human immunodeficiency virus (HIV)-infected individual presenting with both PML and PCNSL who made a remarkable recovery after highly active anti retroviral therapy (HAART) and radiation therapy, and discuss diagnostic and therapeutic aspects of both conditions.

Primary CNS lymphoma

Primary CNS lymphoma, an uncommon form of extranodal non-Hodgkin's lymphoma, has increased in incidence and occurs in both immunocompromised and immunocompetent hosts. Primary CNS lymphoma in immunocompetent patients is associated with unique diagnostic, prognostic and therapeutic issues and the management of this malignancy is different from other forms of extranodal non-Hodgkin's lymphoma. Characteristic imaging features should lead to suspicion of the diagnosis, avoidance of corticosteroids (if possible) and early neurosurgical consultation for stereotactic biopsy. Since primary CNS lymphoma may involve the brain, cerebrospinal fluid and eyes, diagnostic evaluation should include assessment of all of these regions as well as screening for the possibility of occult systemic disease. Resection provides no therapeutic benefit and should be reserved for the rare patient with neurological deterioration due to brain herniation. Whole-brain radiation therapy alone is insufficient for durable tumor control and is associated with a high risk of neurotoxicity in patients over 60 years of age. Neurotoxicity is typically associated with significant cognitive, motor and autonomic dysfunction and has a negative impact on quality of life. Chemotherapy and whole-brain radiation therapy together improve tumor response rates and survival compared with whole-brain radiation therapy alone. Methotrexate-based multiagent chemotherapy without whole-brain radiation therapy is associated with similar tumor response rates and survival compared with regimens that include whole-brain radiation therapy, although controlled trials have not been performed. The risk of neurotoxicity is lower in patients treated with chemotherapy alone. The incidence of HIV-related primary CNS lymphoma has decreased in the era of highly active antiretroviral therapy. Patients with HIV-associated primary CNS lymphoma have a worse prognosis but may respond to highly active antiretroviral therapy, whole-brain radiation therapy or therapies directed against the Epstein-Barr virus.

Primary CNS lymphoma

Non-Hodgkin's lymphoma invades the brain, the vitreous body and nerves of the eye, the meninges, and the nerve roots of brain and spine, leading to the development of a primary CNS lymphoma. The mechanism of involvement of these locations by malignant B lymphocytes is unknown, but it might involve molecular targeting of lymphoma cells generated at cryptic systemic sites. The diagnosis of primary CNS lymphoma has been facilitated by advances in imaging techniques and the discovery of molecular markers. Methotrexate-based regimens, even when radiation is deferred, prolong overall survival to over 5 years, but relapses eventually occur in most cases. Better tools for earlier diagnosis and monitoring of treatment response will emerge from molecular studies of therapeutic targets.

Validation of Roche LightCycler Epstein-Barr virus quantification reagents in a clinical laboratory setting

Epstein-Barr virus (EBV) is associated with a wide range of benign and malignant diseases, including infectious mononucleosis, lymphoma, posttransplant lymphoproliferative disorder, and nasopharyngeal carcinoma. Measurement of EBV viral load in plasma is increasingly used for rapid assessment of disease status. We evaluated the performance characteristics of an EBV polymerase chain reaction assay that uses commercial reagents and instruments from Roche Diagnostics (Indianapolis, IN). DNA was extracted from plasma using a MagNaPure instrument, and viral load was measured by real-time polymerase chain reaction on a LightCycler. Analyte-specific reagents included primers and hybridization probes targeting the EBV LMP2 gene and a spiked control sequence. Accuracy and reproducibility were established using DNA from three cell lines. The assay was sensitive to approximately 750 copies of EBV DNA per milliliter of plasma and was linear across at least four orders of magnitude. The assay detected EBV DNA in three of five samples from nasopharyngeal carcinoma patients, seven of nine infectious mononucleosis samples, and 34/34 samples from immunosuppressed patients with clinically significant EBV-related disease, whereas EBV DNA was undetectable in plasma from 21 individuals without EBV-related disease. In conclusion, this LightCycler EBV assay is rapid, sensitive, and linear for quantifying EBV viral load. The assay appears to be useful for measuring clinically significant EBV levels in immunodeficient patients.

Primary central nervous system lymphoma: presentation, diagnosis and staging

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma that affects the brain, spinal cord, leptomeninges, and eyes. The clinical presentation and neuroimaging appearance of PCNSL differ in immunocompetent patients and in those with acquired immunodeficiency syndrome (AIDS). A magnetic resonance (MR) image of the brain in immunocompetent patients with PCNSL typically demonstrates one or more homogeneously enhancing lesions located in the periventricular white matter, characteristically spanning the corpus callosum. In patients with AIDS, multiple ring-enhancing lesions are more common. After neuroimages raising the suspicion of PCNSL are obtained, a definitive diagnosis should be established in both immunocompetent and AIDS patients by performing pathological analysis of cerebrospinal fluid (CSF), vitreous fluid, or a biopsy specimen. Brain biopsy sampling remains the gold standard for PCNSL diagnosis in all patients, although the possibility of establishing routine, minimally invasive diagnostic procedures in which Epstein-Barr virus polymerase chain reaction (PCR) analysis of the CSF and nuclear imaging are used is currently under investigation in the population of patients with AIDS. At the time of diagnosis, the patient should undergo further evaluation, which should include a physical examination, ophthalmic evaluation with a slit-lamp examination, serum lactate dehydrogenase levels, human immunodeficiency virus testing, computed tomography scans of the chest/abdomen/pelvis, bone marrow biopsy sampling, contrast-enhanced brain MR imaging, and lumbar puncture (LP). Testicular ultrasonography studies should be considered in men. In patients who cannot undergo LP or in those with evidence of spinal cord dysfunction, contrast-enhanced MR imaging of the entire spine should be considered.

Primary Lymphoma of the Nervous System

This review article provides guidelines for the diagnosis, staging, and management of primary nervous system lymphoma based on the results of clinical trials conducted during the last decade. Recent progress in our understanding of the pathogenesis of primary nervous system lymphoma is summarized, and implications of these findings for the development of diagnostic tools and new therapeutic strategies are outlined. We performed a search of the PubMed database (National Center for Biotechnology Information) for articles on primary nervous system lymphoma published between 1970 and May 2005. Primary nervous system lymphoma affects the brain, eye, and meninges as well as cranial, spinal, and peripheral nerves. Although important lessons have been learned from the pathogenesis of extraneural non-Hodgkin's lymphoma, the unique organotropism of primary nervous system lymphoma remains poorly understood. Diagnosis is facilitated by modern imaging techniques and molecular markers. Clinically recognizable "precursors" may exist but frequently elude specific diagnosis. Insight into the peculiar pharmacokinetics of chemotherapy aimed at tumors within the nervous system has led to the development of methotrexate-based regimens that can achieve prolonged progression-free survival without the use of radiation. Long-term survival and, in selected cases, even a cure are possible in primary nervous system lymphoma. Treatment should be provided in specialized multidisciplinary centers. In spite of remarkable progress through methotrexate-based chemotherapy, the majority of patients experience relapse within a few years. Better diagnostic tools are required for earlier diagnosis and monitoring of treatment response. A deeper understanding of the pathogenesis of primary nervous system lymphoma may reveal new therapeutic targets.

Atteintes du système nerveux central et infection par le VIH-1

Central nervous system complications are common in HIV-1 infected patients and occur either as a result of concomitant immunosuppression (opportunistic infections, lymphoma and tumors), as a primary manifestation of HIV infection, or as an adverse effect of therapy (immune restoration and toxicity). These complications contribute largely to patient morbidity and mortality. In the era of highly active antiretroviral therapy (HAART) these disease states have changed in presentation, outcome and incidence. We review in detail the epidemiology, pathogenesis, clinical features, diagnosis, and management of these disorders.

Changing pattern of primary cerebral lymphoma in the highly active antiretroviral therapy era

Before the introduction of highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV)-related primary central nervous system lymphoma (PCNSL) represented one of the most prevalent causes of focal brain lesions in HIV-infected people. The prognosis of PCNSL was very poor, with median survival time not exceeding 2 months. Brain biopsy was the method of choice for the definitive diagnosis, but it was and remains an invasive procedure with morbidity and mortality as well as considerable costs in terms of patients' management and quality of life. The strict association between AIDS-PCNSL and Epstein-Barr virus led to the suggestion that EBV DNA in cerebrospinal spinal fluid (CSF) might serve as a diagnostic marker, reducing the time required for diagnosis and allowing a minimally invasive approach. The clinical usefulness of this methodology has been largely demonstrated through clinical practice. After the introduction of HAART in clinical practice, a survival benefit has been observed for most persons with acquired immunodeficiency syndrome (AIDS)-associated opportunistic infections and cancers. In particular, for patients with non-Hodgkin lymphoma, a higher likelihood of response to chemotherapy as well as a longer survival has been found as a consequence of the use of combined antiretroviral therapy. Although larger studies did not show significant changes in survival of HIV-infected patients with PCNSL in the era of HAART, small case series and anecdotal reports showed the benefit of HAART in the treatment of PCNSL. Nevertheless, these patients' survival still remains very poor and it could be hypothesized that, other than specific cancer prognostic determinants and severe immunodeficiency, viral pathogenesis as well as EBV-specific immunologic dysfunction may be responsible.

Clinical Features and Diagnosis of Primary Central Nervous System Lymphoma

This article reviews the clinical features of primary central nervous system lymphoma (PCNSL) in immunocompetent and immunocompromised patients. Clinical presentation, differential diagnosis, diagnostic testing, and staging evaluation in both immunocompetent and AIDS patients who have PCNSL are discussed. The differing role of biopsy in these two populations also is addressed.

Factors influencing PCR detection of viruses in cerebrospinal fluid of patients with suspected CNS infections

BACKGROUND

Polymerase chain reaction (PCR) is used to detect viruses in the cerebrospinal fluid (CSF) of patients with neurological disease. However, data to assist its use or interpretation are limited.

OBJECTIVE

We investigated factors possibly influencing viral detection in CSF by PCR, which will also help clinicians interpret positive and negative results.

METHODS

CSF from patients with was tested for human herpesviruses types 1-6, JC virus, enteroviruses, and Toxoplasma gondii. The likelihood of central nervous system (CNS) infection was classified as likely, possible, or unlikely. PCR findings in these categories were compared using single variable and logistic regression analysis.

RESULTS

Of 787 samples tested, 97 (12%) were PCR positive for one or more viruses. Of episodes likely to be CNS viral infections, 30% were PCR positive compared to 5% categorised as unlikely. The most frequent positive findings were Epstein Barr virus (EBV), enteroviruses, and herpes simplex virus (HSV). Enteroviruses and HSV were found predominantly in the likely CNS viral infection group, whereas EBV was found mainly in the unlikely group. Positive PCR results were more likely when there were 3-14 days between symptom onset and lumbar puncture, and when CSF white cell count was abnormal, although a normal CSF did not exclude a viral infection.

CONCLUSIONS

The diagnostic yield of PCR can be maximised by using sensitive assays to detect a range of pathogens in appropriately timed CSF samples. PCR results, in particular EBV, should be interpreted cautiously when symptoms cannot readily be attributed to the virus detected.