Prognostic significance of JC virus DNA levels in cerebrospinal fluid of patients with HIV-associated progressive multifocal leukoencephalopathy

Biomarkers for progressive multifocal leukoencephalopathy: emerging data for use of JC virus DNA copy number in clinical trials

Progressive multifocal leukoencephalopathy is a rare but devastating demyelinating disease caused by the JC virus (JCV), for which no therapeutics are approved. To make progress towards addressing this unmet medical need, innovations in clinical trial design are needed. Quantitative JCV DNA in CSF has the potential to serve as a valuable biomarker of progressive multifocal leukoencephalopathy disease and treatment response in clinical trials to expedite therapeutic development, as do neuroimaging and other fluid biomarkers such as neurofilament light chain. Specifically, JCV DNA in CSF could be used in clinical trials as an entry criterion, stratification factor, or predictor of clinical outcomes. Insights from the investigation of candidate biomarkers for progressive multifocal leukoencephalopathy might inform approaches to biomarker development for other rare diseases.

Progressive multifocal leukoencephalopathy in a lung transplant recipient

Progressive multifocal leukoencephalopathy (PML) is a rare and fatal demyelinating disease of the central nervous system (CNS). The case we describe highlights the importance of considering a diagnosis of PML early (<1 year) after lung transplant.

The diagnosis of central nervous system infections in resource-limited settings and the use of novel and molecular diagnostic platforms to improve diagnosis

INTRODUCTION

Central nervous system infections (CNSI) disproportionately affect individuals in low-resource settings where diagnosis is challenging; large proportions of patients never receive a confirmed microbiological diagnosis resulting in inadequate management and high mortality. The epidemiology of CNSI varies globally and conventional diagnostics deployed in resource-limited settings have significant limitations, with an urgent need for improved diagnostic strategies.

AREAS COVERED

This review describes molecular platforms and other novel diagnostics used in the diagnosis of CNSI that are applicable to resource-limited settings. An extensive literature search of Medline and PubMed was performed. The emphasis is on investigations targeting infections of relevance to resource-limited settings either due to variation in regional CNSI epidemiology or due to increased prevalence in patients with immunosuppression. This includes commercially available multiplex PCR platforms, mycobacterial PCR platforms, and rapid diagnostics tests. To offer a framework for the optimal implementation in clinical settings, existing evidence highlighting the advantages and limitations of available platforms is reviewed.

EXPERT OPINION

The implementation of molecular platforms and other novel diagnostics has the potential to transform CNSI diagnosis in resource-limited settings, with several examples of successful rollout of novel diagnostics such as Xpert MTB/RIF Ultra and cryptococcal antigen testing.

Progressive multifocal leukoencephalopathy: a retrospective study of the last 12 years in a tertiary-care hospital

Our study aims to report on the demographic, incidence rate (IR), clinical, and microbiological characteristics of PML patients diagnosed in our tertiary-care hospital over the past 12 years. In this retrospective observational study, we reviewed all requests for JCPyV PCR in CSF from patients with suspected PML. We collected demographic, clinical, and microbiological data of patients diagnosed with PML. Since 2018, real-time quantitative PCR has been used, whereas prior to 2018, samples were sent to our National Reference Center for qualitative diagnosis. Thirteen patients were diagnosed with PML, with 10 of them having a definitive diagnosis and 3 classified as a possible diagnosis with negative PCR results. Eleven patients had advanced HIV, one had non-Hodgkin's lymphoma, and one had systemic lupus erythematosus. Most of the white matter lesions were located at the cerebral level, although the parenchyma and cerebellum were also affected. The most frequent symptoms were behavioral disorders and hemiparesis. The viral load of JCPyV in cerebrospinal fluid was < 1000 copies/mL in three patients. Six patients received compassionate treatment, and all six patients with definitive PML diagnosis died. Although advanced HIV patients were the most affected by PML in our study, it should also be considered in patients with other underlying diseases. While current PCR tests offer high sensitivity and specificity, false negatives can occur. The prognosis of the disease remains poor, and early multidisciplinary diagnosis-including clinical, microbiological, and neuroimaging assessments-remains crucial for improving neurological damage and prognosis.

Cerebellar Progressive Multifocal Leukoencephalopathy Mimicking Anti-Yo-Antibody-Associated Rapidly Progressive Cerebellar Syndrome

A 58-year-old woman with a history of systemic lupus erythematosus (SLE) who was taking prednisolone and mycophenolate mofetil presented with gait disturbances that progressively worsened over a period of 3 months. Her blood test and cerebrospinal fluid (CSF) examination results did not indicate active SLE. Initial brain magnetic resonance imaging (MRI) revealed a small spotty lesion in the left cerebellar peduncle. The clinical course was consistent with rapidly progressive cerebellar syndrome (RPCS), which sometimes involves neuronal antibodies. The line blot assay detected anti-Yo antibodies, but no malignancy was found. Immunohistological techniques using rat brain sections yielded a negative result for anti-Yo antibodies. The second MRI revealed a focal lesion and surrounding spotty lesion in the left cerebellar peduncle, which was consistent with the punctate pattern observed in progressive multifocal leukoencephalopathy (PML). The CSF JCV-DNA test indicated the presence of cerebellar PML. Immunosuppressants were reduced, and mefloquine and mirtazapine were initiated. After approximately 2 years and 1 month, the CSF JCV-DNA results became negative. Cerebellar PML may exhibit a clinical course that is consistent with RPCS. The punctate pattern should be recognized as an early manifestation of PML. The CSF JCV-DNA copy number may serve as a useful indicator of PML stabilization.

Progressive Multifocal Leukoencephalopathy Treated by Immune Checkpoint Inhibitors

OBJECTIVE

Our aim was to assess the real-world effectiveness of immune checkpoint inhibitors for treatment of patients with progressive multifocal leukoencephalopathy (PML).

METHODS

We conducted a multicenter survey compiling retrospective data from 79 PML patients, including 38 published cases and 41 unpublished cases, who received immune checkpoint inhibitors as add-on to standard of care. One-year follow-up data were analyzed to determine clinical outcomes and safety profile. Logistic regression was used to identify variables associated with 1-year survival.

RESULTS

Predisposing conditions included hematological malignancy (n = 38, 48.1%), primary immunodeficiency (n = 14, 17.7%), human immunodeficiency virus/acquired immunodeficiency syndrome (n = 12, 15.2%), inflammatory disease (n = 8, 10.1%), neoplasm (n = 5, 6.3%), and transplantation (n = 2, 2.5%). Pembrolizumab was most commonly used (n = 53, 67.1%). One-year survival was 51.9% (41/79). PML-immune reconstitution inflammatory syndrome (IRIS) was reported in 15 of 79 patients (19%). Pretreatment expression of programmed cell death-1 on circulating T cells did not differ between survivors and nonsurvivors. Development of contrast enhancement on follow-up magnetic resonance imaging at least once during follow-up (OR = 3.16, 95% confidence interval = 1.20-8.72, p = 0.02) was associated with 1-year survival. Cerebrospinal fluid JC polyomavirus DNA load decreased significantly by 1-month follow-up in survivors compared to nonsurvivors (p < 0.0001). Thirty-two adverse events occurred among 24 of 79 patients (30.4%), and led to treatment discontinuation in 7 of 24 patients (29.1%).

INTERPRETATION

In this noncontrolled retrospective study of patients with PML who were treated with immune checkpoint inhibitors, mortality remains high. Development of inflammatory features or overt PML-IRIS was commonly observed. This study highlights that use of immune checkpoint inhibitors should be strictly personalized toward characteristics of the individual PML patient. ANN NEUROL 2023;93:257-270.

JC polyomavirus: a short review of its biology, its association with progressive multifocal leukoencephalopathy, and the diagnostic value of different methods to manifest its activity or presence

INTRODUCTION

JC polyomavirus is the causative agent of progressive multifocal leukoencephalopathy (PML), a demyelinating disease resulting from the lytic infection of oligodendrocytes that may develop in immunosuppressed individuals: HIV1 infected or individuals under immunosuppressive therapies. Understanding the biology of JCPyV is necessary for a proper patient management, the development of diagnostic tests, and risk stratification.

AREAS COVERED

The review covers different areas of expertise including the genomic characterization of JCPyV strains detected in different body compartments (urine, plasma, and cerebrospinal fluid) of PML patients, viral mutations, molecular diagnostics, viral miRNAs, and disease.

EXPERT OPINION

The implementation of molecular biology techniques improved our understanding of JCPyV biology. Deep sequencing analysis of viral genomes revealed the presence of viral quasispecies in the cerebrospinal fluid of PML patients characterized by noncoding control region rearrangements and VP1 mutations. These neurotropic JCPyV variants present enhanced replication and an altered cell tropism that contribute to PML development. Monitoring these variants may be relevant for the identification of patients at risk of PML. Multiplex realtime PCR targeting both the LTAg and the archetype NCCR could be used to identify them. Failure to amplify NCCR should indicate the presence of a JCPyV prototype speeding up the diagnostic process.

Immune profile and radiological characteristics of progressive multifocal leukoencephalopathy

BACKGROUND AND PURPOSE

Progressive multifocal leukoencephalopathy (PML) constitutes a severe disease with increasing incidence, mostly in the context of immunosuppressive therapies. A detailed understanding of immune response in PML appears critical for the treatment strategy. The aim was a comprehensive immunoprofiling and radiological characterization of magnetic resonance imaging (MRI) defined PML variants.

METHODS

All biopsy-confirmed PML patients (n = 15) treated in our department between January 2004 and July 2019 were retrospectively analysed. Data from MRI, histology as well as detailed clinical and outcome data were collected. The MRI-defined variants of classical (cPML) and inflammatory (iPML) PML were discriminated based on the intensity of gadolinium enhancement. In these PML variants, intensity and localization (perivascular vs. parenchymal) of inflammation in MRI and histology as well as the cellular composition by immunohistochemistry were assessed. The size of the demyelinating lesions was correlated with immune cell infiltration.

RESULTS

Patients with MRI-defined iPML showed a stronger intensity of inflammation with an increased lymphocyte infiltration on histological level. Also, iPML was characterized by a predominantly perivascular inflammation. However, cPML patients also demonstrated certain inflammatory tissue alterations. Infiltration of CD163-positive microglia and macrophage (M/M) subtypes correlated with PML lesion size.

CONCLUSIONS

The non-invasive MRI-based discrimination of PML variants allows for an estimation of inflammatory tissue alterations, although exhibiting limitations in MRI-defined cPML. The association of a distinct phagocytic M/M subtype with the extent of demyelination might reflect disease progression.

BK virus-specific T cells for immunotherapy of progressive multifocal leukoencephalopathy: an open-label, single-cohort pilot study

BACKGROUND

Progressive multifocal leukoencephalopathy, a rare disease of the CNS caused by JC virus and occurring in immunosuppressed people, is typically fatal unless adaptive immunity is restored. JC virus is a member of the human polyomavirus family and is closely related to the BK virus. We hypothesised that use of partly HLA-matched donor-derived BK virus-specific T cells for immunotherapy in progressive multifocal leukoencephalopathy would be feasible and safe.

METHODS

We did an open-label, single-cohort pilot study in patients (aged 18 years or older) with clinically definite progressive multifocal leukoencephalopathy and disease progression in the previous month at the National Institutes of Health (NIH) Clinical Center (Bethesda, MD, USA). Overlapping peptide libraries derived from large T antigen and major capsid protein VP1 of BK virus with high sequence homology to JC virus counterparts were used to generate polyomavirus-specific T cells cross-recognising JC virus antigens. Polyomavirus-specific T cells were manufactured from peripheral blood mononuclear cells of first-degree relative donors aged 18 years or older. These cells were administered to patients by intravenous infusion at 1 × 10⁶ polyomavirus-specific T cells per kg, followed by up to two additional infusions at 2 × 10⁶ polyomavirus-specific T cells per kg. The primary endpoints were feasibility (no manufacturing failure based on meeting release criteria, achieving adequate numbers of cell product for clinical use, and showing measurable antiviral activity) and safety in all patients. The safety monitoring period was 28 days after each infusion. Patients were followed up with serial MRI for up to 12 months after the final infusion. This trial is registered at ClinicalTrials.gov, NCT02694783.

FINDINGS

Between April 7, 2016, and Oct 19, 2018, 26 patients were screened, of whom 12 were confirmed eligible and received treatment derived from 14 matched donors. All administered polyomavirus-specific T cells met the release criteria and recognised cognate antigens in vitro. 12 patients received at least one infusion, ten received at least two, and seven received a total of three infusions. The median on-study follow-up was 109·5 days (range 23-699). All infusions were tolerated well, and no serious treatment-related adverse events were observed. Seven patients survived progressive multifocal leukoencephalopathy for longer than 1 year after the first infusion, whereas five died of progressive multifocal leukoencephalopathy within 3 months.

INTERPRETATION

We showed that generation of polyomavirus-specific T cells from healthy related donors is feasible, and these cells can be safely used as an infusion for adoptive immunotherapy of progressive multifocal leukoencephalopathy. Although not powered to assess efficacy, our data provide additional support for this strategy as a potential life-saving therapy for some patients.

FUNDING

Intramural Research Program of the National Institute of Neurological Disorders and Stroke of the NIH.

Grey matter abnormality in progressive multifocal leucoencephalopathy

Progressive multifocal leucoencephalopathy (PML) is a demyelinating white matter disease that most often affects immunocompromised people infected by JC virus. The diagnostic gold standard is demonstrable viral DNA or protein from histopathological tissue. However, there are few detailed descriptions of cortical grey matter involvement on neuroimaging. Here we describe the histopathological correlate of cerebral grey matter involvement and radiological accompaniment in a patient with biopsy proven PML.

Treatment of Progressive Multifocal Leukoencephalopathy Using Immune Restoration

Progressive multifocal leukoencephalopathy (PML) is a viral disease of the brain associated with immunodeficiency, immune suppressing medications, and malignancy. In the absence of effective anti-viral therapy for the causative JC virus, immune restoration has emerged as the critical therapeutic alternative. The evolving treatment of PML (and other rare JC virus-associated neurologic syndromes) requires consideration of baseline immune functioning and comorbid diseases while selecting from a number of therapeutic options to restore an effective immune response. This review focuses on the current options for management of PML in typical situations where this disease presents, including several where immune restoration is a standard therapeutic approach such as in PML associated with HIV/AIDS and in multiple sclerosis associated with natalizumab. Other circumstances in which PML occurs including associated with primary immunodeficiencies, malignancies, and transplants present greater challenges to immune reconstitution, but emerging concepts may enhance therapeutic options for these situations. Particular attention is focused on recent experience with checkpoint inhibitors, guidance for MS drug discontinuation, and strategies to monitor and facilitate immune restoration.

Checkpoint inhibitors for the treatment of JC virus-related progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a frequently fatal brain infection caused by the JC polyomavirus (JCV). PML occurs in people with impaired cellular immunity, and the only effective treatment is restoration of immune function. Infection in immunocompromised hosts is often associated with immune exhaustion, which is mediated by inhibitory cell surface receptors known as immune checkpoints, leading to loss of T cell effector function. Blockade of immune checkpoints can reinvigorate host responses to fight infection. Recently, there have been several reports of checkpoint blockade to treat PML in patients in whom immune reconstitution is otherwise not possible, with some evidence for positive response. Larger studies are needed to better understand efficacy of checkpoint blockade in PML and factors that determine response.

Successful treatment of non-HIV progressive multifocal leukoencephalopathy: case report and literature review

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a subacute onset demyelinating disease caused by JC virus and characterized by multifocal involvement of the subcortical white matter and cerebellar hemispheres or peduncles on magnetic resonance imaging (MRI). However, non-HIV PML patients with brain lesions limited to the cerebellum and brainstem have not been well characterized.

METHODS

We report a 68-year-old man with systemic lupus erythematosus under treatment with immunosuppressants who developed non-HIV PML with brain lesions limited to the cerebellum and brainstem and successfully treated with a combination of mefloquine and mirtazapine. We performed a literature review to characterize patients with non-HIV PML with brain lesions limited to the cerebellum and brainstem.

RESULTS

Eight cases with non-HIV brainstem/cerebellar form PML were identified including our case. All cases had compromised status related underlying diseases. Four (50%) had a good prognosis. Five cases were treated, including 3 with favourable outcomes. Between the good prognosis group (n = 4) and the poor prognosis group (n = 4), treatment status for PML and the interval between the initial manifestation and diagnosis did not differ. Among those who performed contrast-enhanced brain imaging, lesion enhancement was related to good prognosis (good prognosis group vs. poor prognosis group; 100% vs. 0%).

CONCLUSION

PML should be considered in the differential diagnosis of brain lesions limited to the cerebellum and brainstem in immunocompromised patients. The presence of immune response against JC virus and inflammatory reactions may indicate good prognosis in non-HIV brainstem/cerebellar form PML.

Diagnostic and Prognostic Value of JC Virus DNA in Plasma in Progressive Multifocal Leukoencephalopathy

Background

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease caused by the polyomavirus JC (John Cunningham; JCV) that affects patients with impaired immune systems. While JCV-DNA detection in cerebrospinal fluid (CSF) is diagnostic of PML, the clinical significance of plasma JCV-DNA is uncertain.

Methods

We retrospectively analyzed plasma samples from PML patients that were drawn close to disease onset and from controls without PML. In PML patients, we compared plasma JCV-DNA detection and levels to clinical and laboratory parameters, and patient survival.

Results

JCV-DNA was detected in plasma of 49/103 (48%) patients with PML (20/24, 83%, human immunodeficiency virus [HIV] negative; 29/79, 37%, HIV-positive) and of 4/144 (3%) controls without PML (0/95 HIV-negative; 4/49, 8%, HIV-positive), yielding a diagnostic sensitivity and specificity of 48% and 97% (83% and 100% in HIV-negative; 37% and 92% in HIV-positive), respectively. Among 16 PML patients with undetectable CSF JCV-DNA, 4 (25%) had detectable plasma JCV-DNA. Plasma JCV-DNA levels were independently associated with CSF levels (P < .0001) and previous corticosteroid treatment (P = .012). Higher plasma JCV-DNA levels were associated with disease progression in HIV-negative patients (P = .005); in HIV-positive patients, there was an increased risk of progression only in those treated with combination antiretroviral therapy (cART; P < .0001).

Conclusions

Testing JCV-DNA in plasma might complement PML diagnosis, especially when CSF is unavailable or JCV-DNA not detectable in CSF. In addition, JCV-DNA plasma levels could be useful as a marker of disease progression in both HIV-negative and cART-treated, HIV-positive PML patients.

Progressive multifocal leukoencephalopathy: a challenging diagnosis established at autopsy

Progressive multifocal leukoencephalopathy (PML) is a feared entity that occurs most frequently in conditions of extreme immunodeficiency. The diagnosis is often made long after the onset of symptoms due to the physicians’ unfamiliarity, and the unavailability of diagnostic tests in some medical centers. Although the incidence of PML is decreasing among HIV patients with the advent of highly active antiretroviral therapy (HAART), in Brazil this entity is the fourth highest neurological complication among these patients. The authors present the case of a middle-aged man who tested positive for HIV concomitantly with the presentation of hyposensitivity in the face and the right side of the body, accompanied by mild weakness in the left upper limb. The clinical features worsened rapidly within a couple of weeks. The diagnostic work-up pointed to the working diagnosis of PML after brain magnetic resonance imaging; however, the detection of the John Cunningham virus (JCV) in the cerebral spinal fluid was negative. HAART was started but the patient died after 7 weeks of hospitalization. The autopsy revealed extensive multifocal patchy areas of demyelination in the white matter where the microscopy depicted demyelination, oligodendrocytes alterations, bizarre atypical astrocytes, and perivascular lymphocytic infiltration. The immunohistochemistry was positive for anti-SV40, and the polymerase chain reaction of the brain paraffin-embedded tissue was positive for JCV. The authors highlight the challenges for diagnosing PML, as well as the devastating outcome of PML among HIV patients.

Progressive Multifocal Leukoencephalopathy in the Absence of Typical Radiological Changes: Can We Make a Diagnosis?

Patient: Female, 32

Final Diagnosis: Progressive multifocal leukoencephalopathy

Symptoms: Progressive behavioral changes • seizures

Medication: —

Clinical Procedure: Management

Specialty: Neurology

A controlled inflammation and a regulatory immune system are associated with more favorable prognosis of progressive multifocal leukoencephalopathy

OBJECTIVE

In the present study, we analyzed the inflammatory profiles of brain tissues obtained from patients with progressive multifocal leukoencephalopathy (PML) due to John Cunningham (JC) virus infection to identify potential prognostic factors.

METHODS

The study included seven patients (two men, five women) who had been pathologically diagnosed with PML, and all of whom were HIV negative. Fixed brain samples were analyzed via hematoxylin and eosin (HE) staining and Klüver-Barrera (KB) staining. We then performed immunohistochemistry (IHC) specific to JC virus capsid proteins (VP1 and VP2/3) and lymphocyte surface markers (CD4, CD8, CD138, and PD-1).

RESULTS

The mean age at onset was 53.4, while the mean duration until biopsy/autopsy was 4.7 months. Four patients were included in the good prognosis (GP) group, while three were included in the poor prognosis (PP) group. Pathological analysis revealed a significantly larger number of CD4-positive T-cell infiltrations (P = .029) in the GP group, along with a preserved CD4:CD8 ratio. Larger numbers of CD138-positive plasma cells were also observed in the GP group (P = .029) than in the PP group. Linear regression analyses revealed a significant association between the numbers of CD138-positive plasma cells and PD-1-positive cells (R² = 0.80).

CONCLUSIONS

Viral loads in the cerebrospinal fluid, a controlled inflammatory response mediated by CD4- and CD8-positive T cells, and plasma cells are associated with PML prognosis. Our findings further indicate that regulatory plasma cells may regulate inflammatory T-cell activity via a PD-1/PD-L1 immuno-checkpoint pathway, thereby protecting the uninfected brain from excessive immune-mediated damage during an active JC virus infection.

A loop-mediated isothermal amplification assay for the detection and quantification of JC polyomavirus in cerebrospinal fluid: a diagnostic and clinical management tool and technique for progressive multifocal leukoencephalopathy

Background

JC polyomavirus (JCV) is the causative agent of progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the central nervous system in immunosuppressed patients. PML usually has a poor prognosis. Detection and quantification of the JCV genome in cerebrospinal fluid (CSF) is an efficacious tool for the diagnosis and management of PML, for which proper therapeutic interventions are required.

Methods

A loop-mediated isothermal amplification (LAMP) assay was applied for the quantitative detection of JCV. The LAMP assay was evaluated for the efficacy in diagnosis of PML in comparison with the TaqMan-based quantitative real-time PCR (qPCR) assay using 153 CSF specimens collected from patients with suspected PML.

Results

The LAMP assay showed no cross-reactivity against other polyomavirus plasmids, viral DNA, and viral RNA, which causes encephalitis, and detected 1 copy of the standard DNA per reaction. Among 50 qPCR-positives, 42 specimens (containing JCV genome ranged from 3.2 × 10⁰ to 3.2 × 10⁶ copies/reaction) showed positive reactions and 8 specimens (containing 0.9 to 19.9 copies/reaction) showed negative in the LAMP assay. Furthermore, 3 of 103 qPCR-negative specimens showed positive reactions in the LAMP assay. The sensitivity, specificity, positive predictive value, and negative predictive values of the LAMP assay were 84% (42/50), 97% (100/103), 93% (42/45), and 93% (100/108), respectively. The kappa statistic was 0.83. The JCV loads determined by the LAMP assay showed a strong positive correlation with those determined by the qPCR assay for 33 specimens with copy numbers of ≥1 copies/reaction (r = 0.89). Additionally, the LAMP assay could monitor the JCV genome copy number in CSF for sequential samples equivalently to qPCR assay.

Conclusions

The newly developed LAMP assay is highly specific against JCV and detect the JCV genome in the sample DNA containing 20 or more copies of JCV genome per reaction with 100% sensitivity (n = 29), which corresponds to ≥3 × 10³ copies/mL of CSF. The LAMP assay is useful for the diagnosis and offers valuable information for the evaluation and management of PML in the clinical setting.

A case of developing progressive multifocal leukoencephalopathy while using rituximab and mycophenolate mofetil in refractory systemic lupus erythematosus

Progressive multifocal leukoencephalopathy (PML) is a central nervous system infection caused by John Cunningham (JC) virus reactivation in an immunocompromised patient. PML has various neurologic symptoms and has very poor prognosis. A 36-year-old man developed transverse myelitis and had a psychiatric disorder at the age of 26. He was diagnosed with systemic lupus erythematosus (SLE) and neuropsychiatric SLE (NPSLE), on the basis of leukopenia and presence of anti-DNA and anti-nuclear antibodies. Treatment with glucocorticoid (GC) was started, and remission was introduced. Six months before PML onset, his condition was complicated with hemophagocytic lymphohistiocytosis (HLH) due to exacerbation of SLE. Remission re-induction therapy by GC, cyclosporine-A, intravenous cyclophosphamide, and rituximab (RTX) was initiated and HLH improved. However, interleukin-6 levels of the cerebrospinal fluid (CSF) continued to rise. We thought that the disease activity of NPSLE worsened; thus, we introduced mycophenolate mofetil (MMF) 4 months before the PML onset. He developed progressive dysarthria and right hemiplegia. He was diagnosed with PML via magnetic resonance imaging and JC virus polymerase chain reaction in CSF. Considering that immunosuppressants, including RTX and MMF, are precipitating factors of PML, we discussed the RTX removal using plasma exchange (PEx), but we did not introduce PEx, because it was expected that the concentration of RTX was already lowered when he was diagnosed with PML. Treatment for PML with mefloquine and mirtazapine saved his life, but severe residual disabilities remained. This is the first report of a patient who developed PML during combination therapy with RTX and MMF.

The confused oncologic patient: a rational clinical approach

PURPOSE OF REVIEW

The purpose of this review is to provide a practical clinical approach to confusion in the patient with cancer. Confusion in the cancer population has a broader differential diagnosis than in the general medical population. The clinician must consider the usual differential diagnoses as well as causes unique to the cancer patient including direct complications from the cancer and indirect complications related to cancer treatment.

RECENT FINDINGS

In the recent age of precision medicine, the oncologist now utilizes the genomic profile of both the patient and the tumor to provide advanced biologic therapies including targeted anticancer drugs, antiangiogenic agents, and immunotherapy. Such advances carry with them an emerging pattern of neurotoxicity which, although less well described in the literature, is now an important consideration to the clinical approach to confusion in cancer patients.

SUMMARY

Confusion is the most common neurologic complication in cancer and is associated with significant morbidity, mortality, and prolonged hospital stays resulting in increased healthcare costs. Early recognition and treatment of delirium is essential to improve clinical outcomes.

Progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a relatively common complication of HIV disease. In this chapter changes to the epidemiology are discussed along with an update in its pathogenesis and treatment. Immune reconstitution inflammatory syndrome is increasingly frequent in PML; accordingly management strategies and prognosis are detailed.

Progressive multifocal leukoencephalopathy in patients receiving rituximab and cyclophosphamide after haplo-identical T-cell replete transplantation and review of the literature

John Cunningham virus (JCV) reactivation, occurring mainly in immunocompromised patients, leads to progressive multifocal leukoencephalopathy, an uncommon but lethal disease. JCV reactivation after T-cell replete haploidentical stem cell transplantation, in the pre-cyclophosphamide era, is poorly represented in the literature. We therefore describe two cases of acute myeloid leukemia who developed JCV reactivation after receiving cyclophosphamide and rituximab post haploidentical stem cell transplantation, and review the literature, aiming to a better understanding of the disease course and its risk factors.

Progressive multifocal leukoencephalopathy and hematologic malignancies: a single cancer center retrospective review

Progressive multifocal leukoencephalopathy (PML) is an uncommon opportunistic infection with high morbidity and mortality. This is an institutional review board-approved retrospective review of medical records identified by diagnostic coding for PML or John Cunningham virus (JCV) from 2000 to 2015. Inclusion criteria were cerebrospinal fluid (CSF) positive for JCV by polymerase chain reaction or brain biopsy-proven PML in non-HIV patients. There were 16 patients, 12 of whom were men (75%); the median age was 56 years (range, 31-71 years). All had hematologic malignancies (5 [31%] had chronic lymphocytic leukemia, 3 [19%] had acute myeloid leukemia, 3 had [19%] mantle cell lymphoma, and 1 patient each had acute lymphoblastic leukemia, Hodgkin lymphoma, myeloma, or B-cell lymphoma). One patient received no cancer-directed therapy. Of the remaining 15 patients, all received conventional chemotherapy, and 9 (60%) underwent transplant. Thirteen patients (87%) received immunomodulating therapy (predominantly rituximab). The median time from cancer diagnosis to PML diagnosis was 48.5 months. PML was diagnosed a median of 2.1 months from symptom onset; however, the median time to PML diagnosis was 5.4 months for the 4 patients presenting with a cerebellar syndrome. PML was diagnosed by CSF in 12 patients and brain biopsy in 4 following negative CSF test results. Median survival from PML diagnosis was 4.3 months for the 11 patients on treatment and 0.87 months for the 5 without treatment. PML still occurs in patients with hematologic malignancies in the absence of treatment. Twenty-five percent of our patients required brain biopsy for diagnosis, and diagnosis was delayed when the clinical presentation was unusual, such as a cerebellar syndrome.

Detectable cerebrospinal fluid JCV DNA in late-presenting HIV-positive patients: beyond progressive multifocal leukoencephalopathy?

In the absence of effective prophylaxis and treatment, therapeutic options in HIV-positive patients with progressive multifocal leukoencephalopathy (PML) are limited to antiretroviral therapy: nevertheless, outcome is poor. We conducted a retrospective study (2009-2015) describing the outcome of 25 HIV-positive patients with detectable cerebrospinal fluid JC virus DNA: 14 had a probable PML while the others had evidence of other inflammatory central nervous system (CNS) affecting disorders. In the former group, 6-month mortality was 45.5% vs 21.4 in the latter one: survival was higher than previously described but no predictor of poor outcome was identified. Two patients treated with 5HT2-inhibitors survived. The contributing role of JCV replication in other CNS-affecting disorders needs to be assessed as well as the benefits of 5HT2-inhibitors in HIV-positive patients with proven PML.

Polyomaviruses

Over the last 10 years, the number of identified polyomaviruses has grown to more than 35 subtypes, including 13 in humans. The polyomaviruses have similar genetic makeup, including genes that encode viral capsid proteins VP1, 2, and 3 and large and small T region proteins. The T proteins play a role in viral replication and have been implicated in viral chromosomal integration and possible dysregulation of growth factor genes. In humans, the Merkel cell polyomavirus has been shown to be highly associated with integration and the development of Merkel cell cancers. The first two human polyomaviruses discovered, BKPyV and JCPyV, are the causative agents for transplant-related kidney disease, BK commonly and JC rarely. JC has also been strongly associated with the development of progressive multifocal leukoencephalopathy (PML), a rare but serious infection in untreated HIV-1-infected individuals and in other immunosuppressed patients including those treated with monoclonal antibody therapies for autoimmune diseases systemic lupus erythematosus, rheumatoid arthritis, or multiple sclerosis. The trichodysplasia spinulosa-associated polyomavirus (TSAPyV) may be the causative agent of the rare skin disease trichodysplasia spinulosa. The remaining nine polyomaviruses have not been strongly associated with clinical disease to date. Antiviral therapies for these infections are under development. Antibodies specific for each of the 13 human polyomaviruses have been identified in a high percentage of normal individuals, indicating a high rate of exposure to each of the polyomaviruses in the human population. PCR methods are now available for detection of these viruses in a variety of clinical samples.

CSF in acute and chronic infectious diseases

Infections of the nervous system are an important and challenging aspect of clinical neurology. Immediate correct diagnosis enables to introduce effective therapy, in conditions that without diagnosis may leave the patient with severe neurological incapacitation and sometimes even death. The cerebrospinal fluid (CSF) is a mirror that reflects nervous system pathology and can promote early diagnosis and therapy. The present chapter focuses on the CSF findings in neuro-infections, mainly viral and bacterial. Opening pressure, protein and glucose levels, presence of cells and type of the cellular reaction should be monitored. Other tests can also shed light on the causative agent: serology, culture, staining, molecular techniques such as polymerase chain reaction. Specific examination such as panbacterial and panfungal examinations should be examined when relevant. Our chapter is a guide-text that combines clinical presentation and course with CSF findings as a usuaful tool in diagnosis of neuroinfections.

Copy Number Heterogeneity of JC Virus Standards

Quantitative PCR is a diagnostic mainstay of clinical virology, and accurate quantitation of viral load among labs requires the use of international standards. However, the use of multiple passages of viral isolates to obtain sufficient material for international standards may result in genomic changes that complicate their use as quantitative standards. We performed next-generation sequencing to obtain single-nucleotide resolution and relative copy number of JC virus (JCV) clinical standards. Strikingly, the WHO international standard and the Exact v1/v2 prototype standards for JCV showed 8-fold and 4-fold variation in genomic coverage between different loci in the viral genome, respectively, due to large deletions in the large T antigen region. Intriguingly, several of the JCV standards sequenced in this study with large T antigen deletions were cultured in cell lines immortalized using simian virus 40 (SV40) T antigen, suggesting the possibility of transcomplementation in cell culture. Using a cutoff 5% allele fraction for junctional reads, 7 different rearrangements were present in the JC virus sequences present in the WHO standard across multiple library preparations and sequencing runs. Neither the copy number differences nor the rearrangements were observed in a clinical sample with a high copy number of JCV or a plasmid control. These results were also confirmed by the quantitative real-time PCR (qPCR), droplet digital PCR (ddPCR), and Sanger sequencing of multiple rearrangements. In summary, targeting different regions of the same international standard can result in up to an 8-fold difference in quantitation. We recommend the use of next-generation sequencing to validate standards in clinical virology.

Progressive Multifocal Leukoencephalopathy in a HIV Negative, Immunocompetent Patient

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease most common in immunodeficient patients. It occurs due to reactivation of the John Cunningham Virus (JCV) and carries a poor prognosis, with a median life expectancy of 6 months. We report a case of a 66-year-old man with a history of HCV related cirrhosis (HCV) and hepatocellular carcinoma (HCC) who was found to have PML in the setting of a negative viral load in the CSF and a CD4+ >200. He initially presented with two weeks of mild confusion and word-finding difficulty concerning for hepatic encephalopathy. An MRI was notable for extensive T2/FLAIR hyperintensity signal in the left temporal lobe. Brain biopsy was positive for JCV. PML is rare in immunocompetent individuals, especially in the setting of a negative viral load. It is possible, however, that transient states of immunosuppression may have been responsible in this case. Although viral load was reported as negative, virus may still have been detected but was below the quantifiable threshold. It is important for clinicians to note that a negative result does not necessarily exclude the possibility of PML, and care should be taken to review lab values on viral load in closer detail.

Opportunistic Neurologic Infections in Patients with Acquired Immunodeficiency Syndrome (AIDS)

Infections of the central nervous system (CNS) in individuals with human immunodeficiency virus (HIV) remain a substantial cause of morbidity and mortality despite the introduction of highly active antiretroviral therapy (HAART) especially in the resource-limited regions of the world. Diagnosis of these infections may be challenging because findings on cerebrospinal fluid (CSF) analysis and brain imaging are nonspecific. While brain biopsy provides a definitive diagnosis, it is an invasive procedure associated with a relatively low mortality rate, thus less invasive modalities have been studied in recent years. Diagnosis, therefore, can be established based on a combination of a compatible clinical syndrome, radiologic and CSF findings, and understanding of the role of HIV in these infections. The most common CNS opportunistic infections are AIDS-defining conditions; thus, treatment of these infections in combination with HAART has greatly improved survival.

Diagnostic delay in progressive multifocal leukoencephalopathy

We investigated delay in diagnosing progressive multifocal leukoencephalopathy (PML). The median time from initial symptom to diagnosis was 74 days (range 1–1643) in 111 PML patients seen at our institution from 1993 to 2015. Another diagnosis was considered before PML in nearly two–thirds, and more than three–quarters of patients suffered from diagnostic delay greater than 1 month, irrespective of their underlying immunosuppressive condition. Extended diagnostic delay occurred more frequently in patients with possible PML, and among HIV⁺ patients with higher CD4⁺ T‐cell counts at symptom onset. Prompt diagnosis may improve survival of PML in so far as immune reconstitution can be effected, and prevent unnecessary interventions.

Progressive Multifocal Leukoencephalopathy with Negative JC Virus PCR following Treatment of Follicular Lymphoma: Implications for Biologics in the Era of Targeted Cancer Therapy

Anticancer therapy predisposes patients to infections by the immunosuppression that results from treatment. Although 85% of patients with progressive multifocal leukoencephalopathy (PML) have concurrent HIV/AIDS, PML can also develop in patients after they receive chemotherapy for cancer. The case herein describes a 69-year-old man with history of follicular lymphoma who presented with progressive dysarthria and right-sided paralysis. He received rituximab one year prior to presentation. PET scan suggested no recurrence of lymphoma. Cerebrospinal fluid (CSF) analysis was negative and showed fewer than 500 copies/mL of JC virus. However, brain biopsy showed chromatin margination and viropathic change within oligodendrocytes, confirming PML. He was started on mirtazapine and mefloquine with some clinical improvement. To our knowledge, this is the first case of rituximab-associated PML in a patient with negative JC virus PCR from the CSF. Recognition of PML in the differential of oncology patients with CNS symptoms is an important consideration as we enter the era of targeted therapy and personalized cancer medicine involving biologics. Furthermore, screening of patients for presence of subclinical JC viremia prior to the use of biologics may be an important component of assessing patient candidacy for these agents.

JC polyomavirus mutants escape antibody-mediated neutralization

JC polyomavirus (JCV) persistently infects the urinary tract of most adults. Under conditions of immune impairment, JCV causes an opportunistic brain disease, progressive multifocal leukoencephalopathy (PML). JCV strains found in the cerebrospinal fluid of PML patients contain distinctive mutations in surface loops of the major capsid protein, VP1. We hypothesized that VP1 mutations might allow the virus to evade antibody-mediated neutralization. Consistent with this hypothesis, neutralization serology revealed that plasma samples from PML patients neutralized wild-type JCV strains but failed to neutralize patient-cognate PML-mutant JCV strains. This contrasted with serological results for healthy individuals, most of whom robustly cross-neutralized all tested JCV variants. Mice administered a JCV virus-like particle (VLP) vaccine initially showed neutralizing "blind spots" (akin to those observed in PML patients) that closed after booster immunization. A PML patient administered an experimental JCV VLP vaccine likewise showed markedly increased neutralizing titer against her cognate PML-mutant JCV. The results indicate that deficient humoral immunity is a common aspect of PML pathogenesis and that vaccination may overcome this humoral deficiency. Thus, vaccination with JCV VLPs might prevent the development of PML.

Stability of JC virus DNA in cerebrospinal fluid specimens preserved with guanidine lysis buffer for quantitative PCR testing

Quantitative PCR testing for JC virus (JCV) DNA in the cerebrospinal fluid (CSF) is one of the diagnostic standards for progressive multifocal leukoencephalopathy (PML). The present study was conducted to examine its reliability using CSF specimens that had been preserved with guanidine lysis buffers in commercial nucleic acid extraction kits under different conditions. When CSFs were mixed with guanidine buffers, JCV DNA levels were not statistically reduced even after storage for 1 month at room temperature or for 3 months at -80℃, compared with the control samples. In addition, the JCV DNA level was not decreased in a mixture of CSF and guanidine thiocyanate buffer incubated for 3 days at 56℃. These data suggest that CSF specimens mixed with commercial guanidine buffers can be stored without refrigeration, more safely handled, and directly subjected to JCV DNA testing for PML.

JC Virus PCR Detection Is Not Infallible: A Fulminant Case of Progressive Multifocal Leukoencephalopathy with False-Negative Cerebrospinal Fluid Studies despite Progressive Clinical Course and Radiological Findings

We describe a case with a false-negative PCR-based analysis for JC virus in cerebrospinal fluid (CSF) in a patient with clinical and radiological findings suggestive of progressive multifocal leukoencephalopathy (PML) who was on chronic immunosuppressive therapy for rheumatoid arthritis. Our patient developed rapidly progressive global decline with clinical and radiographic findings suggestive of PML, but JC virus PCR in CSF was negative. The patient passed away 3 months from the onset of her neurological symptoms. Autopsy confirmed the diagnosis of PML with presence of JC-polyoma virus by immunohistochemical staining. This case highlights the potential of false-negative JC virus PCR in CSF when radiographic and clinical features are suggestive of “possible PML.” We review the plausible causes of potential false-negative CSF results and suggest that when the clinical presentation is suspicious for PML repeat CSF analysis utilizing ultrasensitive PCR assay and subsequent brain biopsy should be considered if CSF remains negative. Additionally, appropriate exclusion of other neurologic conditions is essential.

Significance of Epstein-Barr virus (HHV-4) and CMV (HHV-5) infection among subtype-C human immunodeficiency virus-infected individuals

PURPOSE

Opportunistic viral infections are one of the major causes of morbidity and mortality in HIV infection and their molecular detection in the whole blood could be a useful diagnostic tool.

OBJECTIVE

The frequency of opportunistic DNA virus infections among HIV-1-infected individuals using multiplex real-time PCR assays was studied.

MATERIALS AND METHODS

The subjects were in two groups; group 1: Having CD4 counts<100 cells/µl (n=118) and the group 2: counts>350 cells/µl (n=173). Individuals were classified by WHO clinical staging system. Samples from 70 healthy individuals were tested as controls. In-house qualitative multiplex real-time PCR was standardised and whole blood samples from 291 were tested, followed by quantitative real-time PCR for positives. In a proportion of samples genotypes of Epstein-Barr virus (EBV) and CMV were determined.

RESULTS

The two major viral infections observed were EBV and CMV. The univariate analysis of CMV load showed significant association with cryptococcal meningitis, oral hairy leukoplakia (OHL), CMV retinitis, CD4 counts and WHO staging (P<0.05) while the multivariate analysis showed an association with OHL (P=0.02) and WHO staging (P=0.05). Univariate analysis showed an association of EBV load with CD4 counts and WHO staging (P<0.05) and multivariate analysis had association only with CD4 counts. The CMV load was significantly associated with elevated SGPT and SGOT level (P<0.05) while the EBV had only with SGOT.

CONCLUSION

This study showed an association of EBV and CMV load with CD4+ T cell counts, WHO staging and elevated liver enzymes. These viral infections can accelerate HIV disease and multiplex real-time PCR can be used for the early detection. Genotype 1 and 2 of EBV and genotype gB1 and gB2 of CMV were the prevalent in the HIV-1 subtype C-infected south Indians.

JC virus quasispecies analysis reveals a complex viral population underlying progressive multifocal leukoencephalopathy and supports viral dissemination via the hematogenous route

Opportunistic infection of oligodendrocytes by human JC polyomavirus may result in the development of progressive multifocal encephalopathy in immunocompromised individuals. Neurotropic JC virus generally harbors reorganized noncoding control region (NCCR) DNA interspersed on the viral genome between early and late coding genes. By applying 454 sequencing on NCCR DNA amplified from body fluid samples (urine, plasma, and cerebrospinal fluid [CSF]) from 19 progressive multifocal leukoencephalopathy (PML) patients, we attempted to reveal the composition of the JC polyomavirus population (the quasispecies, i.e., the whole of the consensus population and minor viral variants) contained in different body compartments and to better understand intrapatient viral dissemination. Our data demonstrate that in the CSF of PML patients, the JC viral population is often a complex mixture composed of multiple viral variants that contribute to the quasispecies. In contrast, urinary JC virus highly resembled the archetype virus, and urine most often did not contain minor viral variants. It also appeared that archetype JC virus could sporadically be identified in PML patient brain, although selection of rearranged JC virus DNA was favored. Comparison of the quasispecies from different body compartments within a given patient suggested a strong correlation between the viral population in plasma and CSF, whereas the viral population shed in urine appeared to be unrelated. In conclusion, it is shown that the representation of viral DNA in the CSF following the high-level DNA replication in the brain underlying PML has hitherto been much underestimated. Our data also underscore that the hematogenous route might play a pivotal role in viral dissemination from or toward the brain.

IMPORTANCE

For the first time, the JC polyomavirus population contained in different body compartments of patients diagnosed with progressive multifocal encephalopathy has been studied by deep sequencing. Two main findings came out of this work. First, it became apparent that the complexity of the viral population associated with PML has been highly underestimated so far, suggestive of a highly dynamic process of reorganization of the noncoding control region of JC polyomavirus in vivo, mainly in CSF and blood. Second, evidence showing viral dissemination from and/or toward the brain via the hematogenous route was provided, confirming a hypothesis that was recently put forward in the field.

Progressive multifocal leukoencephalopathy in patients with a hematological malignancy: review of therapeutic options

In the context of 2 patients with hematological malignancy who developed progressive multifocal leukoencephalopathy (PML), we review the current therapeutic options for this serious complication. Both patients had lymphoma and had been pretreated with the antibody rituximab. Diagnosis of PML was obtained upon the detection of the JC virus. The outcome was fatal in both cases. So far, no standard therapeutic approach for JC virus infection has been established in HIV-negative patients with hematological malignancies and the outcome is usually fatal. Serotonin receptor antagonists might have a beneficial effect by blocking the virus from entering the cells. Although hopes for the efficacy of mefloquine were disappointed by the results of 1 study, several case reports describe improvements in neurological impairment when this drug is administered. Taking the desperate situation of this patient group into consideration, the combination of mirtazapine and mefloquine might be worthy of an attempt.

Holmes tremor in a patient with progressive multifocal leukoencephalopathy

Background:

Progressive multifocal leukencephalopathy (PML) is a rare, sometimes fatal viral disease in patients with primary or secondary immunosuppression.

Case Description:

A 57-year-old immunocompetent female with intractable Holmes tremor and elongated unique brainstem lesion reported to our hospital. The cerebrospinal fluid (CSF) screening for John Cunningham virus was negative and the diagnosis was established by brain biopsy. The course was rapidly fatal.

Conclusion:

This atypical presentation of PML in an immunocompetent patient illustrates that diagnosis can be missed without brain biopsy.

A fatal case of JC virus meningitis presenting with hydrocephalus in a human immunodeficiency virus-seronegative patient

JC virus (JCV) is the etiologic agent of progressive multifocal leukoencephalopathy, JCV granule cell neuronopathy, and JCV encephalopathy. Whether JCV can also cause meningitis has not yet been demonstrated. We report a case of aseptic meningitis resulting in symptomatic hydrocephalus in a human immunodeficiency virus-seronegative patient. Brain imaging showed enlargement of ventricles but no parenchymal lesion. She had a very high JC viral load in the cerebrospinal fluid (CSF) and developed progressive cognitive dysfunction despite ventricular drainage. She was diagnosed with pancytopenia and passed away after 5.5 months. Postmortem examination revealed productive JCV infection of leptomeningeal and choroid plexus cells, and limited parenchymal involvement. Sequencing of JCV CSF strain showed an archetype-like regulatory region. Further studies of the role of JCV in aseptic meningitis and in idiopathic hydrocephalus are warranted.

Progressive multifocal leukoencephalopathy in pediatric patients: case report and literature review

Progressive multifocal leukoencephalopathy is a rare, demyelinating disease of the central nervous system caused by JC virus. Fewer than 30 cases have been reported in HIV- and non-infected children. We report the case of a 15-year-old girl with progressive multifocal leukoencephalopathy and AIDS who presented with nystagmus, dysarthria and ataxia. Following combined antiretroviral therapy, she developed immune reconstitution inflammatory syndrome, which proved fatal.

Central nervous system infections in cancer patients and hematopoietic stem cell transplant recipients

Central nervous system (CNS) infections in cancer patients present a diagnostic and therapeutic challenge for clinicians. While CNS infections are not frequent complications of cancer, its therapies, or hematopoietic stem cell transplantation, the importance of CNS infections lies in their propensity to result in profound morbidity and substantial mortality in this vulnerable patient population. With an expanding population of patients with malignant disease undergoing more potent and aggressive therapies and with the advent of newer immunomodulatory agents, the incidence of CNS infectious complications is likely to rise. This chapter will summarize the clinical and diagnostic evaluation of potential infections of the CNS in these patients and will discuss particular pathogens of interest with regard to this at-risk patient population.

Neurologic diseases in HIV-infected patients

Since the introduction of highly active antiretroviral therapy there has been an improvement in the quality of life for people with HIV infection. Despite the progress made, about 70% of HIV patients develop neurologic complications. These originate either in the central or the peripheral nervous system (Sacktor, 2002). These neurologic disorders are divided into primary and secondary disorders. The primary disorders result from the direct effects of the virus and include HIV-associated neurocognitive disorder (HAND), HIV-associated vacuolar myelopathy (VM), and distal symmetric polyneuropathy (DSP). Secondary disorders result from marked immunosuppression and include opportunistic infections and primary central nervous system lymphoma (PCNSL). A differential diagnosis which can be accomplished by detailed history, neurologic examination, and by having a good understanding of the role of HIV in various neurologic disorders will help physicians in approaching these problems. The focus of this chapter is to discuss neuropathogenesis of HIV, the various opportunistic infections, primary CNS lymphoma, neurosyphilis, CNS tuberculosis, HIV-associated peripheral neuropathies, HIV-associated neurocognitive disorder (HAND), and vacuolar myelopathy (VM). It also relies on the treatment recommendations and guidelines for the above mentioned neurologic disorders proposed by the US Centers for Disease Control and Prevention (CDC) and the Infectious Diseases Society of America.

Continued declining incidence and improved survival of progressive multifocal leukoencephalopathy in HIV/AIDS patients in the current era

To evaluate the situation and perspectives of progressive multifocal leukoencephalopathy (PML) in human immunodeficiency virus (HIV)-infected patients, we investigated changes in the incidence, causes, and long-term outcome of this disease in 72 acquired immunodeficiency syndrome (AIDS) patients who were diagnosed with PML from 1996 to 2011. Patients were classified according to the date of diagnosis in the first (1996-2000, n = 35), second (2001-2006, n = 26), and recent or third highly active antiretroviral therapy (HAART) period (2007-2011, n = 11). Overall, the incidence of PML decreased from 14.8 cases/1,000 patients/year in 1996 to 2.6 in 2005 and 0.8 in 2011, and nearly two-thirds of recent cases (64 %) were observed in HIV patients not attending clinical visits. The baseline median CD4+ count was higher in recently PML-diagnosed patients (77 vs. 86 vs. 101 cells/mm(3); p < 0.01), and this fact was associated with a cerebrospinal fluid (CSF) inflammatory profile (from 11 to 31 to 55 %, p = 0.007) and with a significantly longer survival (attributable death, 54 vs. 35 vs. 36 %, respectively, p < 0.01). Thus, the overall 1-year and 3-year survival rates were 55 and 50 %, respectively, increasing to 79 % at 1 year for patients with CD4+ count above 100 cells/mm(3) at diagnosis. In a Cox regression analysis, an older age (hazard ratio, HR 0.76), a baseline CD4+ count above 100 cells/mm(3) (HR 0.33), and a CSF inflammatory profile (HR 0.12) were significantly associated with a longer survival. The clinical presentation and outcome of PML in AIDS patients continue to change dramatically. Now, a declining incidence and long-term survival is observed.

The human JC polyomavirus (JCPyV): virological background and clinical implications

JC polyomavirus (JCPyV) was the first of now 12 PyVs detected in humans, when in 1964, PyV particles were revealed by electron microscopy in progressive multifocal leukoencephalopathy (PML) tissues. JCPyV infection is common in 35-70% of the general population, and the virus thereafter persists in the renourinary tract. One third of healthy adults asymptomatically shed JCPyV at approximately 50,000 copies/mL urine. PML is rare having an incidence of <0.3 per 100,000 person years in the general population. This increased to 2.4 per 1000 person years in HIV-AIDS patients without combination antiretroviral therapy (cART). Recently, PML emerged in multiple sclerosis patients treated with natalizumab to 2.13 cases per 1000 patients. Natalizumab blocks α4-integrin-dependent lymphocyte homing to the brain suggesting that not the overall cellular immunodeficiency but local failure of brain immune surveillance is a pivotal factor for PML. Recovering JCPyV-specific immune control, e.g., by starting cART or discontinuing natalizumab, significantly improves PML survival, but is challenged by the immune reconstitution inflammatory syndrome. Important steps of PML pathogenesis are undefined, and antiviral therapies are lacking. New clues might come from molecular and functional profiling of JCPyV and PML pathology and comparison with other replicative pathologies such as granule cell neuronopathy and (meningo-)encephalitis, and non-replicative JCPyV pathology possibly contributing to some malignancies. Given the increasing number of immunologically vulnerable patients, a critical reappraisal of JCPyV infection, replication and disease seems warranted.

A study of mefloquine treatment for progressive multifocal leukoencephalopathy: results and exploration of predictors of PML outcomes

Immune reconstitution has improved outcomes for progressive multifocal leukoencephalopathy (PML), a potentially lethal brain disease caused by JC virus (JCV). However, an antiviral treatment to control JCV is needed when immune reconstitution is delayed or not possible. On the basis of in vitro efficacy, this study evaluated the effect of mefloquine on PML and factors that may predict PML outcomes. This 38-week, open-label, randomized, parallel-group, proof-of-concept study compared patients with PML who received standard of care (SOC) with those who received SOC plus mefloquine (250 mg for 3 days, then 250 mg weekly). Patients randomized to SOC could add mefloquine treatment at week 4. The primary endpoint was change from baseline to weeks 4 and 8 in JCV DNA copy number (load) in cerebrospinal fluid (CSF). Exploratory analyses evaluated factors that might correlate with clinical outcome. The majority of enrolled patients were HIV positive. Preplanned interim data analyses suggested that the study was unlikely to successfully demonstrate a significant difference between groups; therefore, the study was terminated prematurely. There was no significant difference between groups in CSF JCV DNA loads or clinical/MRI findings. Decrease in CSF JCV DNA load from baseline to week 4 was associated with a better clinical outcome at 16 weeks, as measured by Karnofsky scores. This study found no evidence of anti-JCV activity by mefloquine. An early decrease of CSF JCV DNA load appears to be associated with a better clinical outcome.