Detection Of JCV DNA Research Articles

Absence of JC polyomavirus in stool samples of patients with multiple sclerosis despite high anti-JCV antibodies in serum

BackgroundNatalizumab is an effective treatment for relapsing multiple sclerosis (MS). During therapy, individuals are at increased risk of developing progressive multifocal leukoencephalopathy (PML). So far, the relevant reservoir for PML-type JC polyomavirus (JCV) remains elusive. We here tested if the detection of JCV-DNA in stool of persons with MS treated with natalizumab could be a future tool for PML risk assessment. MethodsThe presence of JCV-DNA in stool, urine, and whole blood of MS patients treated with natalizumab and known serum anti-JCV antibodies index values (IV) was studied. Different DNA extraction methods, real-time (RT) and droplet digital (dd) PCR techniques were compared. JCV isolates were screened for PML-associated variants by sequencing. ResultsThirty MS patients treated with natalizumab were screened. For 21 patients, blood, stool, and urine samples were available. These patients were stratified according to their serum anti-JCV antibody IV (high (>1.5, n = 12); medium (1.5–0.9, n = 2); low (<0.9, n = 1); negative (n = 6)). JCV-DNA could not be detected in the whole blood or stool samples. Four urine samples had measurable JCV-DNA, ranging from 1.71×104–1.07×108 international units (IU)/mL detected by RT-PCR, corresponding to 4.62×104–9.85×106 copies/mL measured by ddPCR. All JCV variants were wild-type and derived from patients with high antibody IV. ConclusionStool-specific DNA extraction methods provided the highest quality of DNA, while the sensitivity of ddPCR and RT- PCR was comparable. Our findings do not support assessing stool samples for PML risk stratification in persons with MS. Further studies are needed to explore where PML-associated viral variants arise.

Serum Neurofilaments are a reliable biomarker to early detect PML in Multiple Sclerosis patients.

The earliest detection of progressive multifocal leukoencephalopathy (PML) is crucial in Natalizumab (NTZ)-treated Multiple Sclerosis (MS) patients. This study aims to assess serum Neurofilaments (sNFL) ability to early detect PML in longitudinal patients' follow-up. NFL were retrospectively measured in four PML cases occurred at the Regional Referring Center for MS (CRESM, Italy), in samples collected since one year before PML diagnosis, at PML diagnosis, during PML and in post-PML follow-up. sNFL levels were interpreted according to previously defined reference values. Clinical examination and EDSS were performed at each NTZ infusion. Routinary MRI was undertaken every six months; after PML diagnosis, MRI was performed according to clinical evaluation. sNFL were also measured in 45 NTZ-treated patients experiencing NEDA-3 status for at least 12 months. Patients showed different PML onsets and manifestations: in 3 patients routinary brain MRI revealed radiological signs of PML preceding different clinical manifestations, while in one patient brain MRI was performed after the clinical onset. PML diagnosis was defined at the time of the first detection of JCV DNA in cerebrospinal fluid. The following different PML phases were considered: 1. Basal (up to 4 months before PML diagnosis): sNFL values were in the normal range in all patients' samples, except for one (median 9.1 pg/ml, range 6.2-15.1 pg/ml) 2. Pre-PML (within 3 months before PML diagnosis): sNFL were elevated in all available samples (median 19.50 pg/ml, range 15.50-33.80 pg/ml). 3. PML diagnosis: sNFL were elevated in all patients (median 59.20 pg/ml, range 11.1-101.50 pg/ml). 4. PML/IRIS: during this phase, sNFL levels reached their peak (median 96.35 pg/ml, range 20.5-272.9) in all patients. 5. Post-PML (recovery phase, starting from the first MRI without enhancement, up to the end of follow-up): sNFL levels showed a decrease (median 12.80 pg/ml, range 9.30-30.60); however, based on reference values, sNFL were still elevated in 2 out of 4 patients at the end of their follow-up (622 and 887 days after PML diagnosis). sNFL were always elevated when MRI scan suggested a suspicious of PML. In NEDA-3 patients, sNFL levels were in the normal range in all patients' samples (median 4.7 pg/ml, range 1.4-8.6 pg/ml). Elevated sNFL were observed not only at PML diagnosis, but also in pre-PML phase. At PML recovery, sNFL weren't normalized in all patients' samples, suggesting ongoing neuronal degeneration. sNFL represent a reliable biomarker and should be introduced in clinical practice as an additional/alternative parameter to MRI to early detect and monitor PML.

Prevalence of Human Polyomavirus JC and BK in Normal Population.

JC virus (JCV) , and BK virus (BKV) can remain latency in kidney and excrete via urine asymptomatically. JCV has been associated with colorectal and bladder cancers. BKV has been linked with lung, pancreas, liver, urogenital tract, head and neck cancers. Therefore, the frequency of JCV DNA and BKV DNA are essential to evaluate in urine samples of healthy individuals. Materials and Methods:Hundred sixty four urine samples were collected from healthy subjects [96 females and 68 males]. DNA was extracted and detection of JCV DNA and BKV DNA was carried out by PCR . The analysis of sequencing and construction of phylogenetic tree were performed for the samples positive for JCV DNA and BKV DNA. Results:Ten (6.09%) urine samples [5/96(5.2%) females and 5/68( 8.82) males] were tested positive for JCV DNA (P= 0.814). The results of sequencing and phylogenetic tree showed the isolated JCV DNA were cluster with 3A genotype. 21/164 (12.8%) samples were tested positive for BKV DNA [11/96(11.45%) females and males 10/68(14.7%)] ( P= 0.63). The results of sequencing and phylogenetic tree showed that the isolated BKV was cluster with genotype III. Conclusion:In the present study 6.09% and 12.8% of the healthy individuals showed positive for JCV DNA (genotype 3A) and BKV DNA(genotype III) respectively. With regard to life threating diseases by BKV and JCV in immunocomprsied patients , the screening BKV DNA and JCV DNA should be implemented for patients with cancer /autoimmune diseases /organ recipient/ multiple sclerosis (MS), prior to immunosuppression therapy or immunomodulatory agents treatment.

Four cases of progressive multifocal leukoencephalopathy in iatrogenic immunocompromised patients

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) caused by John Cunningham Virus (JCV). We report four PML cases in immunocompromised patients, respectively treated with (1) Natalizumab, (2) Rituximab, (3) autologous stem-cell transplantation, and (4) Tacrolimus. All patients underwent neurological examination, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), JCV-DNA research on biological samples, and lymphocytes subpopulation study. All cases presented with motor, behavioural, and cognitive disorders. Visual, sensitive, and cerebellar deficits developed in three cases. MRI revealed widespread progressive demyelinating areas with active borders; three patients presented contrast enhancement. One patient developed inflammatory reconstitution syndrome (IRIS). At MRS, all cases presented decreased N-acetyl-aspartate (NAA) and three cases showed increased choline (Cho). In one patient, plasma and urine tested positive for JCV-DNA, while cerebrospinal fluid (CSF) analysis confirmed JCV in two patients. The fourth patient had a low JCV-DNA blood titer and brain biopsy showed subacute necrosis. Two patients had abnormal lymphocyte subpopulations. Three patients underwent therapy with Mirtazapine, one of whom received Mefloquine in add-on. No clinical response was registered. Clinical onset, MRI and MRS were highly suggestive of PML in all patients, despite three cases presented contrast enhancement. In three cases JCV-DNA detection in biological samples confirmed the diagnosis. The fourth patient fulfilled diagnosis of “presumptive PML”. Our data confirm the importance to complete the diagnostic workup despite the presence of findings not completely consistent with classical PML. We hypothesize that atypical characteristics could due to the clinical conditions leading to PML.

Dynamic changes of MMP-9 plasma levels correlate with JCV reactivation and immune activation in natalizumab-treated multiple sclerosis patients

The aim of the study was to investigate the changes of matrix metalloproteinase (MMP)-2 and MMP-9 plasma levels during natalizumab treatment and their correlation with JC virus (JCV) reactivation and T-lymphocyte phenotypic modifications in peripheral blood samples from 34 relapsing-remitting multiple sclerosis (RRMS) patients. MMP-9 levels were assessed by zymography in plasma samples. JCV-DNA was detected through quantitative real time PCR in plasma samples. T-lymphocyte phenotype was assessed with flow cytometry. MMP-9 plasma levels resulted increased from 12 to 24 natalizumab infusions. Stratifying plasma samples according to JCV-DNA detection, MMP-9 plasma levels were significantly increased in JCV-DNA positive than JCV-DNA negative samples. MMP-9 plasma levels resulted positively correlated with JCV viral load. CD4 immune senescence, CD8 immune activation and CD8 effector percentages were positively correlated to MMP-9 plasma levels, whereas a negative correlation between CD8 naïve percentages and MMP-9 plasma levels was found. Our data indicate an increase of MMP-9 plasma levels between 12 and 24 natalizumab infusions and a correlation with JCV-DNA detection in plasma, T-lymphocyte immune activation and senescence. These findings could contribute to understand PML pathogenesis under natalizumab treatment, suggesting a potential role of MMP-9 as a predictive marker of PML in RRMS patients.

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

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. 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. 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). 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.

Good outcome of brain stem progressive multifocal leukoencephalopathy in an immunosuppressed renal transplant patient: Importance of early detection and rapid immune reconstitution

Progressive multifocal leukoencephalopathy (PML) is a rare, opportunistic and often fatal disease of the CNS which may occur under immunosuppression in transplant patients. Brain stem PML is associated with a particularly bad prognosis. Here, we present a case of a renal transplant patient treated with mycophenolate mofetil (MMF) and tacrolimus who developed brain stem PML with limb ataxia, dysarthria and dysphagia. Diagnosis was established by typical MRI features and detection of JCV-DNA in the CSF. Immune reconstitution after stopping MMF and tacrolimus led to a complete and sustained remission of symptoms with improvement of the brain stem lesion over a follow-up over 20months.In summary, early detection of PML and consequent treatment may improve neurological outcomes even in brain stem disease with a notorious bad prognosis.

Unusual natalizumab-associated progressive multifocal leukoencephalopathy starting in the brainstem

we report on a 45-year-old German patient with relapsingremitting (RR) multiple sclerosis (MS) who was started on natalizumab (NAT) therapy in November 2007, because of ongoing disease activity despite interferon therapy. She had never been treated with immunosuppressants before. After she tested positive for anti-JCV (John Cunningham Virus)antibodies for the first time, she decided to discontinue NAT treatment in July 2011 (after 49 NAT infusions). At this time point, as well as during NAT therapy, she was clinically stable (EDSS 3.5). Six weeks later in August 2011, she developed new brainstem symptoms, with left facial and trigeminal nerve palsy, double vision and mild dysphagia. On magnetic resonance imaging (MRI), a large brainstem-midbrain lesion was seen (Fig. 1D). The symptoms were initially interpreted as MS relapse and treated with corticosteroids. After transient improvement, she deteriorated again and was seen for the first time at our hospital. Progressive multifocal leukoencephalopathy (PML) was diagnosed in September 2011 after detection of JCV DNA (31 c/ml in CSF, 5 c/ml in serum; EDSS 7.0). Subsequently, she developed severe immune reconstitution inflammatory syndrome (IRIS), deteriorated clinically (EDSS 9.5), and had to be transferred to the intensive care unit (ICU) for several weeks. Finally, she stabilized after repeated courses of high-dose iv glucocorticosteroids (GC) and iv immunoglobulins (IVIgG, 5 days a 0.4 g/kg body weight), as well as concomitant therapy with mefloquine and mirtazapine. Six months later, she had improved, but still showed severe ataxia and brainstem symptoms (EDSS 6.0). Retrospective analysis of all available MRI scans identified a small new-initially asymptomatic-T2 brainstem lesion as the first MRI manifestation of this patient’s PML in November 2010, which slowly progressed over 41 weeks until clinical PML presentation (Fig. 1A–D). Several aspects in this report are unusual: (1) brainstem PML is rare and has been reported in association with NAT therapy in MS patients only once so far [1]; (2) the longlasting pre-symptomatic phase of 41 weeks and clinical manifestation of PML only 6 weeks after NAT was discontinued; and (3) clinical improvement after combined therapy with GC and IVIgG. In this patient, a new, asymptomatic, non-contrast-enhancing T2 lesion appeared in the brainstem in November 2010 (Fig. 1B). Notably, before the MRI lesion was rated as important, the patient decided to stop NAT therapy in July 2011 due to fear of PML. At this time and during NAT treatment, the lesion was completely asymptomatic. The patient developed new brainstem symptoms only 6 weeks after discontinuation of NAT and showed a large brainstem-midbrain lesion on MRI at that time. Detailed retrospective MRI analysis identified that this large lesion had progressed over time from the small brainstem lesion 41 weeks before. NATassociated PML with a pre-symptomatic course up to 24 weeks has been reported, but not in the brainstem so far [2]. More recently, Yousry and colleagues [3] identified common MRI patterns of NAT-associated PML, which help in the early diagnosis of PML. Except for the unusual initial localization in the brainstem and size (\ 3 cm), all J. Havla (&) R. Hohlfeld T. Kumpfel Institute of Clinical Neuroimmunology, Ludwig-Maximilians-University, Medical Campus Grosshadern, Marchioninistr. 15, 81377 Munich, Germany e-mail: joachim.havla@med.lmu.de

Multiplex qPCR assay for ultra sensitive detection of JCV DNA with simultaneous identification of genotypes that discriminates non-virulent from virulent variants

BackgroundJC virus (JCV) is the etiologic agent for progressive multifocal leukoencephalopathy (PML), a demyelinating disease occurring in the brain of patients with underlying immune compromised states. All viable JCV genomes contain a conserved region in the T protein coding nucleotide sequence that when detected by PCR in CSF is a confirmatory diagnostic marker for PML along with clinical and neuroradiological evidence. The non-coding regulatory region (NCRR) is hypervariable, as evidenced by nucleotide sequence of the non-virulent variant, which is predominantly excreted in urine, versus that of virulent variants found in brain and CSF of PML patients. All variants can be found in blood. ObjectiveA single assay that quantifies and identifies JCV DNA in clinical samples and discriminates between variants has significant value to physicians and patients at risk for PML. Study designSeparate primer pairs were tested together to quantitatively detect conserved viral DNA nucleotide sequence in patient samples, while simultaneously detecting the NCRR specific for the non-virulent variant. ResultsIn testing using control plasmids and patients’ CSF, blood, and urine, PML patients predictably demonstrated the non-virulent, archetype NCRR in urine, but virulent NCRR variants in CSF and blood. ConclusionThe JCV qPCR multiplex assay targets two regions in JCV genomes to simultaneously identify and measure viral DNA, as well as distinguish between variants associated with PML and those that are not. The multiplex results could signal risk for PML if patients are viremic with JCV variants closely associated with PML pathogenesis.

Reactivation of human polyomavirus JC in patients affected by psoriasis vulgaris and psoriatic arthritis and treated with biological drugs: Preliminary results

Psoriasis vulgaris (PsV) and psoriatic arthritis (PSA) are inter-related heritable inflammatory skin diseases. Psoriatic lesions develop as a result of abnormal immune responses, hyperproliferation and altered differentiation of keratinocytes, and a notable subset of psoriatic patients develops PsA, characterized by joints inflammation. Recently, biological drugs were introduced to treat these diseases. However, this therapy has already been associated with the development of serious life-threatening infections, such as the reactivation of human polyomavirus JC (JCV), responsible for the progressive multifocal leukoencephalopathy (PML), a lethal demyelinating disease caused by oligodendrocytes lytic infection. Therefore, the aims of our study were the investigation of the possible JCV reactivation in PsV and PsA patients treated with adalimumab, etanercept, and methotrexate, performing quantitative real-time PCR in sera and skin biopsies at the time of recruitment (T0) and after 3 (T3) and 6 (T6) months of treatment, and the sequencing analysis of the JCV non-coding control region (NCCR). We found JCV DNA in 5/15 PsV patients and in 2/15 PsA patients and JCV NCCR sequence analysis always showed a structure similar to non-pathogenic CY archetype, with random occurrence of a few irrelevant point mutations. Nevertheless the poor number of patients analyzed, our preliminary data can pave the way for taking into account that the follow-up of JCV DNA detection and the JCV NCCR sequence analysis in psoriatic patients may be important to evaluate the risk of PML onset, considering that patients affected by autoimmune diseases and treated with biologics continue to rise.

Identification of Polyomavirus JC Genome Sequences in Two HIV-Associated PML Cases in Bulgaria

ABSTRACTActive replication of the Polyomavirus hominis 2 (JCV) in glial cells leads to the fatal, demyelinating disease of the central nervous system, called progressive multifocal leukoencephalopathy (PML). Although more than 80% of the population is infected a significant impairment of the immune system is needed for reactivation of the latent virus. Such reactivation can be verified by a Polymerase Chain Reaction (PCR) test for detection of JCV DNA in brain tissue or cerebrospinal fluid (CSF). Here we report and discuss two cases of Bulgarian HIV-infected patients where identification of JCV supported and confirmed the diagnosis of HIV-associated PML.

Presence, quantitation and characterization of JC virus in the urine of Italian immunocompetent subjects

Human polyomavirus JC (JCV) infects the worldwide population, remains latent in the kidney, and is excreted in the urine. A longitudinal study was performed in order to evaluate JCV excretion, to characterize molecularly the virus and to determine if its presence in urine is a consequence of viral reactivation or merely of epithelial squamous cell shedding. The presence of cellular sediment and the JCV genome were examined in 333 urine samples collected periodically for 3 months from 17 healthy subjects; molecular characterization, and quantitation of the virus were also undertaken. JCV DNA was detected in 40.2% of the samples, with a significant difference (P<0.001) observed between males and females. JCV shedding was independent of the presence of cellular sediment in every individual. JCV genotype 1 was the genome detected most frequently, while all of the amplified strains showed archetypal organization of the transcriptional control region (TCR). No clinical symptoms have been associated with JCV excretion and no microbial load was detected in the urine samples. The lack of correlation between JCV DNA detection and the presence of squamous cells in urine sediment indicates that viruria is regulated by the life cycle of JCV. Thus, the virus is eliminated as consequence of its reactivation.

Frequency and Phenotype of JC Virus-Specific CD8+T Lymphocytes in the Peripheral Blood of Patients with Progressive Multifocal Leukoencephalopathy

JC virus (JCV)-specific CD8+ cytotoxic T lymphocytes (CTL) are associated with a favorable outcome in patients with progressive multifocal leukoencephalopathy (PML) and cross-recognize the polyomavirus BK virus (BKV). We sought to determine the frequency and phenotype in fresh blood of CD8+ T cells specific for two A*0201-restricted JCV epitopes, VP1(p36) and VP1(p100), and assess their impact on JC and BK viremia and viruria in 15 healthy subjects, eight human immunodeficiency virus-positive (HIV+) individuals, and nine HIV+ patients with PML (HIV+ PML patients) classified as survivors. After magnetic pre-enrichment of CD8+ T cells, epitope-specific cells ranged from 0.001% to 0.022% [corrected] by tetramer staining, with no significant difference among the three study groups. By use of seven-color flow cytometry, there was no predominant differentiation phenotype subset among JCV-specific CD8+ T cells in healthy individuals, HIV+ subjects, or HIV+ PML patients. However, in one HIV+ PML patient studied in the acute phase, there was a majority of activated effector memory cells. BKV DNA was undetectable in all blood samples by quantitative PCR, while a low JC viral load was found in the blood of only one HIV+ and two HIV+ PML patients. JCV and BKV DNA were detected in 33.3% and 13.3% of all urine samples, respectively, independent of the presence of JCV-specific CTL. The detection of JCV DNA in the urine was associated with the presence of a JCV VP1(p100) CTL response. Immunotherapies aiming at increasing the cellular immune response against JCV may be valuable in the treatment of HIV+ individuals with PML.

Semiquantitative detection of JCV‐DNA in peripheral blood leukocytes from HIV‐1‐infected patients with or without progressive multifocal leukoencephalopathy

Progressive Multifocal Leukoencephalopathy (PML) is a severe and fatal demyelinating disease that occurs especially in HIV-infected patients. It has been suggested that JC virus (JCV) migrates in peripheral blood leukocytes from the kidney to the central nervous system where it initiates demyelination. To investigate the physiopathological role of the peripheral blood virus in the development of PML, the prevalence of JCV infection and the levels of JCV DNA load were evaluated in peripheral blood leukocytes or mononuclear cells of 10 AIDS patients at the time of onset of PML symptoms, and in 150 non-PML HIV-1-infected patients using a semiquantitative PCR and ELISA-hybridization assay. In PML-AIDS patients, 60% (6/10) were positive for JCV-DNA detection in peripheral blood cells compared with 26% (13/50) and 18% (18/100) positive for non-PML HIV-infected control patients with CD4+ T lymphocyte counts below and above 200.10(6) /l, respectively (60 vs. 26%, P = 0.06; 60 vs. 18%; P = 0.007). The prevalence of JCV infection in the peripheral blood cells taken from controls appeared to be independent of the CDC stage of infection and CD4+ T lymphocyte counts. The predictive positive value of a positive JCV DNA PCR in peripheral blood cells for the diagnosis of PML in an HIV-infected patient was 16% whereas the predictive negative value was 96%. The levels of circulating JCV DNA load, ranging from 1.69 to 2.53 log of copies per 10(6) cells, did not differ between patients at time of PML symptoms onset and controls, and appeared to be independent of the clinical and the biological status in control patients. The findings do not indicate any significant JCV genomic replication activity in peripheral blood cells at the onset of PML disease, and suggest that JCV replication markers in the systemic compartment would not be valuable for predicting the development of PML in AIDS patients.

Human polyomavirus JC latency and reactivation status in blood of HIV-1-positive immunocompromised patients with and without progressive multifocal leukoencephalopathy.

Human polyomavirus JC (JCV) induces human progressive multifocal leukoencephalopathy (PML) in patients with AIDS. Peripheral blood mononuclear cells (PBMC) of HIV-1-positive immunocompetent and immunocompromised patients can harbour JCV genome, but their precise role in JCV latency or reactivation status before the onset of PML remains hypothetical. To assess JCV latency or reactivation status in PBMC of HIV-1-positive immunocompromised patients without PML. A group of 82 HIV-1-positive immunocompromised patients who did not have PML were compared with 10 patients with AIDS and PML and with 69 HIV-1-positive immunocompetent patients without PML. DNA and total RNA were extracted from PBMC. The presence of JCV DNA was demonstrated by a semi-nested polymerase chain reaction (PCR). By using primer pairs specific for an early gene,T, and a late gene, VP1, the expression of both early and late gene mRNA in PBMC could be identified using reverse transcriptase (RT) PCR. JCV DNA was detected by PCR in 17.4% of 69 HIV-1-positive immunocompetent patients, in 23.2% of 82 HIV-1-positive immunocompromised patients, and in 60% of 10 patients with AIDS and PML. No correlation could be drawn between the detection of JCV DNA in the PBMC and the clinical or biological status of the HIV-1-positive patients. By using RT-PCR procedures, no expression of JCV early and late mRNA in PBMC was found in any patients. JCV DNA is detectable in the PBMC of 20.5% of 151 HIV-1-infected patients independently of the CDC (Centers for Disease Control and Prevention) stages of the infection. Moreover, our results suggest that active replication of JCV in PBMC appears to be absent or at least a very rare event in HIV-1-positive immunocompromised patients with and without PML.

Archetypal and rearranged sequences of human polyomavirus JC transcription control region in peripheral blood leukocytes and in cerebrospinal fluid.

Two forms of human polyomavirus JC (JCV) genome are known based upon the structure of the transcriptional control region (TCR) of the virus: the archetypal form, which is commonly detected in urine, and the rearranged form, which was first detected in brain tissue from progressive multifocal leukoencephalopathy (PML) patients. The latter actually includes a group of TCR variants that, relative to the former, are characterized by various deletions and/or duplications. The aim of this study was to establish whether or not a correlation exists among the TCR type, the spreading of the virus within the host and its ability to cause PML. JCV TCR sequences from peripheral blood leukocytes (PBL) and cerebrospinal fluid (CSF) obtained from various groups of patients were compared. JCV with archetypal TCR was detected in CSF and PBL specimens from patients without neurological disorders or who eventually received a diagnosis of a non-PML neurological disorder. Rearranged TCR sequences were detected in all the CSF and PBL specimens from PML patients. The high similarity observed between the TCR structure detected in PBL and CSF specimens from individual patients could strengthen the hypothesis that PBL has a role in spreading JCV to the brain. Moreover, heterogeneous TCR patterns have been shown in individual PBL specimens from PML patients. This supports the hypothesis that, in PBL, JCV may replicate and undergo rearrangements of the TCR. The detection of JCV DNA by PCR in CSF independently from PML, although rare, could suggest that this assay is not sufficient for a virological diagnosis of PML. Further studies are required to assess the usefulness of quantitative assays or TCR typing in combination with PCR for diagnostic purposes.

Detection of JC virus DNA in human tonsil tissue: evidence for site of initial viral infection.

Progressive multifocal leukoencephalopathy is a demyelinating disease of the human central nervous system that results from lytic infection of oligodendrocytes by the polyomavirus JC (JCV). Originally, JCV was thought to replicate exclusively in human glial cells, specifically oligodendrocytes. However, we have recently shown that JCV can replicate in cells of lymphoid origin such as hematopoietic precursor cells, B lymphocytes, and tonsillar stromal cells. To determine whether tonsils harbor JCV, we tested a total of 54 tonsils, 38 from children and 16 from adult donors. Nested PCRs with primer sets specific for the viral T protein and regulatory regions were used for the detection of JCV DNA. JCV DNA was detected in 21 of 54 tonsil tissues, or 39% (15 of 38 children and 6 of 16 adults) by using regulatory-region primers and in 19 of 54 tonsil tissues, or 35% (13 of 38 children and 6 of 16 adults) by using the T-protein primers. The DNA extracted from children's nondissected tonsil tissue, isolated tonsillar lymphocytes, and isolated stromal cells that demonstrated PCR amplification of the JCV regulatory region underwent cloning and nucleotide sequencing. Of the regulatory-region sequences obtained, nearly all contained tandem repeat arrangements. Clones originating from nondissected tonsil tissue and tonsillar lymphocytes were found to have sequences predominantly of the Mad-1 prototype strain, whereas the majority of clones from the DNA of tonsillar stromal cells had sequences characteristic of the Mad-8br strain of JCV. A few clones demonstrated structures other than tandem repeats but were isolated only from tonsillar lymphocytes. These data provide the first evidence of the JCV genome in tonsil tissue and suggest that tonsils may serve as an initial site of viral infection.

Nucleic acid detection as a diagnostic tool in polyomavirus JC induced progressive multifocal leukoencephalopathy

Procedures involved in the diagnosis of JC virus central nervous system infection range from detection of virus specific products in biopsy material to demonstration of viral DNA in cerebrospinal fluid by PCR. Despite the fact that PCR is the most sensitive method for the detection of virus in clinical specimens, diagnostic evaluation is increasingly difficult in view of the possible subclinical activation of persistent JCV infection in the central nervous system of high risk patients. Therefore, PML diagnosis by molecular detection of JCV DNA in biopsy material was compared with diagnosis by PCR on CSF of patients with and without PML. Evaluation of the diagnostic techniques revealed that stereotactic biopsy based PCR diagnosis at present combines speed and sensitivity with the highest specificity available. Although the non invasive technique of JCV detection in CSF by PCR is even more sensitive leading to detection of about 20 genome equivalents per 1 |gml of CSF, the specificity of the method is limited by subclinical presence of JCV DNA in CSF of neurologically asymptomatic HIV infected patients. Additionally, autopsy proven PML cases remaining JCV negative in PCR on CSF become a common finding. Therefore, in cases where biopsy is not performed, diagnosis of PML can only be achieved in combination with neurological and radiological diagnosis. J. Med. Virol. 54:196–203, 1998. © 1998 Wiley-Liss, Inc.

Nucleic acid detection as a diagnostic tool in polyomavirus JC induced progressive multifocal leukoencephalopathy

Procedures involved in the diagnosis of JC virus central nervous system infection range from detection of virus specific products in biopsy material to demonstration of viral DNA in cerebrospinal fluid by PCR. Despite the fact that PCR is the most sensitive method for the detection of virus in clinical specimens, diagnostic evaluation is increasingly difficult in view of the possible subclinical activation of persistent JCV infection in the central nervous system of high risk patients. Therefore, PML diagnosis by molecular detection of JCV DNA in biopsy material was compared with diagnosis by PCR on CSF of patients with and without PML. Evaluation of the diagnostic techniques revealed that stereotactic biopsy based PCR diagnosis at present combines speed and sensitivity with the highest specificity available. Although the non invasive technique of JCV detection in CSF by PCR is even more sensitive leading to detection of about 20 genome equivalents per 1 microl of CSF, the specificity of the method is limited by subclinical presence of JCV DNA in CSF of neurologically asymptomatic HIV infected patients. Additionally, autopsy proven PML cases remaining JCV negative in PCR on CSF become a common finding. Therefore, in cases where biopsy is not performed, diagnosis of PML can only be achieved in combination with neurological and radiological diagnosis.