JC Virus-DNA Detection Is Associated with CD8 Effector Accumulation in Peripheral Blood of Patients with Multiple Sclerosis under Natalizumab Treatment, Independently from JC Virus Serostatus.

Although natalizumab (anti-α4 integrin) represents an effective therapy for relapsing remitting multiple sclerosis (RRMS), it is associated with an increased risk of developing progressive multifocal leukoencephalopathy (PML), caused by the polyomavirus JC (JCV). The aim of this study was to explore natalizumab-induced phenotypic changes in peripheral blood T-lymphocytes and their relationship with JCV reactivation. Forty-four patients affected by RRMS were enrolled. Blood and urine samples were classified according to natalizumab infusion number: 0 (N0), 1-12 (N12), 13-24 (N24), 25-36 (N36), and over 36 (N > 36) infusions. JCV-DNA was detected in plasma and urine. T-lymphocyte phenotype was evaluated with flow cytometry. JCV serostatus was assessed. Ten healthy donors (HD), whose ages and sexes matched with the RRMS patients of the N0 group, were enrolled. CD8 effector (CD8 E) percentages were increased in natalizumab treated patients with detectable JCV-DNA in plasma or urine compared to JCV-DNA negative patients (JCV-) (p < 0.01 and p < 0.001, resp.). Patients with CD8 E percentages above 10.4% tended to show detectable JCV-DNA in plasma and/or urine (ROC curve p = 0.001). The CD8 E was increased when JCV-DNA was detectable in plasma or urine, independently from JCV serology, for N12 and N24 groups (p < 0.01). As long as PML can affect RRMS patients under natalizumab treatment with a negative JCV serology, the assessment of CD8 E could help in the evaluation of JCV reactivation.

Efficient propagation of archetype JC polyomavirus in COS-7 cells: evaluation of rearrangements within the NCCR structural organization after transfection.

John Cunningham virus (JCPyV) is an ubiquitous human pathogen that causes disease in immunocompromised patients. The JCPyV genome is composed of an early region and a late region, which are physically separated by the non-coding control region (NCCR). The DNA sequence of the NCCR distinguishes two forms of JCPyV, the designated archetype and the prototype, which resulted from a rearrangement of the archetype sequence. To date, the cell culture systems for propagating JCPyV archetype have been very limited in their availability and robustness. Prior to this study, it was demonstrated that JCPyV archetype DNA replicates in COS-7 simian kidney cells expressing SV40 TAg and COS-7 cells expressing HIV-1 Tat. Based on these observations, the present study was conducted to reproduce an in vitro model in COS-7 cells transfected with the JCPyV archetype strain in order to study JCPyV DNA replication and analyze NCCR rearrangements during the viral life cycle. The efficiency of JCPyV replication was evaluated by quantitative PCR (Q-PCR) and by hemagglutination (HA) assay after transfection. In parallel, sequence analysis of JCPyV NCCR was performed. JCPyV efficiently replicated in kidney-derived COS-7 cells, as demonstrated by a progressive increase in viral load and virion particle production after transfection. The archetypal structure of NCCR was maintained during the viral cycle, but two characteristic point mutations were detected 28 days after transfection. This model is a useful tool for analyzing NCCR rearrangements during in vitro replication in cells that are sites of viral persistence, such as tubular epithelial cells of the kidney.

Archetype and Rearranged Non-coding Control Regions in Urothelial Bladder Carcinoma of Immunocompetent Individuals.

BACKGROUND: Polyomaviruses (PyVs) are potential transforming viruses. Despite their involvement in human tumours still being debated, there is evidence to suggest a role for PyVs in bladder carcinoma (BC). Therefore, a possible association between PyVs and BC was investigated. MATERIALS AND METHODS: Urine, blood and fresh bladder tissue specimens were collected from 29 patients with BC. PyV prevalence, non-coding control region (NCCR) organization and genotypic analysis were assessed. RESULTS: Data showed a significant prevalence of John Cunningham (JC) PyV in BC tissues and in urine with respect to BKPyV, while simian virus 40 was not revealed. A BKPyV rearranged NCCR sequence was isolated, whereas a JCPyV archetypal structure was consistently retained. A prevalence of European genotypes was observed. CONCLUSION: Our data would suggest a JCPyV involvement in cancer progression and a BKPyV association with BC pathogenesis in immunocompetent patients. However, further work is necessary to better understand the exact role of PyVs in urothelial carcinogenesis.

Natalizumab Affects T-Cell Phenotype in Multiple Sclerosis: Implications for JCV Reactivation.

The anti-CD49d monoclonal antibody natalizumab is currently an effective therapy against the relapsing-remitting form of multiple sclerosis (RRMS). Natalizumab therapeutic efficacy is limited by the reactivation of the John Cunningham polyomavirus (JCV) and development of progressive multifocal leukoencephalopathy (PML). To correlate natalizumab-induced phenotypic modifications of peripheral blood T-lymphocytes with JCV reactivation, JCV-specific antibodies (serum), JCV-DNA (blood and urine), CD49d expression and relative abundance of peripheral blood T-lymphocyte subsets were longitudinally assessed in 26 natalizumab-treated RRMS patients. Statistical analyses were performed using GraphPad Prism and R. Natalizumab treatment reduced CD49d expression on memory and effector subsets of peripheral blood T-lymphocytes. Moreover, accumulation of peripheral blood CD8+ memory and effector cells was observed after 12 and 24 months of treatment. CD4+ and CD8+ T-lymphocyte immune-activation was increased after 24 months of treatment. Higher percentages of CD8+ effectors were observed in subjects with detectable JCV-DNA. Natalizumab reduces CD49d expression on CD8+ T-lymphocyte memory and effector subsets, limiting their migration to the central nervous system and determining their accumulation in peripheral blood. Impairment of central nervous system immune surveillance and reactivation of latent JCV, can explain the increased risk of PML development in natalizumab-treated RRMS subjects.

Increased Prevalence of Human Polyomavirus JC Viruria in Chronic Inflammatory Rheumatic Diseases Patients in Treatment with Anti-TNF α: A 18 Month Follow-Up Study.

Chronic inflammatory rheumatic diseases (CIRDs) are immune-mediated pathologies involving joints. To date, TNFα-blocking agents administration is the most promising therapy, although these treatments are associated with an increased Polyomavirus JC (JCPyV) reactivation, the etiological agent of the Progressive Multifocal Leukoencephalopathy (PML). The aim of this study was the recruitment and the analysis of a CIRDs cohort in order to investigate a possible correlation between JCPyV presence and the influence of anti-TNF-α agents on viral loads. Blood and urine samples were collected from 34 CIRDs subjects prior the first anti-TNF-α infusion (T0) and after 3 (T3), 6 (T6), 12 (T12), and 18 (T18) months. Results showed persistent JC viruria significantly higher than JC viremia throughout the 18 month follow-up study (p = 0.002). In JCPyV positive samples, the non-coding control region (NCCR) was analyzed. Results evidenced archetypal structures (type II-S) in all isolates with the exception of a sequence isolated from a plasma sample, that corresponds to the type II-R found in PML subjects. Finally, the viral protein 1 (VP1) genotyping was performed and results showed the prevalence of the European genotypes 1A, 1B, and 4. Since only few studies have been carried out to understand whether there is a PML risk in CIRDs population infected by JCPyV, this study contributes to enrich literature insight on JCPyV biology in this cluster. Further investigations are necessary in order to recognize the real impact of biologics on JCPyV life cycle and to identify possible and specific viral variants related to increased virulence in CIRDs patients.

High Frequency of JCV DNA Detection in Prostate Cancer Tissues.

BACKGROUND: Prostate cancer (PC) represents the most frequently diagnosed cancer in men. Exposure to infectious agents has been considered to induce prostatic inflammation and cancerous transformation. Controversial data exist concerning the role of the human polyomaviruses BK (BKV) and JC (JCV) in PC etiology. Therefore, a possible association between these polyomaviruses and PC was investigated. MATERIALS AND METHODS: Urine, blood and fresh prostatic tissue specimens were collected from 26 patients with PC. The presence of BKV and JCV, the possible non-coding control region (NCCR) variations and the genotyping analysis of viral protein 1 (VP1) of both viruses were assessed. RESULTS: Data showed a preferential viral re-activation in the urinary compartment and a statistically significant prevalence of JC viruria and of BKV in PC tissues. A BKV DDP-like NCCR sequence was isolated in two patients, whereas JCV NCCR was consistently of an archetypal structural organization. A prevalence of the European genotypes was observed for both viruses. CONCLUSION: Our data demonstrated the presence of JCV DNA in 14/24 (58.3%) cancerous prostatic tissue specimens, confirming the results obtained in a previous study, in which JCV has been defined as common inhabitant of the prostate, and opening the discussion about its potential role in PC.

Human polyomavirus JC replication and non-coding control region analysis in multiple sclerosis patients under natalizumab treatment.

In the last years, the treatment of multiple sclerosis (MS) patients with natalizumab has been associated with the occurrence of progressive multifocal leukoencephalopathy (PML) caused by human polyomavirus JC (JCV). Here, we have shown a significant correlation between patients with JC viruria and positive JC-specific antibody response and patients without JCV-specific antibodies after 1 year of natalizumab (p = 0.0006). Furthermore, JCV-specific quantitative PCR on urine and plasma samples, collected at the enrollment (t0) and every 4 months (t1, t2, t3) in the first year and at two time points (t4 and t5) in the second year of natalizumab treatment, indicated the prevalence of JC viremia rather than JC viruria only in the second year of treatment (p = 0.04). Moreover, the analysis of JCV non-coding control region (NCCR) sequences in peripheral blood mononuclear cells of patients with JC-specific antibodies after 12 natalizumab infusions (t3) revealed the presence of rearranged sequences, whereas the prevalence of genotypes 1A, 1B, and 4 was detected in these patients by VP1 sequence analysis. In summary, JC viruria evaluation seems to be useful to identify early those patients who do not already develop a humoral immune response against JCV. It may also be interesting to study the JCV NCCR rearrangements since they could give us new insights on the onset of neuro-invasive viral variants.

Results, questions, perspectives of a study on human Polyomavirus BK and molecular actors in prostate cancer development.

BACKGROUND: Prostate cancer (PC) is a common tumor in Western countries. Several risk factors play significant roles. MYC, BIRC5/survivin, CDC25 and P53 may contribute to PC risk. As demonstrated, human Polyomavirus BK (BKV) could affect cellular homeostasis contributing to PC pathogenesis. MATERIALS AND METHODS: Biological samples were collected from PC patients. Viral RNA was searched using quantitative polymerase chain reaction (PCR), whereas a qualitative PCR was employed to find particular viral sequences. Proper size amplicons were analyzed. Single nucleotide polymorphisms (SNPs) were detected in p53 coding regions by means of a specific PCR. C-MYC, BIRC5/survivin and CDC25 gene expression was investigated using a Retro Transcriptional Quantitative PCR. RESULTS: Viral DNA copy number was higher in cancer tissues taken from Gleason score 9 patients with Gleason score 7. Different p53 mutated compared to patients exons were found according to tumor advanced stage and a statistical significant correlation was found between Gleason score and p53 mutational rate. C-MYC, BIRC5/survivin and CDC25 expression was de-regulated according to the literature. CONCLUSION: The presence of BKV and its variants in transformed cells does not exclude viral pressure in cell immortalization. Expression of other target genes evidenced a significant change in their regulation, useful for cancer drug discovery and therapies.

Role of BK virus infection in end-stage renal disease patients waiting for kidney transplantation--viral replication dynamics from pre- to post-transplant.

We report the prevalence of BK virus (BKV) infection before renal transplantation and the dynamics of BKV viremia from pre- to post-transplantation. We assessed 60 kidney transplanted patients from a single cohort in Italy, treated with identical immunosuppressive therapy, for BK viremia at pre-transplantation, 12 h, and three and six months post-transplantation. Polymerase chain reaction showed that the prevalence of plasma BKV replication--considered a marker of infection--was 20% in pre-transplant patients. All pre-transplant-positive patients remained positive post-transplant, whereas the majority of pre-transplant-negative patients remained negative. Viremia dynamics classification revealed three clusters of patients: Cluster A++, pre-transplant-positive patients (20%) who tested positive at least once post-transplant; Cluster B-+, pre-transplant-negative patients (28%) who tested positive at least once post-transplant; and Cluster C- -, pre-transplant-negative patients (52%) who remained negative throughout. These clusters presented significant differences related to the prevalence of substantially positive patients with high plasma viral load (>10(3) copies/mL) in cluster A, but not in donors' or grafts' characteristics. We suggest that pre-transplant viral status should be considered as an additional risk factor for post-transplant BKV replication. Therefore, pre-transplant BKV infection screening in kidney transplant patients should be performed for improving planning of personalized immunosuppressant schemes and specific post-transplant surveillance.

Human Polyomavirus JC monitoring and noncoding control region analysis in dynamic cohorts of individuals affected by immune-mediated diseases under treatment with biologics: an observational study.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) onset, caused by Polyomavirus JC (JCPyV) in patients affected by immune-mediated diseases during biological treatment, raised concerns about the safety profile of these agents. Therefore, the aims of this study were the JCPyV reactivation monitoring and the noncoding control region (NCCR) and viral protein 1 (VP1) analysis in patients affected by different immune-mediated diseases and treated with biologics. METHODS: We performed JCPyV-specific quantitative PCR of biological samples collected at moment of recruitment (t0) and every 4 months (t1, t2, t3, t4). Subsequently, rearrangements' analysis of NCCR and VP1 was carried out. Data were analyzed using χ2 test. RESULTS: Results showed that at t0 patients with chronic inflammatory rheumatic diseases presented a JCPyV load in the urine significantly higher (p≤0.05) than in patients with multiple sclerosis (MS) and Crohn's disease (CD). It can also be observed a significant association between JC viruria and JCPyV antibodies after 1 year of natalizumab (p=0.04) in MS patients. Finally, NCCR analysis showed the presence of an archetype-like sequence in all urine samples, whereas a rearranged NCCR Type IR was found in colon-rectal biopsies collected from 2 CD patients after 16 months of infliximab. Furthermore, sequences isolated from peripheral blood mononuclear cells (PBMCs) of 2 MS patients with JCPyV antibody at t0 and t3, showed a NCCR Type IIR with a duplication of a 98 bp unit and a 66 bp insert, resulting in a boxB deletion and 37 T to G transversion into the Spi-B binding site. In all patients, a prevalence of genotypes 1A and 1B, the predominant JCPyV genotypes in Europe, was observed. CONCLUSIONS: It has been important to understand whether the specific inflammatory scenario in different immune-mediated diseases could affect JCPyV reactivation from latency, in particular from kidneys. Moreover, for a more accurate PML risk stratification, testing JC viruria seems to be useful to identify patients who harbor JCPyV but with an undetectable JCPyV-specific humoral immune response. In these patients, it may also be important to study the JCPyV NCCR rearrangement: in particular, Spi-B expression in PBMCs could play a crucial role in JCPyV replication and NCCR rearrangement.

Possible antiviral effect of ciprofloxacin treatment on polyomavirus BK replication and analysis of non-coding control region sequences.

Acute renal dysfunction (ARD) is a common complication in renal transplant recipients. Multiple factors contribute to ARD development, including acute rejection and microbial infections. Many viral infections after kidney transplantation result from reactivation of "latent" viruses in the host or from the graft, such as the human Polyomavirus BK (BKV). We report the case of a 39 year-old recipient of a 2nd kidney graft who experienced BKV reactivation after a second episode of acute humoral rejection. A 10-day treatment with the quinolone antibiotic ciprofloxacin was administered with an increase of immunosuppressive therapy despite the active BKV replication. Real Time PCR analysis performed after treatment with ciprofloxacin, unexpectedly showed clearance of BK viremia and regression of BK viruria. During the follow-up, BK viremia persisted undetectable while viruria decreased further and disappeared after 3 months.BKV non-coding control region sequence analysis from all positive samples always showed the presence of archetypal sequences, with two single-nucleotide substitutions and one nucleotide deletion that, interestingly, were all representative of the subtype/subgroup I/b-1 we identified by the viral protein 1 sequencing analysis.We report the potential effect of the quinolone antibiotic ciprofloxacin in the decrease of the BKV load in both blood and urine.

New insights on human polyomavirus JC and pathogenesis of progressive multifocal leukoencephalopathy.

John Cunningham virus (JCV) is a member of the Polyomaviridae family. It was first isolated from the brain of a patient with Hodgkin disease in 1971, and since then the etiological agent of the progressive multifocal leukoencephalopathy (PML) was considered. Until the human immunodeficiency virus (HIV) pandemic, PML was rare: in fact HIV-induced immunodeficiency is the most common predisposing factor accounting for 85% of all instances of PML. This data led to intense research on JCV infection and resulted in better understanding of epidemiology and clinic-pathologic spectrum. Recently, cases of PML have been observed after the introduction of monoclonal antibodies, such as natalizumab, rituximab, efalizumab, and infliximab, in the treatment of autoimmune disease, underlining the important role of host immunity in PML pathogenesis. In this review current understanding of the JCV infection and the new findings relating to the pathogenesis of PML has been comprehensively revised, focusing our attention on the interaction between the cellular and viral molecular pathways implicated in the JCV infection and the modulating role of host immune surveillance in the viral reactivation from a latent state.

HIV-associated progressive multifocal leukoencephalopathy: longitudinal study of JC virus non-coding control region rearrangements and host immunity.

John Cunningham virus (JCV), the etiological agent of progressive multifocal leukoencephalopathy (PML), contains a hyper-variable non-coding control region usually detected in urine of healthy individuals as archetype form and in the brain and cerebrospinal fluid (CSF) of PML patients as rearranged form. We report a case of HIV-related PML with clinical, immunological and virological data longitudinally collected. On admission (t0), after 8-week treatment with a rescue highly active antiretroviral therapy (HAART), the patient showed a CSF-JCV load of 16,732 gEq/ml, undetectable HIV-RNA and an increase of CD4+ cell count. Brain magnetic resonance imaging (MRI) showed PML-compatible lesions without contrast enhancement. We considered PML-immune reconstitution inflammatory syndrome as plausible because of the sudden onset of neurological symptoms after the effective HAART. An experimental JCV treatment with mefloquine and mirtazapine was added to steroid boli. Two weeks later (t1), motor function worsened and MRI showed expanded lesions with cytotoxic oedema. CSF JCV-DNA increased (26,263 gEq/ml) and JCV viremia was detected. After 4 weeks (t2), JCV was detected only in CSF (37,719 gEq/ml), and 8 weeks after admission (t3), JC viral load decreased in CSF and JCV viremia reappeared. The patient showed high level of immune activation both in peripheral blood and CSF. He died 4 weeks later. Considering disease progression, combined therapy failure and immune hyper-activation, we finally classified the case as classical PML. The archetype variant found in CSF at t0/t3 and a rearranged sequence detected at t1/t2 suggest that PML can develop from an archetype virus and that the appearance of rearranged genotypes contribute to faster disease progression.

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.

Early monitoring of the human polyomavirus BK replication and sequencing analysis in a cohort of adult kidney transplant patients treated with basiliximab.

BACKGROUND: Nowadays, better immunosuppressors have decreased the rates of acute rejection in kidney transplantation, but have also led to the emergence of BKV-associated nephropathy (BKVAN). Therefore, we prospectively investigated BKV load in plasma and urine samples in a cohort of kidney transplants, receiving basiliximab combined with a mycophenolate mofetil-based triple immunotherapy, to evaluate the difference between BKV replication during the first 3 months post-transplantation, characterized by the non-depleting action of basiliximab, versus the second 3 months, in which the maintenance therapy acts alone. We also performed sequencing analysis to assess whether a particular BKV subtype/subgroup or transcriptional control region (TCR) variants were present. METHODS: We monitored BK viruria and viremia by quantitative polymerase chain reaction (Q-PCR) at 12 hours (Tx), 1 (T1), 3 (T2) and 6 (T3) months post-transplantation among 60 kidney transplant patients. Sequencing analysis was performed by nested-PCR with specific primers for TCR and VP1 regions. Data were statistically analyzed using χ² test and Student's t-test. RESULTS: BKV was detected at Tx in 4/60 urine and in 16/60 plasma, with median viral loads of 3.70 log GEq/mL and 3.79 log GEq/mL, respectively, followed by a significant increase of both BKV-positive transplants (32/60) and median values of viruria (5.78 log GEq/mL) and viremia (4.52 log GEq/mL) at T2. Conversely, a significantly decrease of patients with viruria and viremia (17/60) was observed at T3, together with a reduction of the median urinary and plasma viral loads (4.09 log GEq/mL and 4.00 log GEq/mL, respectively). BKV TCR sequence analysis always showed the presence of archetypal sequences, with a few single-nucleotide substitutions and one nucleotide insertion that, interestingly, were all representative of the particular subtypes/subgroups we identified by VP1 sequencing analysis: I/b-2 and IV/c-2. CONCLUSIONS: Our results confirm previous studies indicating that BKV replication may occur during the early hours after kidney transplantation, reaches the highest incidence in the third post-transplantation month and then decreases within the sixth month, maybe due to induction therapy. Moreover, it might become clinically useful whether specific BKV subtypes or rearrangements could be linked to a particular disease state in order to detect them before BKVAN onset.

Polyomavirus JC reactivation and noncoding control region sequence analysis in pediatric Crohn's disease patients treated with infliximab.

The recent introduction of monoclonal antibodies in Crohn's disease (CD) management has been associated with the development of serious complications, such as the progressive multifocal leukoencephalopathy (PML), caused by JC polyomavirus (JCV) reactivation. Therefore, the aims of our study have been the investigation of the possible JCV reactivation in pediatric CD patients treated or not with infliximab, performing quantitative PCR in urine, plasma, and intestinal biopsies at the time of recruitment (t0) and every 4 months in 1 year of follow-up (t1, t2, and t3), and the analysis of the JCV noncoding control region (NCCR) to detect cellular transcription factors binding site mutations. Results obtained showed that, in urine and ileal specimens, JCV load significantly increased in infliximab-treated patients after 1 year of treatment (t3), while viremia was significantly higher at t1. JCV NCCR sequence analysis showed a structure similar to CY archetype in 65/80 analyzed sequences, but the remaining 15/80, obtained exclusively from plasma and biopsies, evidenced a CY NCCR organization with two recurrent nucleotide changes, the 37-T to G transversion in box A Spi-B binding site and the 217-G to A transition in box F, and a box D deletion. These rearrangements were always found at t3 within seven infliximab-treated CD patients, who presented a very severe disease at t0. We can conclude that our rearranged NCCR sequences could be considered a marker of JCV virulence during mAb treatment, although none of our examined patients developed PML, and further studies on a larger cohort of patients should be performed.

Early years of biological agents therapy in Crohn's disease and risk of the human polyomavirus JC reactivation.

Although the remarkable efficacy of biological therapy has resulted in significant success in inflammatory bowel disease (IBD) management, susceptibility to infections remains a concern. The biological agents include the tumor necrosis factor-alpha (TNF-alpha) inhibitors, for instance infliximab, and other immunomodulating agents, such as natalizumab. Progressive multifocal leukoencephalopathy (PML), a rare but mostly fatal opportunistic brain infection caused by reactivation of the human polyomavirus JC virus (JCV), has been found in two patients with multiple sclerosis and one patient with Crohn's disease (CD), linked to treatment with natalizumab. After these cases of PML, the commercial and investigational use of natalizumab was suspended in February 2005 but was subsequently resumed for multiple sclerosis and for CD, only through a special restricted distribution program. This review, starting from an extensive literature search by the PubMed database, resumes the clinical aspects and pathophysiology of CD and focuses on the biologics in current use in CD (infliximab, adalimumab, and natalizumab), in order to provide a reference and gateway to prevention, recognition, and management of JCV, in the early years of biological agents therapy. It also proposed to provide an overview on the hypothetical mechanism of reactivation of JC virus related to the use of these drugs.

Viral infection in bone marrow transplants: is JC virus involved?

Hemorrhagic cystitis is characterized by hematuria due to inflammation of the bladder. In bone marrow transplants, this disease is linked to the infection by human polyomavirus BK, whereas the role of the human polyomavirus JC is unclear. The transcriptional control regions of both viruses contain important cellular transcription factor binding sites that undergo rearrangement process generating suitable variants that could be more active for viral replication and for the onset of hemorrhagic cystitis. In this study urine obtained from seven patients with bone marrow transplant were examined. Polyomavirus genomes were quantified by PCR and viral loads were compared. The transcriptional regions of both viruses were amplified and sequenced to determine the presence of variants. Subtypes of polyomaviruses were determined by amplification and sequencing of the viral protein 1 region. The results showed that four of seven patients were positive for BK DNA, two of seven patients had BK and JC DNA and one of seven had JC DNA. Positive samples were amplified and sequenced successively for transcriptional regions. The viral archetype was always found in both viruses. Finally, typing showed that BK virus subtype I infected patients with BK, whereas JC virus genotype IA and genotype 1B were found in patients infected with JC. The data suggest that new and different approaches are required to improve the morbidity and mortality caused by polyoma-associated hemorrhagic cystitis, since it known that BK virus is involved in the onset of hemorrhagic cystitis, whereas the role of JC virus should be investigated further.

p53 gene mutational rate, Gleason score, and BK virus infection in prostate adenocarcinoma: Is there a correlation?

Prostate cancer represents the second leading cause of cancer deaths in Western countries. Viral infections could play a role in prostate carcinogenesis. Human polyomavirus BK (BKV) is a possible candidate because of its transforming properties. In this study, BKV sequences in urine, blood, fresh, and paraffin-embedded prostate cancer samples from 26 patients were searched using Q-PCR analysis. T antigen (TAg) and p53 localization in neoplastic cells were evaluated by immunohistochemical analysis. Also, the presence of mutations in 5-9 exons of p53 gene was analyzed. Results showed that BKV-DNA was found in urine (54%), plasma (31%), and in fresh prostate cancer specimens (85%). The analysis of p53 gene evidenced several mutations in high Gleason patients, according to tumor advanced stage. Immunohistochemical analysis results evidenced the localization of p53 and TAg into cytoplasm, whereas in TAg-negative tumors, p53 was nuclear. This study suggests that BKV acts as cofactor in the pathogenesis of prostate cancer. These observations emphasize previous studies regarding the cellular pathways that may be deregulated by BKV.