5,355 research outputs found
COULD JC VIRUS PROVOKE METASTASIS IN COLON CANCER?
AIM: to evaluate the prevalence of John Cunningham Virus (JC virus) in a small cohort of patients with colon cancer and to assess its presence in hepatic metastasis.METHOD: Neneteen consecutive patients with histologically diagnosed colon cancer were included in our study, together with ten subjects affected by histologically and serologically diagnosed hepatitis C virus infection. in the patients included in the colon cancer group, JC virus was searched for the surgical specimen; in the control group, JC virus was searched in the hepatic biopsy. The difference in the prevalence of JC virus in the hepatic biopsy between the two groups was assessed through the X2 test. RESULTS: Four of 19 patients with colon cancer had a positive polymerase chain reaction (PCR) test for JC virus, and four had liver metastasis. Among the patients with liver metastasis, three out four had a positive PCR test for JC virus in the surgical specimen and in the liver biopsy; the only patient with liver metastasis with a negative test for JC virus also presenrted a negative test for JC virus in the surgical specimen. in the control group of patients with hepatitis C infection, none of the ten patients presented JC virus infection in the hepatic biopsy. The difference between the two groups regarding JC virus infection was statistically significant (X2=9.55, P=0,002)
Central role of JC virus-specific CD4+ lymphocytes in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome
Progressive multi-focal leucoencephalopathy and progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome are caused by infection of the central nervous system with the JC polyoma virus. Both are complications of monoclonal antibody therapy in multiple sclerosis and other autoimmune diseases. Progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome can obscure the diagnosis of progressive multi-focal leucoencephalopathy and lead to severe clinical disability and possibly death. Different from progressive multi-focal leucoencephalopathy, in which demyelination results from oligodendrocyte lysis by JC virus in the absence of an immune response, tissue destruction in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome is caused by a vigorous immune response within the brain. The cells and mediators that are involved in progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome are as yet poorly understood. We examined two patients with multiple sclerosis, who developed progressive multi-focal leucoencephalopathy and later progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome under natalizumab therapy. Due to initially negative JC viral deoxyribonucleic acid testing in the cerebrospinal fluid, a diagnostic brain biopsy was performed in one patient. Histopathology revealed brain inflammation characterized by a prominent T cell infiltrate (CD4+ > CD8+ T cells), but also B/plasma cells and monocytes. Despite very low JC viral load, both patients showed high intrathecal anti-JC virus antibodies. Brain-infiltrating CD4+ T cells were studied regarding antigen specificity and function. CD4+ T cells were highly specific for peptides from several JC virus proteins, particularly the major capsid protein VP1. T cell phenotyping revealed CD4+ Th1 and bifunctional Th1-2 cells. The latter secrete large amounts of interferon-γ and interleukin-4 explaining the strong brain inflammation, presence of plasma cells and secretion of intrathecal anti-VP1 antibodies. The functional phenotype of brain-infiltrating JC virus-specific CD4+ T cells was confirmed and extended by examining brain-derived JC virus-specific CD4+ T cell clones. Our data provide novel insight into the pathogenesis of progressive multi-focal leucoencephalopathy-immune reconstitution inflammatory syndrome and indicate that JC virus-specific CD4+ T cells play an important role in both eliminating JC virus from the brain, but also in causing the massive inflammation with often fatal outcom
Evaluation of patients treated with natalizumab for progressive multifocal leukoencephalopathy
Background: Progressive multifocal leukoencephalopathy (PML) was reported to have developed in three patients treated with natalizumab. We conducted an evaluation to determine whether PML had developed in any other treated patients.
Methods: We invited patients who had participated in clinical trials in which they received recent or long-term treatment with natalizumab for multiple sclerosis, Crohn's disease, or rheumatoid arthritis to participate. The clinical history, physical examination, brain magnetic resonance imaging (MRI), and testing of cerebrospinal fluid for JC virus DNA were used by an expert panel to evaluate patients for PML. We estimated the risk of PML in patients who completed at least a clinical examination for PML or had an MRI.
Results: Of 3417 patients who had recently received natalizumab while participating in clinical trials, 3116 (91 percent) who were exposed to a mean of 17.9 monthly doses underwent evaluation for PML. Of these, 44 patients were referred to the expert panel because of clinical findings of possible PML, abnormalities on MRI, or a high plasma viral load of JC virus. No patient had detectable JC virus DNA in the cerebrospinal fluid. PML was ruled out in 43 of the 44 patients, but it could not be ruled out in one patient who had multiple sclerosis and progression of neurologic disease because data on cerebrospinal fluid testing and follow-up MRI were not available. Only the three previously reported cases of PML were confirmed (1.0 per 1000 treated patients; 95 percent confidence interval, 0.2 to 2.8 per 1000).
Conclusions: A detailed review of possible cases of PML in patients exposed to natalizumab found no new cases and suggested a risk of PML of roughly 1 in 1000 patients treated with natalizumab for a mean of 17.9 months. The risk associated with longer treatment is not known
Case report of a patient with progressive multifocal leukoencephalopathy under treatment with dimethyl fumarate
BACKGROUND: Progressive multifocal leukoencephalopathy is a severe demyelinating disease caused by the polyoma JC virus in patients with reduced immunocompetence. A few cases of progressive multifocal leukoencephalopathy have been reported in patients treated with fumaric acid esters. CASE PRESENTATION: A 53-year-old Caucasian woman reported to our clinic with a first focal epileptic seizure and mild cognitive impairment. Since 1.5 years, she was treated with fumaderm for her psoriasis. During that time, her lymphocyte counts ranged between 450 and 700/μl. Cerebral magnet resonance imaging showed multifocal subcortical T2 hyperintense lesions with partial gadolinium enhancement. She did not have antibodies against human immunodeficiency virus 1 and 2 and cerebrospinal fluid-polymerase chain reaction for viral infections including a sensitive JC-virus polymerase chain reaction were negative. The diagnosis of progressive multifocal leukoencephalopathy was established by histological analysis and detection of JC-virus desoxyribonucleic acid in brain biopsy specimens. Dimethyl fumarate was stopped and Mirtazapin and Mefloquin were initiated. Neurological examination and imaging remained stable. CONCLUSIONS: Progressive multifocal leukoencephalopathy can occur in patients with lymphocyte counts between 450 and 700/μl, produce only faint symptoms and is not excluded by negative JC-virus-polymerase chain reaction in cerebrospinal fluid. The incidence of progressive multifocal leukoencephalopathy may thus be underestimated and a more careful surveillance of patients would be necessary
JC virus-DNA detection is associated with CD8 fffector 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
Immunological biomarkers identifying natalizumab-treated multiple sclerosis patients at risk of progressive multifocal leukoencephalopathy
Natalizumab-induced progressive multifocal leukoencephalopathy (PML) appears to be unleashed by complex interactions between viral and immunological host factors leading the latent form of JC virus to become pathogenic.
Positive anti–JC virus antibody status, prior use of immunosuppressants, and increasing duration of natalizumab treatment have been proposed as risk factors for PML in multiple sclerosis patients, but while they may help to identify the most appropriate patients for natalizumab, their use have some limitations. Therefore, a large body of studies is ongoing to identify alternative, reliable immunological markers capable to improve the safety and efficacy of therapy and to guide tailored clinical decision
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
EFFICIENT PROPAGATION OF ARCHETYPE JC POLYOMAVIRUS IN COS-7 CELLS: EVALUATION OF REARRANGEMENTS WITHIN NCCR STRUCTURAL ORGANIZATION DURING TRANSFECTION.
John Cunningham virus (JCPyV) is an ubiqui-tous human pathogen that causes disease in immunocom-promised patients. The JCPyV genome is composed of an early region and a late region, which are physically sepa-rated 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 robust-ness. 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 rear-rangements during the viral life cycle. The efficiency of JCPyV replication was evaluated by quantitative PCR (Q-PCR) and by hemagglutination (HA) assay after trans-fection. 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 vitroreplication in cells that are sites of viral persistence, such as tubular epithelial cells of the kidne
Relapsing-remitting multiple sclerosis: advances in disease-modifying therapies
Multiple sclerosis is a demyelinating disease affecting the central nervous system. It is the most prevalent disabling neurological condition among young adults, with onset typically between 20 and 40 years of age. Infiltrating immune cells and microglia activations are associated with inflammatory and neurodegenerative mechanisms. Current available disease modifying therapies suppress or modulate the immune system. These pharmaceuticals differ with respect to administration route and frequency, adverse effects, and efficacy. This paper provides a thorough manuscript illustrating the major prescribing factors, efficacy profiles, adverse events, and contraindications that patients and clinicians should consider while choosing a treatment. Despite the advancements made over the past 20 years, patients with progressive multiple sclerosis have few therapeutic options. Additionally, this paper assesses emerging therapies and disease targets on the pharmaceutical horizon, which have shown promise for all disease phenotypes
JCV-specific T-cells producing IFN-gamma are differently associated with PmL occurrence in HIV patients and liver transplant recipients
Aim of this work was to investigate a possible correlation between the frequency of JCV-specific T-cells and PML occurrence in HIV-infected subjects and in liver transplant recipients. A significant decrease of JCV-specific T-cells was observed in HIV-PML subjects, highlighting a close relation between JCV-specific T-cell immune impairment and PML occurrence in HIV-subjects. Interestingly, liver-transplant recipients (LTR) showed a low frequency of JCV-specific T-cells, similar to HIV-PML subjects. Nevertheless, none of the enrolled LTR developed PML, suggesting the existence of different immunological mechanisms involved in the maintenance of a protective immune response in LT
- …
