Natalizumab-treated Multiple Sclerosis Patients Research Articles

JCV seroconversion rate during the SARS COVID-19 pandemic

The transmission route of the John Cunningham virus (JCV) is not clearly understood. The high prevalence of JCV in urine and sewage and the stability of the viral particles observed suggest that contaminated water, food, and fomites could be the vehicles of JCV transmission through the oral route. Multiple Sclerosis (MS) patients treated with Natalizumab are at risk of developing progressive multifocal leukoencephalopathy (PML), and hence, JCV serology is monitored for risk stratification. Social restrictions introduced in 2020 which intended to limit the transmission of SARS-CoV-2 are associated with decreased rates of other communicable diseases, as has been shown in recent observational studies. We evaluated the prevalence of seroconversion prior to and during the coronavirus disease (COVID -19) pandemic based on clinical records of JCV serology status in a single-center cohort of Natalizumab-treated Multiple Sclerosis patients. We hypothesized that seroconversion rates would decrease due to behavioral changes. However, seroconversion rates were stable during the COVID-19 pandemic compared to the pre-pandemic. These findings support the notion that JCV is transmitted via the GI tract rather than the respiratory system.

T Lymphocyte Serotonin 5-HT7 Receptor Is Dysregulated in Natalizumab-Treated Multiple Sclerosis Patients.

Serotonin (5-HT) is known as a potent immune cell modulator in autoimmune diseases and should be protective in the pathogenesis of multiple sclerosis (MS). Nevertheless, there is limited knowledge about receptors involved in 5-HT effects as well as induced mechanisms. Among 5-HT receptors, the 5-HT7 receptor is able to activate naïve T cells and influence the inflammatory response; however, its involvement in the disease has never been studied so far. In this study, we collected blood sample from three groups: acute relapsing MS patients (ARMS), natalizumab-treated MS patients (NTZ), and control subjects. We investigated the 5-HT7 expression on circulating lymphocytes and evaluated the effects of its activation on cytokine production with peripheral blood mononuclear cell (PBMC) cultures. We found a significant increase in the 5-HT7 surface expression on T lymphocytes and on the different CD4+ T cell subsets exclusively in NTZ-treated patients. We also showed that the selective agonist 5-carboxamidotryptamine (5-CT)-induced 5-HT7R activation significantly promotes the production of IL-10, a potent immunosuppressive cytokine in PBMCs. This study provides for the first time a dysregulation of 5-HT7 expression in NTZ-MS patients and its ability to promote IL-10 release, suggesting its protective role. These findings strengthen the evidence that 5-HT7 may play a role in the immuno-protective mechanisms of NTZ in MS disease and could be considered as an interesting therapeutic target in MS.

Comparison of qPCR with ddPCR for the Quantification of JC Polyomavirus in CSF from Patients with Progressive Multifocal Leukoencephalopathy.

Background: Lytic infection of oligodendrocytes by the human JC polyomavirus (JCPyV) results in the demyelinating disease called progressive multifocal leukoencephalopathy (PML). The detection of viral DNA in the cerebrospinal fluid (CSF) by PCR is an important diagnostic tool and, in conjunction with defined radiological and clinical features, can provide diagnosis of definite PML, avoiding the need for brain biopsy. The main aim of this study is to compare the droplet digital PCR (ddPCR) assay with the gold standard quantitative PCR (qPCR) for the quantification of JC viral loads in clinical samples. Methods: A total of 62 CSF samples from 31 patients with PML were analyzed to compare the qPCR gold standard technique with ddPCR to detect conserved viral DNA sequences in the JCPyV genome. As part of the validation process, ddPCR results were compared to qPCR data obtained in 42 different laboratories around the world. In addition, the characterization of a novel triplex ddPCR to detect viral DNA sequence from both prototype and archetype variants and a cellular housekeeping reference gene is described. Triplex ddPCR was used to analyze the serum from six PML patients and from three additional cohorts, including 20 healthy controls (HC), 20 patients with multiple sclerosis (MS) who had never been treated with natalizumab (no-NTZ-treated), and 14 patients with MS who were being treated with natalizumab (NTZ-treated); three from this last group seroconverted during the course of treatment with natalizumab. Results: JCPyV DNA was detected only by ddPCR for 5 of the 62 CSF samples (8%), while remaining undetected by qPCR. For nine CSF samples (15%), JCPyV DNA was at the lower limit of quantification for qPCR, set at <250 copies/mL, and therefore no relative quantitation could be determined. By contrast, exact copies of JCPyV for each of these samples were quantified by ddPCR. No differences were observed between qPCR and ddPCR when five standardized plasma samples were analyzed for JCPyV in 42 laboratories in the United States and Europe. JCPyV-DNA was undetected in all the sera from HC and MS cohorts tested by triplex ddPCR, while serum samples from six patients with PML tested positive for JCPyV. Conclusion: This study shows strong correlation between ddPCR and qPCR with increased sensitivity of the ddPCR assay. Further work will be needed to determine whether multiplex ddPCR can be useful to determine PML risk in natalizumab-treated MS patients.

Healthcare resource utilization and costs for extended interval dosing of natalizumab in multiple sclerosis.

Aims: Natalizumab is approved as aninfusion every 4 weeks(standard-interval dosing [SID]) in relapsing-remitting multiple sclerosis (MS). Extended-interval dosing (EID) reduces risk of progressive multifocal leukoencephalopathy (PML) compared withSID, but the impact on healthcare resources and costs remains unknown. Methods: In this population-based study, we included 208 natalizumab-treated MS patients who were classified into EID (≤15 infusions in the previous 18months; n=51; age=33.7±11.1years; female=72.5%) and SID (>15 infusions in the previous 18months; n=157; age=36.5±10.8years; female=68.1%) groups. Results: Natalizumab EID had fewer MS outpatient visits(p=0.01) and related costs (p=0.03), and lower natalizumab costs (p<0.01) compared with SID, without changes in other healthcare resources and costs. Conclusion: Natalizumab EID is associated with reduced direct treatment costs, apparently without additional healthcare burden.

Experiences in treatment of multiple sclerosis with natalizumab from a real-life cohort over 15\xa0years

Natalizumab (NTZ) has been used for treatment of highly active relapsing–remitting multiple sclerosis (MS). When stopping NTZ the risk of severe rebound phenomenon has to be considered. We aimed to investigate the use of NTZ in clinical routine and focused on identification of potential risk factors for disease reactivation after treatment discontinuation. At the Medical University of Innsbruck, Austria, we identified all MS patients who were treated with NTZ and performed a retrospective analysis on therapeutic decision making, disease course before, during and after treatment with NTZ and on risk factors for disease reactivation after NTZ discontinuation. 235 NTZ treated MS patients were included, of whom 105 had discontinued treatment. At NTZ start disease duration was 5.09 (IQR 2.09–10.57) years, average number of total relapses was 4 (IQR 3–6) and median EDSS 2.0 (range 0–6.5), whereby these values significantly decreased over time. Reduction of annualized relapse rate (ARR) on treatment was 93% and EDSS remained stable in 64%. In multivariate regression models only conversion to secondary progressive MS (SPMS) on treatment was significantly associated with lower risk of disease reactivation after NTZ, while ARR before treatment was associated with earlier disease reactivation. We could confirm the high therapeutic efficacy of NTZ which trends to be used earlier in the disease course nowadays. Discontinuation of NTZ seems safe only in patients who convert to SPMS during treatment, while higher ARR before NTZ increases the risk of disease reactivation after treatment discontinuation.

Decreased Neurofilament L Chain Levels in Cerebrospinal Fluid and Tolerogenic Plasmacytoid Dendritic Cells in Natalizumab-Treated Multiple Sclerosis Patients - Brief Research Report.

BackgroundNeurofilament Light (NfL) chain levels in both cerebrospinal fluid (CSF) and serum have been correlated with the reduction of axonal damage in multiple sclerosis (MS) patients treated with Natalizumab (NTZ). However, little is known about the function of plasmacytoid cells in NTZ-treated MS patients.ObjectiveTo evaluate CSF NfL, serum levels of soluble-HLA-G (sHLA-G), and eventual tolerogenic behavior of plasmacytoid dendritic cells (pDCs) in MS patients during NTZ treatment.MethodsCSF NfL and serum sHLA-G levels were measured using an ELISA assay, while pDCs (BDCA-2+) were accessed through flow cytometry analyses.ResultsCSF levels of NfL were significantly reduced during NTZ treatment, while the serum levels of sHLA-G were increased. Moreover, NTZ treatment enhanced tolerogenic (HLA-G+, CD274+, and HLA-DR+) molecules and migratory (CCR7+) functions of pDCs in the peripheral blood.ConclusionThese findings suggest that NTZ stimulates the production of molecules with immunoregulatory function such as HLA-G and CD274 programmed death-ligand 1 (PD-L1) which may contribute to the reduction of axonal damage represented by the decrease of NfL levels in patients with MS.

Serum contactin-1 as a biomarker of long-term disease progression in natalizumab-treated multiple sclerosis

Background: Natalizumab treatment provides a model for non-inflammation-induced disease progression in multiple sclerosis (MS). Objective: To study serum contactin-1 (sCNTN1) as a novel biomarker for disease progression in natalizumab-treated relapsing-remitting MS (RRMS) patients. Methods: Eighty-nine natalizumab-treated RRMS patients with minimum follow-up of 3 years were included. sCNTN1 was analyzed at baseline (before natalizumab initiation), 3, 12, 24 months (M) and last follow-up (median 5.2 years) and compared to 222 healthy controls (HC) and 15 primary progressive MS patients (PPMS). Results were compared between patients with progressive, stable, or improved disability according to EDSS-plus criteria. Results: Median sCNTN1 levels (ng/mL,) in RRMS (baseline: 10.7, 3M: 9.7, 12M: 10.4, 24M: 10.8; last follow-up: 9.7) were significantly lower compared to HC (12.5; p ⩽ 0.001). It was observed that 48% of patients showed progression during follow-up, 11% improved, and 40% remained stable. sCNTN1 levels were significantly lower in progressors both at baseline and at 12M compared to non-progressors. A 1 ng/mL decrease in baseline sCNTN1 was consistent with an odds ratio of 1.23 (95% confidence interval 1.04–1.45) (p = 0.017) for progression during follow-up. Conclusion: Lower baseline sCNTN1 concentrations were associated with long-term disability progression during natalizumab treatment, making it a possible blood-based prognostic biomarker for RRMS.

JCPyV miR-J1-5p in Urine of Natalizumab-Treated Multiple Sclerosis Patients.

The use of Natalizumab in Multiple Sclerosis (MS) can cause the reactivation of the polyomavirus JC (JCPyV); this may result in the development of progressive multifocal leukoencephalopathy (PML), a rare and usually lethal disease. JCPyV infection is highly prevalent in worldwide population, but the detection of anti-JCPyV antibodies is not sufficient to identify JCPyV infection, as PML can develop even in patients with negative JCPyV serology. Better comprehension of the JCPyV biology could allow a better understanding of JCPyV infection and reactivation, possibly reducing the risk of developing PML. Here, we investigated whether JCPyV miR-J1-5p—a miRNA that down-regulates the early phase viral protein T-antigen and promotes viral latency—could be detected and quantified by digital droplet PCR (ddPCR) in urine of 25 Natalizumab-treated MS patients. A 24-month study was designed: baseline, before the first dose of Natalizumab, and after 1 (T1), 12 (T12) and 24 months (T24) of therapy. miR-J1-5p was detected in urine of 7/25 MS patients (28%); detection was possible in three cases at T24, in two cases at T12, in one case at T1 and T12, and in the last case at baseline and T1. Two of these patients were seronegative for JCPyV Ab, and viral DNA was never found in either urine or blood. To note, only in one case miR-J1-5p was detected before initiation of Natalizumab. These results suggest that the measurement of miR-J1-5p in urine, could be a biomarker to monitor JCPyV infection and to better identify the possible risk of developing PML in Natalizumab-treated MS patients.

Reduction of the risk of PML in natalizumab treated MS patients in Sweden: An effect of improved PML risk surveillance

BackgroundNatalizumab (NTZ) treatment of multiple sclerosis (MS) has been associated with increased risk of progressive multifocal leukoencephalopathy (PML). The aim of the present study was to evaluate the impact of PML risk assessment on PML incidence in NTZ treated MS patients. MethodsBy using information from the population-based Swedish MS registry a retrospective cohort was established of patients treated with NTZ between 2006-2018. The effect on PML incidence before and after utilizing a risk management plan, including JC virus (JCV) serology, was analyzed. ResultsIn December 2018, 804 PML cases associated with NTZ therapy of MS had been reported globally, including 9 cases from Sweden. The estimated PML incidence 2018 in Sweden and globally was 0.7 (0.3-1.4) and 4.15 (3.9-4.4) per 1,000 person years, respectively. In Sweden, JCV serology was introduced 2012 for PML risk assessment and the cumulative risk of PML was significantly lower 2012-2018 compared to the period 2006-2011 (p=0.042). The mean NTZ exposure time was 60.1 months (SD 37.2) in the first period (2006-2011) and 32.6 months (SD 22.0) in the second period (2012-2018). The number of patients treated with NTZ decreased, and the number of patients at increased risk of PML was 1.9 % at the end of the study period. ConclusionSince 2006 the incidence of PML associated with NTZ treatment of MS has decreased in Sweden. Our findings suggest that this reduction is due to an effective adoptation and adherence to the established risk management plan that implies switching patients at increased PML risk from NTZ to other highly efficacious therapies. A less pronounced decline in PML incidence has recently been observed in France, but not globally.

Differential Effects of Fingolimod and Natalizumab on B Cell Repertoires in Multiple Sclerosis Patients.

Natalizumab and fingolimod are effective multiple sclerosis (MS) therapies that disrupt lymphocyte migration but have differential effects on B cell maturation and trafficking. We investigated their effects on peripheral blood (PB) and cerebrospinal fluid (CSF) B cell repertoires using next-generation deep sequencing. Paired CSF and PB B cell subsets (naïve, CD27+ memory, and CD27-IgD- double-negative B cells and plasmablasts) were collected by applying flow cytometry at baseline and after 6months of treatment and their respective heavy-chain variable region repertoires assessed by Illumina MiSeq. Treatment with fingolimod contracted, whereas natalizumab expanded circulating PB B cells. CSF B cell numbers remained stable following fingolimod treatment but decreased with natalizumab therapy. Clonal overlap between CSF and PB B cells was reduced with natalizumab treatment but remained stable with fingolimod therapy. Lineage analyses of pre- and posttreatment CSF B cell repertoires revealed large, clonally expanded B cell clusters in natalizumab-treated MS patients but no intrathecal clonal expansion following fingolimod therapy. Our findings suggest that natalizumab diminishes the exchange of peripheral and intrathecal B cells without impacting intrathecal clonal expansion. In contrast, fingolimod treatment fails to alter blood-brain barrier B cell exchange but diminishes intrathecal clonal expansion. Sphingosine-1 phosphate receptor inhibition may alter intrathecal B cell biology in MS.

Natalizumab is associated with early improvement of working ability in relapsing-remitting multiple sclerosis patients: WANT observational study results.

The Work Ability in Natalizumab-Treated MS Patients (WANT) study assessed work ability, quality of life, and cognitive processing speed during natalizumab treatment. WANT was a 1-year, prospective, multicenter observational study conducted in Italy. Inclusion criteria included relapsing-remitting multiple sclerosis (MS), natalizumab treatment, full-time worker status, and loss of working hours due to MS as measured by the Work Productivity and Activity Impairment Questionnaire for MS (WPAI:MS). The primary endpoint was change in WPAI:MS domain scores after 1 year on natalizumab. Secondary endpoints included change in annualized relapse rate (ARR), Multiple Sclerosis Impact Scale (MSIS-29) score, and Symbol Digit Modalities Test (SDMT) score. At enrollment, the 91 patients had a mean age of 38.3 (standard deviation [SD], 9.0) years and a mean ARR of 1.5 (SD, 0.8). After 1 year, improvements were observed in all WPAI:MS domains, with significant reductions in Absenteeism (-4.2 [SD, 26.0], p = 0.0190) and Work Productivity Loss (-7.2 [SD, 28.6]; p = 0.0456). These changes were accompanied by a low ARR (0.1), and 87.9% of patients were relapse free. Significant improvement was observed in MSIS-29 physical and psychological domains (reductions of 2.8 [SD, 11.6; p = 0.0295] and 6.3 [SD, 15.6; p = 0.0007], respectively) and SDMT score (increase of 2.4 [SD, 7.9; p = 0.0006]). Adverse events were reported in 32 of 104 patients (30.8%). The reductions in Absenteeism and Work Productivity Loss and the improved physical and psychological functioning reported after 1 year of natalizumab treatment in real-world settings extend our understanding of natalizumab's effects on patient-centric and health economics outcomes.

The 5-year Tysabri global observational program in safety (TYGRIS) study confirms the long-term safety profile of natalizumab treatment in multiple sclerosis

BackgroundNatalizumab is an effective treatment for multiple sclerosis (MS) and has a well-characterized safety profile, with more than 10 years of postmarketing experience. TYGRIS was a 5-year observational cohort study designed to obtain long-term safety data in natalizumab-treated MS patients. We examined the incidence and pattern of serious adverse events (SAEs) in this large postmarketing sample of natalizumab-treated patients. MethodsInvestigators reported SAEs in natalizumab-treated patients. Malignancy incidence rates were compared with rates in the general population using external databases. ResultsOf 6508 enrolled patients, 4938 (75.9%) completed the study. SAEs occurring in more than 0.5% of patients included urinary tract infection (n = 50; 0.8%), pneumonia (n = 46; 0.7%), progressive multifocal leukoencephalopathy (PML; n = 44; 0.7%), and immune reconstitution inflammatory syndrome (n = 44; 0.7%). Fifty-five patients (0.9%) experienced treatment-emergent serious opportunistic infections, 44 of which were PML. Two patients with PML died. The overall malignancy incidence rate was 449.0 per 100,000 patient-years (95% confidence interval [CI], 375.1–533.1). With few exceptions, incidence rates for individual malignancies had 95% CIs encompassing incidence rates in the general population. Hepatotoxic events occurred in 6 patients; 4 patients had evidence of alternative cause or confounders. Of 96 fatal events, investigators considered 81 unrelated or unlikely to be related to treatment and 5 related or possibly related; causality was not provided for 10. ConclusionData from this large, long-term study indicate that the nature, character, and frequency of SAEs in real-world settings are consistent with natalizumab's known safety profile. (Funded by Biogen; ClinicalTrials.gov identifiers: NCT00477113 and NCT00483847.)

Induction of brain-infiltrating T-bet-expressing B cells in multiple sclerosis.

ObjectiveResults from anti‐CD20 therapies demonstrate that B‐ and T‐cell interaction is a major driver of multiple sclerosis (MS). The local presence of B‐cell follicle‐like structures and oligoclonal bands in MS patients indicates that certain B cells infiltrate the central nervous system (CNS) to mediate pathology. Which peripheral triggers underlie the development of CNS‐infiltrating B cells is not fully understood.MethodsEx vivo flow cytometry was used to assess chemokine receptor profiles of B cells in blood, cerebrospinal fluid, meningeal, and brain tissues of MS patients (n = 10). Similar analyses were performed for distinct memory subsets in the blood of untreated and natalizumab‐treated MS patients (n = 38). To assess T‐bet(CXCR3)+ B‐cell differentiation, we cultured B cells from MS patients (n = 21) and healthy individuals (n = 34) under T helper 1‐ and TLR9‐inducing conditions. Their CNS transmigration capacity was confirmed using brain endothelial monolayers.ResultsCXC chemokine receptor 3 (CXCR3)‐expressing B cells were enriched in different CNS compartments of MS patients. Treatment with the clinically effective drug natalizumab prevented the recruitment of CXCR3high IgG1+ subsets, corresponding to their increased ability to cross CNS barriers in vitro. Blocking of interferon‐γ (IFNγ) reduced the transmigration potential and antigen‐presenting function of these cells. IFNγ‐induced B cells from MS patients showed increased T‐bet expression and plasmablast development. Additional TLR9 triggering further upregulated T‐bet and CXCR3, and was essential for IgG1 switching.InterpretationThis study demonstrates that T‐bethigh IgG1+ B cells are triggered by IFNγ and TLR9 signals, likely contributing to enhanced CXCR3‐mediated recruitment and local reactivity in the CNS of MS patients. ANN NEUROL 2019;86:264–278

Serum neurofilaments increase at progressive multifocal leukoencephalopathy onset in natalizumab-treated multiple sclerosis patients.

This study analyzed serum neurofilament light chains (NfL) in 2 European cohorts of 312 multiple sclerosis (MS) patients to investigate whether NfL are biomarkers of progressive multifocal leukoencephalopathy (PML) during natalizumab treatment. The cohort comprised 25 PML, 136 natalizumab-treated, and 151 untreated MS patients. Patients subsequently developing PML had similar NfL to other natalizumab-treated MS patients. At PML onset, NfL were 10-fold higher than in the pre-PML condition and in natalizumab-treated or untreated MS patients, and NfL continued to increase until onset of immune reconstitution inflammatory syndrome. The results suggest that in natalizumab-treated patients, NfL may represent an early and accessible marker of PML. Ann Neurol 2019;85:606-610.

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.

Real-World Lab Data in Natalizumab Treated Multiple Sclerosis Patients Up to 6 Years Long-Term Follow Up.

Natalizumab inhibits the transmigration of immune cells across the blood-brain barrier thus inhibiting inflammation in the central nervous system. Generally, this blockade at the blood-brain barrier has significant influence on the circulating lymphocytes. Up to date, only short-term data on peripheral blood parameters are available which are mostly from controlled clinical trials and not from real-world experience. Real-world lab data of 120 patients diagnosed with highly active disease course of relapsing-remitting multiple sclerosis (RRMS) were analyzed during natalizumab treatment. Patient sampling was performed by consecutive recruitment in the Multiple Sclerosis Center Dresden. Lab testing was performed before and at every third infusion up to 72 months follow-up. After first natalizumab infusion, absolute numbers of all major lymphocyte populations including CD4+ T-cells, CD8+ T-cells, CD19+ B-cells, and NK-cells significantly increased and remained stable during the whole observation period of 72 months. Upon lymphocyte subsets, CD19+ B-cells presented a disproportionate increase up to levels higher than normal level in most of the treated patients. Neutralizing antibodies to natalizumab abrogated the described changes. Intra-individual variation of lymphocytes and its subsets remained in a narrow range for the whole treatment period. CD4/CD8 ratio did not change compared to baseline measurement up to 6 years of natalizumab treatment. Monocytes, eosinophils, and basophils, but not neutrophils persistently increased during natalizumab treatment. Hematological parameters including erythrocyte, platelet count, hemoglobin, and hematocrit remained unchanged compared to baseline. Interestingly, immature precursor cells including erythroblasts were detectable in 36,8% of the treated patients during natalizumab therapy, but not in the pretreatment period. Asymptomatic elevations of liver enzymes were rare, mostly only transient and lower than 3x upper normal limit. Kidney function parameters remained stable within physiological ranges in most patients. CRP levels >20 mg/dl were recognized only in 10 patients during natalizumab therapy and were mostly linked to respiratory tract infections. In our present analysis, we report persistent, but stable increases of peripheral immune cell subtypes in natalizumab treated patients. Additional serological analyses confirm excellent tolerability and safety even 6 years after natalizumab initiation in post-marketing experience.

Brain Atrophy in Natalizumab-treated Patients with Multiple Sclerosis: A 5-year Retrospective Study.

Studies demonstrated a higher brain volume loss in the first year after initiation of natalizumab treatment than in the second year, but the experiences beyond 24 months are scarce until now. We investigated the evolution of brain volume changes in multiple sclerosis (MS) patients receiving natalizumab for at least 60 months. Using annual 3-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) sequences acquired on a 3 Tesla magnetic resonance imaging (MRI), we investigated percentage brain volume changes (PBVCs) in 10 MS patients (9 women, mean age at baseline MRI=29±9 years; median Expanded Disability Status Scale=2±1.5; mean disease duration=6±5 years) after 12, 24, 36, 48, and 60 months. PBVCs were statistically higher during the first 12 months (-1.48±1.05%) when compared to 12-24 months (-.6±.61%; P<.05), but not between 12-24 and 24-36 months (-.43±.54%), 24-36 and 36-48 months (-.28±.49%), and 36-48 and 48-60 months (-.33±.49%; P>.05 for all comparisons). Our results contribute to the increasing knowledge of PBVCs in natalizumab-treated MS patients. Our data suggests that after a significant PBVC decrease in the first year, brain atrophy rates show a slowdown during long-term follow-up.

THUR 171 Natalizumab effectiveness and safety in top uk patients

IntroductionThe TYSABRI® Observational Program (TOP) is an ongoing, global open-label study enrolling natalizumab-treated relapsing-remitting multiple sclerosis patients in real-world settings. Country-specific data can provide information on natalizumab’s benefit-risk in local clinical practice.MethodsClinical outcomes in UK and rest of world (ROW) TOP patients were compared.ResultsAs of May 2016, 134 UK and 5793 ROW patients were enrolled in TOP. Mean baseline Expanded Disability Status Scale (EDSS) score was 4.27 in the UK and 3.45 in ROW. Mean years on natalizumab was 3.52 in the UK and 3.04 in ROW. Annualized relapse rate (ARR) decreased by 89.7% (from 2.21 pre-natalizumab to 0.23 post natalizumab initiation; p&lt;0.0001) in the UK and by 89.0% (from 1.99 to 0.22; p&lt;0.0001) in ROW. In both cohorts, ARR decrease by baseline EDSS score was 91.0%–93.2% for &lt;3.0 and 87.3%–88.9% for ≥3.0; mean EDSS score change from baseline over 6 years was &lt;1.0. Overall, 9 of 134 UK patients (6.7%) experienced ≥1 serious adverse event.ConclusionsNatalizumab demonstrated similar effectiveness in the UK and ROW cohorts. Safety in the UK cohort was consistent with natalizumab’s established safety profile.SupportBiogenDisclosuresRN: grant/travel support from Biogen; KR, SL, SFSF, CS: Biogen employees.

BK Polyomavirus MicroRNA Levels in Exosomes Are Modulated by Non-Coding Control Region Activity and Down-Regulate Viral Replication When Delivered to Non-Infected Cells Prior to Infection.

In immunosuppressed patients, BKPyV-variants emerge carrying rearranged non-coding control-regions (rr-NCCRs) that increase early viral gene region (EVGR) expression and replication capacity. BKPyV also encodes microRNAs, which have been reported to downregulate EVGR-encoded large T-antigen transcripts, to decrease viral replication in infected cells and to be secreted in exosomes. To investigate the interplay of NCCR and microRNAs, we compared archetype- and rr-NCCR-BKPyV infection in cell culture. We found that laboratory and clinical rr-NCCR-BKPyV-strains show higher replication rates but significantly lower microRNA levels than archetype virus intracellularly and in exosomes. To investigate whether rr-NCCR or increased EVGR activity modulated microRNA levels, we examined the (sp1-4)NCCR-BKPyV, which has an archetype NCCR-architecture but shows increased EVGR expression due to point mutations inactivating one Sp1 binding site. We found that microRNA levels following (sp1-4)NCCR-BKPyV infection were as low as in rr-NCCR-variants. Thus, NCCR rearrangements are not required for lower miRNA levels. Accordingly, Sp1 siRNA knock-down decreased microRNA levels in archetype BKPyV infection but had no effect on (sp1-4)- or rr-NCCR-BKPyV. However, rr-NCCR-BKPyV replication was downregulated by exosome preparations carrying BKPyV-microRNA prior to infection. To explore the potential relevance in humans, urine samples from 12 natalizumab-treated multiple sclerosis patients were analysed. In 7 patients, rr-NCCR-BKPyV were detected showing high urine BKPyV loads but low microRNAs levels, whereas the opposite was seen in 5 patients with archetype BKPyV. We discuss the results in a dynamic model of BKPyV replication according to NCCR activity and exosome regulation, which integrates immune selection pressure, spread to new host cells and rr-NCCR emergence.

The functional brain network remains stable in natalizumab-treated multiple sclerosis patients: a one year study (P3.369)

The functional brain network remains stable in natalizumab-treated multiple sclerosis patients: a one year study (P3.369)