Dalfampridine benefits ambulation but not cognition in multiple sclerosis.

BACKGROUND: Impaired cognition and ambulation are common in multiple sclerosis (MS). Dalfampridine is the first Food and Drug Administration (FDA)-approved medication to treat impaired ambulation in MS. Dalfampridine may benefit patients with cognitive impairment, given its effects on saltatory conduction and the association between cognitive and motor function. OBJECTIVE: To examine the effects of dalfampridine on cognition in MS. To determine if the anticipated improved cognition is grounded in dalfampridine's effects on ambulation. METHODS: Adults with MS were randomized to dalfampridine (n = 45) or placebo (n = 16) for 12 weeks. Cognition and motor function were assessed at baseline and end-point. RESULTS: T25FW and 6-minute walk (6MW) performance improved at end-point in the treatment group but not in the placebo group (p < 0.05). Our primary outcome, performance on the Symbol Digit Modalities Test, did not improve. About 30% (n = 12) of the dalfampridine group demonstrated ⩾20% improved ambulation and were categorized "responders." Among "responders", Symbol Digit Modalities test performance did not improve. However, performance on the Paced Auditory Serial Addition Test improved among "responders" (p < 0.05). CONCLUSION: Dalfampridine benefits timed ambulation but not cognition. Some improvement among ambulation "responders" is consistent with prior reports of cognition-motor coupling in MS ( ClinicalTrials.gov #: NCT02006160).

Randomised natalizumab discontinuation study: taper protocol may prevent disease reactivation.

OBJECTIVES: To compare two modes of natalizumab cessation interventions: immediate versus tapered down, as measured by serial MRI and the occurrence of relapses during a 12-month period. BACKGROUND: Weighing progressive multifocal encephalopathy risk associated with ≥24 months of natalizumab therapy against the benefits of disease control, we initiated a natalizumab discontinuation study. METHODS: A phase IV, 12-month, single-blinded randomised (MRI) study. Fifty relapsing patients with multiple sclerosis (MS) who had been on natalizumab therapy ≥24 months and were contemplating natalizumab discontinuation were enrolled. Participants were randomised to either the immediate discontinuation group (IDG) or the tapered group (TG). IDG discontinued natalizumab at once and initiated another disease modifying therapy (DMT) following the last natalizumab infusion, while the TG received two more natalizumab infusions, at 6 and 8 weeks (14 weeks from study entry) before initiating another DMT. Standardised MRI was performed at baseline, 6 and 12 months from the last natalizumab infusion. RESULTS: A higher rate of relapses in the IDG (n=28) compared to the TG (n=8) over 12 months from the last infusion (p=0.007) was observed, most relapses occurred within 3 months of discontinuation (20 vs 7 relapses, p=0.012). The IDG showed a higher number of new T2 lesions within 6-12 months of discontinuation (p=0.025), a higher mean absolute T2-LV change from 0 to 12 months (1.1 vs 0.1 mL, p=0.024) and a higher number of new T1-hypointense lesions over 0-12 months (p=0.005) as well as from baseline to 6 months (p=0.026) compared to the TG. CONCLUSIONS: Natalizumab discontinuation therapy was associated with development of new disease activity. Our tapered protocol showed benefits, as patients in the TG experienced less relapses and lower accumulation of MRI lesions compared to those in the IDG.

Genomic effects of once-weekly, intramuscular interferon-beta1a treatment after the first dose and on chronic dosing: Relationships to 5-year clinical outcomes in multiple sclerosis patients.

PURPOSE: To characterize gene expression in multiple sclerosis (MS) patients after the first dose and chronic dosing of 30 microg, once weekly, intramuscular interferon-beta1a (IFN-beta) and to delineate the pharmacogenomic differences between Good Responders and Partial Responders to IFN-beta therapy. METHODS: The treatment responses after the first IFN-beta dose and chronic IFN-beta dosing were assessed in 22 relapsing MS patients (17 females, 5 males; average age: 41.5+/-SD 10.4 years). Gene expression profiles in peripheral blood mononuclear cells were obtained prior to treatment and at 1, 2, 4, 8, 24, 48, 120, 168 h after the first IFN-beta dose and at 1, 6 and 12 months after chronic dosing with once-weekly 30 microg IFN-beta-1a intramuscularly. Repeated measures statistics with false discovery rate control were used. The functional characteristics, biological pathways and transcription factor sites were analyzed. RESULTS: Of the 1000 genes modulated following the first dose and upon chronic dosing of IFN-beta in MS patients, approximately 35% were up-regulated and 65% were down- regulated; the percentage of modulated genes in common was approximately 50%. The expression of the pharmacodynamic mRNA markers of IFN-beta effect showed differences in time profiles for the Good Responder and Partial Responders to IFN-beta therapy and the Jak-STAT, TNFRSF10B, IL6, TGFbeta, retinoic acid and CDC42 pathways were differentially modulated. The patients with side effects to therapy showed differences in the TGFbeta1, IFNG/STAT3 and TNF pathways. CONCLUSIONS: Gene expression is a valuable tool for understanding the molecular mechanisms of IFN-beta action in MS patients.

Immune cell BDNF secretion is associated with white matter volume in multiple sclerosis.

PURPOSE: To investigate the relationship between immune cell secretion of brain-derived neurotrophic factor (BDNF) with clinical and MRI variables in multiple sclerosis (MS) patients. BACKGROUND: BDNF exerts beneficial effects on neuronal growth and repair and is secreted by both neurons and immune cells. Consequently, it may mediate the crosstalk between the immune system and CNS in autoimmune diseases such as MS. METHODS: Fifty-two relapsing MS patients (41 females, age: 48.8+/-6.6 years, disease duration: 12.7+/-8.4 years) were enrolled. Clinical and MRI measurements (including, T1-, T2- and contrast-enhancing (CE) lesion volumes (LVs); normalized measures of whole brain, white matter (WM) and gray matter (GM) volumes; diffusion weighted imaging measure of mean whole brain (WB) parenchyma diffusivity and magnetization transfer ratio (MTR) measures were obtained. RESULTS: Immune cell BDNF secretion after anti-CD3 plus anti-CD28 stimulation was positively associated with increased CE-LV (p=0.026). The MTR of CE-LV and normal-appearing (NA) WM (NAWM) were negatively associated with immune cell BDNF secretion after anti-CD3 plus anti-CD28 stimulation. Immune cell BDNF secretion after anti-CD3 plus anti-CD28 was positively associated with higher WM volume (p=0.027). Immune cell BDNF secretion after anti-CD3 plus anti-CD28 stimulation was decreased with increasing disease duration (p=0.031). The BDNF secretion was independent of the BDNF Val66Met (dBSNP ID: rs6265) SNP genotype. CONCLUSIONS: Immune cell BDNF secretion is associated with the sites of higher inflammatory activity as evidenced by CE lesions and may represent an important factor associated with the WM volume of patients with MS.

Dynamics of immune cell trafficking in interferon-beta treated multiple sclerosis patients.

PURPOSE: To investigate the effects of interferon-beta-1a (IFN-beta-1a) on the trafficking of cell populations in peripheral blood cells of multiple sclerosis (MS) patients. METHODS: In this open-label pharmacodynamic study, peripheral blood was obtained from 10 relapsing-remitting (RR) MS patients just prior to and at 1, 2, 4, 8, 24, 48, 120, and 168 h after intramuscular injection of 30-microg IFN-beta-1a. Timed samples were also obtained from five controls at 0, 8, 24, 48 and 168 h. The blood cells were analyzed using four-color flow cytometry with antibody conjugates directed against cell surface proteins specific for T cells, B cells, NK cells, and the activation marker, CD69. RESULTS: IFN-beta-1a treatment resulted in selective, time-dependent effects on many cell populations in peripheral blood. The trafficking of T-helper and T-suppressor/cytotoxic subsets of T cells were qualitatively different. The most prominent effects were on the trafficking of natural killer cells, the levels of which decreased to 23.5% of pretreatment values at 8 h after treatment. The levels of CD69-positive NK cells increased to a peak value of 606% of pretreatment levels at the 24-h time point. In untreated controls, these characteristic trafficking effects were not observed. There was inter-patient heterogeneity in the levels of activated NK cells at the 6-month time point that may potentially be relevant for individualizing IFN-beta therapy. CONCLUSIONS: IFN-beta treatment can induce specific, selective, and time-dependent trafficking of cells and its effects on different subsets of a given cell type are not qualitatively similar. The dynamics indicate that the activation of NK cells by IFN-beta is possibly dependent on the trafficking of NK cells. The activated NK cell levels after prolonged therapy may potentially provide a surrogate marker for IFN-beta exposure.

Lisdexamfetamine dimesylate improves processing speed and memory in cognitively impaired MS patients: a phase II study.

Multiple sclerosis (MS) causes cognitive impairment including slowed processing speed and problems with learning and memory. Stimulants are attractive candidates for improving mental speed but carry risk of addiction and other adverse behavioral effects. Lisdexamfetamine dimesylate (LDX) is a D-amphetamine prodrug currently approved for attention deficit (hyperactivity) disorder with the potential to be better tolerated due to its prolonged clinical effect. This phase II placebo-controlled, double-blind study aimed to assess the safety and efficacy of LDX in cognitively impaired MS patients. Subjects were patients with clinically definite MS, aged 18-56 years, and impaired on either of two primary outcomes: the Symbol Digit Modalities Test (SDMT) or the Paced Auditory Serial Addition Test (PASAT). Both SDMT and PASAT are measures of cognitive processing speed. Of 174 MS patients screened, 63 were randomized to 30 mg of LDX or placebo in a 2:1 fashion; the dose was increased as tolerated to 70 mg over 4 weeks and then maintained for another 4 weeks. Secondary outcomes were the Brief Visuospatial Memory Test Revised (BVMTR), the California Verbal Learning Test 2nd edition (CVLT2), both measures of episodic memory, and the Behavioral Rating Inventory of Executive Function for adults (BRIEF-A), a self-report measure of executive function. Fatigue and depression were also evaluated. There was significant improvement in the SDMT score (+4.6 vs. +1.3) and CVLT2 score (+4.7 vs. -0.9) in the LDX group compared with the placebo group among the 49 completers. There was no change on the other outcomes. A high proportion of both LDX-treated and placebo-treated subjects reported adverse events (73.5 % vs. 68.4 %). However, there were no serious adverse events noted in the study. These preliminary data indicate that LDX has the potential to be an efficacious treatment for MS patients with cognitive impairment.

Interferon-beta modulates bone-associated cytokines and osteoclast precursor activity in multiple sclerosis patients.

PURPOSE: Multiple sclerosis (MS) patients have a high risk of low bone density. The purpose of this study was to examine the molecular mechanisms potentially capable of modulating bone homeostasis in response to interferon-beta-1a (IFN-beta-1a) treatment and the focus was the bone-modulating system comprised of receptor activator of nuclear factor-kappaB (RANK), its ligand RANKL and its decoy receptor, osteoprotegerin (OPG). METHODS: In this open-label pharmacodynamic study, peripheral blood was obtained from relapsing-remitting MS patients just prior to and at multiple time points after intramuscular injection of 30 microg IFN-beta-1a. Samples were analysed for RANKL, tumour necrosis factor related apoptosis-inducing ligand (TRAIL), OPG and macrophage inflammatory protein-1 alpha/beta expression. Osteoclast precursor differentiation from peripheral blood cells of MS patients in the presence of exogenously added IFN-beta-1a was also assessed. Additionally, the changes in plasma levels of osteocalcin and the C-telopeptides after 1 year of treatment were measured as surrogate markers of bone formation and degradation, respectively. RESULTS: IFN-beta-1a treatment modulated RANKL and OPG in a selective, time-dependent manner. The levels of OPG protein decreased 25% at the 8-h time point, then increased 43% at the 24-h time point. The levels of free RANKL reached a maximum at the 8-h time point. Increases in the levels of macrophage inflammatory protein-1beta (MIP-1beta), a chemokine that increases osteolysis, were observed. The levels of the bone formation marker, osteocalcin, were lower in MS patients compared to controls and increased after one year of treatment. Ex vivo treatment of peripheral blood lymphocytes with IFN-beta resulted in a marked reduction of osteoclast-like cells in the presence of RANKL and macrophage colony stimulating factor. CONCLUSIONS: IFN-beta treatment induces complex, specific and time-dependent changes in multiple proteins and mRNAs related to bone homeostasis in MS patients.

Risk of bone loss in men with multiple sclerosis.

CONTEXT: Osteoporosis and the increased fracture risk associated with osteoporosis become apparent in men approximately 10 years later than women. However, in recent studies, approximately 20% of healthy men in the age range 55-64 years were found to be osteopenic. Emerging data suggest a significantly increased prevalence of osteoporosis in men and women with multiple sclerosis (MS) compared to age-matched controls, but no specific clinical testing recommendations are available for men. OBJECTIVE: To determine the proportion of male MS patients with osteoporosis and to identify the factors associated with the reduction in bone mass. DESIGN: Consecutive male MS patients seen at our MS clinic were screened with dual-X-ray absorptiometry (DEXA) scan for determining the bone mineral density (BMD). All patients had neurological Expanded Disability Status Scale (EDSS) evaluation. The results were compared to healthy age-matched male reference population using the Z score and to a cohort of women MS patients and women controls. Calcium, total testosterone, sex-hormone binding globulin (SHBG), 25-hydroxy-vitamin-D, and parathyroid hormone (PTH) were evaluated in male patients with decreased BMD. Relevant data on body mass index (BMI), medication, alcohol consumption, smoking, and sexual dysfunction were recorded. SETTING: Academic MS Centre. PATIENTS AND OTHER PARTICIPANTS: Forty consecutive male MS patients, age mean 51.2 +/- 8.7 years, and mean EDSS of 5.8 +/- 1.9 were evaluated with DEXA scan. Of these, 17.5% patients were relapsing-remitting (RR) MS, 57.5% were secondary progressive (SP) MS and 25% were primary progressive (PP) MS. MAIN OUTCOME MEASURE: Proportion of male MS patients with reduced BMD at the lumbar spine and femoral neck. RESULTS: Thirty-two (80%) of our patients had a reduced bone mass of either lumbar spine or the femoral neck; of these 17 patients (42.5%) had osteopenia and 15 patients (37.5%) had osteoporosis. Twenty-one per cent (eight out of 38 patients) had vertebral, rib or extremities fractures. Multivariate linear regression analysis indicated that the EDSS (P < 0.0001) and BMI (P = 0.0004) were the important factors associated with low BMD at the femoral neck and the EDSS was the important factor (P = 0.0017) associated with low BMD at the lumbar spine. The same factors emerged as significantly associated with the corresponding Z scores, which are corrected for age and sex. No clear association between intravenous steroid therapy and BMD was evident in the multivariate analysis. Low levels of 25-hydroxy-vitamin-D were seen in 37.5% of patients. CONCLUSIONS: The proportion of male MS patients with reduced bone mass is high and disproportionate to their age and ambulation, consistent with an association between the MS disease process and pathological bone loss. Increased awareness and bone density screening of male and female MS patients over 40 years of age is warranted.

Genomic effects of IFN-beta in multiple sclerosis patients.

The purpose of this report was to characterize the dynamics of the gene expression cascades induced by an IFN-beta-1a treatment regimen in multiple sclerosis patients and to examine the molecular mechanisms potentially capable of causing heterogeneity in response to therapy. In this open-label pharmacodynamic study design, peripheral blood was obtained from eight relapsing-remitting multiple sclerosis patients just before and at 1, 2, 4, 8, 24, 48, 120, and 168 h after i.m. injection of 30 micro g of IFN-beta-1a. The total RNA was isolated from monocyte-depleted PBL and analyzed using cDNA microarrays containing probes for >4000 known genes. IFN-beta-1a treatment resulted in selective, time-dependent effects on multiple genes. The mRNAs for genes implicated in the anti-viral response, e.g., double-stranded RNA-dependent protein kinase, myxovirus resistance proteins 1 and 2, and guanylate binding proteins 1 and 2 were rapidly induced within 1-4 h of IFN-beta treatment. The mRNAs for several genes involved in IFN-beta signaling, such as IFN-alpha/beta receptor-2 and Stat1, were also increased. The mRNAs for lymphocyte activation markers, such as IFN-induced transmembrane protein 1 (9-27), IFN-induced transmembrane protein 2 (1-8D), beta(2)-microglobulin, and CD69, were also increased in a time-dependent manner. The findings demonstrate that IFN-beta treatment induces specific and time-dependent changes in multiple mRNAs in lymphocytes of multiple sclerosis patients that could provide a framework for rapid monitoring of the response to therapy.