Faculty Bibliography

OBJECTIVE: A previous phase 3 study showed significant improvement in walking ability in multiple sclerosis (MS) patients treated with oral, extended-release dalfampridine (4-aminopyridine) 10mg twice daily. The current study was designed to confirm efficacy and further define safety and pharmacodynamics. METHODS: This was a 39-center, double-blind trial in patients with definite MS of any course type. Participants were randomized to 9 weeks of treatment with dalfampridine (10mg twice daily; n = 120) or placebo (n = 119). Response was defined as consistent improvement on the Timed 25-Foot Walk, with percentage of timed walk responders (TWRs) in each treatment group as the primary outcome. The last on-treatment visit provided data from 8 to 12 hours postdose, to examine maintenance of effect. RESULTS: One patient from each group was excluded from the modified Intention to Treat population. The proportion of TWRs was higher in the dalfampridine group (51/119 or 42.9%) compared to the placebo group (11/118 or 9.3%, p < 0.0001). The average improvement in walking speed among dalfampridine-treated TWRs during the 8-week efficacy evaluation period was 24.7% from baseline (95% confidence interval, 21.0-28.4%); the mean improvement at the last on-treatment visit was 25.7%, showing maintenance of effect over the interdosing period. There were no new safety findings. INTERPRETATION: This interventional study provides class 1 evidence that dalfampridine extended-release tablets produce clinically meaningful improvement in walking ability in a subset of people with MS, with the effect maintained between doses

Fatigue is an extremely prevalent issue for multiple sclerosis (MS) patients. Fatigue can affect quality of life, depression, anxiety, motor function and sleep patterns. There are a number of available rating scales designed to detect and assess fatigue. However, the pathophysiology of fatigue is still not completely understood and the treatment of this symptom remains difficult. A number of clinical trials for fatigue in MS have shown some benefit with different interventions, including medication, physical activity and cognitive-behavioral therapy. Nonetheless, further research and the development of more targeted therapies are needed to improve the management of fatigue.

OBJECTIVE: To investigate utility of a Multiple Sclerosis Severity Scale (MSSS)-based classification system for comparing African American (AA) and white American (WA) multiple sclerosis (MS) subpopulations in the New York State Multiple Sclerosis Consortium (NYSMSC) database. MSSS is a frequency-rank algorithm relating MS disability to disease duration in a large, untreated reference population. Design/ METHODS: Distributions of patients in 6 MSSS-based severity grades were calculated for AA and WA registrants. RESULTS: There were 419 AA and 5,809 WA patients in the NYSMSC, who had EDSS recorded during years 1-30 since symptom onset. Median EDSS was not different in AA and WA (3.5 vs 3.0, p = 0.60), whereas median MSSS in AA was higher than in WA (6.0 vs 4.8, p = 0.001). AA patients were overrepresented in the 2 most severe grades (41.5% vs 29.3% for WA) and underrepresented in the 2 lowest grades (23.4% vs 35.4%; p < 0.001). In multivariable analysis (ordered logistic and median regression), MSSS for AA remained significantly higher than in WA after adjusting for age, gender, disease duration, disease type distribution, and treatment with disease-modifying therapies. CONCLUSIONS: The 6-tiered MSSS grading system is a powerful tool for comparing rate of disease progression in subpopulations of interest. MSSS-based analysis demonstrates that African ancestry is a risk factor for a more rapidly disabling disease course

Anti-myelin basic protein (MBP) antibodies in pediatric-onset MS and controls were characterized. Serum samples were obtained from 94 children with MS and 106 controls. Paired CSF and serum were obtained from 25 children with MS at time of their initial episode of acute demyelinating syndrome (ADS). Complementary assays were applied across samples to evaluate the presence, and the physical binding properties, of anti-MBP antibodies. While the prevalence and titers of serum anti-MBP antibodies against both immature and mature forms of MBP were similar in children with MS and in controls, binding characteristics and formal Surface Plasmon Resonance (SPR) studies indicated surprisingly high binding affinities of all pediatric anti-MBP antibodies. Serum levels of anti-MBP antibodies correlated significantly with their CSF levels, and their presence in children with MS was associated with significantly increased risk of an acute disseminated encephalomyelitis-like initial clinical presentation. While antibodies to both immature and mature forms of MBP can be present as part of the normal pediatric humoral repertoire, these anti-myelin antibodies are of surprisingly high affinity, can access the CNS during inflammation, and have the capacity to modulate disease expression. Our findings identify an immune mechanism that could contribute to the observed heterogeneity in spectrum of clinical presentations in early-onset MS.

OBJECTIVE: We sought to determine if vitamin D status, a risk factor for multiple sclerosis, is associated with the rate of subsequent clinical relapses in pediatric-onset multiple sclerosis. METHODS: This is a retrospective study of patients with pediatric-onset multiple sclerosis or clinically isolated syndrome who were consecutively recruited into a prospective cohort at their clinical visit at the pediatric multiple sclerosis center of University of California, San Francisco or State University of New York at Stony Brook. Of 171 eligible patients, 134 (78%) with multiple sclerosis/clinically isolated syndrome were included in the cohort; a further 24 were excluded from this analysis due to lack of available serum (n = 7) or lack of follow-up (n = 17). Serum 25-hydroxyvitamin D(3) levels were measured and were adjusted to reflect a deseasonalized value. The adjusted serum 25-hydroxyvitamin D(3) level was the primary predictor in a multivariate negative binomial regression model in which the main outcome measure was the number of subsequent relapses. RESULTS: Among the 110 subjects, the mean unadjusted 25-hydroxyvitamin D(3) level was 22 +/- 9 ng/ml. After adjustment for age, gender, race, ethnicity, disease duration, disease-modifying therapy, and length of follow-up, every 10 ng/ml increase in the adjusted 25-hydroxyvitamin D(3) level was associated with a 34% decrease in the rate of subsequent relapses (incidence rate ratio, 0.66; 95% confidence interval, 0.46-0.95; p = 0.024). INTERPRETATION: Lower serum 25-hydroxyvitamin D(3) levels are associated with a substantially increased subsequent relapse rate in pediatric-onset multiple sclerosis or clinically isolated syndrome, providing rationale for a randomized controlled trial of vitamin D supplementation.