Svetlana Egorova

Circulating MicroRNAs as biomarkers for disease staging in multiple sclerosis

MicroRNAs (miRNAs) are single‐stranded, small noncoding RNAs that regulate gene expression. Because they are stable in serum, they are being developed as biomarkers for cancer and other diseases. In multiple sclerosis (MS), miRNAs have been studied in cell populations but not in the circulation. In MS, a major challenge is to develop immune biomarkers to monitor disease. We asked whether circulating miRNAs could be identified in MS and whether they are linked to disease stage and/or disability.

CTLA4Ig treatment in patients with multiple sclerosis: an open-label, phase 1 clinical trial.

Background: The modulation of costimulatory pathways represents an original therapeutic approach to regulate T cell–mediated autoimmune diseases by preventing or reducing autoantigen-driven T-cell activation in humans. Autoreactive CD4+ T cells play a critical role in initiating the immune response leading to the chronic inflammation and demyelination characteristic of multiple sclerosis (MS). Methods: We used IV infusions of CTLA4Ig to block the CD28/B7 T-cell costimulatory pathway in a phase 1 dose-escalation study in MS. Sixteen patients with relapsing–remitting MS received a single CTLA4Ig infusion and were monitored for up to 3 months after treatment. In an extension study, four additional subjects received four doses of CTLA4Ig. Results: CTLA4Ig was well tolerated in patients with MS, and most adverse events were rated as mild. Immunologic assessment of the patients showed a reduction in myelin basic protein (MBP) proliferation within 2 months of infusion and decreased interferon-γ production by MBP-specific lines. Conclusions: Inhibiting costimulatory molecule interactions by using CTLA4Ig seems safe in multiple sclerosis (MS), and the immunologic effects suggest that it may be a promising approach to regulate the inflammatory process associated with MS. GLOSSARY: 1M = 1 month after infusion; 2M = 2 months after infusion; 3M = 3 months after infusion; 8D = 8 days after infusion; AE = adverse event; AI = Ambulation Index; APC = antigen-presenting cell; BL = baseline; BL2 = second baseline; BPF = brain parenchymal fraction; CTLA-4 = cytotoxic T lymphocyte–associated gene 4; EDSS = Expanded Disability Status Scale; FDA = Food and Drug Administration; Gd+ = gadolinium-enhanced; hMBP = human myelin basic protein; IDO = indolamine 2,3-dioxygenase; IFN = interferon; IL = interleukin; MBP = myelin basic protein; MS = multiple sclerosis; MSFC = Multiple Sclerosis Functional Composite; PBMC = peripheral blood mononuclear cell; RA = rheumatoid arthritis; TE = echo time; TR = repetition time; URI = upper respiratory infection; UTI = urinary tract infection; WBC = white blood cell.

Neurovascular Coupling is Impaired in Slow Walkers: The MOBILIZE Boston Study

Neurovascular coupling may be involved in compensatory mechanisms responsible for preservation of gait speed in elderly people with cerebrovascular disease. Our study examines the association between neurovascular coupling in the middle cerebral artery and gait speed in elderly individuals with impaired cerebral vasoreactivity.

Predicting Clinical Progression in Multiple Sclerosis With the Magnetic Resonance Disease Severity Scale

BACKGROUND Individual magnetic resonance imaging (MRI) disease severity measures, such as atrophy or lesions, show weak relationships to clinical status in patients with multiple sclerosis (MS). OBJECTIVE To combine MS-MRI measures of disease severity into a composite score. DESIGN Retrospective analysis of prospectively collected data. SETTING Community-based and referral subspecialty clinic in an academic hospital. PATIENTS A total of 103 patients with MS, with a mean (SD) Expanded Disability Status Scale (EDSS) score of 3.3 (2.2), of whom 62 (60.2%) had the relapsing-remitting, 33 (32.0%) the secondary progressive, and 8 (7.8%) the primary progressive form. MAIN OUTCOME MEASURES Brain MRI measures included baseline T2 hyperintense (T2LV) and T1 hypointense (T1LV) lesion volume and brain parenchymal fraction (BPF), a marker of global atrophy. The ratio of T1LV to T2LV (T1:T2) assessed lesion severity. A Magnetic Resonance Disease Severity Scale (MRDSS) score, on a continuous scale from 0 to 10, was derived for each patient using T2LV, BPF, and T1:T2. RESULTS The MRDSS score averaged 5.1 (SD, 2.6). Baseline MRI and EDSS correlations were moderate for BPF, T1:T2, and MRDSS and weak for T2LV. The MRDSS showed a larger effect size than the individual MRI components in distinguishing patients with the relapsing-remitting form from those with the secondary progressive form. Models containing either T2LV or MRDSS were significantly associated with disability progression during the mean (SD) 3.2 (0.3)-year observation period, when adjusting for baseline EDSS score. CONCLUSION Combining brain MRI lesion and atrophy measures can predict MS clinical progression and provides the basis for developing an MRI-based continuous scale as a marker of MS disease severity.

Rate of brain atrophy in benign vs early multiple sclerosis.

BACKGROUND Benign multiple sclerosis (MS) is defined by minimal or no disability after many years of observation, therefore a less degenerative disease process is suspected to be present in this subset of patients. OBJECTIVE To compare brain atrophy rates in patients with long-standing benign MS vs typical early MS. DESIGN A longitudinal prospective cohort study and a retrospective database review. SETTING An academic MS center. PATIENTS Thirty-nine patients with clinically defined benign MS and an age-matched group of 40 patients with early relapsing-remitting MS. MAIN OUTCOME MEASURES Baseline demographic, treatment, brain magnetic resonance imaging measures, and annualized atrophy rates, derived from serial brain parenchymal fraction measurements across 2 years, were compared. RESULTS In the baseline analysis, patients with benign MS were matched to the early MS group on age, sex, treatment with immunomodulatory therapy, T2 lesion volume, and brain parenchymal fraction. The mean (SD) annualized brain atrophy rate in patients with benign MS (-0.16% [0.51%]) was lower than that in patients with early MS (-0.46% [0.72%]) (P = .02). The difference remained significant after controlling for age, sex, and treatment (P = .04). CONCLUSIONS Serial magnetic resonance imaging revealed a low 2-year rate of brain atrophy in patients with clinically benign MS, suggesting a less prominent degenerative component in its pathogenesis than in patients with typical early MS. Identification of patients with a low rate of brain atrophy may indicate a benign course.

Evaluation of circulating osteopontin levels in an unselected cohort of patients with multiple sclerosis: relevance for biomarker development.

Background: Osteopontin (OPN) is a pleiotropic protein with important roles in inflammation and immunity that has been suggested as a candidate biomarker for disease activity in multiple sclerosis (MS). Objective: We evaluated plasma levels of OPN in an unselected cohort of MS patients, to determine its potential as a biomarker for disease subtype and/or disease activity in a regular clinical setting. Methods: We analyzed OPN plasma levels in 492 consecutive MS patients, using a commercial enzyme-linked immunosorbent assay (ELISA). Results: OPN levels were higher in relapsing–remitting and secondary progressive MS, compared to healthy controls. Treatment with natalizumab or glatiramer acetate was associated with lower OPN levels. There was no significant association between the OPN levels and disease activity, as measured by clinical or radiological criteria. One-third of patients with high OPN levels had concurrent disorders that may also be associated with increased OPN expression, and which may mask a modest effect of MS disease activity on OPN levels. Conclusion: Our data do not support a role for circulating OPN levels as a biomarker for disease activity in a heterogeneous clinical setting, but does not rule out a potential role in the cerebrospinal fluid, in a controlled setting such as a clinical trial, or in concert with other biomarkers.

A Randomized Controlled Double-Masked Trial of Albuterol Add-on Therapy in Patients With Multiple Sclerosis

BACKGROUND Interleukin 12 (IL-12), a cytokine that promotes generation of helper T cells subtype 1, is increased in multiple sclerosis. Albuterol sulfate, a β2-adrenergic agonist, reduces IL-12 expression, so we tested the effect of albuterol as an add-on treatment to glatiramer acetate therapy. OBJECTIVES To investigate the clinical and immunologic effects of albuterol treatment as an add-on therapy in patients starting glatiramer acetate treatment. DESIGN Single-center double-masked clinical trial. SETTING Academic research. Patients Subjects with relapsing-remitting multiple sclerosis. MAIN OUTCOME MEASURES In this single-center double-masked clinical trial, subjects with relapsing-remitting multiple sclerosis were randomized to receive a subcutaneous injection of glatiramer acetate (20 mg) plus an oral dose of placebo daily for 2 years or a subcutaneous injection of glatiramer acetate (20 mg) plus an oral dose of albuterol daily for 2 years. The primary clinical efficacy measurement was the change in Multiple Sclerosis Functional Composite at 2 years, and the primary immunologic end point was the change in expression of IL-13 and interferon γ at each study time point. The classification level of evidence from this trial is C for each question, as this is the first class II clinical trial addressing the efficacy of glatiramer acetate plus albuterol. RESULTS Forty-four subjects were randomized to receive glatiramer acetate plus albuterol or glatiramer acetate plus placebo, and 39 subjects contributed to the analysis. Improvement in the Multiple Sclerosis Functional Composite was observed in the glatiramer acetate plus albuterol group at the 6-month (P = .005) and 12-month (P = .04) time points but not at the 24-month time point. A delay in the time to first relapse was also observed in the glatiramer acetate plus albuterol group (P = .03). Immunologically, IL-13 and interferon-γ production decreased in both treatment groups, and a treatment effect on IL-13 production was observed at the 12-month time point (P < .05). Adverse events were generally mild, and only 3 moderate or severe events were considered related to the treatment. CONCLUSION Treatment with glatiramer acetate plus albuterol is well tolerated and improves clinical outcomes in patients with multiple sclerosis. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00039988.

Incidence and factors associated with treatment failure in the CLIMB multiple sclerosis cohort study

OBJECTIVE To determine the rate of treatment failure in patients outside of a controlled treatment trial and to ascertain the factors physicians used to make this decision. METHODS One hundred and thirty four patients with the diagnosis of relapsing-remitting (RR) multiple sclerosis (MS) or clinically isolated symptom (CIS) enrolled in the CLIMB study (Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Womens Hospital) were treated with either interferon beta or glatiramer acetate as their initial treatment for MS. RESULTS The probability of failing initial treatment within 3 years was 30%. Clinical activity, defined as relapses and/or progression in disability, determined treatment failure in 35.7% (n=10) of nonresponders. New T2 hyperintense or gadolinium-enhancing lesions on MRI was used to define treatment failure in 28.6% (n=8) and new MRI lesions were used in combination with clinical activity in 35.7% (n=10). Treatment failures had a higher T2 hyperintense lesion volume (p=0.015) and number of gadolinium-enhancing lesions (p=0.0001) on the enrollment MRI than responders. CONCLUSIONS These observations demonstrate that treating physicians use both clinical and MRI parameters to define a response to treatment and initiation of a treatment change and that baseline MRI identified those with increased risk of treatment failure.

New Numerical Solution of the Laplace Equation for Tissue Thickness Measurement in Three-Dimensional MRI

Previous work has shown the importance of thickness measurement in vivo using three-dimensional magnetic resonance imaging (3D MRI). Thickness is defined as the length of trajectories, also called streamlines, which follow the gradient of the solution of the Laplace equation solved between the inner and the outer surfaces of the tissue using Dirichlet conditions.We present a new numerical solution of the Laplace equation for 3D MRI. Our method is accurate and computationally fast. High accuracy is obtained by solving the Laplace equation for anisotropic 3D MRI.We present also an fast and accurate algorithm for calculation of the length of the streamlines. This algorithm is based on a 26 voxels neighbors method and consists of the summation of the Euclidean distance between different voxels neighbors on the same streamline.Our approach was tested on set of synthetic images and several medical applications including knee cartilage, cerebral cortex of a normal adult and cerebral cortex of a newborn. We compare the results with the Euclidean distance measured normal to one boundary along a path between the two boundaries. Numerical validation was performed on set of magnetic resonance images of the knee cartilage. It shows that the 3D PDE approach provides a better result than the Euclidean distance.

Functional MRI with variable echo time acquisition

A new functional MRI protocol that integrates variable echo time (TE) acquisition and a block-design paradigm is proposed and evaluated with finger-tapping motor task. Simulations and experimental data show that the blood oxygenation level-dependent (BOLD) sensitivity achieved with this approach is comparable to that achieved using a conventional constant-TE protocol. The proposed variable-TE fMRI protocol provides valuable information that cannot be obtained with the constant-TE protocol. First, a field inhomogeneity map can be derived from the multi-TE data and used to correct EPI geometric distortions. Second, changes of T2* values due to the BOLD effect can be quantified. Third, for brain regions with pronounced susceptibility field gradients, the reduced BOLD sensitivity may be compensated for when the acquired multi-TE data are processed appropriately (e.g., with weighted summation). Fourth, large venules and veins may possibly be identified (depending on the vessel orientation and volume fraction) by evaluating the phase values of the multi-TE data. Finally, magnetic field drift over time can be measured from dynamic field maps available with this protocol.