Guy J. Buckle

Self-antigen tetramers discriminate between myelin autoantibodies to native or denatured protein

The role of autoantibodies in the pathogenesis of multiple sclerosis (MS) and other demyelinating diseases is controversial, in part because widely used western blotting and ELISA methods either do not permit the detection of conformation-sensitive antibodies or do not distinguish them from conformation-independent antibodies. We developed a sensitive assay based on self-assembling radiolabeled tetramers that allows discrimination of antibodies against folded or denatured myelin oligodendrocyte glycoprotein (MOG) by selective unfolding of the antigen domain. The tetramer radioimmunoassay (RIA) was more sensitive for MOG autoantibody detection than other methodologies, including monomer-based RIA, ELISA or fluorescent-activated cell sorting (FACS). Autoantibodies from individuals with acute disseminated encephalomyelitis (ADEM) selectively bound the folded MOG tetramer, whereas sera from mice with experimental autoimmune encephalomyelitis induced with MOG peptide immunoprecipitated only the unfolded tetramer. MOG-specific autoantibodies were identified in a subset of ADEM but only rarely in adult-onset MS cases, indicating that MOG is a more prominent target antigen in ADEM than MS.

Smoking and Disease Progression in Multiple Sclerosis

BACKGROUND Although cigarette smokers are at increased risk of developing multiple sclerosis (MS), the effect of smoking on the progression of MS remains uncertain. OBJECTIVE To establish the relationship between cigarette smoking and progression of MS using clinical and magnetic resonance imaging outcomes DESIGN Cross-sectional survey and longitudinal follow-up for a mean of 3.29 years, ending January 15, 2008. SETTING Partners MS Center (Boston, Massachusetts), a referral center for patients with MS. PATIENTS Study participants included 1465 patients with clinically definite MS (25.1% men), with mean (range) age at baseline of 42.0 (16-75) years and disease duration of 9.4 (0-50.4) years. Seven hundred eighty patients (53.2%) were never-smokers, 428 (29.2%) were ex-smokers, and 257 (17.5%) were current smokers. MAIN OUTCOME MEASURES Smoking groups were compared for baseline clinical and magnetic resonance imaging characteristics as well as progression and sustained progression on the Expanded Disability Status Scale at 2 and 5 years and time to disease conversion to secondary progressive MS. In addition, the rate of on-study change in the brain parenchymal fraction and T2 hyperintense lesion volume were compared. RESULTS Current smokers had significantly worse disease at baseline than never-smokers in terms of Expanded Disability Status Scale score (adjusted P < .001), Multiple Sclerosis Severity Score (adjusted P < .001), and brain parenchymal fraction (adjusted P = .004). In addition, current smokers were significantly more likely to have primary progressive MS (adjusted odds ratio, 2.41; 95% confidence interval, 1.09-5.34). At longitudinal analyses, MS in smokers progressed from relapsing-remitting to secondary progressive disease faster than in never-smokers (hazard ratio for current smokers vs never-smokers, 2.50; 95% confidence interval, 1.42-4.41). In addition, in smokers, the T2-weighted lesion volume increased faster (P = .02), and brain parenchymal fraction decreased faster (P = .02). CONCLUSION Our data suggest that cigarette smoke has an adverse influence on the progression of MS and accelerates conversion from a relapsing-remitting to a progressive course.

Deep gray matter involvement on brain MRI scans is associated with clinical progression in multiple sclerosis.

Conventional brain MRI lesion measures have unreliable associations with clinical progression in multiple sclerosis (MS). Gray matter imaging may improve clinical‐MRI correlations.

Brain MRI lesion load at 1.5T and 3T versus clinical status in multiple sclerosis.

To assess correlation between brain lesions and clinical status with 1.5T and 3T magnetic resonance imaging (MRI).

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.

The relationships among MRI-defined spinal cord involvement, brain involvement, and disability in multiple sclerosis

To determine the interrelationships between MRI‐defined lesion and atrophy measures of spinal cord involvement and brain involvement and their relationships to disability in a small cohort of patients with multiple sclerosis (MS).

HLA B*44: Protective effects in MS susceptibility and MRI outcome measures

Objective: In addition to the main multiple sclerosis (MS) major histocompatibility complex (MHC) risk allele (HLA DRB1*1501), investigations of the MHC have implicated several class I MHC loci (HLA A, HLA B, and HLA C) as potential independent MS susceptibility loci. Here, we evaluate the role of 3 putative protective alleles in MS: HLA A*02, HLA B*44, and HLA C*05. Methods: Subjects include a clinic-based patient sample with a diagnosis of either MS or a clinically isolated syndrome (n = 532), compared to subjects in a bone marrow donor registry (n = 776). All subjects have 2-digit HLA data. Logistic regression was used to determine the independence of each alleles effect. We used linear regression and an additive model to test for correlation between an allele and MRI and clinical measures of disease course. Results: After accounting for the effect of HLA DRB1*1501, both HLA A*02 and HLA B*44 are validated as susceptibility alleles (pA*02 0.00039 and pB*44 0.00092) and remain significantly associated with MS susceptibility in the presence of the other allele. Although A*02 is not associated with MS outcome measures, HLA B*44 demonstrates association with a better radiologic outcome both in terms of brain parenchymal fraction and T2 hyperintense lesion volume (p = 0.03 for each outcome). Conclusion: The MHC class I alleles HLA A*02 and HLA B*44 independently reduce susceptibility to MS, but only HLA B*44 appears to influence disease course, preserving brain volume and reducing the burden of T2 hyperintense lesions in subjects with MS.

Spinal cord lesions and clinical status in multiple sclerosis: A 1.5 T and 3 T MRI study

OBJECTIVE Assess the relationship between spinal cord T2 hyperintense lesions and clinical status in multiple sclerosis (MS) with 1.5 and 3 T MRI. METHODS Whole cord T2-weighted fast spin-echo MRI was performed in 32 MS patients [Expanded Disability Status Scale (EDSS) score (mean+/-SD: 2+/-1.9), range 0-6.5]. Protocols at 1.5 T and 3 T were optimized and matched on voxel size. RESULTS Moderate correlations were found between whole cord lesion volume and EDSS score at 1.5 T (r(s)=.36, p=0.04), but not at 3 T (r(s)=0.13, p=0.46). Pyramidal Functional System Score (FSS) correlated with thoracic T2 lesion number (r(s)=.46, p=0.01) and total spinal cord lesion number (r(s)=0.37, p=0.04) and volume (r(s)=0.37, p=0.04) at 1.5 T. Bowel/bladder FSS correlated with T2 lesion volume and number in the cervical, thoracic, and total spine at 1.5 T (r(s) 0.40-0.57, all p<0.05). These MRI-FSS correlations were non-significant at 3 T. However, these correlation coefficients did not differ significantly between platforms (Chois test p>0.05). Correlations between whole cord lesion volume and timed 25-foot walk were non-significant at 1.5 T and 3 T (p>0.05). Lesion number and volume did not differ between MRI platforms in the MS group (p>0.05). CONCLUSIONS Despite the use of higher field MRI strength, the link between spinal lesions and MS disability remains weak. The 1.5 T and 3 T protocols yielded similar results for many comparisons.

An RNA Profile Identifies Two Subsets of Multiple Sclerosis Patients Differing in Disease Activity

A peripheral blood mononuclear cell transcriptional profile differentiates two subsets of multiple sclerosis patients differing in their probability of a relapse. Blood Cell RNA: A Crystal Ball for MS? Multiple sclerosis (MS) is a devastating inflammatory disease that affects primarily the brain and spinal cord; a key challenge in MS remains the clinician’s inability to predict which patient will do well on a given drug. In a new study, Ottoboni et al. took RNA from peripheral blood cells—cells that play a key role in MS attacks and are the target of current therapies—and developed a profile that identified two subsets of patients. These two subsets were seen in untreated patients as well as in patients treated with one of the two first-line MS therapies: glatiramer acetate (GA) and interferon-β (IFN-β). The RNA signature pointed to molecular pathways involved in immune cell activation as being key in differentiating these two subsets of patients. Patients in one of the two subsets, which was called MSA, were more likely to have MS attacks when treated with either GA or IFN-β. This RNA signature from the peripheral blood of MS patients may be able to help identify individuals who are more likely to relapse when treated with first-line MS drugs. If validated in future studies, this signature could become part of a tool to help neurologists identify those MS patients at higher risk of attacks, who would benefit from more aggressive treatment up front. The multiple sclerosis (MS) patient population is highly heterogeneous in terms of disease course and treatment response. We used a transcriptional profile generated from peripheral blood mononuclear cells to define the structure of an MS patient population. Two subsets of MS subjects (MSA and MSB) were found among 141 untreated subjects. We replicated this structure in two additional groups of MS subjects treated with one of the two first-line disease-modifying treatments in MS: glatiramer acetate (GA) (n = 94) and interferon-β (IFN-β) (n = 128). One of the two subsets of subjects (MSA) was distinguished by higher expression of molecules involved in lymphocyte signaling pathways. Further, subjects in this MSA subset were more likely to have a new inflammatory event while on treatment with either GA or IFN-β (P = 0.0077). We thus report a transcriptional signature that differentiates subjects with MS into two classes with different levels of disease activity.

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.