Monica Marta

Multiple Sclerosis Severity Score Using disability and disease duration to rate disease severity

Background: There is no consensus method for determining progression of disability in patients with multiple sclerosis (MS) when each patient has had only a single assessment in the course of the disease. Methods: Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. In order to compare different methods of detecting such effects the authors simulated the effects of a genetic factor on disability. Results: Cross-sectional EDSS measurements made after the first year were representative of overall disease severity. The MSSS was more powerful than the other methods the authors tested for detecting different rates of disease progression. Conclusion: The Multiple Sclerosis Severity Score (MSSS) is a powerful method for comparing disease progression using single assessment data. The Global MSSS can be used as a reference table for future disability comparisons. While useful for comparing groups of patients, disease fluctuation precludes its use as a predictor of future disability in an individual.

T Cell Ig- and Mucin-Domain-Containing Molecule-3 (TIM-3) and TIM-1 Molecules Are Differentially Expressed on Human Th1 and Th2 Cells and in Cerebrospinal Fluid-Derived Mononuclear Cells in Multiple Sclerosis

T cell Ig- and mucin-domain-containing molecules (TIMs) comprise a recently described family of molecules expressed on T cells. TIM-3 has been shown to be expressed on murine Th1 cell clones and has been implicated in the pathogenesis of Th1-driven experimental autoimmune encephalomyelitis. In contrast, association of TIM-1 polymorphisms to Th2-related airway hyperreactivity has been suggested in mice. The TIM molecules have not been investigated in human Th1- or Th2-mediated diseases. Using real-time (TaqMan) RT-PCR, we show that human Th1 lines expressed higher TIM-3 mRNA levels, while Th2 lines demonstrated a higher expression of TIM-1. Analysis of cerebrospinal fluid mononuclear cells obtained from patients with multiple sclerosis revealed significantly higher mRNA expression of TIM-1 compared with controls. Moreover, higher TIM-1 expression was associated with clinical remissions and low expression of IFN-γ mRNA in cerebrospinal fluid mononuclear cells. In contrast, expression of TIM-3 correlated well with high expression of IFN-γ and TNF-α. These data imply the differential expression of human TIM molecules by Th1 and Th2 cells and may suggest their differential involvement in different phases of a human autoimmune disease.

Unexpected regulatory roles of TLR4 and TLR9 in experimental autoimmune encephalomyelitis

Innate immune mechanisms essential for priming encephalitogenic T cells in autoimmune neuroinflammation are poorly understood. Experimental autoimmune encephalomyelitis (EAE) is a IL‐17‐producing Th (Th17) cell‐mediated autoimmune disease and an animal model of multiple sclerosis. To investigate how upstream TLR signals influence autoimmune T cell responses, we studied the role of individual TLR and MyD88, the common TLR adaptor molecule, in the initiation of innate and adaptive immune responses in EAE. Wild type (WT) C57BL/6, TLR‐deficient and MyD88‐deficient mice were immunized with myelin oligodendrocyte glycoprotein (MOG) in CFA. MyD88–/– mice were completely EAE resistant. Purified splenic myeloid DC (mDC) from MyD88–/– mice expressed much less IL‐6 and IL‐23, and serum and T cell IL‐17 were absent. TLR4–/– and TLR9–/– mice surprisingly exhibited more severe EAE symptoms than WT mice. IL‐6 and IL‐23 expression by mDC and Th17 responses were higher in TLR4–/– mice, suggesting a regulatory role of TLR4 in priming Th17 cells. IL‐6 expression by splenocytes was higher in TLR9–/– mice. Our data suggest that MyD88 mediates the induction of mDC IL‐6 and IL‐23 responses after MOG immunization, which in turn drives IL‐17‐producing encephalitogenic Th17 cell activation. Importantly, we demonstrate that TLR4 and TLR9 regulate disease severity in MOG‐induced EAE.

Is it time to target no evident disease activity (NEDA) in multiple sclerosis

The management of multiple sclerosis is becoming increasingly complex with the emergence of new and more effective disease-modifying therapies (DMT). We propose a new treatment paradigm that individualises treatment based on a choice between two interchangeable therapeutic strategies of maintenance-escalation or induction therapy. We propose treating- to-target of no evident disease activity (NEDA) as defined using clinical and MRI criteria. This algorithm requires active monitoring with a rebaselining MRI, at a point in time after the specific DMT concerned has had sufficient time to work, and at least annual MRI studies to monitor for subclinical relapses. Disease activity on the maintenance-escalation therapy arm of the algorithm indicates a sub-optimal treatment response and should trigger a discussion about switching, or escalating, therapy or the consideration of switching to the induction therapy arm of the algorithm. In comparison, disease activity on an induction therapy arm would be an indication for retreatment or a switch to the maintenance-escalation therapy arm. We envisage the definition of NEDA evolving with time as new technological innovations are adopted into clinical practice, for example the normalisation of whole, or regional, brain atrophy rates and cerebrospinal fluid neurofilament levels.

Myasthenia gravis and neuromyelitis optica spectrum disorder: a multicenter study of 16 patients.

Objective: To describe 16 patients with a coincidence of 2 rare diseases: aquaporin-4 antibody (AQP4-Ab)–mediated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and acetylcholine receptor antibody (AChR-Ab)–mediated myasthenia gravis (AChR-MG). Methods: The clinical details and antibody results of 16 patients with AChR-MG and AQP4-NMOSD were analyzed retrospectively. Results: All had early-onset AChR-MG, the majority with mild generalized disease, and a high proportion achieved remission. Fifteen were female; 11 were Caucasian. In 14/16, the MG preceded NMOSD (median interval: 16 years) and 11 of these had had a thymectomy although 1 only after NMOSD onset. In 4/5 patients tested, AQP4-Abs were detectable between 4 and 16 years prior to disease onset, including 2 patients with detectable AQP4-Abs prior to thymectomy. AChR-Abs decreased and the AQP4-Ab levels increased over time in concordance with the relevant disease. AChR-Abs were detectable at NMOSD onset in the one sample available from 1 of the 2 patients with NMOSD before MG. Conclusions: Although both conditions are rare, the association of MG and NMOSD occurs much more frequently than by chance and the MG appears to follow a benign course. AChR-Abs or AQP4-Abs may be present years before onset of the relevant disease and the antibody titers against AQP4 and AChR tend to change in opposite directions. Although most cases had MG prior to NMOSD onset, and had undergone thymectomy, NMOSD can occur first and in patients who have not had their thymus removed.

Regulation of autoimmune encephalomyelitis by toll-like receptors

Experimental autoimmune encephalomyelitis (EAE) is a Th17-mediated autoimmune disease and an animal model for multiple sclerosis (MS). Complete Freunds adjuvant (CFA) contains pathogen-associated molecular patterns (PAMPs) that bind toll-like receptors (TLRs), and is necessary to induce EAE. Upstream TLR signals modify innate and adaptive immune responses in EAE. In detail, the common TLR adaptor molecule MyD88 is necessary for induction of EAE, and mediates activation of peripheral myeloid dendritic cells (mDCs) and differentiation of autoimmune Th17 cells. The stimulatory TLRs have not yet been identified for Th17 cells. TLR4 down regulates disease severity in EAE and Th17 cell responses, but promotes Th1 cell responses, which may inhibit the differentiation of Th17 cells. Moreover, treatment with a TLR4 ligand tolerizes mice and prevents EAE. TLR9 down regulates disease severity in myelin oligodendrocyte glycoprotein (MOG)-induced EAE, whereas it promotes disease in MOG(35-55)-induced EAE. Thus MyD88, TLR4 and TLR9 modify the disease process in EAE. Both endogenous and CFA-derived TLR ligands are implicated to modulate the disease process.

Memory B Cells are Major Targets for Effective Immunotherapy in Relapsing Multiple Sclerosis.

Although multiple sclerosis (MS) is considered to be a CD4, Th17-mediated autoimmune disease, supportive evidence is perhaps circumstantial, often based on animal studies, and is questioned by the perceived failure of CD4-depleting antibodies to control relapsing MS. Therefore, it was interestingly to find that current MS-treatments, believed to act via T cell inhibition, including: beta-interferons, glatiramer acetate, cytostatic agents, dimethyl fumarate, fingolimod, cladribine, daclizumab, rituximab/ocrelizumab physically, or functionally in the case of natalizumab, also depleted CD19 +, CD27 + memory B cells. This depletion was substantial and long-term following CD52 and CD20-depletion, and both also induced long-term inhibition of MS with few treatment cycles, indicating induction-therapy activity. Importantly, memory B cells were augmented by B cell activating factor (atacicept) and tumor necrosis factor (infliximab) blockade that are known to worsen MS. This creates a unifying concept centered on memory B cells that is consistent with therapeutic, histopathological and etiological aspects of MS.

No evidence for higher risk of cancer in patients with multiple sclerosis taking cladribine

Objective: To compare the cancer risk of cladribine and other disease-modifying drugs (DMDs) in trials of people with relapsing multiple sclerosis (pwRMS). Methods: Meta-analysis of phase III trials of licensed DMDs for pwRMS and a phase III trial of cladribine (CLARITY). Cancer rates were compared using Fisher exact test. Results: Eleven trials were included. Investigated treatments included cladribine, dimethyl fumarate, fingolimod, teriflunomide, natalizumab, alemtuzumab, and glatiramer acetate. The cancer rate in the CLARITY treatment group (0.34%) was not increased compared to all other treatment groups, whether including placebo-controlled trials only (0.6%, p = 0.4631) or all trials, i.e., including those with an active comparator arm (0.67%, p = 0.3669). No cancer was reported in the CLARITY placebo group, whereas the combined cancer rate of all other placebo groups was 1.19% (p = 0.0159). The cancer rate of zero in the CLARITY placebo group was also lower than that in the phase III trial of cladribine in people with clinically isolated syndrome (ORACLE MS, 2.91%, p = 0.0012). In fact, no difference was detected between cancer rates in the treatment groups of CLARITY (0.34%) and ORACLE MS (0.49%) (p = 0.6546). Conclusions: Our study does not support an increased cancer risk from cladribine in the doses used in CLARITY and ORACLE MS, which previously contributed to refusal of market authorization of cladribine in Europe. Longer-term follow-up is required to assess the safety profile of cladribine, as well as currently licensed DMDs, to definitively assess cancer risk.

Biomarker Report from the Phase II Lamotrigine Trial in Secondary Progressive MS – Neurofilament as a Surrogate of Disease Progression

Objective Lamotrigine trial in SPMS was a randomised control trial to assess whether partial blockade of sodium channels has a neuroprotective effect. The current study was an additional study to investigate the value of neurofilament (NfH) and other biomarkers in predicting prognosis and/or response to treatment. Methods SPMS patients who attended the NHNN or the Royal Free Hospital, UK, eligible for inclusion were invited to participate in the biomarker study. Primary outcome was whether lamotrigine would significantly reduce detectable serum NfH at 0-12, 12–24 and 0–24 months compared to placebo. Other serum/plasma and CSF biomarkers were also explored. Results Treatment effect by comparing absolute changes in NfH between the lamotrigine and placebo group showed no difference, however based on serum lamotrigine adherence there was significant decline in NfH (NfH 12–24 months p = 0.043, Nfh 0–24 months p = 0.023). Serum NfH correlated with disability: walking times, 9-HPT (non-dominant hand), PASAT, z-score, MSIS-29 (psychological) and EDSS and MRI cerebral atrophy and MTR. Other biomarkers explored in this study were not found to be significantly associated, aside from that of plasma osteopontin. Conclusions The relations between NfH and clinical scores of disability and MRI measures of atrophy and disease burden support NfH being a potential surrogate endpoint complementing MRI in neuroprotective trials and sample sizes for such trials are presented here. We did not observe a reduction in NfH levels between the Lamotrigine and placebo arms, however, the reduction in serum NfH levels based on lamotrigine adherence points to a possible neuroprotective effect of lamotrigine on axonal degeneration.

Resolution of a 16.8-Mb Autoimmunity-Regulating Rat Chromosome 4 Region into Multiple Encephalomyelitis Quantitative Trait Loci and Evidence for Epistasis

To investigate effects of a 16.8-Mb region on rat chromosome 4q42–43 on encephalomyelitis, we performed a high-resolution mapping using a 10th generation advanced intercross line between the susceptible DA strain and the MHC identical but resistant PVG.1AV1 strain. Clinical signs of myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE) developed in 29% of 772 F10 rats. Three regions controlling disease, Eae20, Eae21, and Eae22, were mapped using 15 microsatellite markers spanning 16.8 Mb. Eae20 was a major genetic determinant within the region whereas Eae21 modified disease severity. Eae22 was identified as an epistatic region because it only displayed an effect together with Piebald Virol Glaxo (PVG) alleles on Eae20. Disease down-regulation by PVG alleles in the telomeric part of Eae20 was also demonstrated in DA rats made congenic for a ∼1.44-Mb chromosomal region from PVG. As the region containing Eae20–Eae22 also regulates arthritis, together with the fact that the syntenic mouse 6F2–F3 region regulates experimental lupus and diabetes, and the syntenic human 12p13.31–13.2 region regulates multiple sclerosis and rheumatoid arthritis, the present data point to genes that control several inflammatory diseases. The pairscan analyses of interaction, which here identified Eae22, are novel in the encephalomyelitis field and of importance in the design of further studies of this region in other diseases and species. The limited number of genes identified in Eae20, Eae21, and Eae22 enables focused examination of their relevance in mechanistic animal studies and screening of their association to human diseases.