Iatrogenic myelodysplastic syndrome complicating multiple sclerosis: A case report.

After 1.5 years of treatment with dimethyl fumarate (DMF) for multiple sclerosis, preceded 8 years earlier by intravenous (IV) cladribine and 1 year earlier by natalizumab, our patient developed myelodysplastic syndrome (MDS). The initial manifestation was a severe drop in absolute neutrophil and lymphocyte counts. Repeat bone marrow biopsy demonstrated a new unbalanced translocation (between the chromosome 1 long arm and chromosome 7 short arm). This case report, to our knowledge, is the first linking iatrogenic MDS to DMF and cladribine, while also suggesting caution with immunosuppressants in multiple sclerosis patients.

A plain language summary on assessing the long-term effectiveness of cladribine tablets in people living with relapsing multiple sclerosis: The CLASSIC-MS study.

WHAT IS THIS SUMMARY ABOUT?: Previous studies have shown that people living with multiple sclerosis (MS) treated with cladribine tablets have fewer relapses (where new symptoms occur or existing symptoms get worse for 24 hours or more) and delayed disability progression (slowing down of the disease getting worse). The CLASSIC-MS study looked at the long-term effectiveness of treatment with cladribine tablets in people living with MS who had taken part in the original CLARITY and CLARITY Extension clinical studies. WHAT WERE THE RESULTS?: Results showed that people treated with cladribine tablets maintained their mobility (the ability to move freely) for longer and experienced other positive effects long after their treatment ended, including being less likely to need further treatment for their MS. WHAT DO THE RESULTS MEAN?: The results obtained from CLASSIC-MS show that the benefits of taking cladribine tablets carry on even when patients stop taking the treatment.

Cyclophosphamide for severe acute forms of central nervous system inflammatory disorders.

Cyclophosphamide (CYC) may be an effective treatment in patients who fail first line therapy for severe central nervous system (CNS) inflammatory disorders including CNS vasculitis, neuromyelitis optica, autoimmune encephalitis, tumefactive and aggressive multiple sclerosis (MS). We performed a retrospective analysis of 46 patients treated with CYC after failing first line therapy for severe CNS inflammatory conditions. Primary outcomes included modified Rankin Scale (mRS) for patients classified into a non-MS group, Expanded Disability Status Score (EDSS) for MS patients, and Targeted Neurological Deficit score (TND) for all patients. Secondary outcome included neuroimaging studies following CYC treatment. By the second follow up period (average of 7 months) mRS in the non-MS group improved from 3.7 to 2.2 and EDSS in the MS group improved from 5.6 to 3.8. Average TND score at 7 months was 2.8 (mild-marked improvement). At first follow up (average 5.6 months), 76.2% (32/42) patients had either stable or improving imaging, and 83.3% (30/36) patients had stable or improving imaging at second follow up (average 13.6 months). Adverse events were reported by 31.9% of patients with most common being nausea and vomiting, headache, alopecia, and hyponatremia. Treatment with CYC can result in disease stabilization of severe CNS inflammatory diseases and is generally well tolerated.

Long-term follow-up of patients with relapsing multiple sclerosis from the CLARITY/CLARITY Extension cohort of CLASSIC-MS: An ambispective study.

BACKGROUND: CLASSIC-MS evaluated the long-term efficacy of cladribine tablets in patients with relapsing multiple sclerosis. OBJECTIVE: Report long-term mobility and disability beyond treatment courses received in CLARITY/CLARITY Extension. METHODS: This analysis represents CLASSIC-MS patients who participated in CLARITY with/without participation in CLARITY Extension, and received ⩾1 course of cladribine tablets or placebo (N = 435). Primary objective includes evaluation of long-term mobility (no wheelchair use in the 3 months prior to first visit in CLASSIC-MS and not bedridden at any time since last parent study dose (LPSD), i.e. Expanded Disability Status Scale (EDSS) score <7). Secondary objective includes long-term disability status (no use of an ambulatory device (EDSS < 6) at any time since LPSD). RESULTS: At CLASSIC-MS baseline, mean ± standard deviation EDSS score was 3.9 ± 2.1 and the median time since LPSD was 10.9 (range = 9.3-14.9) years. Cladribine tablets-exposed population: 90.6% (N = 394), including 160 patients who received a cumulative dose of 3.5 mg/kg over 2 years. Patients not using a wheelchair and not bedridden: exposed, 90.0%; unexposed, 77.8%. Patients with no use of an ambulatory device: exposed, 81.2%; unexposed, 75.6%. CONCLUSION: With a median 10.9 years' follow-up after CLARITY/CLARITY Extension, findings suggest the sustained long-term mobility and disability benefits of cladribine tablets.

Long-term safety and efficacy of daclizumab beta in relapsing-remitting multiple sclerosis: 6-year results from the SELECTED open-label extension study.

OBJECTIVE: SELECTED, an open-label extension study, evaluated daclizumab beta treatment for up to 6 years in participants with relapsing multiple sclerosis who completed the randomized SELECT/SELECTION studies. We report final results of SELECTED. METHODS: Eligible participants who completed 1-2 years of daclizumab beta treatment in SELECT/SELECTION received daclizumab beta 150 mg subcutaneously every 4 weeks for up to 6 years in SELECTED. Safety assessments were evaluated for the SELECTED treatment period; efficacy data were evaluated from first dose of daclizumab beta in SELECT/SELECTION. RESULTS: Ninety percent (410/455) of participants who completed treatment in SELECTION enrolled in SELECTED. Within SELECTED, 69% of participants received daclizumab beta for > 3 years, 39% for > 4 years, and 9% for > 5 years; 87% of participants experienced an adverse event and 26% a serious adverse event (excluding multiple sclerosis relapse). No deaths occurred. Overall, hepatic events were reported in 25% of participants; serious hepatic events in 2%. There were no confirmed cases of immune-mediated encephalitis. Based on weeks from the first daclizumab beta dose in SELECT/SELECTION, adjusted annualized relapse rate (95% confidence interval) for weeks 0-24 was 0.21 (0.16-0.29) and remained low on continued treatment. Overall incidence of 24-week confirmed disability progression was 17.4%. Mean numbers of new/newly enlarging T2 hyperintense lesions remained low; percentage change in whole brain volume decreased over time. CONCLUSIONS: The effects of daclizumab beta on clinical and radiologic outcomes were sustained for up to ~ 8 years of treatment. No new safety concerns were identified in SELECTED. TRIAL REGISTRATION: Clinicaltrials.gov NCT01051349; first registered on January 15, 2010.

Treatment of natalizumab-associated PML with filgrastim.

OBJECTIVE: There is no consensus on the treatment of progressive multifocal leukoencephalopathy (PML) occurring in multiple sclerosis (MS) patients treated with natalizumab (Nz). We report novel immune activating treatment with filgrastim of Nz-associated PML in MS patients treated at Rush University Medical Center. METHODS: We retrospectively analyzed 17 Nz-PML patients treated at this single tertiary referral center between 2010 and 2017. We reviewed the clinical symptoms, diagnostic methods, survival, outcome and MS modifying therapy (MSMT) after Nz-PML. RESULTS: PML occurred after an average of 49 Nz infusions. To facilitate JCV elimination by accelerating immune reconstitution inflammatory syndrome (IRIS), all patients received subcutaneous filgrastim upon PML diagnosis and discontinuation of Nz; eight received plasma exchange (PLEX). Earlier than previously published, PML-IRIS occurred in 15 of 17 (88.2%) patients within a mean of 57.4 days (SD 21.20) after the last Nz infusion. Seven patients recovered to or near baseline. There were no PML/IRIS-related fatalities but one patient committed suicide 2.5 years later. PLEX had no impact on PML outcome. Of 17 patients, 3 (18%) had MS relapses within 1 year after PML, and 5 (29%) beyond 1 year of PML onset, which is lower than expected in highly active MS patients. Eight patients started MSMTs after Nz-PML on an average of 26 months after Nz withdrawal. INTERPRETATION: Our findings indicate that immunoactivation with filgrastim during PML and careful management of subsequent IRIS is likely beneficial in patients with Nz-PML, without worsening MS. The clinical course of MS may be ameliorated by PML.

Glioblastoma in natalizumab-treated multiple sclerosis patients.

We present two natalizumab-treated multiple sclerosis patients who developed glioblastoma multiforme (GBM) with variable outcomes. One patient had an isocitrate dehydrogenase (IDH)-wildtype GBM with aggressive behavior, who declined treatment and died 13 weeks after symptoms onset. The other patient underwent resection of an IDH-mutant secondary GBM that arose from a previously diagnosed grade II astrocytoma. He is still alive 5 years after the diagnosis of GBM. JC virus was not detected in either case. Whether natalizumab played a role in the development of GBM in those patients deserves further investigation.

Safety and efficacy of daclizumab in relapsing-remitting multiple sclerosis: 3-year results from the SELECTED open-label extension study.

BACKGROUND: Daclizumab is a humanized monoclonal antibody against CD25 that modulates interleukin 2 signaling. The SELECT TRILOGY of clinical studies (SELECT/SELECTION/SELECTED) evaluated the safety and efficacy of daclizumab in patients with relapsing-remitting multiple sclerosis (RRMS). We report the long-term safety and efficacy of daclizumab 150 mg subcutaneous every 4 weeks in patients with RRMS in the SELECTED open-label extension study. METHODS: An interim intent-to-treat analysis of all enrolled patients was performed in January 2014 for this ongoing study. RESULTS: The SELECTED study enrolled 90% of patients who completed SELECTION. In the safety and efficacy analysis (N = 410), median treatment time in SELECTED was 25 months (range, <1-45). Adverse events (AEs) were reported in 76% of patients, serious AEs (SAEs) excluding MS relapse in 16%, and treatment discontinuation due to AEs including multiple sclerosis (MS) relapse in 12%. AEs were primarily of mild to moderate severity, and common AEs (≥10%), excluding MS relapse, were nasopharyngitis (12%) and upper respiratory tract infection (12%). Most commonly reported SAEs (in ≥3 patients), excluding MS relapses, were increased serum hepatic enzymes, pneumonia, ulcerative colitis, and urinary tract infection (<1% each). Incidences of AE groups of interest include cutaneous events (28%), cutaneous SAEs (2%), gastrointestinal SAEs (2%), hepatic SAEs, (1%) and malignancies (1%). The incidence of AEs, SAEs, and treatment-related study discontinuations did not increase over time and no deaths were reported. The adjusted annualized relapse rate (95% confidence interval (CI)) analyzed at 6-month intervals was 0.15 (0.10-0.22) for weeks 97-120 and 0.15 (0.10-0.21) for weeks 121-144. In year 3, the adjusted mean (95% CI) number of new/newly enlarging T2 hyperintense lesions was 1.26 (0.93-1.72) and the mean (median) annualized change in brain volume was -0.32% (-0.34%). CONCLUSIONS: The AE incidence did not increase with extension of therapy into year 3 in SELECTED; the safety profile was similar to that previously observed. The clinical efficacy of daclizumab was sustained over the 3 years comprising the SELECT TRILOGY, although potential selection bias cannot be excluded. TRIAL REGISTRATION: Clinicaltrials.gov NCT01051349; first registered January 15, 2010.

Pregnancy Experience: Nonclinical Studies and Pregnancy Outcomes in the Daclizumab Clinical Study Program.

INTRODUCTION: Multiple sclerosis (MS) is more common in women and can occur during childbearing years; thus, information on outcomes following exposure to MS therapy during pregnancy is important. No formal studies of daclizumab have been conducted in pregnant women. Here, we report available nonclinical and clinical data on pregnancy outcomes from the daclizumab clinical study program. METHODS: Reproductive and developmental toxicity studies were conducted in cynomolgus monkeys. Reports of pregnancies that occurred during the daclizumab clinical study program through March 9, 2015 were collated and summarized. In the event of pregnancy, daclizumab was discontinued and safety monitoring continued. RESULTS: Studies in cynomolgus monkeys showed no daclizumab-related effects on maternal well-being, embryo-fetal development, indirect fertility end points, and pre- and postnatal development and growth. Across the clinical study program, 38 pregnancies were reported in 36 daclizumab-exposed women (on treatment ≤6 months from last dose); 20 resulted in live births and four (11%) in spontaneous abortions or miscarriages. One congenital heart defect (complex transposition of great vessels) occurred in one live birth (considered unrelated to daclizumab); daclizumab had been discontinued and intramuscular interferon beta-1a and lisinopril were used at conception. Eight women had an elective termination, two had an ectopic pregnancy, and two were lost to follow-up; two pregnancy outcomes are pending. Six additional pregnancies occurred in five women >6 months after their last daclizumab dose; in one additional pregnancy, exposure was unknown. CONCLUSION: Spontaneous abortion rate in daclizumab-exposed women was consistent with early pregnancy loss in the general population (12%-26%). Data on pregnancies exposed to daclizumab do not suggest an increased risk of adverse fetal or maternal outcomes, although the numbers are too small for definitive conclusions. CLINICALTRIALS. GOV IDENTIFIERS: NCT00390221, NCT01064401, NCT01462318, NCT00870740, NCT01051349, and NCT01797965. FUNDING: Biogen and AbbVie Biotherapeutics Inc.

Is cervical decompression beneficial in patients with coexistent cervical stenosis and multiple sclerosis?

Cervical stenosis (CS) and multiple sclerosis (MS) are two common conditions with distinctive pathophysiology but overlapping clinical manifestations. The uncertainty involved in attributing worsening symptoms to CS in patients with MS due to extremely high prevalence of asymptomatic radiological CS makes treatment decisions challenging. A retrospective review was performed analyzing the medical records of all patients with confirmed diagnosis of MS who had coexistent CS and underwent surgery for cervical radiculopathy/myeloradiculopathy. Eighteen patients with coexistent CS and MS who had undergone cervical spine decompression and fusion were identified. There were six men and 12 women with an average age of 52.7 years (range 40-72 years). Pre-operative symptoms included progressive myelopathy (14 patients), neck pain (seven patients), radiculopathy (five patients), and bladder dysfunction (seven patients). Thirteen of the 14 patients (92.9%) with myelopathy showed either improvement (4/14, 28.6%) or stabilization (9/14, 64.3%) in their symptoms with neck pain and radiculopathy improving in 100% and 80% of patients, respectively. None of the seven patients with urinary dysfunction had improvement in urinary symptoms after surgery. To conclude, cervical spine decompression and fusion can improve or stabilize myelopathy, and significantly relieve neck pain and radiculopathy in the majority of patients with coexistent CS and MS. Urinary dysfunctions appear unlikely to improve after surgery. The low rate of surgical complications in our cohort demonstrates that cervical spine surgery can be safely performed in carefully selected patients with concomitant CS and MS with a good clinical outcome and also eliminate CS as a confounding factor in the long-term management of MS patients.

Autoimmune aquaporin-4 myopathy in neuromyelitis optica spectrum.

IMPORTANCE: Documentation of muscle pathology compatible with targeting of sarcolemmal aquaporin-4 (AQP4) by complement-activating IgG implies involvement of organs beyond the central nervous system in neuromyelitis optica spectrum disorders. OBSERVATIONS: We report on a 51-year-old woman who had relapsing optic neuritis, transverse myelitis, AQP4-IgG seropositivity, and recurrent myalgias with hyperCKemia. A muscle biopsy revealed scattered myofibers with internal nuclei, atrophy, and regeneration but no necrosis. Mild inflammatory exudates, in endomysial and perivascular spaces, consisted of lymphocytes, histiocytes, and scattered eosinophils. The sarcolemma exhibited loss of AQP4 and deposition of IgG and complement activation products, characteristics not seen in control biopsy samples of healthy muscle and immune-mediated myopathies. CONCLUSIONS AND RELEVANCE: Recurrent hyperCKemia accompanying AQP4-IgG seropositivity reflects targeting of skeletal muscle AQP4 by pathogenic IgG. The entity of autoimmune AQP4 myopathy extends the neuromyelitis optica spectrum beyond the central nervous system.

Daclizumab high-yield process in relapsing-remitting multiple sclerosis (SELECTION): a multicentre, randomised, double-blind extension trial.

BACKGROUND: In the SELECT trial, disease activity was reduced in patients with multiple sclerosis who received daclizumab high-yield process (HYP) for 52 weeks. The primary aim of the SELECTION extension study was to assess the safety and immunogenicity of extended treatment with daclizumab HYP. METHODS: A multicentre, randomised, double-blind, 52-week extension trial was done in 74 centres in the Czech Republic, Germany, Hungary, India, Poland, Russia, Ukraine, and the UK between Feb 13, 2009, and Oct 3, 2012. Eligible patients were aged 18-55 years, had relapsing-remitting multiple sclerosis, and had completed the SELECT study. Patients who received placebo in SELECT were randomly assigned (1:1) to receive 150 mg or 300 mg subcutaneous daclizumab HYP every 4 weeks for 52 weeks (treatment initiation group); those who had received daclizumab HYP were randomly assigned (1:1) to continue their present dose with (washout and re-initiation group) or without (continuous treatment group) a washout period of 20 weeks. All randomisation was done with a centralised, interactive voice-response system. Patients and personnel were masked to treatment assignment, except for the site pharmacist who prepared the study drug but had no interaction with patients. The primary endpoints were the safety and immunogenicity of daclizumab HYP. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00870740. FINDINGS: 517 (91%) of 567 patients who completed the SELECT trial entered SELECTION, of whom 170 were in the treatment initiation group, 173 in the continuous treatment group, and 174 in the washout and re-initiation group. 11 patients in the treatment initiation group (6%), 13 in the continuous treatment group (8%), and ten in the washout and re-initiation group (6%) had any serious adverse event other than relapse of multiple sclerosis. One patient in the washout and re-initiation group (300 mg daclizumab HYP) died because of autoimmune hepatitis; a contributory role of daclizumab HYP could not be excluded. Seven patients tested positive for neutralising antidrug antibodies: one (1%) of 128 for whom data were available in the continuous treatment group (this patient also tested positive at SELECTION baseline), four (2%) in the treatment initiation group, and two (2%) of 129 in the washout and re-initiation group. INTERPRETATION: Adverse events and immunogenicity were not increased in the second year of continuous treatment with daclizumab HYP or during treatment washout and re-initiation. These results support further assessment of daclizumab HYP for relapsing-remitting multiple sclerosis. FUNDING: Biogen Idec and AbbVie Biotherapeutics.

Disease-activity-free status in patients with relapsing-remitting multiple sclerosis treated with daclizumab high-yield process in the SELECT study.

BACKGROUND: Daclizumab high-yield process (DAC HYP) is a humanized anti-CD25 monoclonal antibody that inhibits high-affinity interleukin-2 receptor signaling. OBJECTIVE: The objective of this paper is to assess the proportion of DAC HYP- versus placebo-treated patients who were free from disease activity. METHODS: SELECT was a randomized, double-blind, multicenter study of DAC HYP 150 mg or 300 mg, or placebo, administered subcutaneously every four weeks for 52 weeks. In this post-hoc analysis of the SELECT trial, 'disease-activity free' was defined as completion through week 52 without relapses or confirmed three-month disability progression (clinical), with no new/newly enlarging T2-hyperintense lesions and no new gadolinium-enhancing lesions at the week 52 scan (radiological). Primary analyses were based on logistic regression controlling for baseline characteristics. RESULTS: More DAC HYP-treated (39%, n = 156) versus placebo-treated patients (11%, n = 22) were disease-activity free (odds ratio (95% confidence interval), 6.18 (3.71-10.32); p < 0.0001). Furthermore, 77% and 48% of DAC HYP-treated patients were free from clinical or radiological disease activity, respectively, compared with 60% and 18% of placebo-treated patients. CONCLUSION: At one year, DAC HYP resulted in a meaningful increase in the proportion of relapsing-remitting MS patients who were disease-activity free versus placebo.

Daclizumab high-yield process in relapsing-remitting multiple sclerosis (SELECT): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Daclizumab, a humanised monoclonal antibody, modulates interleukin-2 signalling by blocking the α subunit (CD25) of the interleukin-2 receptor. We assessed whether daclizumab high-yield process (HYP) would be effective when given as monotherapy for a 1 year treatment period in patients with relapsing-remitting multiple sclerosis. METHODS: We did a randomised, double-blind, placebo-controlled trial at 76 centres in the Czech Republic, Germany, Hungary, India, Poland, Russia, Ukraine, Turkey, and the UK between Feb 15, 2008, and May 14, 2010. Patients aged 18-55 years with relapsing-remitting multiple sclerosis were randomly assigned (1:1:1), via a central interactive voice response system, to subcutaneous injections of daclizumab HYP 150 mg or 300 mg, or placebo, every 4 weeks for 52 weeks. Patients and study personnel were masked to treatment assignment, except for the site pharmacist who prepared the study drug for injection, but had no interaction with the patient. The primary endpoint was annualised relapse rate. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00390221. FINDINGS: 204 patients were assigned to receive placebo, 208 to daclizumab HYP 150 mg, and 209 to daclizumab HYP 300 mg, of whom 188 (92%), 192 (92%), and 197 (94%), respectively, completed follow-up to week 52. The annualised relapse rate was lower for patients given daclizumab HYP 150 mg (0·21, 95% CI 0·16-0·29; 54% reduction, 95% CI 33-68%; p<0·0001) or 300 mg (0·23, 0·17-0·31, 50% reduction, 28-65%; p=0·00015) than for those given placebo (0·46, 0·37-0·57). More patients were relapse free in the daclizumab HYP 150 mg (81%) and 300 mg (80%) groups than in the placebo group (64%; p<0·0001 in the 150 mg group and p=0·0003 in the 300 mg group). 12 (6%) patients in the placebo group, 15 (7%) of those in the daclizumab 150 mg group, and 19 (9%) in the 300 mg group had serious adverse events excluding multiple sclerosis relapse. One patient given daclizumab HYP 150 mg who was recovering from a serious rash died because of local complication of a psoas abscess. INTERPRETATION: Subcutaneous daclizumab HYP administered every 4 weeks led to clinically important effects on multiple sclerosis disease activity during 1 year of treatment. Our findings support the potential for daclizumab HYP to offer an additional treatment option for relapsing-remitting disease. FUNDING: Biogen Idec and AbbVie Biotherapeutics Inc.

Cross-immunoreactivity between bacterial aquaporin-Z and human aquaporin-4: potential relevance to neuromyelitis optica.

Neuromyelitis optica (NMO) is a chronic inflammatory disease of the CNS that is mediated, in part, by a self-reactive Ab against the astrocyte aquaporin-4 protein. In the current study, we examined the possibility and the biological significance of cross-immunoreactivity between bacterial aquaporin-Z and human aquaporin-4 proteins. Sequence-alignment analysis of these proteins revealed several regions of significant structural homology. Some of the homologous regions were also found to overlap with important immune and disease-relevant epitopes. Cross-immunoreactivity between aquaporin-Z and aquaporin-4 was investigated and ascertained in multiple immune-based assays using sera from patients with neuromyelitis optica, immune mouse serum, and Abs raised against aquaporin-Z. The biological significance of this phenomenon was established in series of experiments demonstrating that induction of an immune response against aquaporin-Z or its homologous regions can also trigger an autoimmune reaction against aquaporin-4 and inflammation of the CNS. Our study indicates that the autoimmune response against aquaporin-4 in neuromyelitis optica may be triggered by infection-induced cross-immunoreactivity and presents a new perspective on the pathogenesis of this disease.

Overexpression of the dominant-negative form of interferon regulatory factor 1 in oligodendrocytes protects against experimental autoimmune encephalomyelitis.

Interferon regulatory factor 1 (IRF-1) is a transcription factor that has been implicated in the pathogenesis of the human autoimmune demyelinating disease multiple sclerosis (MS) and in its animal model, experimental autoimmune encephalomyelitis (EAE). The goal of the present study was to directly examine the role of IRF-1 in oligodendrocyte injury and inflammatory demyelination. For the purpose of this study, we generated a transgenic mouse line (CNP/dnIRF-1) that overexpresses the dominant-negative form of IRF-1 (dnIRF1) specifically in oligodendrocytes. CNP/dnIRF-1 mice exhibited no phenotypic abnormalities but displayed suppressed IRF-1 signaling in oligodendrocytes. The major finding of our study was that the CNP/dnIRF-1 mice, compared with the wild-type mice, were protected against EAE, a phenomenon associated with significant reduction of inflammatory demyelination and with oligodendrocyte and axonal preservation. The observed protection was related to suppressed IRF-1 signaling and impaired expression of immune and proapoptotic genes in oligodendrocytes. No significant differences in the peripheral immune responses between the wild-type and the CNP/dnIRF-1 mice were identified throughout the experiments. This study indicates that IRF-1 plays a critical role in the pathogenesis of EAE by mediating oligodendrocyte response to inflammation and injury. It also suggests that oligodendrocytes are actively involved in the neuroimmune network, and that exploring oligodendrocyte-related pathogenic mechanisms, in addition to the conventional immune-based ones, may have important therapeutic implications in MS.

IRF-1 signaling in central nervous system glial cells regulates inflammatory demyelination.

The present study provides evidence that interferon regulatory factor 1 (IRF-1) signaling in glial cells is involved in the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). Using a bone marrow chimera model of EAE, we demonstrated that CNS IRF-1 regulates inflammatory demyelination and disease severity independently of the peripheral immune cells. In addition, we identified Caspase 1, a pro-inflammatory and pro-apoptotic molecule, as an important transcriptional target of IRF-1. The findings of our study indicate that IRF-1 signaling in glial cells serves as a final common pathway of inflammatory demyelination and may have important clinical implications in MS.

Freedom from disease activity in multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) shares many pathologic features with other immune-mediated inflammatory diseases, such as rheumatoid arthritis, Crohn disease, and psoriasis. The development of effective biologic agents for rheumatoid arthritis has resulted in a treatment paradigm shift such that disease remission is now an explicit goal. EXPERT CLINICAL OPINION: The traditional immunomodulatory disease-modifying therapies for MS (interferon beta and glatiramer acetate) delay disease progression and reduce activity on brain MRI to varying degrees; however, they have not been demonstrated to induce disease remission. Therefore, the concept of disease remission or freedom from disease activity in MS has received little attention from the neurology community. We discuss some potential definitions of disease remission in MS and whether freedom from disease activity can become an increasingly useful measure of therapeutic response. FUTURE DIRECTIONS: Future research should be directed at determining the long-term significance of freedom from disease activity during a short-term clinical trial in relapsing-remitting MS.