Bardia Nourbakhsh

Neutralization of IL-9 Ameliorates Experimental Autoimmune Encephalomyelitis by Decreasing the Effector T Cell Population

Multiple sclerosis is a CD4+ T cell-mediated autoimmune disease affecting the CNS. Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), have been thought to be Th1-mediated diseases. However, recent studies provide strong evidence that the major pathogenic T cell subsets in EAE are Th17 cells. IL-9, a hematopoietic growth factor, is considered to be a mediator of Th17 cells, but the precise mechanisms of its action are largely unknown. The present study was designed to investigate the role of IL-9 in autoimmune demyelination. IL-9 blockade with anti–IL-9 mAb inhibited the development of EAE, reduced the serum levels of IL-17, the CNS mRNA expression of IL-17, IL-6, IFN-γ, and TNF-α, and the myelin oligodendrocyte glycoprotein (MOG)-induced IL-17, IFN-γ secretion of lymphocytes. Furthermore, anti–IL-9 mAb in culture suppressed IL-17 production of MOG-reactive T cells and their potency in adoptive transfer EAE. These findings indicate that the protective effect of IL-9 blockade in EAE was likely mediated via inhibition of the development of MOG peptide-specific T cells, which in turn led to reduced infiltration of T cells into the CNS. Thus, anti–IL-9 mAb treatment may provide an effective therapeutic strategy against autoimmune diseases.

Rebound Syndrome in Patients With Multiple Sclerosis After Cessation of Fingolimod Treatment

IMPORTANCE The appropriate sequencing of agents with strong immune system effects has become increasingly important. Transitions require careful balance between safety and protection against relapse. The cases presented herein highlight that rebound events after ceasing fingolimod treatment may happen even with short washout periods (4 weeks) and may perpetuate despite steroid treatment or the immediate use of fast-acting immune therapies, such as rituximab. OBJECTIVE To describe rebound syndrome in patients with multiple sclerosis (MS) after cessation of fingolimod treatment. DESIGN, SETTING, AND PARTICIPANTS Clinical and demographic data were extracted from electronic medical records from the University of California, San Francisco, Multiple Sclerosis Center from January 2014 to December 2015. Magnetic resonance images were reviewed by MS neurologists (J.S.G., E.W., B.N., and E.C.H.). Rebound syndrome was defined as new severe neurological symptoms after ceasing fingolimod treatment, with the development of multiple new or enhancing lesions exceeding baseline activity. We reviewed the PubMed database from January 2010 to December 2015 for similar cases of severe disease reactivation after ceasing fingolimod treatment using search terms fingolimod and either rebound or reactivation. Participants were included if they stopped receiving fingolimod between January 2014 and December 2015. Five patients were identified who experienced rebound after ceasing fingolimod treatment. EXPOSURES Each patient received treatment with oral fingolimod for various durations. MAIN OUTCOMES AND MEASURES Occurrence of rebound after ceasing fingolimod treatment. RESULTS The mean (SD) age of the 5 female patients presented in this case series was 35.2 (6.4) years. Of the 46 patients that stopped fingolimod treatment within the 2-year period, 5 (10.9%) experienced severe relapse 4 to 16 weeks after ceasing fingolimod treatment. Despite varying prior severity of relapsing-remitting course, all participants experienced unexpectedly severe clinical relapses accompanied by drastic increases in new or enhancing lesions seen on magnetic resonance imaging evidenced by a median (range) increase of 9 (0->30) new gadolinium-enhancing lesions and a median (range) of 9 (0->30) new T2 lesions. New lesion development persisted for 3 to 6 months despite treatment with corticosteroids (n = 3) and initiation of B-cell depleting therapy (n = 2). In addition, 11 patients were identified through literature review reported as having severe relapses consistent with a rebound syndrome and similar features to our 5 cases. CONCLUSIONS AND RELEVANCE These cases provide evidence for a fingolimod rebound syndrome at a clinically relevant frequency, highlighting the need to determine the best methods for sequencing or discontinuing MS therapies. A large prospective registry or population-based study would be helpful to confirm this rebound phenomenon and to determine contributing factors, including immune biomarkers, that increase risk for this syndrome.

IL-9 is important for T cell activation and differentiation in autoimmune inflammation of the central nervous system

Experimental autoimmune encephalomyelitis (EAE) is generally believed to be an autoimmune disease of the central nervous system (CNS) caused by myelin‐specific Th1 and/or Th17 effector cells. The underlying cellular and molecular mechanisms, however, are not fully understood. Using mice deficient in IL‐9 (IL‐9−/−), we showed that IL‐9 plays a critical role in EAE. Specifically, IL‐9−/− mice developed significantly less severe EAE than their WT counterparts following both immunization with myelin proteolipid protein (PLP)180–199 peptide in the presence of Complete Freunds Adjuvant (CFA), and adoptive transfer of PLP180–199 peptide‐specific effector T cells from WT littermates. EAE‐resistant IL‐9−/− mice exhibited considerably fewer infiltrating immune cells in the CNS, with lower levels of IL‐17 and IFN‐γ expression, than their WT littermates. Further studies revealed that null mutation of the IL‐9 gene resulted in significantly lower levels of PLP180–199 peptide‐specific IL‐17 and IFN‐γ production. Moreover, IL‐9−/− memory/activated T cells exhibited decreased C–C chemokine receptors (CCR)2, CCR5, and CCR6 expression. Interestingly, IL‐10 was significantly increased in IL‐9−/− mice compared with WT littermates. Importantly, we found that IL‐9‐mediated Th17‐cell differentiation triggers complex STAT signaling pathways.

Kit (W-sh) Mice Develop Earlier and More Severe Experimental Autoimmune Encephalomyelitis Due to Absence of Immune Suppression

Mast cells (MCs) have been thought to play a pathogenic role in the development of autoimmune diseases, including experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, an immunoregulatory function of these cells has recently been suggested. We investigated the role of MCs in EAE using the W-sh mouse strain, which is MC deficient. W-sh mice developed earlier and more severe clinical and pathological disease with extensive demyelination and inflammation in the CNS. The inflammatory cells were mainly composed of CD4+ T cells, monocyte/macrophages, neutrophils, and dendritic cells. Compared with wild-type mice, MC-deficient mice exhibited an increased level of MCP-1/CCR2 and CD44 expression on CD4+ T cells in addition to decreased production of regulatory T cells, IL-4, IL-5, IL-27, and IL-10. We also found that levels of IL-17, IFN-γ, and GM-CSF were significantly increased in peripheral lymphocytes from immunized W-sh mice compared with those in peripheral lymphocytes from wild-type mice. Reconstitution of W-sh mice downregulated susceptibility to EAE, which correlated with MC recruitment and regulatory T cell activation in the CNS. These findings indicate that responsiveness is not required in the pathogenesis of inflammatory demyelination in the CNS and that, in the absence of MCs, increased MCP-1, CCR2, IL-17, IFN-γ, CD44, and other inflammatory molecules may be responsible for increased severity of EAE.

Serum neurofilament is associated with progression of brain atrophy and disability in early MS

Objective: To investigate a potential effect of riluzole on serum neurofilaments (Nf) compared to placebo and the relationship between longitudinal clinical and MRI outcomes and serum Nf levels. Methods: Serum samples were obtained from participants enrolled in a randomized double-blind trial of neuroprotection with riluzole vs placebo as an add-on to weekly interferon-β (IFN-β)–1a IM initiated 3 months after randomization. Nf measurements were performed by ELISA and electrochemiluminescence immunoassay. Results: Longitudinal serum samples were available from 22 riluzole and 20 placebo participants over 24 months. There was no observed treatment effect with riluzole. Nf light chain (NfL) levels decreased over time (p = 0.007 at 24 months), whereas the Nf heavy chain was unchanged (p = 0.997). Changes in NfL were correlated with EDSS change (p = 0.009) and neuropsychological outcomes. Brain volume decreased more rapidly in patients with high baseline NfL (p = 0.05 at 12 months and p = 0.008 at 24 months) and this relationship became stronger at 24 months (p = 0.024 for interaction). Higher and increasing NfL predicted higher number of gadolinium-enhancing lesions (p < 0.001 for both). Conclusions: Our findings support the potential value of serum NfL as a marker of neuroaxonal injury in early multiple sclerosis. Its reduction over time could represent regression to the mean, or a possible treatment effect of IFN-β-1a. The association with whole brain atrophy and the formation of acute white matter lesions has relevant implications to use serum NfL as a noninvasive biomarker of the overall consequences of brain damage and ongoing disease activity. ClinicalTrials.gov identifier: NCT00501943.

Dietary salt intake and time to relapse in paediatric multiple sclerosis

Background Salt intake was reported to be associated with increased clinical and MRI activity in adult patients with relapsing-remitting multiple sclerosis (MS). Objective To determine if salt intake is associated with time to relapse in patients with paediatric-onset MS. Methods Paediatric-onset MS and patients with clinically isolated syndrome (CIS) within 4 years of disease onset were recruited from 15 paediatric MS centres in the USA as part of a case–control study. Patients with available prospective relapse data subsequent to enrolment were included in this project. Dietary sodium intake was assessed by self-report questionnaire using the validated Block Kids Food Screener. Cox proportional-hazards regression models were employed to determine the association of sodium density, excess sodium intake and sodium density tertiles with time to relapse following study enrolment, adjusting for several confounders. Results 174 relapsing-remitting MS/CIS patients were included in this analysis (mean age of 15.0 years, and 64.9% females). Median duration of follow-up was 1.8 years. In an unadjusted analysis, density of daily sodium intake was not associated with time to relapse, and patients with excess sodium intake had no decrease in time to relapse as compared with patients with non-excess sodium intake. The multivariable analysis demonstrated that patients in the medium and high tertile of sodium density had a HR of 0.69 (95% CI 0.37 to 1.30, p=0.25) and 1.37 (95% CI 0.74 to 2.51, p=0.32) compared with patients in the lowest tertile, respectively. Conclusions Higher salt intake was not associated with decreased time to relapse in patients with paediatric-onset MS.

Salutary Effects of N-Acetylcysteine on Apoptotic Damage in a Rat Model of Testicular Torsion

Introduction: Numerous studies performed in recent years have shown protective effects of N-acetylcysteine (NAC) on cardiac and renal tissue damage following ischemia/reperfusion injury. We assessed the effectiveness of systemic administration of NAC, at a therapeutic dose, in a rat model of a 1-hour 720-degree testicular torsion/detorsion. Materials and Methods: Sprague-Dawley rats were divided into five groups, 14 animals in each: group 1 animals underwent sham operation as the control group; group 2 rats underwent torsion/detorsion and received saline injection, and the animals in groups 3, 4, and 5 received intraperitoneal injections of 150 mg/kg NAC 30 min before torsion, after torsion, and after detorsion, respectively. Markers of oxidative stress as well as germ cell apoptosis indices were assessed 4 and 24 h after detorsion, respectively. Results: The apoptosis indices were significantly higher in group 2 as compared with the control group. Four hours after detorsion, the testicular level of lipid peroxidation was significantly increased, and antioxidant enzyme activities were significantly decreased in group 2 as compared with the controls. Administration of NAC either 30 min before or after torsion (groups 3 and 4) significantly improved the germ cell apoptosis indices and oxidant/antioxidant balance. Administration of NAC after detorsion had no significant effect on biochemical markers or germ cell apoptosis. Conclusion: Administration of NAC prior to torsion or detorsion, but not after detorsion, induces protective effects against ischemia/reperfusion injury in a rat model of testicular torsion.

Fatigue and depression predict quality of life in patients with early multiple sclerosis: a longitudinal study

The clinical predictors of health‐related quality of life (HRQoL) in multiple sclerosis (MS) have mainly been studied in patients with long‐standing disease. The objective of this study was to investigate the longitudinal association among HRQoL and clinical characteristics in early MS.

Low dose zymosan ameliorates both chronic and relapsing experimental autoimmune encephalomyelitis

Zymosan has previously been reported to have both pro-inflammatory and anti-inflammatory effects. Here we demonstrate that low dose zymosan prevented or reversed chronic and relapsing paralysis in EAE. In suppressing CNS autoimmune inflammation, zymosan not only regulated APC costimulator and MHC class II expression, but also promoted differentiation of regulatory T cells. Following adoptive transfer of zymosan-primed CD4(+) T cells, recipient mice were protected from EAE. In contrast, a MAPK inhibitor and a blocker of β-glucan, reversed the effects of zymosan. These results demonstrate that zymosan may be a promising beneficial agent for Multiple Sclerosis (MS).

Longitudinal associations between brain structural changes and fatigue in early MS

BACKGROUND Fatigue is a common and disabling symptom of multiple sclerosis (MS) patients. Structural changes in several brain areas have been reported to correlate with fatigue in MS patients but none consistently. OBJECTIVE To study the association between global and regional measures of brain atrophy and fatigue in patients with early relapsing MS. METHODS Clinically isolated syndrome and relapsing MS patients within 12 months of clinical onset were enrolled in a neuroprotection trial of riluzole versus placebo with up to 36 months of follow-up. MRI metrics included brain volumes measured by SIENAX normalized measurements [normalized brain parenchymal volume (nBPV), normalized normal-appearing white and gray matter volume (nNAWMV and nGMV)] and T2 lesion volume (T2LV). Cortical thickness, thalamic volume and cerebellar cortical volume were measured using Freesurfers longitudinal pipeline (v5.3) and a lesion inpainting approach. Fatigue was evaluated using the Modified Fatigue Impact Scale (MFIS). Mixed model regression measured time trends and associations between imaging and fatigue severity, adjusting for age and sex. RESULTS Forty-three patients (mean age 36 years; 31 females) were enrolled within 7.5 ± 4.9 months of symptom onset. Baseline and change over baseline in lesion volumes, grey matter, white matter, basal ganglia and total parenchymal volumes were not associated with change in MFIS score over time. Lower thalamic volume at baseline predicted increasing physical subscale of MFIS score during the study (p=0.017). There was a trend toward baseline thalamic volume and cerebellar cortical volume predicting subsequent change in total MFIS score (p=0.055 and 0.082 respectively). On-study change in thalamic or cerebellar cortical volume was not associated with on-study change in MFIS score. CONCLUSION Global measures of tissue loss are not strongly associated with fatigue in patients with early MS. However, thalamic and cerebellar cortical atrophy may be predictive of subsequent changes in fatigue in these patients.