Yaping Yan

Fingolimod for the Treatment of Intracerebral Hemorrhage: A 2-Arm Proof-of-Concept Study

IMPORTANCE Pronounced inflammatory reactions occurring shortly after intracerebral hemorrhage (ICH) contribute to the formation and progression of perihematomal edema (PHE) and secondary brain injury. We hypothesized that modulation of brain inflammation reduces edema, thus improving clinical outcomes in patients with ICH. OBJECTIVE To investigate whether oral administration of fingolimod, a Food and Drug Administration-approved sphingosine 1-phosphate receptor modulator for multiple sclerosis, is safe and effective in alleviating PHE and neurologic deficits in patients with ICH. DESIGN, SETTING, AND PARTICIPANTS In this 2-arm, evaluator-blinded study, we included 23 patients with primary supratentorial ICH with hematomal volume of 5 to 30 mL. Clinical and neuroimaging feature-matched patients were treated with standard care with or without oral fingolimod. The study was conducted in Tianjin Medical University General Hospital, Tianjin, China. INTERVENTIONS All patients received standard management alone (control participants) or combined with fingolimod (FTY720, Gilenya), 0.5 mg, orally for 3 consecutive days. Treatment was initiated within 1 hour after the baseline computed tomographic scan and no later than 72 hours after the onset of symptoms. MAIN OUTCOMES AND MEASURES Neurologic status and hematomal and PHE volumes (Ev) and relative PHE, defined as Ev divided by hematomal volume, were monitored by clinical assessment and magnetic resonance imaging, respectively, for 3 months. RESULTS Patients treated with fingolimod exhibited a reduction of neurologic impairment compared with control individuals, regained a Glasgow Coma Scale score of 15 by day 7 (100% vs 50%, P = .01), and had a National Institutes of Health Stroke Scale score reduction of 7.5 vs 0.5 (P < .001). Neurologic functions improved in these patients in the first week coincident with a reduction of circulating lymphocyte counts. At 3 months, a greater proportion of patients receiving fingolimod achieved full recovery of neurologic functions (modified Barthel Index score range, 95-100; 63% vs 0%; P = .001; modified Rankin Scale score range, 0-1; 63% vs 0%; P = .001), and fewer reported ICH-related lung infections. Perihematomal edema volume and rPHE were significantly smaller in fingolimod-treated patients than in control individuals (Ev at day 7, 47 mL vs 108 mL, P = .04; Ev at day 14, 55 mL vs 124 mL, P = .07; rPHE at day 7, 2.5 vs 6.4, P < .001; rPHE at day 14, 2.6 vs 7.7, P = .003, respectively). We recorded no differences between groups in the occurrence of adverse events. CONCLUSIONS AND RELEVANCE In patients with small- to moderate-sized deep primary supratentorial ICH, administration of oral fingolimod within 72 hours of disease onset was safe, reduced PHE, attenuated neurologic deficits, and promoted recovery. The efficacy of fingolimod in preventing secondary brain injury in patients with ICH warrants further investigation in late-phase trials. TRIAL REGISTRATION clinicaltrials.gov Identifier:NCT02002390.

Impact of an immune modulator fingolimod on acute ischemic stroke

Significance In patients with acute ischemic stroke (AIS), the abrupt and massive influx of lymphocytes from the periphery to the ischemic region orchestrates focal inflammatory responses, catalyzes tissue death, and worsens clinical outcomes. In this early phase clinical study, we reduced lymphocyte migration to the brain during the first 72 h of AIS via oral administration of three doses of fingolimod. This administration led to a significant reduction of secondary lesion enlargement, microvascular permeability, and better clinical outcomes during the acute phase and 3-mo follow-up visit. This study will provoke new investigations on the efficacy of modulation of brain inflammation in AIS. Peripheral lymphocytes entering brain ischemic regions orchestrate inflammatory responses, catalyze tissue death, and worsen clinical outcomes of acute ischemic stroke (AIS) in preclinical studies. However, it is not known whether modulating brain inflammation can impact the outcome of patients with AIS. In this open-label, evaluator-blinded, parallel-group clinical pilot trial, we recruited 22 patients matched for clinical and MRI characteristics, with anterior cerebral circulation occlusion and onset of stroke that had exceeded 4.5 h, who then received standard management alone (controls) or standard management plus fingolimod (FTY720, Gilenya, Novartis), 0.5 mg per day orally for 3 consecutive days. Compared with the 11 control patients, the 11 fingolimod recipients had lower circulating lymphocyte counts, milder neurological deficits, and better recovery of neurological functions. This difference was most profound in the first week when reduction of National Institutes of Health Stroke Scale was 4 vs. −1, respectively (P = 0.0001). Neurological rehabilitation was faster in the fingolimod-treated group. Enlargement of lesion size was more restrained between baseline and day 7 than in controls (9 vs. 27 mL, P = 0.0494). Furthermore, rT1%, an indicator of microvascular permeability, was lower in the fingolimod-treated group at 7 d (20.5 vs. 11.0; P = 0.005). No drug-related serious events occurred. We conclude that in patients with acute and anterior cerebral circulation occlusion stroke, oral fingolimod within 72 h of disease onset was safe, limited secondary tissue injury from baseline to 7 d, decreased microvascular permeability, attenuated neurological deficits, and promoted recovery.

Structural MRI substrates of cognitive impairment in neuromyelitis optica

Objective: To identify the clinical and structural MRI markers for predicting cognitive impairment (CI) in patients with neuromyelitis optica (NMO). Methods: Fifty-four patients with NMO and 27 healthy controls underwent extensive neuropsychological testing and multimodal 3.0T MRI. The patient group was classified as CI or cognitively preserved (CP), using a criterion of ≤1.5 SD on at least 2 cognitive domains. MRI measurements included white matter (WM) lesion volume, gray matter (GM), WM, and deep GM (DGM) volume, cortical thickness, and the severity and extent of WM tract diffusion metric alterations based on fractional anisotropy and mean, axial, and radial diffusivity. Groups were compared using a multivariate general linear model, and clinical and MRI measurements were related to average cognition z scores by partial correlations and a stepwise linear regression model. Results: Twenty-six patients with NMO (48.2%) were classified as CI and showed WM tract diffusion abnormalities, particularly increased radial diffusivity, and GM especially DGM atrophy compared with healthy controls. Patients classified as CP also showed alterations of WM tract diffusion but without significant GM atrophy. Compared with the CP group, patients with CI demonstrated a lower level of education and decreased hippocampal volume. In the whole patient group, average cognition z scores were best predicted by the level of education and hippocampal volume (R2 = 0.46, p < 0.001). Conclusion: In patients with NMO, WM tract integrity disruption was identified in both CP and CI groups. GM atrophy, particularly in the DGM, was only found in the CI group. Hippocampal volume is the main MRI predictor of cognition in NMO.

Augmentation of Circulating Follicular Helper T Cells and Their Impact on Autoreactive B Cells in Myasthenia Gravis.

Myasthenia gravis (MG) is a chronic humoral immunity–mediated autoimmune disorder of the neuromuscular junction characterized by muscle weakness. Follicular helper T (Tfh) cells may be the key Th cell subset that promotes MG development, as their major function is helping B cell activation and Ab production. Aberrance of thymus-derived Tfh cells might be implicated in autoimmune diseases including MG; just how circulating Tfh cells, especially those from patients with a normal thymus, contribute to MG pathogenesis remains to be uncovered. In this article, we characterize a population of circulating CD4+CXCR5+PD-1+ Tfh cells in ocular and generalized MG patients without thymic abnormalities and demonstrate that the circulating Tfh cells are significantly enriched in generalized MG patients but not in ocular MG patients compared with healthy subjects, whereas a proportion of follicular regulatory T cells decreased in MG patients. In addition, the frequency of plasma cells and B cells was higher and the serum levels of IL-6/IL-21 were also elevated in these MG patients. The activated Tfh1 and Tfh17 in Tfh cells are the major source for IL-21 production in MG patients. A strong correlation between Tfh cells and the plasma cell frequency and anti–acetylcholine receptor Ab titers was evident in generalized MG patients. In particular, we found that Tfh cells derived from MG patients promoted B cells to produce Abs in an IL-21 signaling–dependent manner. Collectively, our results suggest that circulating Tfh cells may act on autoreactive B cells and thus contribute to the development of MG in patients without thymic abnormalities.

Autoantibody to MOG suggests two distinct clinical subtypes of NMOSD

We characterized a unique group of patients with neuromyelitis optica spectrum disorder (NMOSD) who carried autoantibodies of aquaporin-4 (AQP4) and myelin-oligodendrocyte glycoprotein (MOG). Among the 125 NMOSD patients, 10 (8.0%) were AQP4- and MOG-ab double positive, and 14 (11.2%) were MOG-ab single positive. The double-positive patients had a multiphase disease course with a high annual relapse rate (P=0.0431), and severe residual disability (P>0.0001). Of the double- positive patients, 70% had MS-like brain lesions, more severe edematous, multifocal regions on spinal magnetic resonance imaging (MRI), pronounced decreases of retinal nerve fiber layer thickness and atrophy of optic nerves. In contrast, patients with only MOG-ab had a higher ratio of monophasic disease course and mild residual disability. Spinal cord MRI illustrated multifocal cord lesions with mild edema, and brain MRIs showed more lesions around lateral ventricles. NMOSD patients carrying both autoantibodies to AQP4 and MOG existed and exhibited combined features of prototypic NMO and relapsing- remitting form of MS, whereas NMOSD with antibodies to MOG only exhibited an “intermediate” phenotype between NMOSD and MS. Our study suggests that antibodies against MOG might be pathogenic in NMOSD patients and that determination of anti-MOG antibodies maybe instructive for management of NMOSD patients.

Fingolimod alters inflammatory mediators and vascular permeability in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) leads to high rates of death and disability. The pronounced inflammatory reactions that rapidly follow ICH contribute to disease progression. Our recent clinical trial demonstrated that oral administration of an immune modulator fingolimod restrained secondary injury derived from initial hematoma, but the mechanisms remain unknown. In this study, we aim to investigate the effects of fingolimod on inflammatory mediators and vascular permeability in the clinical trial of oral fingolimod for intracerebral hemorrhage (ICH). The results showed that fingolimod decreased the numbers of circulating CD4+ T, CD8+ T, CD19+ B, NK, and NKT cells and they recovered quickly after the drug was stopped. The plasma ICAM level was decreased and IL-10 was increased by fingolimod. Interestingly, fingolimod protected vascular permeability as indicated by a decreased plasma level of MMP9 and the reduced rT1%. In conclusion, modulation of systemic inflammation by fingolimod demonstrates that it is an effective therapeutic agent for ICH. Fingolimod may prevent perihematomal edema enlargement by protecting vascular permeability.

Association of circulating follicular helper T cells with disease course of NMO spectrum disorders.

While follicular helper T (Tfh) cells have been shown to be involved in many autoimmune diseases, the association of Tfh cells with the disease activity of neuromyelitis optica spectrum disorders (NMOSDs) remains unclear. In this study, the CD4(+)CXCR5(+)PD-1(+) Tfh cell population in peripheral blood mononuclear cells (PBMCs) obtained from NMOSD patients, age- and gender-matched healthy controls, and multiple sclerosis patients was compared by flow cytometry. The serum levels of IL-21, IL-6, IL-17, TNF-α and IL-10 were analyzed by ELISA assays. We found that in NMOSD, the Tfh cell frequency is higher than that of healthy subjects and multiple sclerosis (MS) patients. There are more Tfh cells in the relapsing stage than the remitting stage of NMOSD, thus demonstrating the close association of the Tfh cell population with disease activity. Methylprednisolone, which is used to control disease relapses, significantly decreased the proportion of Tfh cells in NMOSD patients.

Alterations of natural killer cells in traumatic brain injury

To investigate the relationship between natural killer (NK) cells and traumatic brain injury (TBI), we tracked an established phenotype of circulating NK cells at several time points in patients with different grades of TBI. In serial peripheral blood samples, NK cells were prospectively measured by flow cytometry of CD3− CD56+ lymphocytes. Compared to healthy controls, TBI patients had reductions in both the percentage and the absolute number of NK cells. Furthermore, the magnitude of NK cell reduction correlated with the degree of TBI severity at several time points. That is, NK cell population size was independently associated with lower Glasgow Coma Scale scores. In addition, at some time points, a positive correlation was found between the NK cell counts and Glasgow Outcome Scale scores. Our results indicate that TBI induces a reduction in the number of NK cells, and the magnitude of the reduction appears to parallel the severity of TBI.

Glatiramer acetate ameliorates experimental autoimmune neuritis

Glatiramer acetate (GA) is one of the first‐line disease‐modifying medications that have been approved for the treatment of multiple sclerosis via immune modulatory mechanisms. However, it remains unclear whether the immunomodulation effect of GA is central nervous system (CNS) antigen specific. Here, we explored the mechanism of action of GA by subcutaneously injecting GA in experimental autoimmune neuritis (EAN) rats, an animal model for Guillain–Barré syndrome (GBS). Clinical, electrophysiological and histological findings showed that neurological deficits, demyelination and axonal injury of sciatic nerves were all significantly attenuated in Lewis rats when GA was administered before immunization with peripheral nervous system antigen P0. Our results further demonstrated that GA treatment inhibited either P0 or myelin basic protein (MBP) (CNS antigen)‐stimulated auto‐immune T‐cell proliferation in vitro. GA administrated at 10 days after induction of EAN when neurological sign became apparent also ameliorated the severity of disease, inhibited T‐cell response to P0 and MBP and induced shift of proinflammatory and immune modulatory cytokines. Collectively, our findings suggested that GA attenuated neurological deficits in EAN rats and that the immune modulatory mechanisms of GA were not CNS antigen specific.

Low expression of complement inhibitory protein CD59 contributes to humoral autoimmunity against astrocytes

Neuromyelitis optica spectrum disorder is primarily an anti-aquaporin 4 autoantibody-mediated, central nervous system-restricted channelopathy. Patients frequently develop central nervous system-restricted lesions even though autoantigen aquaporin 4 in neuromyelitis optica spectrum disorder is broadly distributed in the central nervous system and peripheral organs. The cause of such tissue-specific immune response remains largely unknown. We confirmed here that CD59, an inhibitory regulator of the complement membrane attack complex, is expressed and co-localized with aquaporin 4 in peripheral organs but is only minimally expressed in astrocytes in the central nervous system. In addition, we further found that CD59 overexpression in mouse brains decreased demyelination, blocked the loss of astrocytes and aquaporin 4, and inhibited membrane attack complex formation and infiltration of inflammatory cells. Inactivation of CD59 in mouse peripheral aquaporin 4-expressing cells and tissues led to complement-dependent cytotoxicity. In accordance with the mouse data, human samples presented higher expression of CD59 in many aquaporin 4-expressing peripheral tissues but not in astrocytes. Silencing or blocking CD59 in aquaporin 4-expressing human tracheal epithelial and skeletal muscle cells induced membrane attack complex formation and cytotoxicity, which suggests a protective role of CD59 in anti-aquaporin 4 antibodies-mediated complement toxicity. Our findings suggest that low CD59 expression in astrocytes may contribute to central nervous system-restricted lesions in neuromyelitis optica spectrum disorder. Restoring CD59 expression in astrocytes may serve as a novel therapeutic target of neuromyelitis optica spectrum disorder.