Jae-Won Hyun

Myelin injury without astrocytopathy in neuroinflammatory disorders with MOG antibodies

Objective To compare myelin and astrocyte injury in patients with antibodies against myelin oligodendrocyte glycoprotein (anti-MOG) or aquaporin-4 (anti-AQP4), and multiple sclerosis (MS). Methods Myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) levels were measured in the cerebral spinal fluid (CSF) from anti-MOG+ or anti-AQP4+ patients tested in both sera and CSF by cell-based assays with live transfected cells. Results In total, 75.6% (68/90) of the patients were positive for either anti-MOG or anti-AQP4 antibodies in both serum and CSF; 74.2% (23/31) were anti-MOG+, and 76.3% (45/59) were anti-AQP4+. No patients were only CSF positive or were positive for both anti-MOG and anti-AQP4 antibodies, and none of the MS patients or controls had these autoantibodies in the serum or CSF. MBP levels were elevated in the anti-MOG+ cases compared to the multiple sclerosis (MS) patients, and the levels found were similar between anti-MOG+ cases and anti-AQP4+ neuromyelitis optica spectrum disorder (NMOSD) cases. Meanwhile, GFAP was only elevated in the anti-AQP4+ NMOSD. Moreover, CSF pleocytosis, high protein levels, and oligoclonal IgG band negativity distinguished the anti-MOG+ cases from MS patients. Conclusions Myelin injury was more severe in the anti-MOG+ cases than in the MS cases, and anti-MOG+ cases have differences in the CSF characteristics compared to MS. GFAP elevation in anti-AQP4+ cases was absent in anti-MOG+ patients (even in cases with NMOSD phenotype), indicating that immune-mediated astrocytopathy is unique to anti-AQP4+ patients. Our study suggests that anti-MOG+ cases are distinct from MS and anti-AQP4+ NMOSD.

Comparative analysis of treatment outcomes in patients with neuromyelitis optica spectrum disorder using multifaceted endpoints

Background: There is still an unmet need for comparative analyses of available treatment options for neuromyelitis optica spectrum disorder (NMOSD). Objective: We aimed to compare the efficacies of the immunosuppressants most commonly prescribed for patients with NMOSD using multifaceted endpoints. Methods: We conducted a retrospective analysis of treatment outcomes in 138 NMOSD patients treated with azathioprine, mycophenolate mofetil (MMF), or rituximab. The primary outcome measures were the annualized relapse rate (ARR), annualized severe relapse rate, time to first relapse, and time to first severe relapse. Results: A comparison of any relapse among the groups revealed that the azathioprine had a significantly higher risk of relapse relative to the rituximab (hazard ratio: 1.82; 95% CI: 1.1–3.1; p=0.03). A comparison of severe relapse among the groups revealed that the hazard ratios of severe relapse for the azathioprine and MMF relative to the rituximab were 11.66 (95% CI: 2.6–52.3; p=0.001) and 5.96 (95% CI: 1.0–35.1; p=0.048), respectively. The times to first relapse and first severe relapse were also significantly different among the treatment groups Conclusions: The present study showed that reductions in the risks of relapse and severe relapse differed among patients who were initially treated with azathioprine, MMF, and rituximab.

Longitudinal analysis of myelin oligodendrocyte glycoprotein antibodies in CNS inflammatory diseases.

Background We evaluated the seroprevalence of myelin oligodendrocyte glycoprotein immunoglobulin G1 (MOG-IgG) and associated clinical features of patients from a large adult-dominant unselected cohort with mainly relapsing central nervous system (CNS) inflammatory diseases. We also investigate the clinical relevance of MOG-IgG through a longitudinal analysis of serological status over a 2-year follow-up period. Methods Serum samples from 505 patients with CNS inflammatory diseases at the National Cancer Center were analysed using cell-based assays for MOG-IgG and aquaporin-4 immunoglobulin G (AQP4-IgG). MOG-IgG serostatus was longitudinally assessed in seropositive patients with available serum samples and at least 2 years follow-up. Results Twenty-two of 505 (4.4%) patients with CNS inflammatory diseases were positive for MOG-IgG. Patients with MOG-IgG had neuromyelitis optica spectrum disorder (NMOSD, n=10), idiopathic AQP4-IgG-negative myelitis (n=4), idiopathic AQP4-IgG-negative optic neuritis (n=4), other demyelinating syndromes (n=3) and multiple sclerosis (n=1). No relapses were seen in patients when they became MOG-IgG seronegative, whereas a persistent positive serological status was observed in patients with clinical relapses despite immunotherapy. Conclusions In a large adult-predominant unselected cohort of mainly relapsing CNS inflammatory diseases, we confirmed that NMOSD phenotype was most commonly observed in patients with MOG-IgG. A longitudinal analysis with 2-year follow-up suggested that persistence of MOG-IgG is associated with relapses.

A Longitudinal Brain Magnetic Resonance Imaging Study of Neuromyelitis Optica Spectrum Disorder

Brain involvement is commonly seen in patients with neuromyelitis optica spectrum disorder (NMOSD). However, little is known about the chronic changes of acute brain lesions on MRI over time. Here, our objective was to evaluate how acute brain MRI lesions in NMOSD changed on follow-up MRI. We reviewed the MRIs of 63 patients with NMOSD who had acute brain lesions and follow-up MRI over an interval of at least 3 months. Of the 211 acute brain lesions, 24% of lesions disappeared completely on T2-weighed images (WI) and a decrease in size ≥50% on T2-WI was observed in 58% of lesions on follow-up MRI. However, 47% of lesions revealed focal T1-hypointensity and, in particular, 18% showed focal cystic changes. Cystic changes were observed most commonly in corticospinal tract and corpus callosal lesions whereas the vast majority of lesions in the cerebellum, basal ganglia and temporal white matter resolved completely. MRI remission on T2-WI occurred in 82% of lesions, while approximately half of the lesions presented foci of T1-hypointensity, which may be considered a severe tissue injury over time. The extent of brain injury following an acute brain lesion in NMOSD may depend on the location of the lesion.

Idiopathic aquaporin-4 antibody negative longitudinally extensive transverse myelitis

Background: Longitudinally extensive transverse myelitis (LETM) is a characteristic manifestation of neuromyelitis optica (NMO). However, not all patients with LETM are positive for aquaporin-4 (AQP4) antibodies. We evaluated the characteristics of idiopathic isolated LETM negative for AQP4 antibodies. Methods: From the National Cancer Center registry of inflammatory diseases of the central nervous system, patients with LETM as an initial manifestation and follow-up for at least two years were enrolled. Their medical records and MRIs were reviewed retrospectively. AQP4 antibody was confirmed by three different validated methods at least three times. Cerebrospinal fluid (CSF) glial fibrillary acidic protein (GFAP) levels were measured to investigate astrocyte damage. Results: Among 108 patients with first-ever LETM, 55 were positive for AQP4 antibodies (P-LETM) and 53 were consistently negative. Of them, seven were later diagnosed with seronegative NMO, and four were positive for MOG antibodies. The remaining 42 patients (N-LETM) showed several features distinct from P-LETM: male predominance, older age of onset, milder clinical presentation, spinal cord confinement and absence of combined autoimmunity. CSF GFAP levels were not increased in N-LETM but were markedly elevated in P-LETM. Conclusions: Idiopathic isolated N-LETM is not that rare among first-ever LETM, and has many features distinct from P-LETM where astrocytic damage is evident.

Steroid-Resistant Relapsing IgG4-Related Pachymeningitis Treated With Methotrexate

IMPORTANCE IgG4-related disease, which is newly recognized, is characterized by lymphoplasmacytic infiltration with increased IgG4-secreting plasma cells. Although a favorable response to steroids has previously been reported, the durations of follow-up to confirm the long-term benefits and clinical courses were limited. We describe long-term favorable response of oral methotrexate in a patient with IgG4-related pachymeningitis who was resistant to steroid therapy. OBSERVATIONS A patient in his mid-60s with pathologically proven IgG4-related pachymeningitis who was resistant to steroid therapy and experienced an exacerbation of symptoms 4 times is described. Low-dose oral methotrexate induced significant clinical and radiological improvement, with sustained remission of the disease over 2 years without complications. CONCLUSIONS AND RELEVANCE The long-term favorable response to oral methotrexate in the current patient suggests that methotrexate is a useful alternative treatment option in patients with IgG4-related pachymeningitis who are resistant to steroid therapy or who experience adverse effects from steroids.

Tumefactive demyelinating lesions as a first clinical event: Clinical, imaging, and follow-up observations.

BACKGROUND Tumefactive demyelinating lesions (TDLs) are associated with a variety of demyelinating diseases in the central nervous system (CNS). However, there are no current guidelines describing how to classify and treat patients with this rare phenotype. Thus, the present study aimed to determine the long-term evolution and disease course of patients initially presenting with TDLs and to describe their clinical and radiographic characteristics. METHODS From the National Cancer Center registry of inflammatory diseases of the CNS, 31 patients initially presenting with TDLs with follow-up for at least 12 months were enrolled and their demographic, clinical, and radiographic characteristics were evaluated. RESULTS The median follow-up duration was 37.6 months, during which time 11 patients were diagnosed with neuromyelitis optica spectrum disorder (NMOSD), seven with multiple sclerosis (MS), and 11 remained idiopathic; six did not experience any further clinical events (isolated demyelinating syndrome), and five patients experienced recurrent demyelinating events that were not consistent with either MS or NMOSD. Of the remaining two patients, one was diagnosed with hyperthyroidism-associated demyelination and one with tacrolimus-induced demyelination. CONCLUSIONS The majority of TDLs evolve into MS or NMOSD. However, despite extensive diagnostic work-ups and long-term follow-ups, the etiology of TDLs was unknown for some patients.

Short segment myelitis as a first manifestation of neuromyelitis optica spectrum disorders

Background: Some patients with neuromyelitis optica spectrum disorders (NMOSD) present with spinal cord lesions extending fewer than three vertebral segments (short transverse myelitis, STM), hindering an early diagnosis. Objective: We investigated the frequency and imaging characteristics of STM lesions in patients presenting with myelitis as an initial manifestation of NMOSD. Methods: Patients seen at three referral hospitals in Korea between June 2005 and March 2015 who met the following inclusion criteria were recruited for review: seropositivity for aquaporin-4 antibody, initial presentation with myelitis and spinal cord magnetic resonance imaging (MRI) performed within 1 month of initial myelitis onset. Results: Of the 76 enrolled patients, 65 (85.5%) collectively had 69 longitudinally extensive transverse myelitis lesions, while the remaining 11 (14.5%) had a total of 15 STM lesions. Of the 15 STM lesions, 5 spanned 2.5 vertebral segments, 6 were continuous over two segments, 3 showed a length of 1.5 segments and 1 was confined to a single segment. On axial imaging, all of the STM lesions involved the central grey matter. Conclusion: These MRI findings suggested that STM does not preclude the possibility of an NMOSD diagnosis.

Cognitive impairment differs between neuromyelitis optica spectrum disorder and multiple sclerosis.

Objective: To compare the frequency and pattern of cognitive impairment (CI) between patients with neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). Methods: A total of 82 NMOSD patients, 58 MS patients, and 45 healthy controls (HCs) underwent a neuropsychological assessment. Results: CI was observed in 29% of NMOSD and 50% of MS patients (p < 0.001); CI was considered present if a patient scored lower than the fifth percentile compared with HCs in at least three domains. A lower frequency of CI was consistently found when CI was indicated by at least two failed tests (p < 0.001). MS patients performed worse than did NMOSD patients on verbal learning and verbal and visual memory tests. Levels of education and depression and the interval from disease onset to treatment were associated with a negative influence on cognition in patients with NMOSD. Conclusion: CI in patients with NMOSD may be not as common as in patients with MS. MS patients exhibited severe impairment, particularly on learning and memory tests, compared with NMOSD patients. Differential prevalence and patterns of CI between NMOSD and MS patients suggest that the two diseases have different mechanisms of brain injury.

Bright spotty lesions on the spinal cord: an additional MRI indicator of neuromyelitis optica spectrum disorder?

Neuromyelitis optica spectrum disorder (NMOSD) is a devastating inflammatory disease of the central nervous system (CNS), thus, an early and accurate diagnosis is important.1 The aquaporin-4 (AQP4) antibody is a specific marker of NMOSD that has generally modest sensitivity but is not always available in time. The radiological characteristics, such as longitudinally extensive transverse myelitis (LETM), are helpful in the diagnosis, but LETM is not a pathognomonic feature of NMOSD. Therefore, it would be good to identify the other specific features associated with NMOSD. Bright spotty lesions (BSLs) on spinal MRIs have recently been identified as a discriminative feature that distinguishes NMOSD from multiple sclerosis (MS).2 However, previous study was conducted with a small number of patients and the timing of the MRIs was not controlled. Furthermore, it has not been investigated whether BSLs may help to discriminate NMOSD from other entities, such as idiopathic transverse myelitis (ITM), which share many similar features with NMOSD. Thus, the present study investigated whether BSLs can be utilised as a discriminative feature of NMOSD to distinguish it from MS and ITM in a large cohort of patients with myelitis, particularly during the acute phases. A total of 114 patients, who presented with acute myelitis and underwent spinal MRIs (≤3 weeks since the latest clinical attack), were enrolled from the National Cancer Centre registry of CNS idiopathic inflammatory diseases between 2005 and 2014. Of 114 patients, 59 patients with NMOSD were positive for AQP4 antibody, 31 patients met the McDonald criteria for MS and 24 patients fulfilled the criteria for ITM.3 All patients with MS and ITM were negative for AQP4 antibody following repeated assays of three different methods.4 Myelin-oligodendroglycoprotein (MOG) antibodies were also tested using a cell-based assay at Tohoku University and all patients were negative for MOG antibodies.4 …