Nationwide Laboratory Surveillance of Progressive Multifocal Leukoencephalopathy in Japan: Fiscal Years 2011-2020.

Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disease caused by JC virus (JCV), predominantly affecting patients with impaired cellular immunity. PML is a non-reportable disease with a few exceptions, making national surveillance difficult. In Japan, polymerase chain reaction (PCR) testing for JCV in the cerebrospinal fluid (CSF) is performed at the National Institute of Infectious Diseases to support PML diagnosis. To clarify the overall profile of PML in Japan, patient data provided at the time of CSF-JCV testing over 10 years (FY2011-2020) were analyzed. PCR testing for 1537 new suspected PML cases was conducted, and 288 (18.7%) patients tested positive for CSF-JCV. An analysis of the clinical information on all individuals tested revealed characteristics of PML cases, including the geographic distribution, age and sex patterns, and CSF-JCV-positivity rates among the study subjects for each type of underlying condition. During the last five years of the study period, a surveillance system utilizing ultrasensitive PCR testing and widespread clinical attention to PML led to the detection of CSF-JCV in the earlier stages of the disease. The results of this study will provide valuable information not only for PML diagnosis, but also for the treatment of PML-predisposing conditions.

Clinical and immunological differences between MOG associated disease and anti AQP4 antibody-positive neuromyelitis optica spectrum disorders: Blood-brain barrier breakdown and peripheral plasmablasts.

BACKGROUND: Patients with anti-aquaporin-4 (AQP4) water channel antibody-positive neuromyelitis optica spectrum disorders (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein (MOG) associated disease (MOGAD) often present with similar clinical symptoms, and some cases are hard to differentiate at the time of onset. In this study, we compared the clinical characteristics, cerebrospinal fluid (CSF) analysis parameters, and peripheral T/B lymphocyte subsets during the active and chronic phases in AQP4-NMOSD and MOGAD. METHODS: A total of 17 MOGAD cases and 24 AQP4-NMOSD cases were studied. The clinical characteristics in both groups were summarized, including disease duration, total number of attacks, lesions, prevention of relapse during remission, and CSF analysis results during the active phase. T/B lymphocyte subsets were further investigated in the active and chronic phases. RESULTS: In the comparative study on clinical symptoms, a large proportion of optic neuritis was unilateral in MOGAD. In the comparative study on CSF analysis, protein level was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.006); myelin basic protein was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.04); albumin quotient was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.02); and IgG Quotient was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.05). In the analysis of T/B lymphocyte subsets, plasmablasts of the B cell subset in the active phase were significantly lower in MOGAD (2.1 ± 2.4) compared to AQP4-NMOSD (7.8 ± 7.2) (p < 0.05). In the chronic phase, transitional B cells were significantly higher in MOGAD (2.1 ± 1.8) compared to AQP4-NMOSD (0.6 ± 0.4) (p < 0.01). CONCLUSION: Clinical characteristics of MOGAD were similar to those of AQP4-NMOSD, but increased blood brain barrier permeability was suggested to be less severe in MOGAD compared to AQP4-NMOSD from CSF analysis. Furthermore, the pathogenesis of the two diseases was clearly distinct as plasmablasts in the active phase were not elevated in MOGAD, but were increased in AQP4-NMOSD.

Tacrolimus is effective for neuromyelitis optica spectrum disorders with or without anti-AQP4 antibody.

BACKGROUND: Neuromyelitis optica spectrum disorders (NMOSD) are a group of inflammatory central nervous system disorders characterized by optic neuritis, transverse myelitis, and anti-aquaporin 4 (AQP4) antibody production. However, it has recently been shown that some cases of typical NMOSD can be anti-AQP4 antibody-negative as well. In this study, we retrospectively investigated the disorder relapse-suppressing effect of tacrolimus (TAC) when combined with prednisolone (PSL) in anti-AQP4 antibody-positive and -negative NMOSD cases. METHODS: Subjects were NMOSD outpatients treated at our hospital in August 2016 who fulfilled the 2015 International Panel for NMO Diagnosis criteria and whose medical history before visiting our department was known; anti-myelin oligodendrocyte glycoprotein antibody-positive cases were excluded. We retrospectively investigated the annualized relapse rate (ARR) before and after combined TAC and PSL treatment in 50 NMOSD cases who had been using TAC with PSL for at least 1 year and whom we were also able to observe. RESULTS: There were 42 anti-AQP4 antibody-positive cases and 8 negative cases. Observation periods of the anti-AQP4 antibody-positive cases were 1.1 years before TAC and 5.1 years after TAC. ARR before TAC was 1.0 and 0.08 after TAC, indicating a relapse-suppression rate of 92% (p < 0.001) and clear improvement. In the anti-AQP4 antibody-negative group, the observation period was 5.6 years before and 4.1 years after TAC. ARR before TAC was 0.5 and 0.07 after TAC. The relapse-suppression rate was 86% (p < 0.05), which was obviously as effective as in the anti-AQP4 antibody-positive group. PSL dose in the anti-AQP4 antibody-positive group was 15.0 mg/day at the start of TAC and was reduced to 6.3 mg/day after 2 years (p < 0.001). The Expanded Disability Status Scale (EDSS) score decreased from 4.5 at the start of TAC to 2.0 after 2 years in the anti-AQP4 antibody-positive group (p < 0.05), which was a clear improvement. CONCLUSION: Combined use of TAC with PSL clearly suppressed relapse of both anti-AQP4 antibody-positive and -negative NMOSD. In the anti-AQP4 antibody-positive group, both PSL dose and EDSS score decreased compared with the dose at the start of the study.

A clinical predictive score for postoperative myasthenic crisis.

OBJECTIVE: Myasthenia gravis (MG) is an autoimmune disease mostly caused by autoantibodies against acetylcholine receptor associated with thymus abnormalities. Thymectomy has been proven to be an efficacious treatment for patients with MG, but postoperative myasthenic crisis often occurs and is a major complication. We aimed to develop and validate a simple scoring system based on clinical characteristics in the preoperative status to predict the risk of postoperative myasthenic crisis. METHODS: We studied 393 patients with MG who underwent thymectomy at 6 tertiary centers in Japan (275 patients for derivation and 118 for validation). Clinical characteristics, such as gender, age at onset and operation, body mass index, disease duration, MG subtype, severity, symptoms, preoperative therapy, operative data, and laboratory data, were reviewed retrospectively. A multivariate logistic regression with LASSO penalties was used to determine the factors associated with postoperative myasthenic crisis, and a score was assigned. Finally, the predictive score was evaluated using bootstrapping technique in the derivation and validation groups. RESULTS: Multivariate logistic regression identified 3 clinical factors for predicting postoperative myasthenic crisis risk: (1) vital capacity < 80%, (2) disease duration < 3 months, and (3) bulbar symptoms immediately before thymectomy. The postoperative myasthenic crisis predictive score, ranging from 0 to 6 points, had areas under the curve of 0.84 (0.66-0.96) in the derivation group and 0.80 (0.62-0.95) in the validation group. INTERPRETATION: A simple scoring system based on 3 preoperative clinical characteristics can predict the possibility of postoperative myasthenic crisis. Ann Neurol 2017;82:841-849.

[A case of cerebellar brainstem form of progressive multifocal leukoencephalopathy associated with idiopathic CD4+ lymphocytopenia].

A 77-year-old woman presented with a 6-month history of slowly progressive cerebellar ataxia. T2-weighted MRI showed high signal intensity in the left upper dorsal pons and bilateral middle cerebellar peduncles. JC virus (JCV) DNA was detected in cerebrospinal fluid (CSF). The patient had no HIV infection, collagen disease, or a history of immunosuppressive treatment, but she was found to have CD4+ lymphocytopenia. We made a diagnosis of cerebellar brainstem form of progressive multifocal leukoencephalopathy (PML) presenting as cerebellar ataxia, which was presumably associated with idiopathic CD4+ lymphocytopenia. Following the treatment with mefloquine, the patient slightly improved clinically and JCV-DNA became negative in CSF.

[A case of neuromyelitis optica spectrum disorder developing a fulminant course with multiple white-matter lesions following fingolimod treatment].

A 49-year-old female neuromyelitis optica spectrum disorder (NMOSD) patient with positive anti-aquaporin 4 (AQP4) antibody was treated with fingolimod (FTY720). Ten days later, she developed acute disturbance of consciousness, aphasia, right hemi-spatial neglect, and right hemiparesis. Brain MRI showed multiple white-matter lesions with slight Gadolinium enhancement. She was diagnosed of acute exacerbation of NMOSD. Thus, fingolimod may be associated with the development of a fulminant course in NMOSD patients with positive anti-AQP4 antibody.