Clinical profile of patients with paraneoplastic neuromyelitis optica spectrum disorder and aquaporin-4 antibodies

Impact of comorbidities on relapsing rates of Neuromyelitis Optica Spectrum Disorders: Insights from a longitudinal study in Taiwan

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory demyelinating disease characterized by relapsing clinical episodes and the presence of autoantibodies. The impact of comorbidities on relapsing rate of NMOSD patients in Taiwan remains unclear.

METHODS

We conducted a longitudinal retrospective study using the largest hospital system in Taiwan from 2006 to 2021. Demographic characteristics, annualized relapse rates (ARR), and comorbidities were examined.

RESULTS

We identified 485 NMOSD patients from 2006 to 2021. Of these, 466 had the adult form and 19 (3.9 %) had the pediatric form of NMOSD. The median ARR was 0.51 (interquartile range (IQR): 0.26-1.11) for adults and 0.39 (IQR: 0.21-0.77) for pediatric patients. Comorbidities included malignancy (6.7 %) and autoimmune diseases (21.7 %). The recommended age for malignancy surveillance in NMOSD patients was 43.3 years. Neither malignancy nor autoimmune disease increased the ARR within 3 years post diagnosis in NMOSD patients with comorbidities compared with those without comorbidities.

CONCLUSIONS

Our study revealed the ARR within the initial three years after diagnosis was significantly higher, emphasizing the importance of early treatment. We also observed an association between malignancy and NMOSD, and a significantly higher risk of malignancy in adult patients with NMOSD than in the general population (the relative risk was 5.99) that requiring further investigations into the underlying mechanisms. These findings contribute to a better understanding of NMOSD and its comorbidities in Taiwan.

Paraneoplastic neuromyelitis optica spectrum disorder associated with ovarian dysgerminoma: a case report and literature review

Neuromyelitis optica spectrum disorder (NMOSD) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. We report a case with paraneoplastic NMOSD that improved after immunosuppressive therapy, surgical resection, and chemotherapy. A 48-year-old woman initially presented with gradual binocular visual loss over the course of one week. The patient was evaluated using magnetic resonance imaging (MRI), computed tomography (CT), visual evoked potential (VEP), pathological biopsy, immunohistochemistry, and autoimmune antibody testing. The brain MRI findings were normal. The VEP revealed prolonged P100 latencies in the right eye and an absence of significant waves in the left eye. Positive serum AQP4-IgG antibodies were found. The patient was diagnosed as NMOSD. Then the patient responded well to treatment with methylprednisolone. An ovarian tumor was found in the patient using abdominal MRI and CT. The tumor was surgically resected, and a pathological biopsy revealed that it was ovarian dysgerminoma. The patient received four rounds of chemotherapy after surgery. One month after the final chemotherapy treatment, a positron emission tomography (PET) scan revealed no tumor. The vision of the patient gradually recovered and serum AQP4 was negative. Furthermore, we summarized the characteristics of patients diagnosed with paraneoplastic NMOSD associated with ovarian neoplasms in previous studies. This is a characteristic case of overlapping NMOSD and ovarian dysgerminoma, demonstrating the importance of tumor therapy in cases of paraneoplastic NMOSD.

Immune-Mediated Myelopathies

OBJECTIVE

Immune-mediated myelopathies are conditions in which the immune system attacks the spinal cord. This article describes the distinguishing characteristics of immune-mediated myelopathies and treatment strategies for patients affected by these disorders.

LATEST DEVELOPMENTS

New biomarkers, such as aquaporin 4 and myelin oligodendrocyte glycoprotein antibodies, in the blood and spinal fluid have led to the identification of antigen-specific immune-mediated myelopathies and approved therapies to prevent disease progression.

ESSENTIAL POINTS

The first step in the diagnosis of an immune-mediated myelopathy is confirming that the immune system is the cause of the attack by excluding non-immune-mediated causes. The second step is to narrow the differential diagnosis based on objective biomarkers such as serology and MRI patterns. The third step is to treat the specific immune-mediated myelopathy by using evidence-based medicine.

Clinical approach to diagnosis of paraneoplastic neurologic syndromes

The correct diagnosis of a paraneoplastic neurologic syndrome (PNS) first requires the identification of the syndrome as one of those defined as high-risk (previously called classical) or intermediate-risk for cancer in the 2021 PNS diagnostic criteria. Testing for neuronal antibodies should be restricted to these syndromes as indiscriminate request decreases the diagnostic value of the antibodies. Identifying onconeural (high-risk for cancer) or intermediate-risk for cancer antibodies supports the paraneoplastic diagnosis and mandates the search for an underlying cancer. Tumor screening must follow the published guidelines. Repeated screening is indicated in neurologic syndromes with onconeural antibodies and patients with high-risk for cancer neurologic syndromes unless they present neuronal antibodies which are not associated with cancer. Neuronal antibodies should be screened by immunohistochemistry and confirmed by immunoblot (intracellular antigens) or cell-based assay (CBA) (surface antigens). Positive results only by immunoblot or CBA should be taken with caution. Although the 2021 diagnostic criteria for PNS do not capture all PNS, as they do not allow to diagnose definite PNS neurologic syndromes without neuronal antibodies, the updated criteria represent a step forward to differentiate true PNS from neurologic syndromes that coincide in time with cancer diagnosis without having a pathogenic link.

Epidemiology of paraneoplastic neurologic syndromes

Paraneoplastic neurologic syndromes (PNS), initially depicted as seemingly cryptic remote manifestations of malignancy, were first described clinically in the early 20th century, with pathophysiologic correlates becoming better elucidated in the latter half of the century. There remain many questions not only about the pathophysiology but also regarding the epidemiology of these conditions. The continuous discovery of novel autoantigens and related neurologic disease has broadened the association in classical PNS to include conditions such as paraneoplastic cerebellar degeneration. It has also brought into focus several other neurologic syndromes with a putative neoplastic association. These conditions are overall rare, making it difficult to capture large numbers of patients to study, and raising the question of whether incidence is increasing over time or improved identification is driving the increased numbers of cases. With the rise and increasing use of immunotherapy for cancer treatment, the incidence of these conditions is additionally expected to rise and may present with various clinical symptoms. As we enter an era of clinical trial intervention in these conditions, much work is needed to capture more granular data on population groups defined by socioeconomic characteristics such as age, ethnicity, economic resources, and gender to optimize care and clinical trial planning.

Management of Paraneoplastic Syndromes in the Era of Immune Checkpoint Inhibitors

OPINION STATEMENT

Our understanding of paraneoplastic neurologic syndromes (PNS) has blossomed over the past few decades. Clinicians have access to more robust diagnostic criteria and have a heightened index of suspicion for these disorders. Nonetheless, treatment, which typically includes immunosuppression, and response to treatment, varies. Due to persistent difficulty in making a definitive diagnosis, we favor empiric treatment when a possible diagnosis of PNS is suspected, and other alternative causes have substantially been excluded (e.g., infections, toxic-metabolic derangements, metastasis, or leptomeningeal disease). Treatment of the underlying cancer, if identified, is the first therapeutic step and can prevent disease worsening and in rare cases, can reverse neurologic symptoms. In addition to anti-cancer treatment, first line immunotherapies, which include corticosteroids, intravenous immunoglobulins (IVIG), or plasma exchange (PLEX) are typically used. If partial or no benefit is seen, second line immunotherapeutic agents such as rituximab are considered. Additionally, the severity of the initial presentation and possible risk for relapse influences the use of the latter agents. Symptomatic management is also an important component in our practice and will depend on the syndrome being treated. One of the more novel entities we are facing currently is the management of immune checkpoint (ICI)-induced PNS. In those cases, current American Society of Clinical Oncology (ASCO) guidelines are followed.

Antibodies to neural cell surface and synaptic proteins in paraneoplastic neurologic syndromes

Among patients with paraneoplastic neurologic syndromes (PNS), emphasis has historically been placed on neural antibodies against intracellular proteins that have a strong association with malignancy. Because of the intracellular location of their antigenic targets, these antibodies are typically considered to be non-pathogenic surrogate markers of immune cell-mediated neural injury. Unfortunately, patients with these antibodies often have suboptimal response to immunotherapy and poor prognosis. Over the last two decades, however, dramatic advancements have been made in the discovery and clinical characterization of neural antibodies against extracellular targets. These antibodies are generally considered to be pathogenic, given their potential to directly alter antigen structure or function, and patients with these antibodies often respond favorably to prompt immunotherapy. These antibodies also associate with tumors and may thus occur as PNS, albeit more variably than neural antibodies against intracellular targets. The updated 2021 PNS diagnostic criteria, which classifies antibodies as high-risk, intermediate-risk, or lower-risk for an associated cancer, better clarifies how neural antibodies against extracellular targets relate to PNS. Using this recently created framework, the clinical presentations, ancillary test findings, oncologic associations, and treatment responses of syndromes associated with these antibodies are discussed.

Paraneoplastic/autoimmune myelopathies

Paraneoplastic myelopathies are a rare but important category of myelopathy. They usually present with an insidious or subacute progressive neurologic syndrome. Risk factors include tobacco use and family history of cancer. Cerebrospinal fluid analysis usually shows lymphocytic pleocytosis with elevated protein. MRI findings suggest that paraneoplastic myelopathies include longitudinally extensive T2 hyperintensities that are tract-specific and accompanied by enhancement, but spinal MRIs can also be normal. The most commonly associated neural antibodies include amphiphysin and collapsin-response-mediator-protein-5 (CRMP5/anti-CV2) antibodies with lung and breast cancers being the most frequent oncologic accompaniments. The differential diagnosis of paraneoplastic myelopathies includes nutritional deficiency myelopathy (B12, copper) as well as autoimmune/inflammatory conditions such as primary progressive multiple sclerosis or spinal cord sarcoidosis. Patients treated with immune checkpoint inhibitors for cancer may develop myelitis, that can be considered along the spectrum of paraneoplastic myelopathies. Management of paraneoplastic myelopathy includes oncologic treatment and immunotherapy. Despite these treatments, the prognosis is poor and the majority of patients eventually become wheelchair-dependent.

Paraneoplastic Neurologic Syndromes

OBJECTIVE

Progress is ongoing in understanding paraneoplastic neurologic disorders, with new syndromes and antibodies being described and more detailed evidence available to guide workup for diagnosis and treatment to improve outcomes. Many excellent reviews have summarized the molecular features of different antibodies, but this article emphasizes the clinical features of each syndrome that may help guide initial diagnosis and treatment, which often should occur before an antibody or cancer is found to confirm the diagnosis.

LATEST DEVELOPMENTS

Recent findings include updated diagnostic criteria with validated sensitivity and specificity, discovery of novel antibodies, and clinical findings that increase the likelihood of an underlying paraneoplastic disorder. Suggestive syndromes that have been recently identified include faciobrachial dystonic seizures and pilomotor auras in anti-leucine-rich glioma inactivated protein 1 encephalitis, extreme delta brush on EEG in N-methyl-d-aspartate (NMDA)-receptor encephalitis, déjà vu aura in anti-glutamic acid decarboxylase 65 (GAD65) encephalitis, and sleep disturbances in several disorders. In addition, there is confirmed utility of brain positron emission tomography (PET) and CSF markers, including carcinoembryonic antigen and oligoclonal bands, as well as improved tests for the presence of leptomeningeal cancer cells in CSF. Associations of cancer immunotherapies with paraneoplastic syndromes and herpes simplex virus encephalitis (and COVID-19) with NMDA-receptor encephalitis have been described.

ESSENTIAL POINTS

All neurologists should be aware of advances regarding paraneoplastic neurologic syndromes, as patients can present with a wide variety of neurologic symptoms and earlier diagnosis and treatment can improve outcomes.

Aquaporin-4-IgG positive neuromyelitis optica spectrum disorder in a paraneoplastic context

OBJECTIVE

The association between aquaporin-4-immunoglobulin-G-positive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD) and cancer via a plausible immunological response has been reported. Here, we investigated the frequency of cancer in a large cohort of patients with AQP4-IgG-NMOSD.

METHODS

Between May 2005 and January 2023, patients with AQP4-IgG-NMOSD and a history of cancer were included by searching for diagnostic codes of both NMOSD and cancer in the electronic medical records and/or reviewing the database of the National Cancer Center registry of inflammatory diseases of the central nervous system. Probable paraneoplastic AQP4-IgG-NMOSD was defined according to the 2021 Criteria for Paraneoplastic Neurological Syndrome.

RESULTS

Of 371 patients with AQP4-IgG-NMOSD, 23 (6.2%) had a history of cancer and four (1.1%) experienced NMOSD in a paraneoplastic context. Among the four patients with probable paraneoplastic AQP4-IgG-NMOSD, the types of cancer were lung (1 adenocarcinoma, 1 squamous cell carcinoma) and colorectal (2 adenocarcinomas). In three patients, the first NMOSD symptoms developed after a cancer diagnosis (median, 8 months [range, 4-23]), and one patient's symptoms preceded the cancer diagnosis (6 months). Compared to the 367 non-paraneoplastic patients, those in the paraneoplastic context had an older age at onset (median: 59.5 vs. 37 years, p = 0.012) and a higher proportion of longitudinally extensive transverse myelitis (LETM) as an initial manifestation (4/4[100%] vs. 130/367[35.4%], p = 0.017).

CONCLUSIONS

In a large cohort of patients with AQP4-IgG-NMOSD, the frequency of cancer was low. Older age, LETM features at onset, and adenocarcinoma as the histological type were usually observed in patients with AQP4-IgG-NMOSD in a paraneoplastic context.

Paraneoplastic Neuromyelitis Optica Spectrum Disorder: A Rare Case of Advanced Breast Cancer with Intractable Nausea and Vomiting

BACKGROUND Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating disease of the central nervous system that includes the triad of transverse myelitis, optic neuritis, and area postrema syndrome (APS), characterized by intractable nausea and vomiting. NMOSD can be part of a paraneoplastic syndrome and is associated with seropositivity to aquaporin-4 (AQP-4). We present a patient with uncontrollable nausea and vomiting who developed herpes zoster and acute myelitis and was finally diagnosed with paraneoplastic NMOSD due to breast cancer. CASE REPORT A 51-year-old woman was hospitalized due to 2 weeks of intractable nausea and vomiting. Although contrast-enhanced thoracoabdominal computed tomography (CT) on day 4 suggested breast cancer in her left breast, the etiology of her symptoms remained unknown. On day 13, she developed herpes zoster, followed by acute myelitis on day 25. Magnetic resonance imaging (MRI) showing longitudinal extensive transverse myelitis and an elevated serum AQP-4 antibody level led to the diagnosis of NMOSD. Brain MRI detected a small lesion in the dorsal medulla oblongata, which explained the preceding APS. After starting intravenous methylprednisolone pulse therapy, her nausea and vomiting rapidly subsided. Breast cancer was resected on day 63, and immunohistochemical staining revealed overexpression of AQP-4 in the tumor cells, suggesting paraneoplastic NMOSD. CONCLUSIONS This report has highlighted the presentation and diagnosis of NMOSD and supports the possibility that this can present as part of a paraneoplastic syndrome. In addition, diagnosis of NMOSD preceded by APS requires meticulous history taking and careful interpretation of MRI in the dorsal medulla oblongata.

The temporal relationship of paraneoplastic aquaporin-4-IgG seropositive neuromyelitis optica spectrum disorder (NMOSD) and breast cancer: a systematic review and meta-analysis

OBJECTIVE

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune astrocytopathy with evidence of neuroinflammation and demyelination that affects the central nervous system and is mediated by aquaporin-4 (AQP4) immunoglobulin (IgG). AQP4-IgG may also be present in paraneoplastic syndromes secondary to malignancy such as breast cancer.

METHODS

A systematic review and meta-analysis of the literature were completed using PubMed, Scopus, and ScienceDirect databases (CRD42022352109).

RESULTS

A total of 12 publications, which included 19 cases, met the inclusion criteria and were assessed in both the qualitative and quantitative synthesis. The mean age was 51.26 years (SD: 13.12, SEM: 3.01), and 100% of the cases were reported in women. Speech abnormalities and symptoms of myelopathy were the most observed neurological manifestations. MRI often revealed longitudinally extensive transverse myelitis (LETM) involving the cervical spine. Three of 19 (15.9%) cases were diagnosed with NMOSD and breast cancer within the same month. Five of 19 (26.1%) cases had a diagnosis of breast cancer preceding that of NMOSD. Eight of 19 (42.1%) cases were diagnosed with breast cancer after NMOSD. The median time of breast cancer diagnosis was 1.0 months (range 216 months) after NMOSD.

CONCLUSIONS

The diagnosis of breast cancer most often occurs after the onset of the paraneoplastic NMOSD symptoms. However, a wide time range for the diagnosis of breast cancer was observed both before and after the onset of neurological symptoms. Older women with a new diagnosis of NMOSD should be considered for frequent breast cancer screening.

The Role of MRI in Differentiating Demyelinating and Inflammatory (not Infectious) Myelopathies

Demyelinating and inflammatory myelopathies represent a group of diseases with characteristic patterns in neuroimaging and several differential diagnoses. The main imaging patterns of demyelinating myelopathies (multiple sclerosis, neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis, and myelin oligodendrocyte glycoprotein antibody-related disorder) and inflammatory myelopathies (systemic lupus erythematosus-myelitis, sarcoidosis-myelitis, Sjögren-myelitis, and Behçet's-myelitis) will be discussed in this article, highlighting key points to the differential diagnosis.

Investigating the association between neoplasms and MOG antibody-associated disease

Introduction

The association of myelin oligodendrocyte glycoprotein (MOG) antibody associated disease (MOGAD) and tumors has seldom been reported. We aim to investigate the occurrence of tumors in a cohort of patients with MOGAD and to describe their clinical features, in addition to previously reported cases.

Methods

We retrospectively identified patients with MOGAD (i.e., compatible clinical phenotype and positive MOG antibodies analysed with a live cell-based assay) from 1/1/2015 to 1/1/2023 who had a neoplasm diagnosed within 2  years from MOGAD onset. Furthermore, we performed systematic review of literature to identify previously reported cases. Clinical, paraclinical and oncological findings were collected and reported as median (range) or number (percentage).

Results

Two of 150 MOGAD patients (1%) had a concomitant neoplasm in our cohort. Fifteen additional cases were retrieved from literature. Median age was 39 (16-73) years-old, 12 patients were female. ADEM (n = 4;23.5%), encephalomyelitis (n = 3;17.6%), and monolateral optic neuritis (n = 2;11.8%) were the most frequent phenotypes. Median number of treatments was 1 (range 1-4), improvement was reported in 14/17 cases (82.4%). Oncological accompaniments were teratoma (n = 4), CNS (n = 3), melanoma (n = 2), lung (n = 2), hematological (n = 2), ovary (n = 1), breast (n = 1), gastrointestinal (n = 1), and thymic (n = 1) neoplasms. Median time from tumor diagnosis to MOGAD onset was 0 (range - 60 to 20) months. MOG expression in neoplastic tissue was reported in 2/4 patients. Median PNS-CARE score was 3 (range 0-7): 11 patients were classified as "non-PNS," 5 as "possible PNS," and 1 as "probable PNS."

Discussion

Our study confirms that MOG is a low-risk antibody for paraneoplastic neurological syndromes and that the clinical presentation and oncological accompaniments are extremely variable. Most of these patients were classified as non-PNS, whereas only a minority was diagnosed with possible/probable PNS, frequently in association with ovarian teratoma. These findings support the notion that MOGAD is not a paraneoplastic disease.

White blood cell count profiles in anti-aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder and anti-myelin oligodendrocyte glycoprotein antibody-associated disease

White blood cell (WBC) count profiles in anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are still unknown. This study evaluated the total WBC count, differential WBC counts, monocyte-to-lymphocyte ratio (MLR), and neutrophil-to-lymphocyte ratio (NLR) in patients with these diseases within three months from an attack before acute treatment or relapse prevention and compared the profiles with those in matched volunteers or in multiple sclerosis (MS) patients. AQP4-NMOSD patients (n = 13) had a higher neutrophil count (p = 0.0247), monocyte count (p = 0.0359), MLR (p = 0.0004), and NLR (p = 0.0037) and lower eosinophil (p = 0.0111) and basophil (p = 0.0283) counts than those of AQP4-NMOSD-matched volunteers (n = 65). Moreover, patients with MOGAD (n = 26) had a higher overall WBC count (p = 0.0001), neutrophil count (p < 0.0001), monocyte count (p = 0.0191), MLR (p = 0.0320), and NLR (p = 0.0002) than those of MOGAD-matched volunteers (n = 130). The three demyelinating diseases showed similar levels of the total and differential WBC counts; however, MOGAD and MS showed different structures in the hierarchical clustering and distributions on a two-dimensional canonical plot using differential WBC counts from the other three groups. WBC count profiles were similar in patients with MOGAD and MS but differed from profiles in matched volunteers or patients with AQP4-NMOSD.

Update on the diagnosis and treatment of neuromyelits optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part I: Diagnosis and differential diagnosis

The term 'neuromyelitis optica spectrum disorders' (NMOSD) is used as an umbrella term that refers to aquaporin-4 immunoglobulin G (AQP4-IgG)-positive neuromyelitis optica (NMO) and its formes frustes and to a number of closely related clinical syndromes without AQP4-IgG. NMOSD were originally considered subvariants of multiple sclerosis (MS) but are now widely recognized as disorders in their own right that are distinct from MS with regard to immunopathogenesis, clinical presentation, optimum treatment, and prognosis. In part 1 of this two-part article series, which ties in with our 2014 recommendations, the neuromyelitis optica study group (NEMOS) gives updated recommendations on the diagnosis and differential diagnosis of NMOSD. A key focus is on differentiating NMOSD from MS and from myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD), which shares significant similarity with NMOSD with regard to clinical and, partly, radiological presentation, but is a pathogenetically distinct disease. In part 2, we provide updated recommendations on the treatment of NMOSD, covering all newly approved drugs as well as established treatment options.

Paraneoplastic Neurologic Disorders

PURPOSE OF REVIEW

To provide an overview and highlight recent updates in the field of paraneoplastic neurologic disorders.

RECENT FINDINGS

The prevalence of paraneoplastic neurologic disorders is greater than previously reported and the incidence has been rising over time, due to improved recognition in the era of antibody biomarkers. Updated diagnostic criteria that are broadly inclusive and also contain diagnostic risk for clinical presentations (high and intermediate) and diagnostic antibodies (high, intermediate, and low) have replaced the original 2004 criteria. Antibody biomarkers continue to be characterized (e.g., KLHL-11 associated with seminoma in men with brainstem encephalitis). Some paraneoplastic antibodies also provide insight into likely immunotherapy response and prognosis. The rise of immune checkpoint inhibitors as cancer therapeutics has been associated with newly observed immune-mediated adverse effects including paraneoplastic neurological disorders. The therapeutic approach to paraneoplastic neurologic disorders is centered around cancer care and trials of immune therapy. The field of paraneoplastic neurologic disorders continues to be advanced by the identification of novel antibody biomarkers which have diagnostic utility, and give insight into likely treatment responses and outcomes.

Origins and immunopathogenesis of autoimmune central nervous system disorders

The field of autoimmune neurology is rapidly evolving, and recent discoveries have advanced our understanding of disease aetiologies. In this article, we review the key pathogenic mechanisms underlying the development of CNS autoimmunity. First, we review non-modifiable risk factors, such as age, sex and ethnicity, as well as genetic factors such as monogenic variants, common variants in vulnerability genes and emerging HLA associations. Second, we highlight how interactions between environmental factors and epigenetics can modify disease onset and severity. Third, we review possible disease mechanisms underlying triggers that are associated with the loss of immune tolerance with consequent recognition of self-antigens; these triggers include infections, tumours and immune-checkpoint inhibitor therapies. Fourth, we outline how advances in our understanding of the anatomy of lymphatic drainage and neuroimmune interfaces are challenging long-held notions of CNS immune privilege, with direct relevance to CNS autoimmunity, and how disruption of B cell and T cell tolerance and the passage of immune cells between the peripheral and intrathecal compartments have key roles in initiating disease activity. Last, we consider novel therapeutic approaches based on our knowledge of the immunopathogenesis of autoimmune CNS disorders.

Neuromyelitis optica spectrum disorders: a review with a focus on children and adolescents

Neuromyelitis optica spectrum disorder (NMOSD) is a rare and severe inflammatory disorder of the central nervous system (CNS). It is strongly associated with anti-aquaporin 4 antibodies (AQP4-IgG), and it mainly affects young women from non-white ethnicities. However, ∼ 5 to 10% of all cases have onset during childhood. Children and adolescents share the same clinical, radiologic, and laboratory presentation as adults. Thus, the same NMOSD diagnostic criteria are also applied to pediatric-onset patients, but data on NMOSD in this population is still scarce. In seronegative pediatric patients, there is a high frequency of the antibody against myelin oligodendrocyte glycoprotein (MOG-IgG) indicating another disease group, but the clinical distinction between these two diseases may be challenging. Three drugs (eculizumab, satralizumab, and inebilizumab) have been recently approved for the treatment of adult patients with AQP4-IgG-positive NMOSD. Only satralizumab has recruited adolescents in one of the two pivotal clinical trials. Additional clinical trials in pediatric NMOSD are urgently required to evaluate the safety and efficacy of these drugs in this population.

Non-immune system comorbidity in neuromyelitis optica spectrum disorders

Comorbidities may influence the clinical features, prognosis, and treatment outcomes of neuromyelitis optica spectrum disorders (NMOSD). The aim of this study was to determine the status of non-immune system comorbidities in patients with NMOSD and the effect on treatment response and prognosis. We retrospectively collected data from all patients who met the 2015 NMOSD diagnostic criteria from the NMOSD database established by our center. Patients were divided into positive and negative groups based on the presence of non-immune disease comorbidities. Patient data, clinical characteristics, treatment response, prognosis, and mortality were compared between the two groups. A total of 138 patients with NMOSD plus comorbidities were included, and 404 patients without comorbidities were selected as controls. The average age at onset was older (45 years vs 38 years, P < 0.001), the mean body mass index was higher (23.12 vs 22.04, P = 0.042) and more patients experienced relapse after immunotherapy (68.5 % vs 54.5 %, P = 0.020) in the comorbidity group than in the non-comorbidity group. Multifocal central nervous system lesions as an initial symptom was more common in the comorbidity group than in the non-comorbidity group (30.4 % vs 18.32 %, P = 0.003). Further, more patients experienced severe vision attacks (28.3 % vs 15.8 %, P = 0.003) and severe motor attacks (30.4 % vs 11.9 %, P < 0.001) in the comorbidity group than in the non-comorbidity group. In conclusion, patients with NMOSD with comorbidities tended to be older, less responsive to treatment, and at a higher risk of vision loss and paralysis.

Development of Paraneoplastic Neuromyelitis Optica after Lung Resection in a Patient with Squamous Cell Carcinoma

Neurological paraneoplastic syndrome is a relatively rare condition in patients with malignant tumors. Recently, it has been reported that anti-Aquaporin 4 (AQP4) antibody is highly specific for neuromyelitis optica. The patient was a 76-year-old man. He underwent right upper lobectomy for squamous cell carcinoma of the lung. Although the immediate postoperative course was uneventful, neurological symptoms became apparent from postoperative day (POD) 4. Magnetic resonance imaging showed longitudinally extended edematous lesions in the spinal cord, and a cerebrospinal fluid examination was positive for anti-AQP4 antibody, leading to the diagnosis of paraneoplastic neuromyelitis optica. Despite multiple rounds of steroid pulse therapy and plasma exchange, the neurological symptoms worsened and the patient died on POD 46. The development of neuromyelitis optica in the early postoperative period could be related to the influence of surgical stress or epidural anesthesia.

AQP4-IgG-positive neuromyelitis optica spectrum disorder and temporally detected neoplasms: case report and systematic review

BACKGROUND

An increasing number of reports on associations between neoplasms and neuromyelitis optica spectrum disorder (NMOSD) have been published over the past decade. However, types of neoplasms and temporal relationships have not been widely studied.

OBJECTIVE

To report cases and determine the associations between neoplasms and NMOSD.

METHOD

A retrospective chart review of possible paraneoplastic NMOSD patients at a university hospital was performed. Articles related to "neoplasm" and "NMOSD" were systematically searched and reviewed. We included aquaporin-4 (AQP4)-IgG-seropositive NMOSD patients whose onset of NMOSD and cancer diagnosis or recurrence were within 24 months of one another. Temporal relationship, types of neoplasms involved, treatments, and outcomes of both NMOSD and neoplasms were determined. The subgroup analysis was based on the AQP4 expression of neoplasm histology.

RESULTS

We identified 3 cases (1.3%) from a cohort of 224 AQP4-IgG-seropositive NMOSD at our hospital and retrieved 68 cases from a systematic review, totaling 71 cases of possible paraneoplastic NMOSD. The median age at onset of NMOSD was 55 (IQR 41-64) years. Eighty percent were female. The most frequently identified types of neoplasms were lung and breast, accounting for 21.1% and 18.3%, respectively. The other tumor types were ovarian tumors and hematologic malignancy, both at 12.7%. The most commonly identified tissue histology was adenocarcinoma (52.1%). We also reported the first case of melanoma in an NMOSD patient. Twenty-eight patients (39.4%) were diagnosed with cancer before the onset of NMOSD with a median duration of 9.5 (range 1-24) months. Of those, eight patients had NMOSD after surgical removal of neoplasms, and one patient had NMOSD after radiotherapy of prostate adenocarcinoma. Twenty-three patients (32.4%) had NMOSD before cancer diagnosis by a median of 3 (range 1-24) months, and the rest were diagnosed concurrently during the same admission. Three cases were diagnosed with NMOSD around the time of tumor recurrence. Tumor tissue expressed AQP4 in 82.4%.

CONCLUSION

A small proportion of AQP4-IgG-positive NMOSD is associated with malignancy. In newly diagnosed NMOSD patients without symptoms of neoplasms, screening for age- and risk-appropriate cancer should be recommended, similar to the general population. The occurrence of NMOSD in cancer patients might suggest tumor recurrence.

A Novel approach using O-CVP to treat paraneoplastic NMO spectrum disorder associated with follicular lymphoma

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neuroinflammatory disorder of the central nervous system that very rarely may be a paraneoplastic phenomenon. We describe the case of a woman with a longitudinally extensive transverse myelitis (LETM). We identified a previously undiagnosed, follicular lymphoma and she was treated with the immunochemotherapy regime (obinutuzumab, cyclophosphamide, vincristine and prednisolone; O-CVP) for paraneoplastic NMOSD. Following two cycles, there was almost complete radiological remission of the myelitis and the patient showed some improvement in her neurological function. This case illustrates the heterogeneous aetiology that LETM may have and that O-CVP may be used as therapeutic option in patients with NMOSD driven by follicular lymphoma.

Investigating paraneoplastic aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorder through a data-driven approach

BACKGROUND

Aquaporin-4 IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG NMOSD) might occur in association with cancer. According to diagnostic criteria, a probable paraneoplastic NMOSD can be diagnosed only in patients with isolated myelitis and adenocarcinoma or tumors expressing AQP4. The aim of this study was to explore the features of paraneoplastic NMOSD through a data-driven approach.

METHODS

A systematic literature review was performed. Patients with AQP4-IgG positivity in association with tumor in the absence of history of checkpoint inhibitors administration/central nervous system metastases were included. Demographic, clinical, and oncological data were collected. A hierarchical cluster analysis (HCA) was performed and data were compared between resulting clusters.

RESULTS

A total of 1333 records were screened; 46 studies (72 patients) fulfilled inclusion criteria. Median age was 54 (14-87) years; adenocarcinoma occurred in 41.7% of patients, and 44% of cases had multifocal index events. Cancer and NMOSD usually co-occurred. HCA classified patients in three clusters that differed in terms of isolated/multifocal attacks, optic neuritis, pediatric onset, and type of underlying tumor. Age, time from neoplasm to NMOSD onset, and tumor AQP4 staining did not differ between clusters.

CONCLUSIONS

Our data-driven approach reveals that paraneoplastic NMOSD does not present a homogeneous phenotype nor peculiar features. Accordingly, cancer screening may be useful in AQP4-IgG NMOSD regardless of age and clinical presentation.

Neuroimaging features in inflammatory myelopathies: A review

Spinal cord involvement can be observed in the course of immune-mediated disorders. Although multiple sclerosis (MS) represents the leading cause of inflammatory myelopathy, an increasing number of alternative etiologies must be now considered in the diagnostic work-up of patients presenting with myelitis. These include antibody-mediated disorders and cytotoxic T cell-mediated diseases targeting central nervous system (CNS) antigens, and systemic autoimmune conditions with secondary CNS involvement. Even though clinical features are helpful to orient the diagnostic suspicion (e.g., timing and severity of myelopathy symptoms), the differential diagnosis of inflammatory myelopathies is often challenging due to overlapping features. Moreover, noninflammatory etiologies can sometimes mimic an inflammatory process. In this setting, magnetic resonance imaging (MRI) is becoming a fundamental tool for the characterization of spinal cord damage, revealing a pictorial scenario which is wider than the clinical manifestations. The characterization of spinal cord lesions in terms of longitudinal extension, location on axial plane, involvement of the white matter and/or gray matter, and specific patterns of contrast enhancement, often allows a proper differentiation of these diseases. For instance, besides classical features, such as the presence of longitudinally extensive spinal cord lesions in patients with aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD), novel radiological signs (e.g., H sign, trident sign) have been recently proposed and successfully applied for the differential diagnosis of inflammatory myelopathies. In this review article, we will discuss the radiological features of spinal cord involvement in autoimmune disorders such as MS, AQP4+NMOSD, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and other recently characterized immune-mediated diseases. The identification of imaging pitfalls and mimics that can lead to misdiagnosis will also be examined. Since spinal cord damage is a major cause of irreversible clinical disability, the recognition of these radiological aspects will help clinicians achieve a correct and prompt diagnosis, treat early with disease-specific treatment and improve patient outcomes.

Paraneoplastic Syndromes in Neuro-Ophthalmology

Paraneoplastic neurological syndromes (PNS) occur in about 1 in 300 cases of cancer. The usual mechanism is that an antigen on the cancer sets off an immune response that then cross-reacts with a nervous system antigen. The presentation is usually with a subacute progressive neurological disorder. The management of these conditions is usually of both the underlying tumor and immunomodulation to suppress the autoimmune response. There are a number of these conditions that can present to the Neuro-Ophthalmology clinic, either as a discrete condition affecting vision or eye movements or as part of a more widespread neurological disorder. This article will discuss these conditions, their management and prognosis.

Aquaporin-4-Positive Triple-Negative Breast Cancer Presenting with Paraneoplastic Neuromyelitis Optica Spectrum Disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory central nervous system disorder that preferentially affects the optic nerve and the spinal cord. Although NMOSD is more commonly an idiopathic autoimmune condition associated with antibodies against aquaporin-4 (AQP4)-IgG, the disease may also occur as a paraneoplastic syndrome in rare instances. In these cases, the expression of AQP4 by the tumor is likely the trigger of the autoimmune response.

CASE PRESENTATION

We describe the case of a 32-year-old woman who presented with progressive tetraparesis, cranial involvement, respiratory failure, and spinal cord MRI compatible with longitudinally extensive transverse myelitis, few days after being diagnosed with a T3N1M0 triple-negative right breast cancer. Due to the history of concurrent breast cancer and after ruling out metastatic spinal cord involvement, the possibility of a paraneoplastic origin was raised. AQP4-IgG were found in the serum and CSF by cell-based assay, confirming the diagnosis of NMOSD. The patient was treated with corticosteroids, plasma exchange, and rituximab. Concomitantly, breast cancer therapy was started with an adapted neoadjuvant chemotherapy scheme based on carboplatin and paclitaxel. An initial slight improvement slowed down; so, a right mastectomy with lymphadenectomy was performed. Expression of AQP4 was demonstrated in the tumor. The patient presented a significant neurological improvement after combined treatment regaining muscular balance and strength in upper and lower extremities.

CONCLUSION

NMOSD may have a paraneoplastic origin associated with breast cancer and the importance of its early detection since the combination of tumoral and immunosuppressive therapy may improve the patient's prognosis.

Can Immune Tolerance Be Re-established in Neuromyelitis Optica?

Neuromyelitis optica (NMO) is a chronic inflammatory disease of the central nervous system that primarily affects the optic nerves and spinal cord of patients, and in some instances their brainstem, diencephalon or cerebrum as spectrum disorders (NMOSD). Clinical and basic science knowledge of NMO has dramatically increased over the last two decades and it has changed the perception of the disease as being inevitably disabling or fatal. Nonetheless, there is still no cure for NMO and all the disease-modifying therapies (DMTs) are only partially effective. Furthermore, DMTs are not disease- or antigen-specific and alter all immune responses including those protective against infections and cancer and are often associated with significant adverse reactions. In this review, we discuss the pathogenic mechanisms of NMO as they pertain to its DMTs and immune tolerance. We also examine novel research therapeutic strategies focused on induction of antigen-specific immune tolerance by administrating tolerogenic immune-modifying nanoparticles (TIMP). Development and implementation of immune tolerance-based therapies in NMO is likely to be an important step toward improving the treatment outcomes of the disease. The antigen-specificity of these therapies will likely ameliorate the disease safely and effectively, and will also eliminate the clinical challenges associated with chronic immunosuppressive therapies.

Opticoneuromyelitis associated with melanoma. Case report

This article presents a clinical review of a patient with an extremely rare assotiation of opticoneuromyelitis and skin melanoma. The paper noted the typical clinical and neuroimaging signs of opticoneuromyelitis and the rare manifestations of myelitic syndrome such as segmental muscle hypertonicity and hand hyperkinesis. The question remains open as to whether these two processes in a patient are linked by a single pathogenesis in the form of a paraneoplastic neurological syndrome or whether two independent diseases are represent there. Two observations of a combination of melanoma and opticoneuromyelitis as a manifestation of the paraneoplastic syndrome have been analysed in the literature. The article highlights the difficulties in the treatment of this patient, as the immunomodulatory therapy used for both diseases has a different vectorial focus. Immunosuppression is recommended for the treatment of opticoneuromyelitis, while immune activation is recommended for melanoma.

[Paraneoplastic ophthalmopathies]

Ocular paraneoplastic syndromes are rare conditions that can affect any part of the eye at any age. Thus, every ophthalmologist should be familiar with their management, as some of them may reveal severe, life-threatening conditions. These consist overwhelmingly of neuro-ophthalmological manifestations, affecting the optic nerve (paraneoplastic optic neuritis), retina (paraneoplastic retinopathy) or neurological pathways generating eye movements (saccadic intrusion, oculomotor palsy, nystagmus...); occasionally, they involve the anterior segment, orbit or uveal tract. As some of these manifestations appear to be quite common and non-specific, any systemic or especially neurologic comorbidities should increase suspicion. Treatment relies first on oncologic management, and then often more targeted therapy for the associated immune involvement.

Neuromyelitis optica spectrum disorder (NMOSD) associated with cancer: A systematic review

NMOSD: is a disease shown to be highly associated with other diseases such as autoimmune diseases. There are a few reports of this association with cancer. So, this systematic review aimed to obtain a broad understanding on the cancers associated in NMOSD, including the source of common perceptions and assumptions in this regard.

METHODS

in this study, we systematically searched the PubMed, EMBASE, SCOPUS, Web of Sciences, Proquest, Ovid, conference proceedings, and reference lists of the retrieved articles. All NMOSD cases who met the last version of criteria for its diagnosis, which reported the patients with a history of cancer before or after the onset of neurological symptoms without time limitations, and those who were referred as paraneoplastic neuromyelitis optica in articles published in English language (both the abstract & full text), were assessed. Finally, each study was critically appraised.

RESULTS

Only 47 studies met the inclusion criteria, so they were assessed for qualitative synthesis. Considering the Euro network criteria, only 62 cases met this issue. The mean age of 52.21 ± 17.14 and 52.16 ± 17.21 was reported for cancer and NMOSD cases with female predominance (79%), respectively. The most reported organ in the cancer population were genitourinary (n = 14, 22.3%), breast (n = 12, 19.4%), lung (n = 12, 19.3%), gastrointestinal (n = 7, 11.3%), and hematology (n = 6, 9.7%), respectively.

CONCLUSION

In older NMOSD patients without suspicious symptoms, we recommend paying more attention to lung, breast and genitourinary (especially ovary) cancer screening. Also, cancer resection had positive effect on the attack numbers after receiving treatment and NMOSD recovery.

Pediatric paraneoplastic neuromyelitis optica spectrum disorder associated with ovarian teratoma

Neuromyelitis optica spectrum disorder is an inflammatory condition of the central nervous system typically manifesting as myelitis, optic neuritis, and/or area postrema syndrome. Here, we present a pediatric patient who developed symptoms consistent with area postrema syndrome with positive anti-aquaporin-4 (AQP4) antibodies who was also found to have an ovarian teratoma. Pathological specimens revealed the presence of aquaporin-4. This was felt to be the antigenic trigger that led to the patient's condition. She suffered no further clinical attacks and seroconverted to negative AQP4 status upon teratoma removal. This case varies from others, in that the paraneoplastic presentation occurred in a pediatric patient and in that the patient has not required maintenance immunotherapy after teratoma removal.

Pathogenesis of autoimmune demyelination: from multiple sclerosis to neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody-associated disease

Autoimmunity plays a significant role in the pathogenesis of demyelination. Multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody‐associated disease (MOGAD) are now recognised as separate disease entities under the amalgam of human central nervous system demyelinating disorders. While these disorders share inherent similarities, investigations into their distinct clinical presentations and lesion pathologies have aided in differential diagnoses and understanding of disease pathogenesis. An interplay of various genetic and environmental factors contributes to each disease, many of which implicate an autoimmune response. The pivotal role of the adaptive immune system has been highlighted by the diagnostic autoantibodies in NMOSD and MOGAD, and the presence of autoreactive lymphocytes in MS lesions. While a number of autoantigens have been proposed in MS, recent emphasis on the contribution of B cells has shed new light on the well‐established understanding of T cell involvement in pathogenesis. This review aims to synthesise the clinical characteristics and pathological findings, discuss existing and emerging hypotheses regarding the aetiology of demyelination and evaluate recent pathogenicity studies involving T cells, B cells, and autoantibodies and their implications in human demyelination.

Cells to the Rescue: Emerging Cell-Based Treatment Approaches for NMOSD and MOGAD

Cell-based therapies are gaining momentum as promising treatments for rare neurological autoimmune diseases, including neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody-associated disease. The development of targeted cell therapies is hampered by the lack of adequate animal models that mirror the human disease. Most cell-based treatments, including HSCT, CAR-T cell, tolerogenic dendritic cell and mesenchymal stem cell treatment have entered early stage clinical trials or have been used as rescue treatment in treatment-refractory cases. The development of antigen-specific cell-based immunotherapies for autoimmune diseases is slowed down by the rarity of the diseases, the lack of surrogate outcomes and biomarkers that are able to predict long-term outcomes and/or therapy effectiveness as well as challenges in the manufacturing of cellular products. These challenges are likely to be overcome by future research.

Paraneoplastic AQP4-IgG-Seropositive Neuromyelitis Optica Spectrum Disorder Associated With Teratoma: A Case Report and Literature Review

Objectives

To assess a case of paraneoplastic aquaporin-4 (AQP4)-immunoglobulin G (IgG)–seropositive neuromyelitis optica spectrum disorder (NMOSD) associated with teratoma and determine whether it is a paraneoplastic neurologic disorder.

Methods

A single case study and literature review of 5 cases.

Results

A 27-year-old woman presented with diplopia, facial nerve palsy, paraplegia, sensory dysfunction of lower limbs, dysuria, nausea, and vomiting. Spinal cord MRI detected an extensive longitudinal lesion in the spinal cord, and brain MRI detected abnormal lesions in the right cerebral peduncle and tegmentum of the pons. CSF analysis revealed positive oligoclonal IgG bands (OCBs). The patient tested positive for AQP4-IgG, confirming a diagnosis of NMOSD. An abdominal CT scan detected an ovarian tumor. After steroid therapy and tumor removal, the patient progressively improved, with only mild sensory dysfunction. Histopathologic analysis of the tumor revealed a teratoma and the presence of glial fibrillary acidic protein (GFAP)⁺ neural tissue with AQP4 immunoreactivity, accompanied by lymphocyte infiltration. Including the present case, there have been 6 reported cases of AQP4-IgG–seropositive NMOSD associated with ovarian teratoma (mean onset age, 32.7 years). Of these patients, 5 (83%) presented with nausea and/or vomiting, positive OCB, and dorsal brainstem involvement. Pathologic analyses of the teratoma were available in 5 cases, including the present case, revealing neural tissue with AQP4 immunoreactivity and lymphocyte infiltration in all cases.

Conclusions

This study suggests that ovarian teratoma may trigger the development of AQP4-IgG–seropositive NMOSD. Further studies are needed to elucidate the pathogenesis of teratoma-associated NMOSD.

Pathogenesis, diagnosis and treatment of paraneoplastic neurologic syndromes

Introduction: Paraneoplastic neurological syndromes (PNS) are a rare heterogeneous group of neurological diseases associated with tumors. These syndromes are the result of a cross-reactive immune response against antigens shared by the tumor and the nervous system. The discovery of an increasing number of autoantigens and the identification of tumoral factors leading to a substantial antitumoral immune response makes this topic highly innovative.Areas covered: This review covers the clinical, oncological, pathophysiological aspects of both immunological PNS groups. One is associated with autoantibodies against intracellular onconeural antibodies, which are highly specific for an underlying tumor, although the disease is mainly T-cell mediated. In contrast, PNS associated with pathogenic surface-binding/receptor autoantibodies, which are often responsive to immunosuppressive treatment, may manifest as paraneoplastic and non-paraneoplastic diseases. The most frequent tumors associated with PNS are (small cell) lung cancer, gynecological tumors, thymoma, lymphoma, and, in children, neuroblastoma. A special interest is given to PNS, induced by immune checkpoint-inhibitors (ICIs).Expert opinion: Research in PNS, including the group of ICI-induced PNS provide new insights in both the pathophysiology of PNS and tumor immune interactions and offers new treatment options for this group of severe neurological diseases.

Paraneoplastic neuromyelitis optica spectrum disorder associated with malignant melanoma: A case report

Neuromyelitis optica spectrum disorders (NMOSDs) are autoimmune demyelinating diseases involving the central nervous system, affecting the spinal cord and optic nerves. There are few reports of paraneoplastic NMOSD associated with malignant melanoma. Here, we report a rare case of anti‐aquaporin 4 (AQP4) antibody‐positive NMOSD associated with malignant melanoma. A 61‐year‐old Japanese woman was diagnosed with malignant melanoma and lung metastasis four years after a diagnosis of anti‐AQP4 antibody‐positive NMOSD. When diagnosing and treating patients with NMOSD, physicians should be aware of the development of malignancy for at least several years.

Neuromyelitis optica spectrum disorder as a paraneoplastic syndrome: a rare and challenging diagnosis

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system, often associated with aquaporin-4 antibodies (AQP4-Ab). NMOSD may present as a subacute myelopathy, progressing over days with MRI revealing a contiguous inflammatory lesion of the spinal cord, ≥3 vertebral segments, a longitudinally extensive transverse myelitis. We describe an unusual paraneoplastic form of AQP4-Ab NMOSD that developed in a patient with an advanced diffuse large B-cell lymphoma. The patient had an unusual hyperacute onset, reaching a clinical nadir within hours.

Increased proportion of CD20+ T cells after rituximab treatment in patient with neuromyelitis optica later diagnosed with lung B-cell lymphoma: A case report

INTRODUCTION

Neuromyelitis optica (NMO) is a rare inflammatory autoimmune disorder of the CNS. Rituximab is used to treat antibody-mediated autoimmune diseases.

CASE PRESENTATION

We report the case a patient with NMO, who was treated with rituximab and presented CD20+ T cells by flow cytometry after treatment, later diagnosed with lung B-cell lymphoma.

CONCLUSION

This is the first report of CD20+ T cell detection in an NMO patient. We found that CD20+ T cells recovered faster than B cells after rituximab treatment and that CD20+ T cells seemed to play a role in suppressing tumor growth and memory T cell activity.

Serum Biomarkers in Neuro-Ophthalmology: When to Test

Discovery and characterization of serologic biomarkers has revolutionized the diagnostic framework of systemic and paraneoplastic autoimmune neuro-ophthalmic diseases. Expanding recognition of the multiple ocular and visual manifestations of these conditions highlights the important role of the referring provider in identifying potential cases. Increasing ease of access to serologic testing also enables these practitioners to initiate the diagnostic work-up in suspected cases. We aimed to provide an update on the current knowledge surrounding and use of relevant autoimmune biomarkers by correlating specific clinical neuro-ophthalmic manifestations with autoantibody biomarkers. The utility of select biomarkers for myasthenia gravis, neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein-IgG-associated disorder, opsoclonus-myoclonus syndrome, anti-collapsin-response mediator protein-5 optic neuropathy, and glial fibrillary acidic protein-IgG-associated disease are discussed with particular focus on the clinical contexts in which to consider testing.

Paraneoplastic neurological syndrome: an evolving story

Paraneoplastic neurological syndrome (PNS) comprises a group of neurological disorders that result from a misguided immune response to the nervous system triggered by a distant tumor. These disorders frequently manifest before the diagnosis of the underlying neoplasm. Since the first reported case in 1888 by Oppenheim, the knowledge in this area has evolved rapidly. Several classic PNS have been described, such as limbic encephalitis, paraneoplastic cerebellar degeneration, encephalomyelitis, opsoclonus-myoclonus, sensory neuronopathy, Lambert-Eaton Myasthenic syndrome, and chronic gastrointestinal dysmotility. It is now recognized that PNS can have varied nonclassical manifestations that extend beyond the traditional syndromic descriptions. Multiple onconeural antibodies with high specificity for certain tumor types and neurological phenotypes have been discovered over the past 3 decades. Increasing use of immune checkpoint inhibitors (ICIs) has led to increased recognition of neurologic ICI-related adverse events. Some of these resemble PNS. In this article, we review the clinical, oncologic, and immunopathogenic associations of PNS.

Neoplastic Myelopathies

PURPOSE OF REVIEW

This article reviews the current classification system of primary spinal cord tumors and explores evolving diagnostic and therapeutic strategies for both primary tumors and metastatic tumors to various compartments of the spinal cord.

RECENT FINDINGS

The 2016 World Health Organization classification system allows for more precise prognostication of and therapy for spinal cord tumors and has identified new entities, such as the diffuse midline glioma, H3 K27M mutant. Whole-exome sequencing reveals that the genetic background of primary glial spinal cord neoplasms differs from that of their intracranial histologic counterparts in ways that can potentially influence therapy. Targeted and immune checkpoint therapies have improved survival for patients with melanoma and lung cancer and have simultaneously produced novel complications by enhancing radiation toxicity in some cases and by facilitating the emergence of novel autoimmune and paraneoplastic syndromes involving the spinal cord, such as neuromyelitis optica spectrum disorder and syndromes associated with anti-Hu and collapsin response mediator protein-5 (CRMP-5) antibodies. These conditions must be distinguished from tumor or infection. Epidural spinal cord compression treatment paradigms have changed with the advent of robotic surgery and advances in radiation therapy.

SUMMARY

Neoplastic myelopathies subsume a wide spectrum of pathologies. Neoplastic cord involvement may be primary or secondary and may be approached diagnostically by the particular spinal cord compartment localization. Primary spinal cord tumors account for only 2% to 4% of primary central nervous system tumors, ranging from low-grade glial neoplasms to malignant tumors. Metastatic malignancy to the epidural or leptomeningeal spaces is more common than primary cord tumors. Differential diagnoses arising in the course of evaluation for cord tumors include myelopathies related to radiation or chemotherapy and paraneoplastic syndromes, all of which are sources of significant morbidity. Knowledge of genetic syndromes and the biologic behavior of diverse histologies together with selective application of surgery, radiation, and targeted therapies can facilitate diagnosis, minimize surgical morbidity, and prolong quality of life.

Paraneoplastic neuromyelitis optica spectrum disorders: a case series

Aquaporin-4 antibody (AQP4-IgG) neuromyelitis optica spectrum disorders (NMOSD) are rare idiopathic autoimmune diseases, presenting with optic neuritis (ON), longitudinally extensive transverse myelitis (LETM), and brainstem syndromes and a prevalence range between 0.5 and 4/100,000. Only 3% to 25% of NMOSD have been described as a paraneoplastic (PN) syndrome (PNNMOSD). Both idiopathic NMOSD (INMOSD) and PNNMOSD cases mostly affect females, but PNNMOSD usually presents with a spinal cord or brainstem involvement in elderly patients. Few cases of both malignancies (for the majority breast or lung cancer) and benign tumors (monoclonal gammopathy) were previously reported. Currently, there is no consensus on treatment approach for PNNMOSD (only surgical removal or surgery combined with chronic immunosuppression). Here, we present a series of three newly diagnosed PNNMOSD cases, who differ from each other for demographic and clinical features, tumor association, long-term treatment, and outcome. We propose that a PN etiology should be considered always whenever a new diagnosis of NMOSD is made, not only in patients over 50 years old or in spinal cord/brainstem lesions presentations. Our findings add to existing evidence and raise awareness on PNNMOSD. We enhance the importance for the clinicians of recognizing tumor symptoms and signs whenever a NMOSD is newly diagnosed.

Hiccups, severe vomiting and longitudinally extensive transverse myelitis in a patient with prostatic adenocarcinoma and Aquaporin-4 antibodies

Neuromyelitis optica spectrum disorder (NMOSD) is not defined as a classical paraneoplastic neurological syndrome, however there are growing evidences that NMOSD may be rarely associated with cancer. Older (>45 years old) male patients with longitudinally extensive transverse myelitis (LETM) or patients with "area postrema" syndrome (intractable vomiting and hiccups) at onset are at higher risk for neoplasm-associated NMOSD. We report the case of 79-years old man who developed, a month after radiotherapy for prostatic adenocarcinoma, an area postrema syndrome rapidly followed by a LETM involving the whole spinal cord (from C2 to the conus). Aquaporin-4-IgG antibodies were positive in serum.

Expression and significance of aquaporin-4 in thyroid carcinoma

OBJECTIVE

To investigate the expression of aquaporin-4 (AQP4) in thyroid carcinoma (TC) and explore its clinical significance.

MATERIALS AND METHODS

The formalin-fixed paraffin-embedded specimens including 275 TC cancer tissues, 258 corresponding paracancerous thyroid tissues and their clinicopathologic data were retrospectively analyzed. Immunohistochemical EnVision two-step method was used to detect the expression of AQP4 in the cancer tissues and adjacent thyroid tissues, and its clinical significance was analyzed.

RESULTS

AQP4 could be expressed in both TC cancer tissues and paracancerous thyroid tissues. In TC cancer tissues, the positive expression rate was 99.3% (273/275), and the positive expression rate was 86.4% (223/258) in paracancerous thyroid tissues. The expression level of AQP4 in cancer tissues was significantly higher than that in paracancerous thyroid tissues, and the difference was statistically significant (P < 0.05). The positive expression rates of AQP4 in papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), medullary thyroid carcinoma (MTC) and undifferentiated thyroid carcinoma (UTC) were 99.2% (258/260), 100.0% (6/6), 100.0% (6/6) and 100.0% (3/3), respectively and there was little difference in different types of TC. Analysis of relationship between expression level of AQP4 in 275 TC cancer tissues and 260 PTC cancer tissues and clinicopathologic characteristics of patients was not significant correlation (P > 0.05). Among the 275 patients, one (0.4%, 1/275) was diagnosed as neuromyelitis optica spectrum disorder (NMOSD) associated with TC.

CONCLUSIONS

AQP4 is generally expressed in TC cancer tissues and paracancerous thyroid tissues. Expression level of AQP4 in cancer tissues was significantly higher than that in paracancerous thyroid tissue. Expression level of AQP4 in TC cancer tissues is not related to the clinicopathological characteristics of the patients. Paraneoplastic NMOSD caused by TC is rare, and whether its specific pathogenesis is related to the expression of AQP4 in TC still needs further study.

A comparative evaluation of different neuromyelitis optica spectrum disorder sets of criteria

BACKGROUND AND PURPOSE

Three different sets of criteria have been proposed for the diagnosis of neuromyelitis optica spectrum disorder (NMOSD). The objective was to compare the specificity, sensitivity and diagnostic accuracy of the three different sets of NMOSD criteria in patients presenting with inflammatory disorders of the central nervous system suggestive of NMOSD.

METHODS

For 236 suspected NMOSD patients referred for serum aquaporin-4 immunoglobulin G antibody (AQP4-IgG) testing between 2012 and 2014, the three sets of NMOSD criteria [1999, 2006 NMO criteria and 2015 International Panel for NMO Diagnosis (IPND) criteria] were applied and compared to the final diagnosis.

RESULTS

Seventy-six patients fulfilled at least one set of criteria and 28 patients fulfilled all NMOSD sets of criteria. The final diagnosis was NMOSD in 66 cases, multiple sclerosis according to the MacDonald 2010 criteria in 85 cases and another diagnosis in 85 cases. The 2006 NMO criteria have the highest specificity (99%) and the 2015 IPND NMOSD criteria the highest sensitivity (97%). For the 1999, 2006 and 2015 IPND NMOSD criteria, the accuracy was respectively 82%, 87% and 97%.

CONCLUSIONS

Our study highlights the limitations of the first set of criteria that include the optico-spinal form of multiple sclerosis. The accuracy of NMOSD diagnostic criteria improved from 1999 to 2015. It confirms the increased performance of the last set of criteria which covers a larger spectrum of clinical presentation. This study raises some concerns for classifying patients with seronegative transverse myelitis or optic neuritis, and myelin oligodendrocyte glycoprotein (MOG) antibody- associated disease.