Anaplastic astrocytoma with aquaporin-4 positive in CSF: A case report

Single-cell RNA sequencing reveals changes in glioma-associated macrophage polarization and cellular states of malignant gliomas with high AQP4 expression

Glioma is the most common primary central nervous system tumor in adults. Aquaporin-4, as a water channel protein encoded by AQP4 in the brain, is reported to alter its aggregation status to affect plasma membrane dynamics and provide the potential for metastasis of tumor cells and components of the tumor microenvironment. We performed single-cell RNA transcriptome sequencing of 53059 cells from 13 malignant glioma samples and spotted that the expression of AQP4 differed between samples. The same result was observed in the TCGA glioma database, showing poor overall survival and poor response to chemotherapy in AQP4 overexpressed populations. Concomitant with the overexpression of AQP4, genes related to the immune system were also over-expressed, such as CD74, HES1, CALD1, and HEBP2, indicating AQP4 may relate to immune factors of tumor progression. We also found that tumor-associated macrophages tended to polarize toward M2 macrophages in the high AQP4 group. In glioblastoma samples, we examined cell status differences and identified that cell status differs according to AQP4 expression levels. Briefly, our study revealed substantial heterogeneity within malignant gliomas with different AQP4 expression levels, indicating the intricate connection between tumor cells and the tumor immune environment.

Astrocytoma with myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis: A case report

BACKGROUND

Demyelination is similar with malignancy in clinical symptoms. Magnetic resonance imaging (MRI) is an important auxiliary examination in the diagnosis of demyelinating diseases and malignancy. Since MRI and symptoms can be difficult to distinguish demyelination from malignancy, other auxiliary examinations, such as demyelinating disease-specific antibodies, play an important role in distinguishing them. Previous studies have reported demyelinating disease-specific antibodies in patients with malignancy. What's more, it is more difficult to confirm the diagnosis when the malignant tumor co-occurs with demyelinating diseases, which has never been reported in previous studies. We report the diagnosis of myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis (MOG-EM) in a patient who had astrocytoma for several years.

CASE PRESENTATION

Patient's concerns and diagnoses: our case report records a 49-year-old woman with astrocytoma for more than 4 years, who recently developed the symptoms of MOG-EM, including dizziness, vomiting, and vision loss. This astrocytoma patient was diagnosed with MOG-EM according to comprehensive evidence, including MRI, visual evoked potential (VEP), serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG), and therapeutic effect. Interventions and outcomes: this patient was diagnosed with astrocytoma by surgical biopsy 4 years earlier. This patient has been treated with tumor resection, postoperative radiation treatment and chemotherapy. After treatment, the patient was left with right limb weakness while other symptoms were improved. Recently, the intravenous steroid agent was used to treat this patient after being diagnosed with MOG-EM. Dizziness, vomiting, and vision loss have gone into remission. This patient did not relapse in 7 months after discharge. This patient is still being followed up at the outpatient clinic. And the patient will next be treated with azathioprine.

CONCLUSIONS

In previous studies, polyclonal antibody has been found in cancer patients, such as aquaporin-4 and MOG-IgG in astrocytoma patients. But the case of our study finds that astrocytoma can coexist with MOG-EM. Therefore, MOG-EM should not be excluded easily in astrocytoma patients when the relative antibody of encephalomyelitis is positive. What's more, it reminds us that the pathogenesis of MOG-EM might be related to astrocytoma.

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.

Glioblastoma as an autoimmune limbic encephalitis mimic: A case and review of the literature

A 43-year-old woman presented with cognitive decline, focal seizures, brain MRI showing non-enhancing, bilateral hippocampal lesions, but normal cerebrospinal fluid findings, which fulfilled the Graus et al., 2016 criteria for autoimmune limbic encephalitis (ALE). Subjective improvements were observed after immunotherapy. A repeat brain MRI showed new contrast enhancement and positron emission tomography revealed left hippocampal uptake. Biopsy of the right parahippocampus yielded high-grade glioma. Five similar cases, among the 14 with unilateral hippocampal lesions on MRI, were identified in the literature whereby suspected ALE preceded the high-grade glioma diagnosis. Gliomas confined to hippocampi can have clinical features overlapping with ALE.

Neuromyelitis Optica: Review and Utility of Testing Aquaporin-4 Antibody in Typical Optic Neuritis

Neuromyelitis optica (NMO) is an autoimmune, inflammatory demyelinating disorder often leading to severe vision impairment and disability. The discovery of a diagnostic biomarker, the aquaporin-4 antibody (AQP4-IgG), transformed the clinical diagnosis and treatment of NMO and broadened the spectrum of disease [NMO spectrum disorders (NMOSD)]. Though the antibody is highly sensitive and specific to NMOSD, routine testing in patients with typical optic neuritis is considered controversial. This article will provide a brief review of NMOSD and highlight the pros and cons of routine testing in typical optic neuritis.