Marco Zoccarato

Aquaporin-4 antibody neuromyelitis optica following anti-NMDA receptor encephalitis

Encephalitis associated with anti-N-Methyl-D-Aspartate Receptor (NMDAR) antibodies is an autoimmune encephalopathy often associated with teratoma [1]. Neuromyelitis optica (NMO) is an inflammatory demyelinating disorder of the central nervous system (CNS) associated with antibodies against aquaporin 4 (AQP4) [2]. Here, we report the case of a patient who developed limbic encephalitis (LE) followed by NMO, whose serum harbored anti-NMDAR and anti-AQP4 IgG antibodies. A 50-year-old woman presented with subacute, shortterm memory loss, confusion, and behavioral changes. Routine blood tests, an infectious disease screening, an electroencephalogram (EEG) and cerebral spinal fluid (CSF) tests were all negative, whereas a brain MRI showed a T2-weighted, hyperintense medial temporal cortex. A pelvic mass was detected by computed tomography (CT) scan. Two months later, she underwent a hystero-adnexectomy with the removal of an ovarian teratoma. A diagnosis of paraneoplastic LE was made. Tests for classical onconeural antibodies (Hu, Ri, Ma2, CV2/CMRP5, amphiphysin, Yo) proved negative. Her memory deficit started to improve 4 months after surgery, when she received repeated courses of low-dose oral steroids. One month later, she had only residual retrograde amnesia (Fig. 1e). Five months later, she developed drowsiness, cervical itching, and impaired gait. Within 2 weeks, she had developed paraplegia and MRI showed multiple T2weighted hyperintense lesions in the pons, hypothalamus, medulla oblongata, and cervical spine (Fig. 1a–c). A CSF analysis proved negative (normal white cell count and proteins, and absence of IgG intrathecal synthesis). Plasmaexchange and high-dose intravenous steroids were initiated, resulting in a slow improvement of strength. Nine months later, she presented with left-eye optic neuritis. High-dose intravenous steroids were partially effective. Three months later, a relapse occurred with weakness of the right limbs. An MRI disclosed new lesions in the pons and dorsal spine (Fig. 1d). Her serum and CSF were tested for AQP4-IgG-Ab by indirect immunofluorescence on a commercial assay (Euroimmun, Lubeck, Germany) [3], proving positive on serum (titer 1:100). The test was extended to NMDAR-IgG-Ab, also proving positive on serum (1:32) and on CSF. The patient was treated with plasma-exchange and oral steroids, with benefit. Three months later, her CSF analysis revealed a normal white cell count and increased protein content (84 mg/dl); matching oligoclonal bands were detected in the CSF and serum. Human leukocyte typing disclosed the presence of the class I allele B8 and class II DR3-DQ2 (DRB1*03-DQB1*02). AQP4-IgG-Aband NMDAR-IgG-Ab-positivity were both confirmed, but a decrease in serum Ab titer was shown (both Abs serum titer 1:10; NMDAR-Ab CSF titer 1:3, 2); VGCC-, AMPAR-, GABAbR-, LGI1and CASPR2-Abs tested negative. Treatment with azathioprine was started. Eight months later, her conditions were stable. This patient presented with LE followed by NMO 1 year later, and tested positive for AQP4and NMDAR-Abs. To M. Zoccarato M. F. Pelizza B. Giometto L. Zuliani (&) Department of Neurology, Ospedale Ca’Foncello, Azienda Unita Locale Socio-Sanitaria 9 Treviso, Piazza Ospedale 1, 31100 Treviso, Italy e-mail: luigizuliani77@gmail.com

Plasma exchange in pediatric anti-NMDAR encephalitis: A systematic review

OBJECTIVE To clarify the most frequent modalities of use of plasma exchange (PE) in pediatric anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis and to establish the most effective association with other immunotherapies. METHODS Systematic literature review on PE in pediatric anti-NMDAR encephalitis (2007-2015). RESULTS Seventy-one articles were included (mostly retrospective), reporting a total of 242 subjects (73.2%, 93/127 females; median age at onset 12years, range 1-18). Median time to immunotherapy was 21days (range 0-190). In most cases, PE was given with steroids and IVIG (69.5%, 89/128), or steroids only (18%, 23/128); in a minority, it was associated with IVIG only (7%, 9/128), or was the only first-line treatment (5.5%, 7/128). In 54.5% (65/119), PE was the third treatment after steroids and IVIG, in 31.1% (37/119) the second after steroids or IVIG; only in 14.3% (17/119) was it the first treatment. Second-line immunotherapies were administered in 71.9% (100/139). Higher rates of full/substantial recovery at follow-up were observed with immunotherapy given ⩽30days from onset (69.4%, 25/36) compared to later (59.2%, 16/27), and when PE was associated with steroids (66.7%, 70/105) rather than not (46.7%, 7/15). Significant adverse reactions to PE were reported in 6 patients. CONCLUSION Our review disclosed a paucity of quality data on PE in pediatric anti-NMDAR encephalitis. PE use in this condition has been increasingly reported, most often with steroids and IVIG. Despite the limited number of patients, our data seem to confirm the trend towards a better outcome when PE was administered early, and when given with steroids.

Glycine receptor antibodies in 2 cases of new, adult-onset epilepsy

Autoimmune encephalitides have been recognized in association with antibodies targeting neuronal surface antigen antibodies [NSAbs].1 Glycine receptors (GlyRs) are fundamental in motor neuron excitability, and antibodies against GlyRα1 (GlyR-Abs) were identified in a case of progressive encephalomyelitis with rigidity and myoclonus (PERM)2 and subsequently in other cases related to the stiff person syndrome spectrum.3

Clinical spectrum and IgG subclass analysis of anti-myelin oligodendrocyte glycoprotein antibody-associated syndromes: a multicenter study

Anti-myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) recently emerged as a potential biomarker in patients with inflammatory demyelinating diseases of the central nervous system. We here compare the clinical and laboratory findings observed in a cohort of MOG-Ab seropositive and seronegative cases and describe IgG subclass analysis results. Consecutive serum samples referred to Verona University Neuropathology Laboratory for aquaporin-4 (AQP4)-Ab and/or MOG-Ab testing were analysed between March 2014 and May 2017. The presence of AQP4-Ab was determined using a cell-based assay. A live cell immunofluorescence assay was used for the detection of MOG-IgG and IgG subclass analysis. Among 454 analysed samples, 29 were excluded due to AQP4-Ab positivity or to the final demonstration of a disorder not compatible with MOG-Ab. We obtained clinical data in 154 out of 425 cases. Of these, 22 subjects resulted MOG-Ab positive. MOG-Ab positive patients were mainly characterised by the involvement of the optic nerve and/or spinal cord. Half of the cases presented relapses and the recovery was usually partial. Brain MRI was heterogeneous while short lesions were the prevalent observation on spinal cord MRI. MOG-Ab titre usually decreased in non-relapsing cases. In all MOG-IgG positive cases, we observed IgG1 antibodies, which were predominant in most subjects. IgG2 (5/22), IgG3 (9/22) and IgG4 (3/22) antibodies were also detectable. We confirm that MOG-Ab-related syndromes have distinct features in the spectrum of demyelinating conditions, and we describe the possible role of the different IgG subclasses in this condition.

Paraneoplastic cerebellar degeneration with anti-Yo antibodies associated with metastatic uveal melanoma

Paraneoplastic cerebellar degeneration (PCD) is characterized by subacute development of pancerebellar dysfunction as a remote effect of a systemic cancer and usually develops in patients affected by gynecological tumors. Uveal melanoma is a very rare disease with a severe prognosis. A 58-year-old man affected by uveal melanoma developed anti-Yo positive paraneoplastic cerebellar degeneration (PCD) 42 months after the initial diagnosis. The onset and worsening of the neurological symptoms were parallel to the course of liver metastasis. To our knowledge this is the first case of PCD in a patient with uveal melanoma. We speculate that the cerebellar degeneration-related protein 2 (CDR2), to which the anti-Yo antibodies are directed, may have been expressed in melanoma cells and conferred proliferative advantage to the disease.

Clinical, Immunological and Therapeutic Aspects of Autoimmune Encephalitis

Autoimmune encephalitis is a heterogeneous group of disorders probably resulting from a reaction of the immune system against antigens of the central nervous system. Historically, the autoimmune hypothesis was based on the neuropathological discovery of an immune cellular infiltrate in the brain parenchyma and around the cerebral blood vessels, resembling a form of viral encephalitis without any detectable viral antigens. These syndromes can be divided into forms with prevalent grey matter involvement, forms with prevalent white matter damage and forms in which the target of the immune process is the vessels. In this paper, we review recent knowledge about the syndromes belonging to the first group. This group encompasses syndromes in which there is neuronal loss and antibodies directed against antigens expressed in the neurons (anti-neuronal antibodies) are frequently detected in the sera or cerebrospinal fluid. These antibodies are not necessarily the cause of neurological impairment but are important markers for these syndromes. It is essential to acquire knowledge on these disorders since they are an important cause of rapidly progressive cognitive decline and behavioural problems which may remain underrecognized, but often improve with immunomodulatory therapies.

Diagnostics of autoimmune encephalitis associated with antibodies against neuronal surface antigens

This document presents the guidelines for testing antibodies against neuronal surface antigens that have been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Essential clinical information on autoimmune encephalitis associated with antibodies against neuronal surface antigens, indications and limits of testing for such antibodies, instructions for result interpretation, and an agreed laboratory protocol (Appendix A) are reported for the communicative community of neurologists and clinical pathologists.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis Causing a Prolonged Depressive Disorder Evolving to Inflammatory Brain Disease

Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a rapidly evolving condition that combines psychiatric and neurologic manifestations. Much remains unclear about its clinical onset and subsequent course. Although successful treatment depends on diagnosing the disorder early and therefore minimizing long-term complications, this is a difficult task owing to the atypical onset of this condition and the prolonged clinical course that has been observed in some patients. This report, illustrating a patient with slowly progressing psychiatric manifestations, unusual imaging and electrophysiological features, extends the information on varied clinical phenotypes. Case Report: A 32-year-old woman suffered from an isolated depressive disorder for 4 months before undergoing psychiatric evaluation. During the following 5 months, she manifested hypersexuality, dysarthria, imbalance, dyskinesias and decreased word output. Brain magnetic resonance imaging (MRI) showed multifocal hyperintense T2/FLAIR lesions, a few contrast-enhanced, involving the corona radiata, the periventricular white matter, the deep gray nuclei, the optic nerves and the brainstem. MRI spectroscopy disclosed confluent bilateral demyelination and focal optic nerve involvement suggesting widespread encephalitis. Visual evoked potential studies indicated a demyelinating disorder. Serological screening and total body positron-emission tomography yielded negative findings for malignancies. Cerebrospinal fluid examination disclosed IgG oligoclonal bands and anti-NMDAR antibodies. Corticosteroids and intravenous immunoglobulin provided only slight improvement, whereas switching to cyclophosphamide markedly improved her neurological status. Conclusion: In patients with a prolonged clinical course, including psychiatric and neurological symptoms, the differential diagnosis should be anti-NMDAR encephalitis. This report expands the known disease phenotypes in this emerging condition.

Diagnostics of paraneoplastic neurological syndromes

This document presents the guidelines for onconeural antibody testing that have been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Essential clinical information on paraneoplastic neurological syndromes, indications and limits of onconeural antibody testing, instructions for result interpretation, and an agreed laboratory protocol (Appendix) are reported for the communicative community of neurologists and clinical pathologists.

Diagnostics of the neuromyelitis optica spectrum disorders (NMOSD)

This document presents the guidelines for anti-aquaporin-4 (AQP4) antibody testing that has been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Essential clinical information on neuromyelitis optica spectrum disorders, indications and limits of anti-AQP4 antibody testing, instructions for result interpretation, and an agreed laboratory protocol (Appendix) are reported for the communicative community of neurologists and clinical pathologists.