Paraneoplastic Antineuronal Antibodies Research Articles

Myoclonus status revealing COVID 19 infection

IntroductionAt the beginning of the coronavirus virus (COVID-19) pandemic, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) was thought to cause mainly respiratory symptoms, largely sparing the brain and the rest of the nervous system. However, as the knowledge about COVID-19 infection progresses and the number of COVID19-related neurological manifestations reports increases, neurotropism and neuroinvasion were finally recognized as major features of the SARS-CoV-2. Neurological manifestations involving the central nervous system are sparse, ranging from headaches, drowsiness, and neurovascular attacks to seizures and encephalitis [1]. Thus far, several cases of non-epileptic myoclonus were reported in critical patients [2,3]. Here, we report the first case of myoclonus status as the inaugural and sole symptom of COVID-19 in a conscious patient. ObservationA 60-year-old man with unknown family history and no medical issues other than smoking one cigarette packet a day over the span of 25 years. The patient presented with 5 days of abnormal movements in bilateral arms following the COVID vaccination. They were described as brief, involuntary jerking, like in sleep starts, in the proximal part of their upper members, and his face with a regular tremor in his arms exacerbated by movements and emotion. His movement disorder worsened the second day, and he developed an abnormal gait with slurred speech, concomitantly with diarrhea. Seven days following the symptoms onset, the patient was alert. His neurological exam revealed multifocal myoclonic jerks affecting four limbs predominantly proximal, the face, and the trunk (video 1). The myoclonic jerks were sensitive to tactile and auditory stimuli, without enhanced startle response or hyperekplexia. His gait was unsteady due to severe myoclonus, without cerebellar ataxia (video 2) and he had mild dysarthria. No dysmetria at the finger-to-nose and heel-to-shin tests were found. Examination of eye movements revealed paralysis of Down-Gaze and no opsoclonus was detected. Physical exam was unremarkable, including lack of fever and meningitis signs. The electroencephalogram (EEG) did not show any abnormalities concomitant with myoclonic jerks (Fig.1). The cerebral Magnetic Resonance Imaging (MRI) was normal (Fig. 2). An extensive biological work-up including a complete blood count, a comprehensive metabolic panel, an arterial blood gas analysis, a urine drug screen, a thyroid function test, a vitamin B12, folate, and ammonia level, and HIV and syphilis serologies were inconclusive. Testing for autoimmune and paraneoplastic antineuronal antibodies including anti-NMDA-R was negative. The cerebrospinal fluid (CSF) study was unremarkable (0.3 g/l of proteinorachia, 1 white blood cell). Polymerase chain reaction (PCR) for herpes simplex virus, varicella-zoster virus, and SARS-CoV-2 in CSF was negative. However, the patient tested positive for COVID-19 through PCR for viral RNA from the nasopharyngeal swab. After the administration of 12mg/day of Dexamethasone for 3 days, along with clonazepam and levetiracetam, the patient's symptoms started improving on day 3 and he displayed a very slow but progressive recovery. DiscussionOur patient presented with acute isolated multifocal myoclonus status without cognitive impairment. These movements were prominent, spontaneous, worsened by action, and sensitive to touch and sound. The anatomical source of this myoclonus could be cortical or subcortical despite the absence of evident EEG discharges. Several diseases can cause acute myoclonus such as severe hypoxia, metabolic disturbances, and paraneoplastic syndromes. these diagnoses were ruled out in our patient. Post-vaccinal origin was also suggested, but its accountability was not proven. Thus, the two hypothetic etiologies raised were either para-infectious or infectious mechanisms in relation to SARS-Cov 2 infection. HIV, VZV, HSV, and syphilis infections were eliminated and the patient tested positive for SARS-Cov2 infection. In the literature, COVID-19-related myoclonus was reported as a complication of an already-known SARS-CoV-2 infection in about 50 patients so far. It generally occurs between 6 days and 26 days following the SARS-CoV-2 infection [2–5], and affects critical illness patients with cognitive decline, mainly from the intensive care unit [3,4]. Yet, our patient did not display any symptoms of COVID-19 infection before the occurrence of these abnormal movements. Furthermore, he had a relatively good general condition and no cognitive impairment. Several pathophysiological mechanisms were suggested regarding the COVID-19-related myoclonus. Either central nervous invasion by SARS-Cov 2 after transneuronal spread and/or auto-immune cross-reactivity reaction, are likely incriminated in the pathophysiology of most of the cases [6]. We believe that there is an inflammatory process involved with increased levels of proinflammatory cytokines and systemic inflammation, including cytokine storm or cytokine release syndrome targeting the brain and more specifically the cortex and basal ganglia [6]. Data collection in clinical registries is needed to increase our knowledge of the prevalence of neurological symptoms in patients with COVID-19 and will hopefully clarify the causal relationship between SARS-CoV-2 infection and post-COVID-19 myoclonic syndrome.

KNOCK KNOCK, HU'S THERE? POSITIVE ANTI-HU ANTIBODY IN EXTRAPULMONARY SMALL CELL CARCINOMA OF LYMPH NODE

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: To date, small cell carcinoma (SCC) has been primarily recognized as a pulmonary malignancy and research has been skewed towards this area. Extrapulmonary SCC is rare, accounting for 2.5% of SCC, out of which lymph node SCC are far and few between. CASE PRESENTATION: A 59-year-old gentleman was initially admitted to neurology for sensory neuropathy and weight loss. He was referred to the respiratory medicine team after imaging revealed subcarinal and left hilar lymphadenopathy. He is a chronic smoker and there was a concern for malignancy. Initial endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) using 22 gauge needle showed lymphoid yield. Serum paraneoplastic panel (Hu, Yo, Ri, CV2, Amphiphysin, PNMA2/Ta, recoverin, SOX1, titin, zic4, GAD65, Tr(DNER)) was performed as part of the diagnostic work up. Anti-Hu antibody was 1:101 (strongly positive); reference titer 1:<10. Fluorodeoxyglucose-positron emission tomography-computed tomography (FDG-PET-CT) scan revealed FDG avid subcarinal (SUVmax:11.1) and left hilar (SUVmax:13.2) nodes. In view of the anti-Hu antibody results and FDG-PET-CT findings, a repeat EBUS-TBNA using 19 gauge needle was performed and histology confirmed SCC. DISCUSSION: Paraneoplastic syndrome was first described by M. Auché in 1890 and is known to affect up to 8% of patients with cancer; most notably small cell lung cancer. Anti-Hu is an onconeural antibody first discovered by F. Grouse in 1985. Its moniker is type I anti-neuronal nuclear antibody (ANNA-1) and has been a signpost for paraneoplastic sensory neuropathy or encephalomyelitis. (Positive anti-Hu antibody titers have a reported specificity of 99% and sensitivity of 82%). It is recognized as a distinct clinical disease, “anti-Hu syndrome”, with characteristic clinical picture and imaging findings. A Dutch study in 2002 found that 85% of patients with positive anti-Hu antibody also have a tumor. Of note, anti-Hu antibodies can also be positive in antecedent inflammatory diseases like systemic lupus erythematosus or Sjogren’s syndrome which can confound the diagnosis. Thus, positive anti-Hu antibody levels should prompt further evaluation and follow up even in absence of concurrent malignancy. Early diagnosis of lymph node SCC has prognostic implications when compared to pulmonary and extrapulmonary SCC, thus making the distinction necessary. CONCLUSIONS: This study highlights the diagnostic implications of an abnormal paraneoplastic panel, emphasizing the role of anti-Hu antibody in its specificity for SCC. The presence of FDG avid thoracic lymph nodes with elevated anti-Hu antibody titers warrants a repeat biopsy. It is imperative for clinicians to identify occult neoplasms in the setting of paraneoplastic syndromes. Reference #1: Koike H, Sobue G. Paraneoplastic neuropathy. Handb Clin Neurol. 2013;115:713-26. Reference #2: Graus F, Cordon-Cardo C, Posner JB. Neuronal antinuclear antibody in sensory neuronopathy from lung cancer. Neurology. 1985 Apr;35(4):538–43. Sehgal IS, Kaur H, Dhooria S, et al. Extrapulmonary small cell carcinoma of lymph node: Pooled analysis of all reported cases. World J Clin Oncol. 2016;7(3):308-20. Graus F, Keime-Guibert F, Reñe R, Benyahia B, Ribalta T, Ascaso C, Escaramis G, Delattre JY. Anti-Hu-associated paraneoplastic encephalomyelitis: analysis of 200 patients. Brain. 2001;124(6):1138-1148. Senties-Madrid H, Vega-Boada F. Paraneoplastic syndromes associated with anti-Hu antibodies. Isr Med Assoc J. 2001 Feb;3(2):94-103. Reference #3: Benyahia B, Amoura Z, Rousseau A, Le Clanche C, Carpentier A, Piette JC, Delattre JY. Paraneoplastic antineuronal antibodies in patients with systemic autoimmune diseases. J Neurooncol. 2003 May;62(3):349-51. Sillevis Smitt P, Grefkens J, de Leeuw B, van den Bent M, van Putten W, Hooijkaas H, Vecht C. Survival and outcome in 73 anti-Hu positive patients with paraneoplastic encephalomyelitis/sensory neuronopathy. J Neurol. 2002 Jun;249(6):745-53. Kim KO, Lee HY, Chun SH, et al. Clinical overview of extrapulmonary small cell carcinoma. J Korean Med Sci. 2006;21(5):833-7. Kannoth S. Paraneoplastic neurologic syndrome: A practical approach. Ann Indian Acad Neurol. 2012;15(1):6-12. DISCLOSURES: No relevant relationships by John Abisheganaden, source=Web Response No relevant relationships by Caroline Choong, source=Web Response No relevant relationships by Sharlene Ho, source=Web Response No relevant relationships by Chuen Peng Lee, source=Web Response No relevant relationships by Ziqin Ng, source=Web Response No relevant relationships by Ser Hon Puah, source=Web Response No relevant relationships by HUIJIA WANG, source=Web Response No relevant relationships by Kim Hoong Yap, source=Web Response

Multiplex serology of paraneoplastic antineuronal antibodies

Paraneoplastic neurological syndromes (PNS) are devastating neurological disorders secondary to cancer, associated with onconeural autoantibodies. Such antibodies are directed against neuronal antigens aberrantly expressed by the tumor. The detection of onconeural antibodies in a patient is extremely important in diagnosing a neurological syndrome as paraneoplastic (70% is not yet known to have cancer) and in directing the search for the underlying neoplasm. At present six onconeural antibodies are considered ‘well characterized’ and recognize the antigens HuD, CDR62 (Yo), amphiphysin, CRMP-5 (CV2), NOVA-1 (Ri), and Ma2. The gold standard of detection is the characteristic immunohistochemical staining pattern on brain tissue sections combined with confirmation by immunoblotting using recombinant purified proteins. Since all six onconeural antibodies are usually analyzed simultaneously and objective cut-off values for these analyses are warranted, we developed a multiplex assay based on Luminex technology. Reaction of serial dilutions of six onconeural standard sera with microsphere-bound antigens showed lower limits of detection than with Western blotting. Using the six standard sera at a dilution of 1:200, the average within-run coefficient of variation (CV) was 4% (range 1.9–7.3%). The average between-run within-day CV was 5.1% (range 2.9–6.7%) while the average between-day CV was 8.1% (range 2.8–11.6%). The shelf-life of the antigen coupled microspheres was at least two months. The sensitivity of the multiplex assay ranged from 83% (Ri) to 100% (Yo, amphiphysin, CV2) and the specificity from 96% (CV2) to 100% (Ri). In conclusion, Luminex-based multiplex serology is highly reproducible with high sensitivity and specificity for the detection of onconeural antibodies. Conventional immunoblotting for diagnosis of onconeural antibodies in the setting of a routine laboratory may be replaced by this novel, robust technology.

Screening for Well-Characterized Paraneoplastic Antineuronal Antibodies in Multiple Sclerosis

ABSTRACTSome epidemiological surveys have shown an increased incidence of malignancies in patients with multiple Sclerosis (MS). Furthermore, in rare cases central demyelinating disorders like optic neuritis, encephalomyelitis, and myelitis could be of paraneoplastic origin. Antineuronal antibodies are frequently associated with paraneoplastic neurological syndromes (PNS) but are also described in cancer patients without neurological symptoms. In this study, we retrospectively analyzed sera from 247 patients with MS and clinically isolated syndrome (CIS) for the presence of anti-HuD, Yo, Ri, CV2/CRMP5, Ma2, and amphiphysin antibodies using ELISA employing recombinant onconeural antigens. None of the sera revealed high titers of antineuronal antibodies and only two sera from MS patients show weak reactivity, representing in all probability background activity. Furthermore, cancer incidence in our study is low (0.8%). Our analysis does not support an association between MS and well-characterized paraneoplastic antineuronal antibodies, suggestive of a secondary humoral autoimmune response, underlying latent malignancy, or paraneoplastic origin in our cohort. In reverse, negative screening results in samples of MS patients confirm the high specificity of these antibodies for PNS.

Paraneoplastic antibody during follow-up of a patient with anti-Ri-associated paraneoplastic neurological syndrome

The role of classical antineuronal antibody determinations to confirm the paraneoplastic aetiology of a neurological syndrome is well established. However, the value of antineuronal antibody estimation during follow-up of paraneoplastic neurological syndromes (PNS) is not known. Prospective analysis of antibody concentrations in follow-up serum samples from a patient with anti-Ri-associated PNS. Semiquantitative estimation of antibody concentrations with an ELISA using recombinant Ri antigen. Semiquantitative estimation of circulating anti-Ri antibodies demonstrated a renewed increase in antibody levels preceding relapse of the cancer, as confirmed using F-fluorodeoxyglucose positron emission tomography (FDG-PET). This is the first prospective report on serial anti-Ri antibody determinations. As a large increase in antineuronal antibody concentrations in follow-up serum samples preceded relapse of the cancer, paraneoplastic antineuronal antibodies may represent a marker for tumour activity in this case. These results warrant further multicentre studies to investigate the ability of serial quantification of classical antineuronal antibodies in monitoring PNS and in predicting relapse of cancers.

Recombinant immunoblot for assessment of intrathecally synthesised paraneoplastic antineuronal antibodies in cerebrospinal fluid from patients with paraneoplastic neurological syndromes

Recombinant immunoblot for assessment of intrathecally synthesised paraneoplastic antineuronal antibodies in cerebrospinal fluid from patients with paraneoplastic neurological syndromes

Recombinant immunoblot for assessment of intrathecally synthesised paraneoplastic antineuronal antibodies in cerebrospinal fluid from patients with paraneoplastic neurological syndromes

Background: Beside of pathophysiological interest, estimation of intrathecal synthesis (IS) of paraneoplastic antineuronal antibodies may increase the diagnostic sensitivity in rare cases of patients with clinically suggestive paraneoplastic neurological syndromes (PNS) and negative or uncertain results in serum. Detection of antigen-specific oligoclonal bands (OCB) in CSF seems to be the most sensitive marker of IS. However, this technique is not suitable for routine laboratory testing.

?Fu�kribbeln?, Vergesslichkeit und progrediente Wesensver�nderung bei einer 63-j�hrigen Patientin

A 63-year-old female was admitted to the hospital with leg and forearm paresthesias. We found progressive ataxia, dementia, and psychosocial deterioration. The clinical symptoms, the neurologic and psychiatric abnormalities together with the inflammatory cerebrospinal fluid alteration and the cerebral magnetic resonance imaging changes suggested a paraneoplastic etiology. It was confirmed by paraneoplastic antineuronal antibodies in the patient's serum and the histological diagnosis of a small cell bronchial carcinoma. The prognosis of patients with paraneoplastic symptoms is the better the earlier a diagnosis is established and antitumor therapy is initiated.

Paraneoplastic antineuronal antibodies in patients with systemic autoimmune diseases.

Sera from 71 patients with primary Sjögren's syndrome (PSS) and from 102 patients with systemic lupus erythematosus (SLE) were tested by immuno-dot blotting against HuD, Ri, Yo and amphiphysin recombinant proteins. For Ri, Yo and amphiphysin antigens, no immunoreactivity was found in the 173 sera tested. One PSS patient with a clinical picture of subacute sensory neuronopathy had high titers of anti-Hu antibodies. An extensive search for an underlying tumor was initially negative but a small cell lung cancer was eventually discovered three years later. Another patient with SLE and a clinical picture of demyelinating polyradiculoneuropathy had anti-Hu antibodies. Repeated search for an underlying tumor remains negative after five years follow-up in this young non-smoking patient. In addition, the neuropathy progressively improved and the anti-Hu antibodies titer slowly decreased from 1:8000 to 1:2000, making the diagnosis of paraneoplastic syndrome unlikely in this patient. This study indicates that the detection of anti-Hu antibodies in patients with known symptomatic systemic autoimmune diseases such as PSS or SLE should induce the same work-up than the detection of these antibodies in the absence of other immune diseases, i.e. repeated search for occult cancer during several years. As illustrated by our first patient, this strategy may be fruitful. Nevertheless, the clinician should know that anti-Hu antibodies may exceptionally (0.6% in this series) occur in systemic autoimmune disorders with neurological complications, in the absence of an underlying neoplastic disease.

A Controlled Study of Serum Anti-locus Ceruleus Antibodies in REM Sleep Behavior Disorder

The newly identified association of human nonnarcoleptic rapid eye movement (REM) sleep behavior disorder (RBD) with human leukocyte antigen (HLA) DQw1 class II genes raises the possibility that RBD may arise from autoimmune mechanisms. Two recent case reports involving postmortem brain stem histochemical analyses in elderly males with RBD identified severe monoaminergic cell loss in the locus ceruleus (LC). Thus, we designed a study to detect anti-LC antibodies in RBD. Ten Caucasian males (mean age, 66 years) with polygraphically confirmed RBD (n = 5, idiopathic RBD: n = 5, RBD with Parkinson's disease), but without narcolepsy, idiopathic hypersomnia, or autoimmune disease, were recruited for this study, along with 10 Caucasian male controls (mean age, 63 years) without a history of sleep disorder or autoimmune disease. In a blinded design, sera from the RBD patients and their controls were tested against human LC and other brainstem neurons. Brainstem tissue was obtained from autopsies of neurologically normal individuals. The presence of anti-LC antibodies was examined using immunohistochemistry on brainstem sections. Sections incubated with sera from normal individuals and sera from patients with paraneoplastic antineuronal antibodies (anti-Hu and anti-Ri) were used as controls. No reactivity with LC or any other brainstem area was identified with sera from either RBD patients or their controls, or from the other group of normal individuals. In contrast, sera from patients with paraneoplastic anti-Hu and anti-Ri antibodies reacted strongly with nuclei of LC and other brainstem neurons, sparing the nucleoli, and reacted to a lesser extent with the cytoplasm of these neurons. Therefore, it is unlikely that human RBD is associated with anti-LC antibodies. However, an autoimmune process in RBD has not been excluded by this study.

Regression of small-cell lung carcinoma in patients with paraneoplastic neuronal antibodies

We describe three patients with known or suspected small-cell lung cancer (SCLC), paraneoplastic neurological syndromes, and antineuronal antibodies who had unusually benign clinical courses. One patient survived 8 years free of disease and was positive for the anti-Hu antibody. A second patient survived 6 years after spontaneous tumour regression and had an atypical antineuronal antibody. A third patient with both the anti-Hu and atypical antineuronal antibody had spontaneous regression of a lung mass. All three patients had a subacute sensory neuropathy. Since paraneoplastic antineuronal antibodies also bind to tumour cells, these cases suggest that some (paraneoplastic) neurological syndromes without identifiable tumour may result from immune-mediated eradication of tumour cells.