Paraneoplastic antibodies coexist and predict cancer, not neurological syndrome

Initial screening for neuronal autoantibodies and their putative impact on survival in patients with small-cell lung cancer

INTRODUCTION

Small-cell lung cancer (SCLC) may be associated with neuronal autoantibodies and paraneoplastic neurological syndromes. It has been suggested that neuronal autoantibodies, especially antineuronal nuclear antibody type 1 (Hu) autoantibodies, are associated with longer survival of patients with SCLC. The objective of this study was to determine the frequency and distribution of neuronal autoantibodies at the time of diagnosis of SCLC patients and assess survival rates in relation to autoimmunity.

METHODS

In this retrospective study, serum from 40 patients with biopsy-proven SCLC at the time of diagnosis was studied prior to treatment. The sera originated from a cancer registry at the Oncology Department, Vejle Hospital from 2007 to 2010. The sera were analyzed blindly to clinical status for the presence of neuronal autoantibodies. Medical records were reviewed for neurological symptoms.

RESULTS

Neuronal autoantibodies were detected in 22/40 (55%) of the SCLC patients. A broad range of neurological symptoms was recorded in 28/40 (70%) patients, of which 14/28 (50%) were positive for neuronal autoantibodies. The most frequently detected autoantibodies were Hu (7/40, 17.5%) followed by GAD65 (6/22, 15.0%). Striational and P/Q- or N-type voltage-gated calcium channel antibodies were less common, with each found in five patients (12.5%). Eight patients (20%) had coexisting autoantibodies. Autoantibody-positivity was not associated with survival.

CONCLUSION

Neuronal autoantibodies were at time of diagnosis found in approximately half of the treatment-naïve SCLC patients. Neither autoantibody positivity at diagnosis nor neurological manifestations correlated with survival and their clinical importance requires further studies in larger, prospective cohorts.

Evaluation of potential prevalence of onconeural antibodies in women with breast cancer

OBJECTIVE

Aim: To analyse onconeural antibodies in the blood serum of breast cancer patients without neurological symptoms..

PATIENTS AND METHODS

Materials and Methods: The study included 48 women with breast cancer. Paraneoplastic Neurologic Syndromes 12 Ag (IgG) Euroline by EUROIMMUN test was used to determine onconeural antibodies: anti-Hu, anti-Yo, anti-Ri, anti-CV2, anti-Ma/anti-Ta, anti-amphiphysin, anti-recoverin, anti-SOX1, anti-tytin, anti-zic4, anti-GAD65 and anti-Tr (DNER).

RESULTS

Results: The conducted analysis revealed the presence of onconeural antibodies such as: anti-recoverin, anti-CV2, anti-Zic4, anti-SOX1, anti-MA2/Ta and antititin in blood serum of women with breast cancer.

CONCLUSION

Conclusions: Further analysis may allow the assessment of the possible clinical usefulness of these determinations.

Paraneoplastic neuropathies and peripheral nerve hyperexcitability disorders

Peripheral neuropathy is a common referral for patients to the neurologic clinics. Paraneoplastic neuropathies account for a small but high morbidity and mortality subgroup. Symptoms include weakness, sensory loss, sweating irregularity, blood pressure instability, severe constipation, and neuropathic pain. Neuropathy is the first presenting symptom of malignancy among many patients. The molecular and cellular oncogenic immune targets reside within cell bodies, axons, cytoplasms, or surface membranes of neural tissues. A more favorable immune treatment outcome occurs in those where the targets reside on the cell surface. Patients with antibodies binding cell surface antigens commonly have neural hyperexcitability with pain, cramps, fasciculations, and hyperhidrotic attacks (CASPR2, LGI1, and others). The antigenic targets are also commonly expressed in the central nervous system, with presenting symptoms being myelopathy, encephalopathy, and seizures with neuropathy, often masked. Pain and autonomic components typically relate to small nerve fiber involvement (nociceptive, adrenergic, enteric, and sudomotor), sometimes without nerve fiber loss but rather hyperexcitability. The specific antibodies discovered help direct cancer investigations. Among the primary axonal paraneoplastic neuropathies, pathognomonic clinical features do not exist, and testing for multiple antibodies simultaneously provides the best sensitivity in testing (AGNA1-SOX1; amphiphysin; ANNA-1-HU; ANNA-3-DACH1; CASPR2; CRMP5; LGI1; PCA2-MAP1B, and others). Performing confirmatory antibody testing using adjunct methods improves specificity. Antibody-mediated demyelinating paraneoplastic neuropathies are limited to MAG-IgM (IgM-MGUS, Waldenström's, and myeloma), with the others associated with cytokine elevations (VEGF, IL6) caused by osteosclerotic myeloma, plasmacytoma (POEMS), and rarely angiofollicular lymphoma (Castleman's). Paraneoplastic disorders have clinical overlap with other idiopathic antibody disorders, including IgG4 demyelinating nodopathies (NF155 and Contactin-1). This review summarizes the paraneoplastic neuropathies, including those with peripheral nerve hyperexcitability.

Paraneoplastic antibodies targeting intracellular antigens

Although they are relatively rare, the diagnosis of paraneoplastic neurologic syndromes (PNS) can be aided by the identification of neural autoantibodies in patients' serum and cerebrospinal fluid (CSF). They often clinically manifest as characteristic syndromes, including limbic encephalitis, opsoclonus-myoclonus syndrome, paraneoplastic cerebellar degeneration, and paraneoplastic encephalomyelitis. The antibodies are directed either toward intracellular targets, or epitopes on the cell surface. As compared to cell surface antibodies, intracellular paraneoplastic autoantibodies are more classically associated with cancer, most often lung, breast, thymoma, gynecologic, testicular, and/or neuroendocrine cancers. The malignancies themselves tend to be small and regionally contained, attesting to the strength of the immune system in cancer immunosurveillance. Typically, the intracellular antibodies are not directly pathogenic and tend to be associated with PNS that are poorly responsive to treatment. With some notable exceptions, including patients with PNS associated with testicular cancer, patients with intracellular antibodies are typically older individuals, in their 7th decade of life and beyond. Many of them are current or former smokers. Treatment strategies include tumor removal as well as immunotherapy to treat the concomitant PNS. Newer technologies and the ever-broadening use of cancer immunotherapies are contributing to the continued identification of novel intracellularly targeted autoantibodies.

Clinical Impact of Pre-Existing Autoantibodies in Patients With SCLC Treated With Immune Checkpoint Inhibitor: A Multicenter Prospective Observational Study

Introduction

Although pretreatment autoantibodies have been associated with immune-related adverse events (irAEs) and immune checkpoint inhibitor treatment efficacy in some types of cancer, their importance has not been evaluated in patients with SCLC.

Methods

A multicenter prospective observational study was conducted on a total of 52 patients with extensive-disease SCLC who received immune checkpoint inhibitors in combination with chemotherapy as the first-line treatment at either of the six participating centers in Japan. Pretreatment serum samples were collected and analyzed for autoantibodies (rheumatoid factor, antinuclear antibodies, and antithyroid). Moreover, 12 antineuronal antibodies (AMPH, CV2, PNMA2, Ri, Yo, Hu, Recoverin, SOX1, Titin, Zic4, GAD65, and Tr) were analyzed using immunoblot assays. The primary end point was the incidence of irAEs with or without autoantibodies. The secondary end points were progression-free survival (PFS) and overall survival (OS) on the basis of the presence or absence of autoantibodies.

Results

PFS and OS were 4.4 and 25.3 months, respectively. Autoantibodies (rheumatoid factor, antinuclear antibodies, and antithyroid antibodies) were detected in 29 patients (56%). In total, irAEs were observed in 18 patients (35%); irAE incidence was 48% in the autoantibody-positive group and 17% in the autoantibody-negative group (p = 0.039). There was no difference in PFS or OS between patients with and without autoantibodies (4.4 mo versus 4.6 mo, p = 0.36; 15.3 mo versus 18.2 mo, p = 0.36). Antineuronal antibodies were detected in 16 patients (31%). However, the development of neurologic irAEs was not observed in both groups.

Conclusions

Vigilance is required against the development of irAEs in pretreatment antibody-positive patients.

Clonal redemption of B cells in cancer

Potentially self-reactive B cells constitute a large portion of the peripheral B cell repertoire in both mice and humans. Maintenance of autoreactive B cell populations could conceivably be detrimental to the host but their conservation throughout evolution suggests performance of a critical and beneficial immune function. We discuss herein how the process of clonal redemption may provide insight to preservation of an autoreactive B cell pool in the context of infection and autoimmunity. Clonal redemption refers to additional recombination or hypermutation events decreasing affinity for self-antigen, while increasing affinity for foreign antigens. We then review findings in murine models and human patients to consider whether clonal redemption may be able to provide tumor antigen-specific B cells and how this may or may not predispose patients to autoimmunity.

Autoimmune Axonal Neuropathies

OBJECTIVE

This article reviews autoimmune axonal neuropathies, their characteristic clinical features, disease and antibody associations, appropriate ancillary testing, treatment, and prognosis.

LATEST DEVELOPMENTS

In 2021, the American College of Rheumatology and the Vasculitis Foundation released new summary guidelines for the treatment of antineutrophil cytoplasmic autoantibody-associated vasculitides. In addition, novel autoantibodies have been recently identified; they are often paraneoplastic and associated with axonal neuropathies.

ESSENTIAL POINTS

Recognition of autoimmune axonal neuropathies is important because of the potential for effective treatment to either reverse deficits or slow the progression of disease. It is necessary to properly assess for associations with other systemic disorders (eg, systemic vasculitis, connective tissue disease, neoplasm) so that adequate treatment for both neurologic and non-neurologic aspects of the disease can be initiated.

Identification of SKOR2 IgG as a novel biomarker of paraneoplastic neurologic syndrome

Introduction

The development of new autoantigen discovery techniques, like programmable phage immunoprecipitation sequencing (PhIP-Seq), has accelerated the discovery of neural-specific autoantibodies. Herein, we report the identification of a novel biomarker for paraneoplastic neurologic syndrome (PNS), Sloan-Kettering-Virus-Family-Transcriptional-Corepressor-2 (SKOR2)-IgG, utilizing PhIP-Seq. We have also performed a thorough clinical validation using normal, healthy, and disease/cancer control samples.

Methods

Stored samples with unclassified staining at the junction of the Purkinje cell and the granule cell layers were analyzed by PhIP-Seq for putative autoantigen identification. The autoantigen was confirmed by recombinant antigen-expressing cell-based assay (CBA), Western blotting, and tissue immunofluorescence assay colocalization.

Results

PhIP-Seq data revealed SKOR2 as the candidate autoantigen. The target antigen was confirmed by a recombinant SKOR-2-expressing, and cell lysate Western blot. Furthermore, IgG from both patient samples colocalized with a commercial SKOR2-specific IgG on cryosections of the mouse brain. Both SKOR2 IgG-positive patients had central nervous system involvement, one presenting with encephalitis and seizures (Patient 1) and the other with cognitive dysfunction, spastic ataxia, dysarthria, dysphagia, and pseudobulbar affect (Patient 2). They had a refractory progressive course and were diagnosed with adenocarcinoma (Patient 1: lung, Patient 2: gallbladder). Sera from adenocarcinoma patients without PNS (n=30) tested for SKOR2-IgG were negative.

Discussion

SKOR2 IgG represents a novel biomarker for PNS associated with adenocarcinoma. Identification of additional SKOR2 IgG-positive cases will help categorize the associated neurological phenotype and the risk of underlying malignancy.

AMPAR autoimmunity: Neurological and oncological accompaniments and co-existing neural autoantibodies

α -amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) encephalitis is rare but treatable. We reviewed the clinical and autoantibody profiles of 52 AMPAR-IgG-positive patients (median age 48 years [range 12-81]; 38 female) identified at the Mayo Clinic neuroimmunology laboratory. Main presentation was encephalitis; symptoms other than encephalitis associated with co-existing antibodies (p = 0.004). A tumor was found in 33/44; mostly thymoma. Most patients had partial (14/29) or complete (11/29) immunotherapy response. Thirty-one patients had at least one co-existing antibody that predicted thymoma in paraneoplastic patients (p = 0.008). In conclusion, in AMPAR encephalitis co-existing antibodies predict clinical presentation other than encephalitis and thymoma.

Postvaccinal GABA-B receptor antibody encephalitis after ChAdOx1 nCoV-19 vaccination

Several cases of autoimmune encephalitis have been reported after ChAdOx1 nCoV-19 (AZD1222) vaccination. We encountered a male patient who presented with generalized tonic-clonic seizures, cognitive decline, and gait disturbance that occurred suddenly after the second dose of the ChAdOx1 nCoV-19 vaccine. Clinical presentation and magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) test results were compatible with limbic encephalitis. Synaptic autoantibody tests confirmed serum and CSF GABA B receptor antibodies were present. The patient was treated with immunotherapy with intravenous immunoglobulin and rituximab. This GABA-B receptor antibody encephalitis case occurred presumably due to transient autoantibody production following vaccine administration.

Anti-Neuronal Nuclear Antibody 3 Autoimmunity Targets Dachshund Homolog 1

The antigen specificity of Anti-Neuronal Nuclear Antibody-type 3 (ANNA3)-IgG is unknown. We identified Dachshund-homolog 1 (DACH1) as the ANNA3 autoantigen and confirmed it by antigen-specific assays, immunohistochemical colocalization and immune absorption experiments. Patients' median age was 63.5 years (range, 49-88); 67% were female. Neurological manifestations (information available for 30 patients) included one or more of neuropathy, 12; cognitive difficulties, 11; ataxia, 8; dysautonomia, 7. Evidence of a neoplasm was present in 27 of 30 (90%), most of neuroendocrine lineage. DACH1-IgG is rare and represents a novel proposed biomarker of neurological autoimmunity and cancer. ANN NEUROL 2022;91:670-675.

Gastric cancer complicated by paraneoplastic neurological syndrome which presented with extremity numbness: a case report

Background

Paraneoplastic neurological syndromes refer to a group of neurological disorders, which occur as distant effects of malignant tumors and are not caused by metastasis, nutritional disorders, or side effects of antitumor drugs.

Case presentation

A 70-year-old woman complained of a 1-month history of extremity numbness. Upon presentation to our hospital, she had worsening numbness, and experienced staggering and falling. Physical examination revealed diminished tendon reflexes in both lower limbs, stocking and glove-type abnormal sensation, and left-sided dominant high-steppage gait due to weakness of the bilateral tibialis anterior muscles. Blood tests indicated anemia, and upper gastrointestinal endoscopy revealed gastric cancer, leading to laparoscopic distal gastrectomy. A nerve conduction velocity test showed demyelinating peripheral neuropathy. Further blood tests and imaging studies ruled out nutritional disorders, such as vitamin deficiency, diabetes-related diseases, connective tissue diseases, and central nervous system metastasis, leading to the suspicion of paraneoplastic neurological syndrome. After laparoscopic distal gastrectomy, the progression of symptoms stopped, and with intravenous high-dose immunoglobulin and steroid therapy, the symptoms improved to only minor numbness in the peripheral limbs as of the 18-month follow-up. As of the 2-year follow-up, there has been no cancer recurrence or metastasis.

Conclusions

When paraneoplastic neurological syndrome is suspected, early diagnosis and a multidisciplinary approach, including surgical treatment, are important before irreversible neurological damage occurs.

LGI1 antibody encephalitis: acute treatment comparisons and outcome

OBJECTIVE

To compare acute treatment responses and long-term outcome in leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis.

METHODS

Retrospective case series of 118 patients with LGI1 antibody encephalitis evaluated at Mayo Clinic across all US sites from 1 May 2008 to 31 March 2019. Patient clinical data were identified and analysed through the neuroimmunology laboratory and electronic medical record. LGI1 antibody detection was by cell-based indirect immunofluorescence assay of serum, cerebrospinal fluid or both. Clinical outcomes were faciobrachial dystonic seizure (FBDS) resolution, modified Rankin Scale (mRS) score, Kokmen Short Test of Mental Status (STMS) score (0-38 point scale) and neuropsychometric testing results.

RESULTS

Compared with intravenous immunoglobulin (IVIg) (n=21), patients treated with single-agent acute corticosteroids (intravenous, oral or both) (n=49) were more likely to experience resolution of FBDS (61% vs 7%, p=0.002) and improvements in mRS score (ΔmRS score 2 vs 0, p=0.008) and median Kokmen STMS scores (ΔKokmen STMS score 5 points vs 0 points, p=0.01). In 54 patients with long-term follow-up (≥2 years), the median mRS score was 1 (range 0-6) and the median Kokmen STMS score was 36 (range 24-38) after all combinations of immunotherapy. Neuropsychometric testing in 32 patients with long-term follow-up (≥2 years) demonstrated short-term memory impairments in 37%.

CONCLUSIONS

Corticosteroids appeared more effective acutely than IVIg in improving LGI1 antibody encephalitis in this retrospective comparison of immunotherapies. While improvement with immunotherapy is typical and long-term outcome is favourable, short-term memory deficits are noted in approximately a third of the patients.

CASPR2-IgG-associated autoimmune seizures

OBJECTIVE

This study was undertaken to report clinical presentations and outcomes of CASPR2-IgG-associated seizures.

METHODS

Mayo Clinic Neuroimmunology database was queried to identify CASPR2-IgG-seropositive (CASPR2-IgG+) patients evaluated at our institution (2009-2019).

RESULTS

Of the 53 CASPR2-IgG+ patients (titer ≥ 1:10), 20 had seizures (38%). All seizure patients were male, with median onset age of 68 years. Eighteen (90%) had seizures at initial presentation. One patient was found to have malignancy (colon adenocarcinoma). Two patients had coexisting LGI1-IgG. Twelve patients had archived sera, which on titration had CASPR2-IgG titers ≥ 1:100. Fifteen patients (75%) met criteria for autoimmune encephalitis. Patients most commonly presented with focal onset, nonmotor seizures with impaired awareness (n = 14, 70%). Eleven patients also had focal motor and/or sensory seizures as one of the seizure semiologies. The majority of patients (n = 11, 55%) developed generalized tonic-clonic seizures during their disease course. Seizure clusters occurred in 12 patients. In addition to seizures, patients developed cognitive disturbance (n = 16, 80%), episodic emotional lability (n = 13, 65%), paroxysmal dizziness (n = 9, 45%), episodic ataxia (n = 6, 30%), and chronic ataxia (n = 9, 45%). Only three patients (15%) had coexisting peripheral nervous system involvement. Frontotemporal or temporal ictal and/or interictal electroencephalographic abnormalities were present among nine patients, and three had multifocal epileptiform abnormalities. Eight patients (40%) had medial temporal T2/fluid-attenuated inversion recovery hyperintensity on brain magnetic resonance imaging. Elevated cerebrospinal fluid protein and/or lymphocytic pleocytosis was present in most cases (13/14, 93%). Thirteen patients reached seizure freedom following initiation of antiseizure medication (ASM; n = 4) or a combination of immunotherapy and ASM (n = 9). Median duration of follow-up was 25 months (range = 2-136 months).

SIGNIFICANCE

CASPR2-IgG evaluation should be considered among older male patients with new onset focal seizures and impaired awareness often occurring in clusters with/without features of encephalitis. Coexisting neurological manifestations, including episodic emotional lability, ataxia, and paroxysmal dizziness, also aid in the diagnosis.

Louis EK. Objective sleep profile in LGI1/CASPR2 autoimmunity

STUDY OBJECTIVES

Rapid eye movement (REM) sleep behavior disorder (RBD) and other sleep disturbances are frequent in leucine-rich, glioma inactivated protein 1-IgG (LGI1) and contactin-associated protein 2-IgG (CASPR2) autoimmunity, yet polysomnographic analyses of these disorders remain limited. We aimed to characterize clinical presentations and analyze polysomnographic manifestations, especially quantitative REM sleep without atonia (RSWA) in LGI1/CASPR2-IgG seropositive (LGI/CASPR2+) patients.

METHODS

We retrospectively analyzed clinical and polysomnographic features and quantitative RSWA between LGI1+/CASPR2+ patients and age-sex matched controls. Groups were compared with Wilcoxon rank-sum and chi-square tests. Combined submentalis and anterior tibialis (SM + AT) RSWA was the primary outcome.

RESULTS

Among 11 (LGI1+, n = 9; CASPR2+, n = 2) patients, Morvan syndrome sleep features were present in seven (63.6%) LGI1+/CASPR2+ patients, with simultaneous insomnia and dream enactment behavior (DEB) in three (27.3%), and the most common presenting sleep disturbances were DEB (n = 5), insomnia (n = 5), and sleep apnea (n = 8; median apnea-hypopnea index = 15/hour). Median Epworth Sleepiness Scale was nine (range 3-24; n = 10), with hypersomnia in four (36.4%). LGI1+/CASPR2+ patients had increased N1 sleep (p = .02), decreased REM sleep (p = .001), and higher levels of SM + AT any RSWA (p < .001). Eight of nine (89%) LGI1+ exceeded RBD RSWA thresholds (DEB, n = 5; isolated RSWA, n = 3). RSWA was greater in AT than SM. All 10 LGI1+/CASPR2+ patients treated with immunotherapy benefitted, and 5/10 had improved sleep disturbances.

CONCLUSIONS

LGI1/CASPR2-IgG autoimmunity is associated with prominent dream enactment, insomnia, RSWA, sleep apnea, and shallower sleep. Polysomnography provides objective disease markers in LGI1+/CASPR2+ autoimmunity and immunotherapy may benefit associated sleep disturbances.

Cancer-Associated Retinopathy in Patients with Newly Diagnosed Breast Tumor

INTRODUCTION

Paraneoplastic neurological syndromes (PNS) are rare neurological conditions and they are mostly triggered by autoimmune mechanisms. Cancer-related retinopathies (CAR) are even rarer and commonly related with breast tumor in woman. This limits our knowledge about pathophysiology of CAR. In this study, we question the association between histopathological findings and onconeural antibodies in breast cancer.

METHOD

Thirty-two patients with newly diagnosed breast cancer admitted to the oncology outpatient clinic were included in the study. None of the participants have visual complaints. After the neurological examination of the patients, two tubes of 5 cc venous blood were obtained by screening onconeuronal antibodies. Samples were investigated in ASDETAE (İstanbul University Experimental Medicine Research Institute).

RESULTS

Patients included in the study included one patinet (3.1%) with grade 1, 14 patients (43.8%) with grade 2 and 17 patients (53.1%) with grade 3 invasive breast cancer. Perineural invasion was detected in 5 (15.6%) patients. Progesterone receptor positivity was found in 26 (81.2%) patients and estrogen receptor positivity was found in 27 (84.4%) patients. In 7 (21.9%) patients, CERBB2 was positive and in 25 (78.1%) patients, Ki 67 was positive. A total of 12 (37.5%) patients had onconeuroneal antibody positivity. Antibody positivity was significantly higher in patients with high grade tumor (p=0.008).

CONCLUSION

There may be a relationship between tumor grade and the presence of onconeuronal antibodies in breast cancer patients. By the detection of new biochemical markers, significant contribution can be made to the early diagnosis and treatment of underlying cancer.

Phase II trial of natalizumab for the treatment of anti-Hu associated paraneoplastic neurological syndromes

Background

Paraneoplastic neurological syndromes with anti-Hu antibodies (Hu-PNS) have a very poor prognosis: more than half of the patients become bedridden and median survival is less than 12 months. Several lines of evidence suggest a pathogenic T cell-mediated immune response. Therefore, we conducted a prospective open-label phase II trial with natalizumab.

Methods

Twenty Hu-PNS patients with progressive disease were treated with a maximum of three monthly natalizumab cycles (300 mg). The primary outcome measure was functional improvement, this was defined as at least one point decrease in modified Rankin Scale (mRS) score at the last treatment visit. In addition, treatment response was assessed wherein a mRS score ≤3 after treatment was defined as treatment responsive.

Results

The median age at onset was 67.8 years (SD 8.4) with a female predominance (n = 17, 85%). The median time from symptom onset to Hu-PNS diagnosis was 5 months (IQR 2–11). Most patients had subacute sensory neuronopathy (n = 15, 75%), with a median mRS of 4 at baseline. Thirteen patients had a tumor, all small cell lung cancer. After natalizumab treatment, two patients (10%) showed functional improvement. Of the remaining patients, 60% had a stable functional outcome, while 30% showed further deterioration. Treatment response was classified as positive in nine patients (45%).

Conclusions

Natalizumab may ameliorate the disease course in Hu-PNS, but no superior effects above other reported immunosuppressive and immunomodulatory were observed. More effective treatment modalities are highly needed.

Trial registration

https://www.clinicaltrialsregister.eu/ctr-search/trial/2014-000675-13/NL

Evaluation and Management of Acute Myelopathy

Acute myelopathies are spinal cord disorders characterized by a rapidly progressive course reaching nadir within hours to a few weeks that may result in severe disability. The multitude of underlying etiologies, complexities in confirming the diagnosis, and often unforgiving nature of spinal cord damage have always represented a challenge. Moreover, certain slowly progressive myelopathies may present acutely or show abrupt worsening in specific settings and thus further complicate the diagnostic workup. Awareness of the clinical and magnetic resonance imaging characteristics of different myelopathies and the specific settings where they occur is fundamental for a correct diagnosis. Neuroimaging helps distinguish compressive etiologies that may require urgent surgery from intrinsic etiologies that generally require medical treatment. Differentiation between various myelopathies is essential to establish timely and appropriate treatment and avoid harm from unnecessary procedures. This article reviews the contemporary spectrum of acute myelopathy etiologies and provides guidance for diagnosis and management.

Analysis of the Repertoires of Circulating Autoantibodies' Specificities as a Tool for Identification of the Tumor-Associated Antigens: Current Problems and Solutions

Circulating autoantibodies against tumor-associated autoantigens (TAA) may serve as valuable biomarkers for a wide range of diagnostic purposes. Modern immunology offers a large variety of methods for in-depth comparative analysis of the repertoires of circulating antibodies' antigenic specificities in health and disease. Nevertheless, this research field so far has met somewhat limited clinical success, while numerous data on the repertoires of circulating autoantibodies' specificities in cancer patients are poorly integrated into the contemporary picture of the immunological and molecular landscapes of human tumors. This review is an attempt to identify and systematize the key and essentially universal conceptual and methodological limitations of analyses of the repertoires of circulating antibodies' antigenic specificities in cancer (expression bias, redundancy of TAA repertoires, identification of natural IgG, the absence of the pathogenetically relevant context in the experimental systems used to detect TAA), as well as to discuss potential and already known methodological improvements that may significantly increase the detectability of the pathogenetically relevant and diagnostically significant bona fide TAA.

Paraneoplastic neurologic syndromes with multiple neural autoantibodies: A report of two cases

We present two patients who presented with classical paraneoplastic syndromes with multiple central nervous system (CNS) autoantibodies in each case. The presence of multiple antibodies made the detection of a malignancy more likely and both patients were subsequently diagnosed with small cell lung carcinoma (SCLC). We highlight that the presence of multiple CNS autoantibodies increases the likelihood of detecting a malignancy but that the clinical presentation and response to treatment can vary despite similar antibody profiles. Clinicians should be alert to the need to search for occult malignancy in patients with multiple CNS autoantibodies.

Antibody-Mediated Autoimmune Diseases of the CNS: Challenges and Approaches to Diagnosis and Management

Antibody-mediated disorders of the central nervous system (CNS) are increasingly recognized as neurologic disorders that can be severe and even life-threatening but with the potential for reversibility with appropriate treatment. The expanding spectrum of newly identified autoantibodies targeting glial or neuronal (neural) antigens and associated clinical syndromes (ranging from autoimmune encephalitis to CNS demyelination) has increased diagnostic precision, and allowed critical reinterpretation of non-specific neurological syndromes historically associated with systemic disorders (e.g., Hashimoto encephalopathy). The intracellular vs. cell-surface or synaptic location of the different neural autoantibody targets often helps to predict the clinical characteristics, potential cancer association, and treatment response of the associated syndromes. In particular, autoantibodies targeting intracellular antigens (traditionally termed onconeural autoantibodies) are often associated with cancers, rarely respond well to immunosuppression and have a poor outcome, although exceptions exist. Detection of neural autoantibodies with accurate laboratory assays in patients with compatible clinical-MRI phenotypes allows a definite diagnosis of antibody-mediated CNS disorders, with important therapeutic and prognostic implications. Antibody-mediated CNS disorders are rare, and reliable autoantibody identification is highly dependent on the technique used for detection and pre-test probability. As a consequence, indiscriminate neural autoantibody testing among patients with more common neurologic disorders (e.g., epilepsy, dementia) will necessarily increase the risk of false positivity, so that recognition of high-risk clinical-MRI phenotypes is crucial. A number of emerging clinical settings have recently been recognized to favor development of CNS autoimmunity. These include antibody-mediated CNS disorders following herpes simplex virus encephalitis or occurring in a post-transplant setting, and neurological autoimmunity triggered by TNFα inhibitors or immune checkpoint inhibitors for cancer treatment. Awareness of the range of clinical and radiological manifestations associated with different neural autoantibodies, and the specific settings where autoimmune CNS disorders may occur is crucial to allow rapid diagnosis and early initiation of treatment.

PD-1-inhibitor-induced PCA-2 (MAP1B) Autoimmunity in a Patient with Renal Cell Carcinoma

Immune check point inhibitors (ICIs) are a group of anti-cancer pharmacological agents which modify T cell activity in order to potentiate an effective immune response against tumor cells. While these drugs prove extremely potent against several types of malignancies, they may be associated with significant autoimmune adverse events. We report a patient who developed a subacute cerebellar syndrome shortly after starting treatment with nivolumab, a PD-1 inhibitor, for renal clear cell carcinoma, with detectable paraneoplastic PCA-2 antibodies. The tumor specimen stained positively for MAP1B, the antigen of PCA-2. The patient responded well to treatment with glucocorticosteroids. This is the first case to our knowledge of PCA-2 paraneoplastic cerebellar degeneration associated with ICI use, which presents in a patient with a malignancy not typically associated with neurological paraneoplastic phenomena. Treatment with immune checkpoint inhibitors (ICIs) is extremely effective in potentiating an immune response against tumor cells, but bears a substantial risk for the development of autoimmune phenomena, including paraneoplastic neurological syndromes. Increasing use of ICIs is leading to increasing numbers of patients with new-onset neurological symptoms. Awareness of these novel entities will aid in early diagnosis and proper treatment.

Clinical Utility of Striational Antibodies in Paraneoplastic and Myasthenia Gravis Paraneoplastic Panels

OBJECTIVE

To critically assess the clinical utility of striational antibodies (StrAbs) within paraneoplastic and myasthenia gravis (MG) serologic evaluations.

METHODS

All Mayo Clinic patients tested for StrAbs from January 1, 2012, to December 31, 2018, utilizing Mayo's Unified Data Platform (UDP) were reviewed for neurologic diagnosis and cancer.

RESULTS

A total of 38,502 unique paraneoplastic evaluations and 1,899 patients with MG were tested. In paraneoplastic evaluations, the StrAbs positivity rate was higher in cancer vs without cancer (5% [321/6,775] vs 4% [1,154/31,727]; p < 0.0001; odds ratio [OR] 1.35; confidence interval [CI] 1.19-1.53), but receiver operating characteristic (ROC) analysis indicated no diagnostic accuracy in cancer (area under the ROC curve [AUC] 0.505). No neurologic phenotype was significantly associated with StrAbs in the paraneoplastic group. Positivity was more common in all MG cancers compared to paraneoplastic cancers (p < 0.0001). In MG evaluations, the StrAbs positivity rate was higher in those with cancer vs without (46% [217/474] vs 26% [372/1,425]; p < 0.0001; OR 2.39, CI 1.9-2.96), with ROC analysis indicating poor diagnostic accuracy for thymic cancer (AUC 0.634, recommended cutoff = 1:60, sensitivity = 56%, specificity = 71%), with worse accuracy for extrathymic cancers (AUC 0.543). In paraneoplastic or MG evaluations, the value of antibody positivity did not improve cancer predictions. Paraneoplastic evaluated patients with positive StrAbs were more likely to obtain CT (p = 0.0001), with cancer found in 3% (12/468).

CONCLUSION

Despite a statistically significant association with cancer, an expansive review of performance in clinical service demonstrates that StrAbs are neither specific nor sensitive in predicting malignancy or neurologic phenotypes. CT imaging is overutilized with positive StrAbs results. Removal of StrAbs from paraneoplastic or MG evaluations will improve the diagnostic characteristics of the current MG test.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that the presence of StrAbs does not accurately identify patients with malignancy or neurologic phenotypes.

Neurological complications of immune checkpoint inhibitor cancer immunotherapy

Neurological autoimmunity is increasingly recognized as a complication of immune checkpoint inhibitor (ICI) cancer immunotherapy. ICIs act by enhancing endogenous anti-tumor immune responses and can also lead to autoimmunity affecting all organs. ICI-related neurological autoimmunity is rare, most often manifests with neuromuscular involvement and more rarely affects the central nervous system. Neurological complications often often present in the first three months of ICI treatment but can also appear after ICI discontinuation. These can occur in patients with tumors not traditionally associated with paraneoplastic neurological autoimmunity, such as melanoma and renal-cell carcinoma and should be suspected when a new neurological symptoms present while on ICI and cannot be explained by disease progression or as a consequence of metabolic dysfunction. Treatment consists of ICI discontinuation or withdrawal depending on the severity with or without immunosuppression. Generally, improvement is observed depending on the patient's baseline characteristics and neurological presentation.

Autoimmune encephalopathies presenting as dementia of subacute onset and rapid progression

The terms autoimmune dementia and autoimmune encephalopathy may be used interchangeably; autoimmune dementia is used here to emphasize its consideration in young-onset dementia, dementia with a subacute onset, and rapidly progressive dementia. Given their potential for reversibility, it is important to distinguish the rare autoimmune dementias from the much more common neurodegenerative dementias. The presence of certain clinical features [e.g. facio-brachial dystonic seizures that accompany anti-leucine-rich-glioma-inactivated-1 (LGI1) encephalitis that can mimic myoclonus] can be a major clue to the diagnosis. When possible, objective assessment of cognition with bedside testing or neuropsychological testing is useful to determine the degree of abnormality and serve as a baseline from which immunotherapy response can be judged. Magnetic resonance imaging (MRI) head and cerebrospinal fluid (CSF) analysis are useful to assess for inflammation that can support an autoimmune etiology. Assessing for neural autoantibody diagnostic biomarkers in serum and CSF in those with suggestive features can help confirm the diagnosis and guide cancer search in paraneoplastic autoimmune dementia. However, broad screening for neural antibodies in elderly patients with an insidious dementia is not recommended. Moreover, there are pitfalls to antibody testing that should be recognized and the high frequency of some antibodies in the general population limit their diagnostic utility [e.g., anti-thyroid peroxidase (TPO) antibodies]. Once the diagnosis is confirmed, both acute and maintenance immunotherapy can be utilized and treatment choice varies depending on the accompanying neural antibody present and the presence or absence of cancer. The target of the neural antibody biomarker may help predict treatment response and prognosis, with antibodies to cell-surface or synaptic antigens more responsive to immunotherapy and yielding a better overall prognosis than those with antibodies to intracellular targets. Neurologists should be aware that autoimmune dementias and encephalopathies are increasingly recognized in novel settings, including post herpes virus encephalitis and following immune-checkpoint inhibitor use.

Leucine Zipper 4 Autoantibody: A Novel Germ Cell Tumor and Paraneoplastic Biomarker

OBJECTIVE

This study was undertaken to describe a novel biomarker of germ cell tumor and associated paraneoplastic neurological syndrome (PNS).

METHODS

Archival sera from patients with germ cell tumor-associated PNS were evaluated. We identified a common autoantigen in a human testicular cancer cell line (TCam-2) by Western blot and mass spectrometry. Its identity was confirmed by recombinant-protein Western blot, enzyme-linked immunosorbent assay (ELISA), and cell-based assay. Autoantibody specificity was confirmed by analyzing assorted control sera/cerebrospinal fluid.

RESULTS

Leucine zipper 4 (LUZP4)-immunoglobulin G (IgG) was detected in 28 patients' sera, 26 of whom (93%) were men. The median age at neurological symptom onset was 45 years (range = 28-84). Median titer (ELISA) was 1:300 (1:50 to >1:6,400, normal value < 1:50). Coexistent kelchlike protein 11-IgG was identified in 18 cases (64%). The most common presenting phenotype was rhombencephalitis (17/28, 61%). Other presentations included limbic encephalitis (n = 5, 18%), seizures and/or encephalitis (n = 2, 7%), and motor neuronopathy/polyradiculopathy (n = 4, 14%). The most common malignancy among cancer-evaluated PNS patients was seminoma (21/27, 78%). Nine of the 21 seminomas detected by whole-body fluorodeoxyglucose positron emission tomography scan (43%) were extratesticular. Both female patients had ovarian teratoma. Regressed testicular germ cell tumors were found in 4 patients. Exposure of T-cell-dendritic-cell cocultures from chronic immunosuppression-naïve LUZP4-IgG-seropositive patients to recombinant LUZP4 protein evoked a marked increase in CD69 expression on both CD4+ and CD8+ T cells when compared to vehicle-exposed and healthy control cultures.

INTERPRETATION

LUZP4-IgG represents a novel serological biomarker of PNS and has high predictive value for germ cell tumors. The demonstrated antigen-specific T-cell responses support a CD8+ T-cell-mediated cytotoxic paraneoplastic and antitumor potential. ANN NEUROL 2021;89:1001-1010.

Simultaneous bilateral optic neuropathy and myelitis revealing paraneoplastic neurological syndrome associated with multiple onconeuronal antibodies

Paraneoplastic neurological syndromes (PNS) are immune-mediated complications of cancer associated with a broad spectrum of clinical manifestations. Optic neuropathy (ON) and myelitis are frequent manifestations of multiple sclerosis and neuromyelitis optic spectrum disorders but are considered as non-classical in PNS. Here, we report a case of PNS revealed by simultaneous bilateral ON and myelitis related to a cluster of three neural autoantibodies, in the setting of small cell lung cancer.

Myasthenia Gravis and Myeloproliferative Neoplasms - Mere Association or Paraneoplastic Neurologic Syndrome: A Mini-Review

Myasthenia Gravis (MG) is a rare neurological condition characterized by muscle weakness that worsens after use. Myeloproliferative Neoplasms (MPNs) are disorders due to stem-cell hyperplasia characterized by an increased peripheral blood cell count, overactive bone marrow, and proliferation of mature hematopoietic cells. MPNs may be Philadelphia (Ph) chromosome-positive or Negative .A systematic review of case reports was conducted by searching PubMed, Scopus, and Google scholar to identify case reports in which there is an association between MG and MPN and know whether MG can be considered a possible neurological paraneoplastic syndrome in patients with MPNs. A total of 13 cases of MPNs associated with MG were identified. The most common type of MPN associated with MG was chronic myeloid leukemia (CML) (10 out of 13 patients).  In most of the patients, MG symptoms appeared after a diagnosis of MPN was made. Considering that 10 out of the 13 patients in our cohort had positive auto-antibodies though only 4 of them had thymic hyperplasia, we hypothesize that bone marrow proliferation was responsible for the production of autoantibodies in these patients.As the clonal cell population cannot be eliminated entirely in the bone marrow even after treatment with tyrosine kinase inhibitors (TKI) in Ph +ve MPNs and JAK2 inhibitors in Ph -ve MPNS, MG can occur even in patients who are treated with these agents. A high index of suspicion is needed to diagnose it early, and treatment should be initiated immediately with steroids and anticholinergic agents.

Neuropsychiatric Disorders Due to Limbic Encephalitis: Immunologic Aspect

Limbic encephalitis (LE) is a rare cause of encephalitis presenting as an acute and subacute onset of neuropsychiatric manifestations, particularly with memory deficits and confusion as core features, along with seizure occurrence, movement disorders, or autonomic dysfunctions. LE is caused by neuronal antibodies targeting the cellular surface, synaptic, and intracellular antigens, which alter the synaptic transmission, especially in the limbic area. Immunologic mechanisms involve antibodies, complements, or T-cell-mediated immune responses in different degree according to different autoantibodies. Sensitive cerebrospinal fluid markers of LE are unavailable, and radiographic findings may not reveal a typical mesiotemporal involvement at neurologic presentations; therefore, a high clinical index of suspicions is pivotal, and a neuronal antibody testing is necessary to make early diagnosis. Some patients have concomitant tumors, causing paraneoplastic LE; therefore, tumor survey and treatment are required in addition to immunotherapy. In this study, a review on the molecular and immunologic aspects of LE was conducted to gain awareness of its peculiarity, which we found quite different from our knowledge on traditional psychiatric illness.

Neuronal intermediate filament IgGs in CSF: Autoimmune Axonopathy Biomarkers

Objectives

To describe CSF‐defined neuronal intermediate filament (NIF) autoimmunity.

Methods

NIF‐IgG CSF‐positive patients (41, 0.03% of 118599 tested, 1996–2019) were included (serum was neither sensitive nor specific). Criteria‐based patient NIF‐IgG staining of brain and myenteric NIFs was detected by indirect immunofluorescence assay (IFA); NIF‐specificity was confirmed by cell‐based assays (CBAs, alpha internexin, neurofilament light [NF‐L]), heavy‐[NF‐H] chain).

Results

Sixty‐one percent of 41 patients were men, median age, 61 years (range, 21–88). Syndromes were encephalopathy predominant (23), cerebellar ataxia predominant (11), or myeloradiculoneuropathies (7). MRI abnormalities (T2 hyperintensities of brain, spinal cord white matter tracts. and peripheral nerve axons) and neurophysiologic testing (EEG, EMG, evoked potentials) co‐localized with clinical neurological phenotypes (multifocal in 29%). Thirty patients (73%) had ≥ 1 immunological perturbation: cancer (paraneoplastic), 22; systemic infection (parainfectious [including ehrlichosis, 3] or HIV), 7; checkpoint‐inhibitor cancer immunotherapy, 4; other, 5. Cancers were as follows: neuroendocrine‐lineage carcinomas, 12 (small cell, 6; Merkel cell, 5; pancreatic, 1 [11/12 had NF‐L‐IgG detected, versus 8/29 others, P = 0.0005]) and other, 11. Onset was predominantly subacute (92%) and accompanied by inflammatory CSF (75%), and immunotherapy response (77%). In contrast, CSF controls (15684 total) demonstrated NIF‐IgG negativity (100% of test validation controls), and low frequencies of autoimmune diagnoses (20% of consecutively referred clinical specimens) and neuroendocrine‐lineage carcinoma diagnosis (3.1% vs. 30% of NIF cases), P < 0.0001. Median NF‐L protein concentration was higher in 8 NF‐L‐IgG‐positive patients (median, 6718 ng/L) than 16 controls.

Interpretation

Neurological autoimmunity, defined by CSF‐detected NIF‐IgGs, represents a continuum of treatable axonopathies, sometimes paraneoplastic or parainfectious.

Case Report: Innate Immune System Challenge Unleashes Paraneoplastic Neurological Autoimmunity

Paraneoplastic autoimmune neurological disorders reflect tumor-initiated immune responses against onconeural antigens. Symptoms and signs can affect the central and/or peripheral nervous systems, neuromuscular junction or muscle, and typically evolve subacutely before an underlying neoplasm is discovered. We describe four patients whose neurological symptoms were precipitated by potent innate immune system challenges: bladder instillation of BCG, tick bite and an "alternative cancer therapy" with bacterial extracts and TNF-α. We hypothesize that a tumor-initiated autoimmune response (evidenced by autoantibody profiles), pre-dating the immune system challenge, was unmasked or amplified in these patients by cytokines released systemically from innate immune cells activated by microbial pathogen-associated molecular patterns (PAMPs). The resultant upregulation of cognate onconeural peptides as MHC1 protein complexes on neural cell surfaces would render those cells susceptible to killing by CD8+ T cells, thus precipitating the patient's neurological symptoms.

Paraneoplastic Myeloneuropathies: Clinical, Oncologic, and Serologic Accompaniments

Objective

To test the hypothesis that myeloneuropathy is a presenting phenotype of paraneoplastic neurologic syndromes we retrospectively reviewed clinical, radiologic, and serologic features of 32 patients with concomitant paraneoplastic spinal cord and peripheral nervous system involvement.

Methods

Observational study investigating patients with myeloneuropathy and underlying cancer or onconeural antibody seropositivity.

Results

Among 32 patients with paraneoplastic myeloneuropathy, 20 (63%) were women with median age 61 years (range 27–84 years). Twenty-six patients (81%) had classified onconeural antibodies (amphiphysin, n = 8; antineuronal nuclear antibody [ANNA] type 1 [anti-Hu], n = 5; collapsin response mediator protein 5 [CRMP5] [anti-CV2], n = 6; Purkinje cell cytoplasmic antibody type 1 [PCA1] [anti-Yo], n = 1; Purkinje cell cytoplasmic antibody type 2 [PCA2], n = 2; kelch-like protein 11 [KLHL11], n = 1; and combinations thereof: ANNA1/CRMP5, n = 1; ANNA1/amphiphysin, n = 1; ANNA3/CRMP5, n = 1). Cancer was confirmed in 25 cases (onconeural antibodies, n = 19; unclassified antibodies, n = 3; no antibodies, n = 3). Paraneoplastic myeloneuropathies had asymmetric paresthesias (84%), neuropathic pain (78%), subacute onset (72%), sensory ataxia (69%), bladder dysfunction (69%), and unintentional weight loss >15 pounds (63%). Neurologic examination demonstrated concomitant distal or asymmetric hyporeflexia and hyperreflexia (81%), impaired vibration and proprioception (69%), Babinski response (68%), and asymmetric weakness (66%). MRI showed longitudinally extensive (45%), tract-specific spinal cord T2 hyperintensities (39%) and lumbar nerve root enhancement (38%). Ten of 28 (36%) were unable to ambulate independently at last follow-up (median 24 months, range 5–133 months). Combined oncologic and immunologic therapy had more favorable modified Rankin Scale scores at post-treatment follow-up compared to those receiving either oncologic or immunologic therapy alone (2 [range 1–4] vs 4 [range 2–6], p < 0.001).

Conclusions

Paraneoplastic etiologies should be considered in the evaluation of subacute myeloneuropathies. Recognition of key characteristics of paraneoplastic myeloneuropathy may facilitate early tumor diagnosis and initiation of immunosuppressive treatment.

Paraneoplastic Focal Outer Retinitis and Optic Neuropathy in a Patient with Small Cell Lung Carcinoma and Anti-CRMP5, Anti-HU and Anti-Amphiphysin Antibodies

Our aim is to describe clinical and optical coherence tomographic features of acute paraneoplastic focal outer retinitis associated with optic neuropathy in a patient diagnosed with small cell lung carcinoma. Bilateral focal outer retinitis, bilateral optic disc oedema and vitritis were identified in a patient with progressive bilateral visual loss and ataxia. Spectral domain optical coherence tomography (SD-OCT) revealed various extents of granular hyperreflectivity and atrophy of the macular outer retinal layers. Serum and cerebrospinal fluid positivity for anti-CRMP5, anti-HU and anti-amphiphysin antibodies intensified the search for an underlying malignancy, and a small cell lung carcinoma (SCLC) was finally diagnosed. Local and oral steroids along with systemic chemotherapy and radiotherapy achieved cancer remission and partial recovery from the ophthalmic manifestations. Focal outer retinitis associated with optic disc oedema and antibody positivity facilitated the diagnosis of SCLC in a localized stage. SD-OCT allowed the characterization of this entity, expanding the spectrum of paraneoplastic ophthalmological syndromes.

Granzyme B in peripheral blood mononuclear cells as a measure of cell-mediated immune response in paraneoplastic neurological syndromes and malignancy

Background

Paraneoplastic neurological syndromes (PNS) may coexist with ovarian or lung cancers. Some tumors coexisting with PNS are smaller and have a better prognosis than tumors without PNS. PNS may constitute an opportunity to observe a natural immune antitumor response. We aimed to investigate a cytotoxic immune response by measuring granzyme B (GrB) in peripheral blood mononuclear cells (PBMC) in patients affected with ovarian or lung malignancy, with and without accompanying PNS.

Methods

We enrolled patients with: nonmalignant lesions (n = 21), ovarian cancer (n = 19), lung cancer (n = 57), and PNS (n = 30). PBMC were isolated by density gradient centrifugation with Ficoll–Paque. We evaluated the expression of GrB in PBMC lysates by ELISA and normalized to protein content as measured by the Lowry method.

Results

GrB levels in PBMC in the group with malignant tumors—median 1650 pg/mg protein (interquartile range 663–3260 pg/mg) and in patients with PNS—median 1890 pg/mg protein (range 1290–2640 pg/mg) was lower than in control group with nonmalignant lesions—median 5240 pg/mg protein (range 2160–7440 pg/mg), p = 0.0003 and p = 0.0038, respectively. The differences in GrB levels in PBMC between these groups were independent of epidemiological factors—age, sex, body mass index (BMI), and the number of immune cells, as confirmed by multiple regression analysis. Within the group of patients with malignancy and PNS, GrB levels in PBMC were elevated if onconeural antibodies were detected (2610; 2390–3700 pg/mg protein) as compared to patients without antibodies (1680; 970–1880 pg/mg protein, p = 0.035). GrB in PBMC was higher if the malignancy was diagnosed at the low (3060; 2120–5220 pg/mg protein) as compared to the high stage (1330; 348–2140, p = 0.00048). In patients with lung cancer, the expression of GrB in PBMC was lower (1430; 635–2660 pg/mg protein) than in the group with ovarian cancer (2580; 1730–3730, p = 0.02).

Conclusion

The cytotoxic response measured in peripheral blood by GrB in PBMC is impaired both in the course of malignancy and PNS. Levels of GrB in PBMC were higher if onconeural antibodies were detected. Tracking reactive immune responses, such as GrB in PBMC may have diagnostic and monitoring value in malignancy and PNS.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02750-1) contains supplementary material, which is available to authorized users.

Determination of Paraneoplastic neuropathy in newly diagnosed breast tumor patients

Objective

The presence of paraneoplastic neuropathy in newly diagnosed breast tumor patients will be investigated. Aim of study is conduce of early diagnosis of the disease and new biomarkers responsible for the pathogenesis to be identify.

Materials and Methods

Thirty-two patients admitted to the Oncology outpatient clinic with newly diagnosed breast cancer were included in the study. After the neurological examination of the patients, Lanss neuropathic pain scale and blood tests were performed. Before chemotherapy all patients underwent electromyography (EMG). Two tubes of 5 cc of venous blood were obtained by screening onconeuronal antibodies.

Results

Patients included in the study; 1 (3.1%) grade 1, 14 (43.8%) grade 2, 17 (53.1%) grade 3 invasive breast cancer was diagnosed. Perineural invasion was detected in 5 (15.6%) patients. Progesterone receptor positivity was found in 26 (81.2%) patients and estrogen receptor positivity was found in 27 (84.4%) patients. In 7 (21.9%) patients, CERBB2 was positive for Ki 67 in 25 (78.1%) patients. Neuropathic findings were present in 6 (18.8%) patients. Sensory neuropathy was detected by electrophsiologic tests in only 2 (6.2%) patients. A total of 12 (37.5%) patients had onconeuroneal antibody positivity. Antibody positivity was significantly higher in patients with high grade tumor (p = 0.008).

Conclusion

Paraneoplastic neuropathies can be confused with neuropathies due to non-cancerous causes both clinically and electrophysiologically. When approaching paraneoplastic neuropathies, pathological findings should be carefully reviewed and evaluated with other findigs.

It should be remembered that an underlying breast tumor may be present in women with cancer-related neuropathic complaints.

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Frequency of onconeuronal antibodies is so high in breast tumor.

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The presence of onconeural antibodies is a guide for paraneoplastic syndromes.

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Tumor grade has a positive correlation with onconeural antibodies antibodies.

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Mostly CV2 and Hu antibodies are responsible for cancer-related neuropaties.

Anti-Ri-associated paraneoplastic ophthalmoplegia-ataxia syndrome in a woman with breast cancer: a case report and review of the literature

Background

Breast cancer is the most common cancer in women. However, in the management of breast cancer, paraneoplastic neurological syndromes represent a diagnostic and therapeutic challenge. The diagnosis of paraneoplastic neurological syndromes is difficult due to the heterogeneity of symptoms, the timing of presentation, and the absence of antibodies, and it generally occurs before the diagnosis of breast cancer in 80% of patients who develop paraneoplastic neurological syndromes. We describe a 72-year-old woman with subacute ophthalmoplegia-ataxia syndrome who was subsequently diagnosed as having breast cancer and anti-Ri antibodies.

Case presentation

A 72-year-old post-menopausal Caucasian woman, with a positive medical history for diabetes mellitus and hypertension, presented with a 3-month onset of blurred vision, diplopia, and progressive gait disturbance. Serological tests were positive for well-characterized onconeural antibodies (anti-Ri). A whole-body computed tomography scan revealed a nodular opacity under her left nipple and axillary adenopathy. A biopsy of her left breast was performed, and histological examination showed ductal carcinoma. She underwent a superoexternal quadrantectomy with left axillary dissection. The final diagnosis showed infiltrating ductal carcinoma of the breast (T1c N1 M0, stage IIA) associated with paraneoplastic ophthalmoplegia-ataxia syndrome. At a 6-month follow-up, she showed no clinical or instrumental evidence of neoplastic recurrence with partial clinical improvement of neurological symptoms, such as ataxia and diplopia.

Conclusion

The diagnosis of paraneoplastic neurological syndromes is often late, as in this patient, but treatment at an early stage may provide a good prognosis. Furthermore, this is one of several cases of an anti-Ri paraneoplastic neurological syndrome not associated with myoclonus, which reinforces the belief that opsoclonus myoclonus syndrome is not pathognomonic of the associated anti-Ri paraneoplastic neurological syndromes.

Immune-mediated epilepsy with GAD65 antibodies

Anti-GAD65 antibodies have been identified in both acute/subacute seizures (limbic encephalitis and extralimbic encephalitis) and chronic isolated epilepsy. The evidence of high serum titers and intrathecal synthesis play a fundamental role in diagnosis but poorly correlate with disease severity or response to therapies. It remains controversial whether anti-GAD65 Abs are the pathogenic entity or only serve as a surrogate marker for autoimmune disorders mediated by cytotoxic T cells. Unlike other immune-mediated epilepsy, although multiple combinations of therapeutics are used, the efficacy and prognosis of patients with GAD65-epilepsy patients are poor. Besides, GAD65-epilepsy is more prone to relapse and potentially evolve into a more widespread CNS inflammatory disorder. This article reviews the recent advances of GAD65-epilepsy, focusing on the diagnosis, epidemiology, pathophysiology, clinical features, and treatment, to better promote the recognition and provide proper therapy for this condition.

Multiple co-existing antibodies in autoimmune encephalitis: A case and review of the literature

A 66-year-old man with a history of chronic tobacco use presented with two months of progressive memory deficits, ataxia, diplopia, and opsoclonus. His brain magnetic resonance imaging (MRI) showed limbic and brainstem encephalitis, and antibody testing was positive for anti-Ma1/Ma2, anti-N-methyl-d-aspartate receptor (anti-NMDA-R) and anti-glutamic acid decarboxylase 65 (anti-GAD65) antibodies. His encephalitis improved with intravenous steroids, plasmapheresis, and rituximab initiation. His PET/CT was suspicious for lung malignancy, but a progressive deterioration of his respiratory status prevented full investigation. Multiple auto-antibodies may be produced in response to a malignancy and overlapping of clinical presentations may occur with multiple auto-antibodies.

General principles and escalation options of immunotherapy in autoantibody-associated disorders of the CNS

Autoimmune diseases associated with antineuronal and antiglial autoantibodies (Abs) is one of the most rapidly expanding research fields in clinical neuroimmunology, with more than 30 autoantibodies described so far. Being associated with a wide range of clinical presentations these syndromes can be diagnostically challenging. Surface or intracellular antigen localizations are crucial for the treatment response and outcome. In the latter Abs are mostly of paraneoplastic cause and tumor management should be performed as soon as possible in order to stop peripheral antigen stimulation. Immunotherapy should be started early in both groups, before irreversible neuronal loss occurs. Despite serious prognosis, aggressive therapeutic approaches can be effective in many cases. In this article we review main pathogenic mechanisms leading to Abs-related syndromes and describe standard as well as emerging strategies of immunotherapy, including tocilizumab and bortezomib. Several special therapeutic approaches will be illustrated by clinical cases recently treated in our department.

Collapsin Response-Mediator Protein 5-Associated Retinitis, Vitritis, and Optic Disc Edema

PURPOSE

Collapsin response-mediator protein 5 (CRMP5) immunoglobulin G (IgG) has been associated with paraneoplastic optic neuritis, vitritis, retinitis, or a combination thereof, but few reports of these findings exist in the literature. We reviewed the neuro-ophthalmic findings and visual outcomes in a large series of CRMP5 IgG-positive patients to characterize further its clinical phenotype and response to treatment.

DESIGN

Retrospective case series.

PARTICIPANTS

Seventy-six patients with CRMP5 autoimmunity examined at the Mayo Clinic, Rochester, Minnesota.

METHODS

Single academic medical center chart review of all CRMP5 IgG-positive (serum titer, >1:240) patients seen between 2001 and 2017.

MAIN OUTCOME MEASURES

Neuro-ophthalmic manifestations and outcomes of CRMP5 autoimmunity, coexisting neural autoantibody presence and paraneoplastic associations, and the impact of immunosuppressant therapy.

RESULTS

Twenty-nine of 76 patients (38%) demonstrated neuro-ophthalmic manifestations. Of the 29 patients with neuro-ophthalmic findings, the median age was 67 years (range, 33-88 years) and 20 (69%) were women. Cancer was diagnosed in 62% of the patients (small-cell carcinoma in 83%). Neuro-ophthalmic symptoms occurred before the diagnosis of cancer in 72%. Seventeen of 29 patients (59%) showed ocular (i.e., anterior visual pathway or intraocular) manifestations; presenting median visual acuity was 20/50 (range, 20/20-counting fingers) and the final median visual acuity was 20/40 (range, 20/20-hand movements). Fourteen of 17 patients (82%) demonstrated optic neuropathy, with 12 of these patients also showing retinitis or uveitis. Three of 17 patients (18%) showed retinitis or uveitis without optic neuropathy. All 12 patients with optic neuropathy and a documented fundus examination at visual symptom onset demonstrated optic disc edema. No patients showed optic nerve enhancement on magnetic resonance imaging. Twelve of 29 patients (41%) demonstrated ocular motility dysfunction consisting of central nystagmus and diplopia. Among those receiving immunosuppressive therapy, visual function improved in 50%.

CONCLUSIONS

In our cohort of 29 CRMP5 IgG-positive patients with neuro-ophthalmic manifestations, optic neuropathy presented with optic disc edema, often associated with uveitis, retinitis, or both. The combination of retinitis, vitritis, and optic disc edema without optic nerve enhancement should prompt serologic testing for CRMP5 IgG to expedite vision-sparing immunosuppressant therapy and a targeted search for a systemic cancer.