Clinical characteristics of patients with autoimmune nodopathy with anti-neurofascin155 antibodies

Background

According to the latest guidelines on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), patients with CIDP with anti-neurofascin 155 (NF155) antibodies are referred to as autoimmune nodopathy (AN), an autoimmune disorder distinct from CIDP. We aimed to compare the clinical data of patients with AN with anti-NF155 antibodies with those of anti-NF155 antibodies-negative patients with CIDP, and to summarize the clinical characteristics of patients with AN with anti-NF155 antibodies.

Methods

Nine patients with AN with anti-NF155 antibodies and 28 serologically negative patients with CIDP were included in this study. Diagnosis was made according to the diagnostic criteria in the European Academy of Neurology (EAN)/Peripheral Nerve Society (PNS) guidelines on CIDP published in 2021. Demographics, clinical manifestations, electrophysiological examination, cerebrospinal fluid (CSF) tests, and response to treatment were retrospectively analyzed.

Results

Compared with serologically negative patients with CIDP, those patients with AN with anti-NF155 antibodies were younger (p=0.007), had a younger onset age (p=0.009), more frequent ataxia (p=0.019), higher CSF protein levels (p=0.001), and more frequent axon damage in electrophysiology (p=0.025). The main characteristics of patients with AN with anti-NF155 antibodies include younger age and onset age, limb weakness, sensory disturbance, ataxia, multiple motor-sensory peripheral neuropathies with demyelination and axonal damage on electrophysiological examination, markedly elevated CSF protein levels, and varying degrees of response to immunotherapy.

Conclusions

Patients with AN with anti-NF155 antibodies differed from serologically negative patients with CIDP in terms of clinical characteristics. When AN is suspected, testing for antibodies associated with the nodes of Ranvier is essential for early diagnosis and to guide treatment.

[Cutting edge of diagnosis and treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) based on the EAN/PNS guideline 2021]

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a most common chronic immune-mediated demyelinating neuropathy, and includes a number of clinical subtypes. The major phenotype is "typical CIDP", which is characterized by symmetric polyneuropathy and "proximal and distal" muscle weakness. During the historical changes in the concept of CIDP, multifocal motor neuropathy, anti-myelin-associated glycoprotein (MAG) neuropathy, and autoimmune nodopathy have been excluded. Currently CIDP is considered as a syndrome including typical CIDP and CIDP variant such as distal CIDP and multifocal CIDP. In 2021, the international guideline of diagnosis and treatment for CIDP, European Academy of Neurology (EAN)/Peripheral Nerve Society (PNS) Guideline, was published. This review article introduces the putline of the guideline with medical-social situation in Japan. The diagnosis of CIDP is based on (1) phenotype of typical CIDP or variant, (2) electrophysiologic evidence of peripheral nerve demyelination, and (3) exclusion criteria. The first-line treatments are corticosteroids or immunoglobulin therapy, and plasma exchange should be considered if the 2 treatments were not effective sufficiently. This guideline recommends intravenous or subcutaneous immunoglobulin as a maintenance therapy, and suggests other immune-suppressive agents. In the near future, new treatment with biologics, such as monoclonal antibodies against neonatal Fc receptors, complements, and CD19/20 will be approved.

Cytokines and chemokines in patients with chronic inflammatory demyelinating polyradiculoneuropathy and multifocal motor neuropathy: A systematic review

Advances in the understanding of cytokines have revolutionized mechanistic treatments for chronic inflammatory and autoimmune diseases, as exemplified by rheumatoid arthritis. We conducted a systematic literature review on the role of cytokines and chemokines in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). Ovid Medline, EMBASE and Web of Science were searched until August 31, 2022 for human studies investigating cytokines levels in CIDP or MMN. Fifty-five articles on 1061 CIDP patients and 86 MMN patients were included, with a median of 18 patients per study (range 3-71). Studies differed in the inclusion criteria, type of assay, manufacturer, control subjects, and tested biological material. Only a minority of studies reported data on disease activity. Interleukin (IL)-6, IL-17, CXCL10, and tumor necrosis factor alpha (TNF-α), were elevated in CIDP compared to controls in most of the studies. IL-6 and TNF-α levels are also correlated with disability. In MMN patients, IL-1Ra was elevated in the majority of the reports. While acknowledging the challenges in comparing studies and the various limitations of the studies, including small patient numbers, particularly in MMN, our review suggests that IL-6, IL-17, CXCL10, and TNF-α might play a role in CIDP pathogenesis. Larger studies are needed in MMN.

Impact of 2021 European Academy of Neurology/Peripheral Nerve Society diagnostic criteria on diagnosis and therapy of chronic inflammatory demyelinating polyradiculoneuropathy variants

BACKGROUND AND PURPOSE

There are different criteria for the diagnosis of different variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) guidelines provide specific clinical criteria for each CIDP variant even if their therapeutical impact has not been investigated.

METHODS

We applied the clinical criteria for CIDP variants of the 2021 EAN/PNS guidelines to 369 patients included in the Italian CIDP database who fulfilled the 2021 EAN/PNS electrodiagnostic criteria for CIDP.

RESULTS

According to the 2021 EAN/PNS clinical criteria, 245 patients achieved a clinical diagnosis of typical CIDP or CIDP variant (66%). We identified 106 patients with typical CIDP (29%), 62 distal CIDP (17%), 28 multifocal or focal CIDP (7%), four sensory CIDP (1%), 27 sensory-predominant CIDP (7%), 10 motor CIDP (3%), and eight motor-predominant CIDP (2%). Patients with multifocal, distal, and sensory CIDP had milder impairment and symptoms. Patients with multifocal CIDP had less frequently reduced conduction velocity and prolonged F-wave latency and had lower levels of cerebrospinal fluid protein. Patients with distal CIDP more frequently had reduced distal compound muscle action potentials. Patients with motor CIDP did not improve after steroid therapy, whereas those with motor-predominant CIDP did. None of the patients with sensory CIDP responded to steroids, whereas most of those with sensory-predominant CIDP did.

CONCLUSIONS

The 2021 EAN/PNS criteria for CIDP allow a better characterization of CIDP variants, permitting their distinction from typical CIDP and more appropriate treatment for patients.

Rehabilitation of Rare Neurological Complications of COVID-19 Infection in Health Resort Settings

There is increasing evidence of neurological involvement in patients with coronavirus disease. Reports of neurological manifestations include altered mental status, Guillain-Barré syndrome (GBS) and its forms, encephalopathy, psychosis, neurocognitive (dementia) syndrome, ischemic strokes, intracerebral hemorrhage, and acute transverse myelitis. We present three patients with rare neurological manifestations of the COVID-19 disease, with a special focus on rehabilitation in a health resort setting. Outcomes were evaluated based on neurological examination and the modified Barthel index. We highlight the importance of an interdisciplinary approach to reduce disability and improve functionality and quality of life.

Evaluation of diagnostic yield of the 2021 European Academy of Neurology/Peripheral Nerve Society diagnostic criteria for CIDP

INTRODUCTION/AIMS

It is unclear whether the revised European Academy of Neurology/Peripheral Nerve Society diagnostic criteria (EAN/PNS 2021 criteria) improved the diagnostic yield for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) compared with the previous version. Therefore, this study aimed to compare the sensitivity and specificity of the EAN/PNS 2021 criteria and the European Federation of Neurological Societies/Peripheral Nerve Society 2010 diagnostic criteria (EFNS/PNS 2010 criteria), with a specific focus on the electrodiagnostic criteria.

METHODS

Data of patients with clinically suspected CIDP who exhibited objective treatment response, and of those with chronic axonal neuropathies, obtained between 2009 and 2021, were extracted retrospectively from our database. Patients who underwent nerve conduction studies in at least unilateral upper and lower extremities were enrolled. We compared the sensitivity and specificity of the EAN/PNS 2021 and EFNS/PNS 2010 criteria.

RESULTS

In total, 55 patients with clinically suspected CIDP and 36 patients with chronic axonal neuropathies were enrolled. When considering the "possible CIDP" category, the EAN/PNS 2021 criteria showed lower sensitivity than the EFNS/PNS 2010 criteria (78% vs. 93%, p < .05), whereas its specificity was higher (78% vs. 61%, p < .05). The lower sensitivity was caused mainly by the failure to fulfill the sensory nerve conduction criteria. The revised definition of abnormal temporal dispersion of the tibial nerve contributed markedly to the improved specificity.

DISCUSSION

To improve the sensitivity of the EAN/PNS 2021 criteria, increasing the number of tested sensory nerves may be necessary.

Rate and characteristics of inflammatory neuropathies associated with brentuximab vedotin therapy

BACKGROUND AND PURPOSE

Peripheral neuropathy is a frequent complication of brentuximab vedotin (BV), used in CD30+ lymphoma treatment. Classic BV-induced neuropathy (BV-CN) is a mild distal sensory axonal polyneuropathy. Severe BV-induced inflammatory neuropathies (BV-IN) have been described. BV-IN contribute to lymphoma-associated morbidity but might be immunotherapy-responsive. Our primary objective was to evaluate the rate of BV-IN. Our secondary objectives were to determine risk factors and warning signs.

METHODS

We conducted a retrospective cohort study on all patients treated with BV at our center between April 2014 and September 2021. Clinical, biological, and electrophysiological data were collected. BV-induced neuropathy was defined as the occurrence of neuropathy up to 3 months after BV discontinuation. BV-IN was defined with criteria adapted from European Academy of Neurology/Peripheral Nerve Society 2021 electrodiagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy. Other neuropathies were classified as BV-CN.

RESULTS

Among 83 patients, 41 (49%) developed neuropathy: 35 BV-CN and 6 BV-IN. Thus, the rate of BV-IN was 7.2%. Compared to patients with BV-CN, no predisposing factor was identified. However, patients with BV-IN more frequently presented muscle weakness (67% vs. 5.7%, p < 0.05), gait disorders (83% vs. 20%, p < 0.05), or acute or subacute onset (67% vs. 14%, p < 0.05). BV-IN was frequently more severe (Common Terminology Criteria for Adverse Events grade ≥3; 50% vs. 0%, p < 0.05). Four patients were treated with immunotherapy.

CONCLUSIONS

Brentuximab vedotin-induced neuropathy is an overlooked complication. Based on four easily identifiable "red flags", we provide an algorithm to help non-neurologist physicians that care for BV-treated patients to detect BV-IN. The aim of the algorithm is to decrease the diagnostic and management delay of this disabling neuropathy.

Synergistic effects of immune checkpoints and checkpoint inhibitors in inflammatory neuropathies: Implications and mechanisms

Immune checkpoint molecules play pivotal roles in the regulation of immune homeostasis. Disruption of the immune checkpoints causes autoimmune/inflammatory as well as malignant disorders. Over the past few years, the immune checkpoint molecules with inhibitory function emerged as potential therapeutic targets in oncological conditions. The inhibition of the function of these molecules by using immune checkpoint inhibitors (ICIs) has brought paradigmatic changes in cancer therapy due to their remarkable clinical benefits, not only in improving the quality of life but also in prolonging the survival time of cancer patients. Unfortunately, the ICIs soon turned out to be a "double-edged sword" as the use of ICIs caused multiple immune-related adverse effects (irAEs). The development of inflammatory neuropathies such as Guillain-Barré syndrome (GBS) and Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) as the secondary effects of immunotherapy appeared very challenging as these conditions result in significant and often permanent disability. The underlying mechanism(s) through which ICIs trigger inflammatory neuropathies are currently not known. Compelling evidence suggests autoimmune reaction and/or inflammation as the independent risk mechanism of inflammatory neuropathies. There is a lack of understanding as to whether prior exposure to the risk factors of inflammatory neuropathies, the presence of germline genetic variants in immune function-related genes, genetic variations within immune checkpoint molecules, the existence of autoantibodies, and activated/memory T cells act as determining factors for ICI-induced inflammatory neuropathies. Herein, we highlight the available pieces of evidence, discuss the mechanistic basis, and propose a few testable hypotheses on inflammatory neuropathies as irAEs of immunotherapy.

Repeated Acute Exacerbations of Chronic Inflammatory Demyelinating Polyradiculoneuropathy Accompanied by Pain and Swelling in Distal Extremities

An 81-year-old man experienced acute progression of weakness in the extremities accompanied by a fever, tenderness, and swelling in distal parts of the extremities. He had flaccid tetraparesis with fasciculations and general hyporeflexia. Nerve conduction studies indicated demyelinating sensorimotor neuropathy. A cerebrospinal fluid examination revealed elevated proteins without pleocytosis. Immunological treatments were effective, but his symptoms exhibited repeated relapse and remission phases. He was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with an acute onset. The highlight of this case is pain with inflammatory reaction recognized as red flags of CIDP, with the clinical course and electrophysiological findings compatible with CIDP.

Central nervous system involvement in chronic inflammatory demyelinating polyradiculoneuropathy-MRS and DTI study

Objective

The current research aimed to analyze the alterations within the motor cortex and pyramidal pathways and their association with the degree of damage within the peripheral nerve fibers in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). To achieve that goal, we investigated the microstructural changes within the pyramidal white matter tracts using diffusion tensor imaging (DTI) parameters, evaluated metabolic alterations in both precentral gyri using magnetic resonance spectroscopy (MRS) ratios, and correlated them with the neurographic findings in patients with CIDP.

Methods

The spectroscopic ratios of NAA/Cr, Cho/Cr, and mI/Cr from both precentral gyri and the values of fractional anisotropy (FA), axial diffusivity (AD), and mean diffusivity (MD) from both of the corticospinal tracts were correlated with the results of neurological and neurographic findings. The comparison of DTI parameters between the patients and controls was performed using Student's t-test or the Mann-Whitney U test. Due to the lack of normal distribution of most variables, Spearman's Rho rank coefficient was used to test all correlations. All analyses were performed at a significant level of alpha = 0.05 using STATISTICA 13.3.

Results

Compared to the control group (CG), the patient group showed significantly lower ratios of NAA/Cr (1.66 ± 0.11 vs. 1.61 ± 0.15; p = 0.022), higher ratios of ml/Cr in the right precentral gyrus (0.57 ± 0.15 vs. 0.61 ± 0.08; p = 0.005), and higher levels of Cho/Cr within the left precentral gyrus (0.83 ± 0.09 vs. 0.88 ± 0.14, p = 0.012). The DTI parameters of MD from the right CST and AD from the right and left CSTs showed a strong positive correlation (0.52-0.53) with the sural sensory nerve action potential (SNAP) latency of the right sural nerve. There were no other significant correlations between other DTI and MRS parameters and neurographic results.

Significance

In our study, significant metabolic alterations were found in the precentral gyri in patients with CIDP without clinical symptoms of central nervous system involvement. The revealed changes reflected neuronal loss or dysfunction, myelin degradation, and increased gliosis. Our results suggest coexisting CNS damage in these patients and may provide a new insight into the still unknown pathomechanism of CIDP.

[Prospect of novel therapies in immune-mediated neuropathies]

The efficacy of immunotherapies such as steroids, plasmapheresis, and intravenous immunoglobulin have been proven in various immune-mediated neuropathies. However, these treatments sometimes lack the efficacy in a part of patients with the immune-mediated neuropathies. In addition, anti-myelin associated glycoprotein (MAG) neuropathy is usually refractory to the treatments. Recently, novel therapies targeting a molecule which are associated with pathogenesis of immune-mediated diseases, have been developed. These molecularly targeted therapies are notable in immune-mediated neuropathies as novel drug candidates. In the present article, current treatments and future prospect of novel therapies in immune-mediated neuropathies will be reviewed.

The distribution pattern of nerve enlargement in clinical subtypes of chronic inflammatory demyelinating polyneuropathy

BACKGROUND AND PURPOSE

We aim to investigate nerve enlargement patterns and their correlation with clinical subtypes and treatment response using nerve ultrasound in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

Between March 2015 and December 2021, 135 CIDP patients were recruited. Nerve ultrasound and electrophysiological studies were performed on the median and ulnar nerves. The responses to intravenous immunoglobulin (IVIg) or prednisone were evaluated with the disability score.

RESULTS

There were 99 typical CIDP cases, 10 Lewis-Sumner syndrome (LSS) cases, 15 distal acquired demyelinating symmetric neuropathy (DADS) cases, nine pure motor CIDP cases, and two pure sensory CIDP cases. Sixty (61%) typical CIDP and seven (78%) pure motor CIDP patients had moderately increased or normal cross-sectional area (CSA), and 10 (67%) DADS and seven (70%) LSS patients had significantly increased CSA. The peripheral nerve showed a diffuse enlargement pattern in 46 (51%) typical CIDP, five (50%) LSS, three (25%) DADS, and three (33%) pure motor CIDP patients and a proximal regional enlargement pattern in 11 (12%) typical CIDP, one (10%) LSS, six (50%) DADS, and four (44%) pure motor CIDP patients. Patients with diffusely moderate enlargement patterns and those with proximal regional enlargement showed a higher response rate to glucocorticoids than to IVIg.

CONCLUSIONS

Various distribution patterns of nerve enlargement existed in CIDP. Although almost all patterns could be detected in each CIDP subtype, diffusely moderate enlargement was more common in typical CIDP and LSS, while proximal regional enlargement was more common in DADS and pure motor CIDP. Different enlargement patterns might indicate different treatment responses.

Case Report: Chronic inflammatory demyelinating polyradiculoneuropathy rather than hemophagocytic lymphohistiocytosis-the initial phenotype of PRF1 gene mutation

Perforin is essentially involved in the granule-dependent killing activities of cytotoxic T lymphocytes and NK cells. Monoallelic PRF1 mutation increases the risk of autoimmune diseases, and biallelic PRF1 mutation causes familial hemophagocytic lymphohistiocytosis-2. Here, we report a case of a 12-year-old girl with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), followed by a rapidly progressive onset of hemophagocytic lymphohistiocytosis (HLH) 9 months later, alongside manifestations of demyelinating encephalopathy. Genetic sequencing revealed a heterozygous nonsense mutation in the PRF1 gene (c.984G>A; p.W328*) and a heterozygous missense mutation in the PRF1 gene (c.1349C>T; p.T450M). Eventually, she died because of no suitable allogeneic hematopoietic stem cell available in time. Our observations suggest that CIPD might represent the initial phenotype of biallelic PRF1 mutation and could serve as an early sign of subsequent HLH. A comprehensive understanding of this condition is paramount for timely diagnosis, treatment, and ultimately improved patient outcomes.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy as a Presentation of Plasmacytoma

Polyneuropathy, organomegaly, endocrinopathy, M protein elevation, and skin changes (POEMS) syndrome is one of the rare paraneoplastic disorders of the multiorgan association whose initialism describes the principal clinical features as polyneuropathy, organomegaly, endocrinopathy, M-protein elevation, and skin changes caused by an underlying plasma cell disorder, one of the major diagnostic criteria for which is the presence of an osseous lesion. We present a case of POEMS syndrome with nearly all signs and symptoms on clinical and hematological examinations, which was further investigated with MRI of the whole spine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan, as the latter is a very useful imaging modality for evaluation of any paraneoplastic syndromes, including myeloproliferative disorders such as plasmacytoma or multiple myeloma, and lymphoproliferative or other malignancies.

Hyaluronidase-facilitated subcutaneous immunoglobulin 10% as maintenance therapy for chronic inflammatory demyelinating polyradiculoneuropathy: The ADVANCE-CIDP 1 randomized controlled trial

BACKGROUND AND AIMS

ADVANCE-CIDP 1 evaluated facilitated subcutaneous immunoglobulin (fSCIG; human immunoglobulin G 10% with recombinant human hyaluronidase) efficacy and safety in preventing chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) relapse.

METHODS

ADVANCE-CIDP 1 was a phase 3, double-blind, placebo-controlled trial conducted at 54 sites in 21 countries. Eligible adults had definite or probable CIDP and adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability scores of 0-7 (inclusive), and received stable intravenous immunoglobulin (IVIG) for ≥12 weeks before screening. After stopping IVIG, patients were randomized 1:1 to fSCIG 10% or placebo for 6 months or until relapse/discontinuation. fSCIG 10% was administered at the same dose (or matching placebo volume) and interval as pre-randomization IVIG. The primary outcome was patient proportion experiencing CIDP relapse (≥1-point increase in adjusted INCAT score from pre-subcutaneous treatment baseline) in the modified intention-to-treat population. Secondary outcomes included time to relapse and safety endpoints.

RESULTS

Overall, 132 patients (mean age 54.4 years, 56.1% male) received fSCIG 10% (n = 62) or placebo (n = 70). CIDP relapse was reduced with fSCIG 10% versus placebo (n = 6 [9.7%; 95% confidence interval 4.5%, 19.6%] vs n = 22 [31.4%; 21.8%, 43.0%], respectively; absolute difference: -21.8% [-34.5%, -7.9%], p = .0045). Relapse probability was higher with placebo versus fSCIG 10% over time (p = .002). Adverse events (AEs) were more frequent with fSCIG 10% (79.0% of patients) than placebo (57.1%), but severe (1.6% vs 8.6%) and serious AEs (3.2% vs 7.1%) were less common.

INTERPRETATION

fSCIG 10% more effectively prevented CIDP relapse than placebo, supporting its potential use as maintenance CIDP treatment.

Idiopathic Intracranial Hypertension Secondary to Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common immune-mediated inflammatory polyneuropathy, defined as progressive or relapsing symptoms for over two months with pathological or electrophysiological evidence of peripheral nerve demyelination. Papilledema is optic nerve head edema secondary to increased intracranial pressure or infiltrative/infectious etiologies. Regardless of the cause, visual loss is one of the feared manifestations due to optic nerve damage. We present a 50-year-old female patient with CIDP who developed papilledema that was secondary to increased intracranial pressure from high protein content in the cerebrospinal fluid (CSF) and elevated body mass index (BMI) secondary to prednisone use. Treatment with acetazolamide completely resolved the papilledema and headaches, and the patient was later maintained on mycophenolate, intravenous immunoglobulin (IVIG), rituximab, and prednisone. To the best of our knowledge, this is the first case that describes successful medical management of increased intracranial pressure in the setting of CIDP.

Fungal Gut Microbiome in Myasthenia Gravis: A Sub-Analysis of the MYBIOM Study

An altered gut microbiota is a possible contributing pathogenic factor in myasthenia gravis (MG), an autoimmune neuromuscular disease. However, the significance of the fungal microbiome is an understudied and neglected part of the intestinal microbiome in MG. We performed a sub-analysis of the MYBIOM study including faecal samples from patients with MG (n = 41), non-inflammatory neurological disorder (NIND, n = 18), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP, n = 6) and healthy volunteers (n = 12) by sequencing the internal transcribed spacer 2 (ITS2). Fungal reads were obtained in 51 out of 77 samples. No differences were found in alpha-diversity indices computed between the MG, NIND, CIDP and HV groups, indicating an unaltered fungal diversity and structure. Overall, four mould species (Penicillium aurantiogriseum, Mycosphaerella tassiana, Cladosporium ramonetellum and Alternaria betae-kenyensis) and five yeast species (Candida. albicans, Candida. sake, Candida. dubliniensis, Pichia deserticola and Kregervanrija delftensis) were identified. Besides one MG patient with abundant Ca. albicans, no prominent dysbiosis in the MG group of the mycobiome was found. Not all fungal sequences within all groups were successfully assigned, so further sub-analysis was withdrawn, limiting robust conclusions.

Red Flags for Chronic Inflammatory Demyelinating Polyradiculoneuropathy Associated with Sarcoidosis or Connective Tissue Diseases

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare autoimmune disorder of the peripheral nervous system. Diagnosis relies on clinical and electrophysiological criteria. Various disorders requiring specific treatment regimens may be associated with CIDP, including sarcoidosis (SAR-CIDP) and connective tissue disease (CTD-CIDP). Therefore, it is important to distinguish between CIDP, SAR-CIDP and CTD-CIDP. In this retrospective monocentric study, we analyzed 16 patients with SAR-CIDP and 11 with CTD-CIDP and compared them with a group of 17 patients with idiopathic CIDP. SAR-CIDP patients had a frequently acute or subacute CIDP onset. CTD-CIDPs were mostly Sjögren's syndrome and lupus, and patients had a chronic onset. An older age at onset (64.5 vs. 54 years, p = 0.04), more atypical presentation (19/25 (76%) vs. 6/17 (35%), p = 0.008), acute/subacute onset of symptoms (15/25 (60%) vs. 1/17 (6%), p = 0.0004) and more frequent weight loss (7/16 (44%) vs. 0/17 (0%), p = 0.017) were identified SAR-CIDP and CTD-CIDP groups. Response to intravenous immunoglobulin therapy was lower in the combined SAR-CIDP and CTD-CIDP group (44% versus 82%, p = 0.005). As sarcoidosis and CTDs might be associated with CIDP and require specific management, the "red flags" mentioned above should be kept in mind by clinicians managing patients with CIDP.

Fingolimod ameliorates chronic experimental autoimmune neuritis by modulating inflammatory cytokines and Akt/mTOR/NF-κB signaling

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated disease that targets the myelin sheaths of the peripheral nerves. Fingolimod is a sphingosine 1 phosphate (S1P) receptor antagonist with a high affinity for S1P receptors through the Akt-mTOR pathway, and prior research has suggested that it might be helpful in autoimmune illnesses.

METHODS

Chronic experimental autoimmune neuritis (c-EAN) was induced by immunizing Lewis rats with the S-palm P0(180-199) peptide, and then the treatment group was intraperitoneally injected with fingolimod (1 mg/kg) daily. Hematoxylin and eosin staining was used to assess the severity of nerve injury. Immunohistochemistry staining showed that fingolimod's anti-inflammatory effects on c-EAN rats might be realized through the NF-κB signaling pathway. Tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin-1beta (IL-1β), interleukin 6 (IL-6), inducible nitric oxide synthase (iNOS), and intercellular adhesion molecule-1 (ICAM-1) were measured to evaluate the inflammation levels, and pAkt, p-S6, and p-p65 were used to measure the abundance of downstream activation markers to determine whether the Akt/mTOR/NF-κB signaling pathway was activated in the c-EAN model.

RESULTS

Fingolimod treatment reduced the inflammatory reaction and the expression of NF-κB in sciatic nerves. It also decreased the mRNA levels of the proinflammatory cytokines TNF-α, IFN-γ, IL-1β, IL-6, iNOS, and ICAM-1 and pAkt, p-S6, and p-p65, representing the Akt/mTOR/NF-κB signaling pathway.

CONCLUSION

Our data showed that fingolimod could improve the disease course, alleviate the decrease in inflammation, and reduce proinflammatory cytokines through the Akt/mTOR/NF-κB axis in c-EAN rats, which could be beneficial for the development of CIDP-related research.

A diagnostic score for anti-myelin-associated-glycoprotein neuropathy or chronic inflammatory demyelinating polyradiculoneuropathy in patients with anti-myelin-associated-glycoprotein antibody

BACKGROUND AND PURPOSE

A diagnostic score was developed to discriminate anti-myelin-associated-glycoprotein (MAG) neuropathy from chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and applied it to patients with atypical anti-MAG neuropathy.

METHODS

The clinical and electrophysiological features of patients with a diagnosis of typical anti-MAG neuropathy were compared to those of patients with a diagnosis of CIDP. The association of each feature with the diagnosis was assessed in the two groups. Features showing a significant association with the diagnosis were included in a multivariable logistic regression model and adjusted odds ratios were estimated for each feature. A score ranging from 1 to 3 was applied to each feature based on the magnitude of the estimated odds ratios. The score was then applied to patients with a clinical diagnosis of CIDP who also had high anti-MAG antibody titers (CIDP-MAG).

RESULTS

Thirty-one anti-MAG neuropathy patients, 45 typical CIDP patients and 16 CIDP-MAG patients were included. Scores in anti-MAG antibody patients ranged from 1 to 5 and in CIDP patients from -7 to -1. Using the score, 4/16 CIDP-MAG patients were diagnosed to have anti-MAG neuropathy and 12/16 patients to have CIDP. Response to intravenous immunoglobulin in the CIDP-MAG patients classified as CIDP was similar to that of definite CIDP patients and higher than that of anti-MAG neuropathy patients.

CONCLUSIONS

Our score allowed an accurate discrimination to be made, amongst patients with anti-MAG antibodies, of those affected by CIDP and the patients with anti-MAG neuropathy. This score may help proper treatment to be chosen for patients with anti-MAG antibodies with a CIDP-like presentation.

Sex differences in Guillain Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy and experimental autoimmune neuritis

Guillain Barré syndrome (GBS) and its variants, and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP and its variants, are regarded as immune mediated neuropathies. Unlike in many autoimmune disorders, GBS and CIDP are more common in males than females. Sex is not a clear predictor of outcome. Experimental autoimmune neuritis (EAN) is an animal model of these diseases, but there are no studies of the effects of sex in EAN. The pathogenesis of GBS and CIDP involves immune response to non-protein antigens, antigen presentation through non-conventional T cells and, in CIDP with nodopathy, IgG4 antibody responses to antigens. There are some reported sex differences in some of these elements of the immune system and we speculate that these sex differences could contribute to the male predominance of these diseases, and suggest that sex differences in peripheral nerves is a topic worthy of further study.

Pathology of Initial Axon Segments in Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Related Disorders

The diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is based on a combination of clinical, electrodiagnostic and laboratory features. The different entities of the disease include chronic immune sensory polyradiculopathy (CISP) and autoimmune nodopathies. It is debatable whether CIDP occurring in the course of other conditions, i.e., monoclonal IgG or IgA gammopathy, should be treated as a separate disease entity from idiopathic CIDP. This study aims to evaluate the molecular differences of the nodes of Ranvier and the initial axon segment (AIS) and juxtaparanode region (JXP) as the potential cause of phenotypic variation of CIDP while also seeking new pathomechanisms since JXP is sequestered behind the paranode and autoantibodies may not access the site easily. The authors initially present the structure of the different parts of the neuron and its functional significance, then discuss the problem of whether damage to the juxtaparanodal region, Schwann cells and axons could cause CIDP or if these damages should be separated as separate disease entities. In particular, AIS's importance for modulating neural excitability and carrying out transport along the axon is highlighted. The disclosure of specific pathomechanisms, including novel target antigens, in the heterogeneous CIDP syndrome is important for diagnosing and treating these patients.

Usefulness and prognostic value of diagnostic tests in patients with possible chronic inflammatory demyelinating polyradiculoneuropathy

INTRODUCTION/AIMS

Recent guidelines define chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and possible CIDP. The aims of our study were to evaluate the value of diagnostic tests to support the diagnosis of CIDP in patients with possible CIDP and to identify prognostic factors of therapeutic success.

METHODS

We conducted an observational retrospective two-center study between 2014 and 2019. We selected patients with a clinical presentation suggesting CIDP, but whose electrodiagnostic (EDX) test results did not meet the EFNS/PNS 2021 criteria. We analyzed epidemiologic and clinical features, axonal loss on EDX, cerebrospinal fluid (CSF), somatosensory evoked potentials (SSEPs), plexus magnetic resonance imaging (MRI), nerve biopsy, and therapeutic response.

RESULTS

We selected 75 patients, among whom 30 (40%) responded to treatment. The positivity rates of CSF analysis, MRI and SSEPs were not influenced by the clinical presentation or by the delay between symptom onset and medical assessment. A high protein level in CSF, female gender, and a relapsing-remitting course predicted the therapeutic response.

DISCUSSION

It is important to properly diagnose suspected CIDP not meeting EFNS/PNS 2021 EDX criteria by using supportive criteria. Specific epidemiological factors and a raised CSF protein level predict a response to treatment. Further prospective studies are needed to improve diagnosis and the prognostic value of diagnostic tests in CIDP.

Original Surgical Treatment and Long-term Follow-up for Chronic Inflammatory Demyelinating Polyradiculoneuropathy Causing A Compressive Cervical Myelopathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic relapsing disease of unknown aetiology. The diagnosis of this disease is still very complicated. The treatment is medical but, in some cases, a surgical decompression might be required. In rare cases it develops a radicular hypertrophy that can cause a cervical myelopathy; this pathology should be put in differential diagnosis with neurofibromatosis 1 (NF-1) and Charcot Marie Tooth (CMT) syndromes. The cases of CIDP cervical myelopathy reported in the literature are rare and even more rarely a surgical decompression was described. Here we report a first and unique case of CIDP cervical myelopathy treated with an open-door laminoplasty technique with 10-years post-operative follow-up (FU). The surgical decompression revealed to be effective in stopping the progression of myelopathy without destabilizing the spine. The patient that before surgery presented a severe tetra-paresis could return to walk and gained back his self-care autonomy. At 10-years FU he didn't complain of neck pain and didn't develop a cervical kyphosis. In case of cervical myelopathy caused by radicular hypertrophy CIDP should be kept in mind in the differential diagnosis and an open-door laminoplasty is indicated to stop myelopathy progression.

Epidemiology of chronic inflammatory demyelinating polyradiculoneuropathy in The Netherlands

BACKGROUND AND AIMS

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare but disabling disorder that often requires long-term immunomodulatory treatment. Background incidence rates and prevalence and risk factors for developing CIDP are still poorly defined. In the current study, we used a longitudinal population-based cohort study in The Netherlands to assess these rates and demographic factors and comorbidity associated with CIDP.

METHODS

We determined the incidence rate and prevalence of CIDP between 2008-2017 and the occurrence of potential risk factors in a retrospective Dutch cohort study using the Integrated Primary Care Information (IPCI) database. Cases were defined as CIDP if the diagnosis of CIDP was described in the electronic medical file.

RESULTS

In a source population of 928,030 persons with a contributing follow-up of 3,525,686 person-years, we identified 65 patients diagnosed with CIDP. The overall incidence rate was 0.68 per 100,000 person-years (95% CI 0.45-0.99). The overall prevalence was 7.00 per 100,000 individuals (95% CI 5.41-8.93). The overall incidence rate was higher in men compared to woman (IRR 3.00, 95% CI 1.27-7.11), and higher in elderly of 50 years or older compared to people <50 years of age (IRR 17 95% CI 4-73). Twenty percent of CIDP cases had DM and 9% a co-existing other autoimmune disease.

INTERPRETATION

These background rates are important to monitor changes in the frequency of CIDP following infectious disease outbreaks identify potential risk factors, and to estimate the social and economic burden of CIDP.

Chronic Inflammatory Demyelinating Polyneuropathy in Patients With Crohn's Disease on Infliximab Therapy

Crohn’s disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract that is frequently accompanied by systemic complications including peripheral neuropathies. Anti-tumor necrosis factor-alpha agents such as infliximab are an established treatment for immune-mediated diseases. However, they have been associated with adverse effects, including local reactions, infections, congestive heart failure, malignancies, and, rarely, they can cause neurological adverse effects on the central nervous system, as well as peripheral nervous system demyelination. Here, we report the case of an 80-year-old man with CD on infliximab therapy who presented with progressive weakness and numbness. A neurological examination and a nerve conduction study suggested chronic inflammatory demyelinating polyneuropathy (CIDP). The patient was started on oral corticosteroids and experienced transient improvement of his symptoms at the end of this course. Thus, CIDP could be one of the extraintestinal presentations of CD.

Acute-onset polyradiculoneuropathy after SARS-CoV2 vaccine in the West and North Midlands, United Kingdom

INTRODUCTION/AIMS

We aimed to determine whether specific severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccines may be associated with acute-onset polyradiculoneuropathy and if they may result in particular clinical presentations.

METHODS

We retrospectively reviewed records of all persons presenting with acute-onset polyradiculoneuropathy from January 1, 2021, to June 30, 2021, admitted to two Neuroscience centers, of the West and North Midlands, United Kingdom. We compared subjects with previous SARS-CoV2 vaccine exposure with a local cohort of persons with acute-onset polyradiculoneuropathy admitted between 2005 and 2019 and compared admission numbers for the studied time frame with that of the previous 3 years.

RESULTS

Of 24 persons with acute-onset polyradiculoneuropathy, 16 (66.7%) presented within 4  weeks after first SARS-CoV2 vaccine. Fourteen had received the AstraZeneca vaccine and one each, the Pfizer and Moderna vaccines. The final diagnosis was Guillain-Barré syndrome (GBS) in 12 and acute-onset chronic inflammatory demyelinating polyneuropathy in 4. Among AstraZeneca vaccine recipients, facial weakness in nine persons (64.3%), bulbar weakness in seven (50%), and the bifacial weakness and distal paresthesias GBS variant in three (21.4%), were more common than in historical controls (P = .01; P = .004, and P = .002, respectively). A 2.6-fold (95% confidence interval: 1.98-3.51) increase in admissions for acute-onset polyradiculoneuropathy was noted during the studied time frame, compared to the same period in the previous 3 years.

DISCUSSION

Despite a low risk, smaller than that of SARS-CoV2 infection and its complications, exposure to the first dose of AstraZeneca SARS-CoV2 vaccine may be a risk factor for acute-onset polyradiculoneuropathy, characterized by more common cranial nerve involvement.

Axonal damage determines clinical disability in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): A prospective cohort study of different CIDP subtypes and disease stages

BACKGROUND AND PURPOSE

Monitoring of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is challenging in daily medical practice because the interrelationship between clinical disability, CIDP subtype, and neuronal degeneration is still elusive. The aim of this prospective cohort study was to investigate the role of different electrophysiological variables in CIDP monitoring.

METHODS

Comprehensive bilateral nerve conduction studies (NCS) and structured clinical examinations were performed in 95 patients with typical CIDP and CIDP variants (age at inclusion 58.6 ± 11.6 years; median [range] inflammatory neuropathy cause and treatment overall disability score (INCAT-ODSS) 3 [0-9]), at time of first diagnosis in 25 of these patients (based on data from the prospective Immune-mediated Neuropathies Biobank registry). After 12 months, 33 patients underwent follow-up examination. Typical CIDP patients and patients with CIDP variants were characterized electrophysiologically and each individual NCS variable and the overall sum score for axonal damage and demyelination were then correlated to clinical disability scores (INCAT-ODSS, modified Medical Research Council (MRS) sum score, and INCAT sensory score).

RESULTS

As opposed to demyelination markers, the NCS axonal damage variable correlated strongly with disability at both first diagnosis and advanced disease stages in cross-sectional and longitudinal analyses. Distal compound muscle action potential amplitudes of the upper limbs were found to have the strongest correlation with overall clinical function. Typical and atypical CIDP variants had distinct electrophysiological characteristics but, in typical CIDP, axonal degeneration markers were more strongly associated with clinical disability.

CONCLUSIONS

Total disability is largely determined by the degree of axonal damage, especially in typical CIDP. Although most patients have symptoms predominantly in the legs, NCS of the upper limbs are essential for the monitoring of patients with CIDP and CIDP variants.

Misdiagnosis and diagnostic pitfalls of chronic inflammatory demyelinating polyradiculoneuropathy

Background and purpose

The aim of this study was to determine the frequency of over‐ and underdiagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and to identify related diagnostic pitfalls.

Methods

We conducted a retrospective study in Dutch patients referred to the Erasmus University Medical Centre Rotterdam between 2011 and 2017 with either a diagnosis of CIDP or another diagnosis that was revised to CIDP. We used the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) 2010 diagnostic criteria for CIDP to classify patients into three groups: overdiagnosis, underdiagnosis, or confirmed diagnosis of CIDP. Clinical and laboratory features and treatment history were compared between groups.

Results

A referral diagnosis of CIDP was revised in 32% of patients (31/96; overdiagnosis). Of 81 patients diagnosed with CIDP, 16 (20%) were referred with another diagnosis (underdiagnosis). In the overdiagnosed patients, 20% of muscle weakness was asymmetric, 48% lacked proximal muscle weakness, 29% only had distal muscle weakness, 65% did not fulfil the electrodiagnostic criteria for CIDP, 74% had an elevated cerebrospinal fluid (CSF) protein level, and 97% had another type of neuropathy. In the underdiagnosed patients, all had proximal muscle weakness, 50% had a clinically atypical CIDP, all fulfilled the electrodiagnostic criteria for CIDP, and 25% had an increased CSF protein level.

Conclusion

Over‐ and underdiagnosis of CIDP is common. Diagnostic pitfalls include lack of attention to proximal muscle weakness as a diagnostic hallmark of CIDP, insufficient recognition of clinical atypical phenotypes, overreliance on CSF protein levels, misinterpretation of nerve conduction studies and poor adherence to electrodiagnostic criteria, and failure to exclude other causes of polyneuropathy.

Genetic biomarkers for intravenous immunoglobulin response in chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND AND PURPOSE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a clinical and electrophysiological heterogeneous immune-mediated polyneuropathy. Intravenous immunoglobulin (IVIg), corticosteroids, and plasma exchange are proven effective treatments for CIDP. The clinical response to IVIg is variable between patients and currently unexplained. Finding biomarkers related to treatment response can help to understand the diversity of CIDP and personalise treatment choice.

METHODS

We investigated whether genetic variation between patients may explain some of these differences in treatment response. Based on previous publications, we selected six candidate genes that might affect immune and axonal functions, IVIg metabolism, and treatment response in CIDP. Genetic variants were assessed in 172 CIDP patients treated with at least one course of IVIg (2 g/kg). A response to IVIg was defined by ≥1 grade improvement on the modified Rankin Scale. Blood samples were tested for variations in CNTN2, PRF1, FCGRT, FCGR2B, GJB1, and SH2D2A genes.

RESULTS

In univariate analysis, patients with the FCGR2B promoter variant 2B.4/2B.1 responded more often to IVIg than patients with the 2B.1/2B.1 variant (odds ratio [OR] = 6.9, 95% confidence interval [CI] = 1.6-30; p = 0.003). Patients with the p.(Ala91Val) variant of PRF1 were less often IVIg responsive (OR = 0.34, 95% CI = 0.13-0.91; p = 0.038). In multivariate analysis, both PRF1 and FCGR2B showed discriminative ability to predict the chance of IVIg response (area under the curve = 0.67).

CONCLUSIONS

Variations in PRF1 and the promoter region of FCGR2B are associated with the response to IVIg in CIDP. These findings, which require validation, are a first step towards the understanding of the heterogeneity in the treatment response in CIDP.

The Noninvasive Diagnostic Value of MRN for CIDP: A Research from Qualitative to Quantitative

STUDY DESIGN

We examined the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and non-CIDP patients who have similar symptoms and difficult to differential diagnosis with CIDP by magnetic resonance neurography to find the difference among them.

OBJECTIVE

To investigate the differential diagnostic value of magnetic resonance neurography (MRN) for CIDP and other peripheral neuropathies.

SUMMARY OF BACKGROUND DATA

Thirty-two consecutive patients with CIDP and 22 non-CIDP patients with symptoms similar to CIDP and difficult to be discriminate were recruited and imaged as a control group between May 2017 and May 2019.

METHODS

In this prospective study, the brachial plexus and lumbosacral plexus of 32 CIDP patients and 22 non-CIDP patients were examined by MRN. The clinical features and the nerve roots cross-sectional area (CSA) of the brachial plexus and lumbosacral plexus were measured.

RESULTS

The CSA of nerve roots of CIDP, Charcot-Marie-Tooth disease type-1 and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome patients were all shown extensive by MRN. The sensitivity of MRN in diagnosing CIDP was 81.25% (26/32), the specificity was 68.18% (15/22), the positive predictive value was 78.79% (26/33), the negative predictive value was 71.43% (15/21), the accuracy was 75.93% (40/54), the misdiagnosis rate was 24.07% (13/54), and the kappa value was 0.498. Receiver operating characteristic analysis showed higher diagnostic accuracy for CIDP with the CSA of the lumbosacral plexus (area under the curve [AUC] = 0.762) and that of the brachial plexus (AUC = 0.762), and the combined of both examinations did not improve the diagnostic efficacy compared with either (AUC = 0.769).

CONCLUSIONS

The nerve roots of CIDP, Charcot-Marie-Tooth disease type-1, and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome were difficult to distinguish by MRN. Atypical CIDP patients had less nerve root injury compared with typical CIDP patients. MRN of either the brachial plexus or the lumbosacral plexus had a high diagnostic accuracy for CIDP, and it is not necessary to perform both parts of the examination.

LEVEL OF EVIDENCE

2.

Chronic inflammatory demyelinating polyradiculoneuropathy: can a diagnosis be made in patients not fulfilling electrodiagnostic criteria?

BACKGROUND AND PURPOSE

The aim was to identify the clinical and diagnostic investigations that may help to support a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in patients not fulfilling the European Federation of Neurological Societies and Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria.

METHODS

The data from patients with a clinical diagnosis of CIDP included in a national database were retrospectively reviewed.

RESULTS

In all, 535 patients with a diagnosis of CIDP were included. This diagnosis fulfilled the EFNS/PNS criteria in 468 patients (87.2%) (definite in 430, probable in 33, possible in three, while two had chronic immune sensory polyradiculopathy). Sixty-seven patients had a medical history and clinical signs compatible with CIDP but electrodiagnostic studies did not fulfill the EFNS/PNS criteria for CIDP. These patients had similar clinical features and frequency of abnormal supportive criteria for the diagnosis of CIDP compared to patients fulfilling EFNS/PNS criteria. Two or more abnormal supportive criteria were present in 40 (61.2%) patients rising to 54 (80.6%) if a history of a relapsing course as a possible supportive criterion was also included. Increased cerebrospinal fluid proteins and response to immune therapy most frequently helped in supporting the diagnosis of CIDP. Response to therapy was similarly frequent in patients fulfilling or not EFNS/PNS criteria (87.3% vs. 85.9%).

CONCLUSIONS

Patients with a clinical diagnosis of CIDP had similar clinical findings, frequency of abnormal supportive criteria and response to therapy compared to patients fulfilling EFNS/PNS criteria. The presence of abnormal supportive criteria may help in supporting the diagnosis of CIDP in patients with a medical history and clinical signs compatible with this diagnosis but non-diagnostic nerve conduction studies.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Background: Both Guillain–Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are neurodegenerative and inflammatory demyelination disorders. Sporadic reports showed that the increased levels of thyroid function and autoantibodies are associated with GBS, CIDP, or both, but no systematic study has been reported. We assessed the differences of thyroid function and autoantibodies between GBS and CIDP in a Chinese cohort.

Methods: A total of 256 patients were enrolled in this study. 175 clinically confirmed GBS and CIDP patients were selected. Meanwhile, 81 patients hospitalized for diseases other than GBS or CIDP with mild symptoms were enrolled as a control group. Relevant clinical data, including thyroid function, and autoantibody examinations, were collected for statistical analysis.

Results: In the comparison of thyroid function and autoantibody parameters, the levels of total thyroxine (TT4), thyroid peroxidase antibody (TPO-Ab), and thyroglobulin antibody (TG-Ab) in the GBS group were all higher than those in the CIDP and Control groups (P < 0.01). The thyroid antibody positive rates in the GBS and CIDP groups were 70.10 and 14.10%, respectively (P < 0.01). In the receiver operating characteristic (ROC) curve analysis, TT4, TPO-Ab, and TG-Ab were higher in the GBS group and lower in the CIDP group (P < 0.01). To achieve a high specificity of 97–99%, the diagnostic cutoff value of TPO-Ab was higher than 133 IU/mL (Sensitivity: 11.34%) or lower than 0.01 IU/mL (Sensitivity: 9.09%), while the diagnostic cutoff value of TG-Ab was higher than 261.1 IU/mL (Sensitivity: 2.06%) or lower than 0.46 IU/mL (Sensitivity: 11.69%). Multivariate logistic regression analysis showed that the differences in TPO-Ab were statistically significant between GBS patients with TPO-Ab was higher than 133 IU/mL and CIDP patients (P < 0.01); the differences in TG-Ab were statistically significant between GBS patients with TG-Ab was higher than 261.1 IU/mL and CIDP patients (P < 0.05).

Conclusion: The elevation of thyroid autoantibodies was associated with GBS. TPO-Ab higher than 133 IU/mL or lower than 0.01 IU/mL and TG-Ab higher than 261.1 IU/mL or lower than 0.46 IU/mL had high specificity for differentiating between GBS and CIDP; therefore, TPO-Ab and TG-Ab can be used as biomarkers for the differential diagnosis of GBS and CIDP.

Acute and chronic neuropathies

Peripheral nerve disorders are common and often treatable. The 'default' presentation of a polyneuropathy is a chronic, length-dependent, sensorimotor axonopathy. Recognizing deviations from this default, informed by the clinical features and investigations, can help identify the cause of a neuropathy in most cases. For inflammatory causes, such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, there are effective immunomodulatory treatments. For other neuropathies, management consists of supportive care and treatment of the underlying cause, to prevent or limit progression.

An international multicenter efficacy and safety study of IqYmune in initial and maintenance treatment of patients with chronic inflammatory demyelinating polyradiculoneuropathy: PRISM study

This prospective, multicenter, single‐arm, open‐label phase 3 study aimed to evaluate the efficacy and safety of IqYmune in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Patients received one induction dose of 2 g/kg and then seven maintenance doses of 1 g/kg at 3‐week intervals. The primary endpoint was the responder rate at the end of study (EOS), defined as an improvement of ≥1 point on the adjusted inflammatory neuropathy cause and treatment (INCAT) disability scale. The responder rate was compared with the responder rate of a historical placebo group (33.3%). Secondary endpoints included changes from baseline to EOS of adjusted INCAT disability score, grip strength, Medical Research Council (MRC) sum score, Rasch‐modified MRC sum score, Rasch‐built overall disability scale score and the clinical global impression. Forty‐two patients, including 23 Ig‐naïve and 19 Ig‐pre‐treated, were included in the efficacy set. The overall response rate at EOS was 76.2% (95% confidence interval [60.5%‐87.9%]). The superiority of IqYmune compared to the historical placebo control was demonstrated (P < .0001). The responder rate was numerically higher in Ig‐pre‐treated than in Ig‐naïve patients but confidence intervals were overlapping (84.2% [60.4%‐96.6%] vs 69.6% [47.1%‐86.8%]). All secondary endpoints confirmed this conclusion. The median time to response was 15 weeks [8.9‐19.1 weeks]. A total of 156 adverse events including five serious were considered related to IqYmune, 87.2% were mild. Neither hemolysis nor signs of renal or hepatic impairment were observed. These results demonstrate that IqYmune is an effective and well‐tolerated treatment in patients with CIDP.

[Chronic inflammatory demyelinating polyradiculoneuropathy with myelopathy due to massively enlarged nerve roots]

We report a 77-year-old man who presented with numbness and weakness of the feet bilaterally, that had progressed over 13 years. He was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) on the basis of nerve conduction studies and a sural nerve biopsy; however, he was inadequately treated and his weakness had progressed. At 76 years of age, he developed spasticity in the legs as well as bladder and rectal incontinences. Gd-enhanced MRI revealed severe compression of the cervical cord by massively enlarged nerve roots. A cervical laminectomy was performed to decompress the cervical cord. A fascicular biopsy of the C5 dorsal root showed a prominent lymphocyte infiltration and edema. Repeated methylprednisolone pulse therapy and IVIg ameliorated the weakness. We concluded that the main cause of nerve root hypertrophy in this patient was active inflammation.

[A case of neurofascin-155 antibody-positive chronic inflammatory demyelinating polyradiculoneuropathy successfully treated with Cyclosporine A]

A 41-year-old man noticed numbness of the fingers and toes, and gradually developed limb weakness and sensory impairment. The patient was diagnosed with typical chronic inflammatory demyelinating polyradiculoneuropathy. Over the course of clinical diagnosis, the limb and trunk ataxia, and finger tremor became prominent, and the presence anti-neurofascin-155 antibody was examined and confirmed positive. The effects of corticosteroids, intravenous immunoglobulin, and plasma apheresis were limited, and the disease progressed slowly and noticeably. Therefore, cyclosporine was introduced as treatment, and the patient's weakness and ataxia significantly improved. Rituximab treatment is expected to be effective in patients with the same antibody and immunosuppressant treatment may be useful in intractable cases.

Chronic inflammatory demyelinating polyradiculoneuropathy relapse after mexiletine withdrawal in a patient with concomitant myotonia congenita: A case report on a potential treatment option

INTRODUCTION

we report on the first case of a woman affected by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and recessive myotonia congenita (MC), treated with mexiletine. We aimed at describing the possible role of mexiletine in CIDP management.

PATIENT CONCERNS

A 44-year-old female affected by CIDP and MC, gained beneficial effects for CIDP symptoms (muscle weakness, cramps, and fatigue) and relapses, after mexiletine intake (200 mg twice a day). The patient presented with detrimental effects after mexiletine drop out, with a worsening of CIDP symptoms.

INTERVENTIONS

The patient reported a nearly complete remission of muscle stiffness and weakness up to 3 years since mexiletine intake. Then, she developed an allergic reaction with glottis edema, maybe related to mexiletine intake, as per emergency room doctors' evaluation, who suggested withdrawing the drug.

OUTCOMES

The patient significantly worsened after the medication drop out concerning both CIDP and MC symptoms.

CONCLUSION

This is the first report on the association of CIDP and MC in the same patient. Such diseases may share some clinical symptoms related to a persistent sodium currents increase, which maybe due either to the over-expression of sodium channels following axonal damage due to demyelination or to the chloride channel genes mutations. This is the possible reason why mexiletine maybe promising to treat CIDP symptoms.

Diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy in clinical practice: A survey among Dutch neurologists

The diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is often a challenge. The clinical presentation is diverse, accurate biomarkers are lacking, and the best strategy to initiate and maintain treatment is unclear. The aim of this study was to determine how neurologists diagnose and treat CIDP. We conducted a cross‐sectional survey on diagnostic and treatment practices among Dutch neurologists involved in the clinical care of CIDP patients. Forty‐four neurologists completed the survey (44/71; 62%). The respondents indicated to use the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) 2010 CIDP guideline for the diagnosis in 77% and for treatment in 50%. Only 57% of respondents indicated that the presence of demyelinating electrophysiological findings was mandatory to confirm the diagnosis of CIDP. Most neurologists used intravenous immunoglobulins (IVIg) as first choice treatment, but the indications to start, optimize, or withdraw IVIg, and the use of other immune‐modulatory therapies varied. University‐affiliated respondents used the EFNS/PNS 2010 diagnostic criteria, nerve imaging tools, and immunosuppressive drugs more often. Despite the existence of an international guideline, there is considerable variation among neurologists in the strategies employed to diagnose and treat CIDP. More specific recommendations regarding: (a) the minimal set of electrophysiological requirements to diagnose CIDP, (b) the possible added value of nerve imaging, especially in patients not meeting the electrodiagnostic criteria, (c) the most relevant serological examinations, and (d) the clear treatment advice, in the new EFNS/PNS guideline, would likely support its implementation in clinical practice.

Inhaled Solvent Abuse Mimicking Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Exposure to n-hexane or toluene-containing solvents such as glue or gasoline can produce clinical symptoms and neurophysiological findings that can mimic chronic inflammatory demyelinating polyneuropathy. The authors present a case of a boy with severe sensorimotor polyneuropathy with demyelinating features. Cerebrospinal fluid testing and magnetic resonance imaging spine did not show findings typical of chronic inflammatory demyelinating polyneuropathy. His lack of response to immunosuppressive therapy prompted a nerve biopsy which was instrumental in confirming a diagnosis of chronic organic solvent exposure, subsequently confirmed on history. This case highlights the importance of additional testing to ensure diagnostic certainty which allows appropriate treatment and/or disease management to be tailored appropriately including in this instance, the involvement of mental health counseling and avoidance of immunosuppressant medication.

Efficacy and Safety of Rituximab in Refractory CIDP With or Without IgG4 Autoantibodies (RECIPE): Protocol for a Double-Blind, Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated peripheral neuropathy that is currently classified into several clinical subtypes, which are presumed to have different pathogenic mechanisms. Recently, studies identified a subgroup of patients with CIDP who were positive for IgG4 autoantibodies against paranodal proteins, such as neurofascin-155 and contactin-1, who respond poorly to first-line therapies for typical CIDP, including intravenous immunoglobulin therapy.

OBJECTIVE

This study aims to evaluate the efficacy and safety of intravenous rituximab according to IgG4 autoantibody status in patients with refractory CIDP.

METHODS

The Evaluation of the Efficacy and Safety of Rituximab in Refractory CIDP Patients with IgG4 Autoantibodies in the Exploratory Clinical (RECIPE) trial consists of 2 cohorts: a multicenter, placebo-controlled, randomized study cohort of 15 patients with IgG4 autoantibody-positive CIDP (rituximab:placebo = 2:1) and an open-label trial cohort of 10 patients with antibody-negative CIDP. The primary endpoint is improvement in functional outcome assessed using the adjusted Inflammatory Neuropathy Cause and Treatment Disability Scale score at 26, 38, or 52 weeks after the start of treatment with rituximab in patients with CIDP and anti-paranodal protein antibodies. Secondary outcome measures include grip strength, manual muscle testing sum scores, results of nerve conduction studies, and other functional scales.

RESULTS

We plan to enroll 25 cases for the full analysis set. Recruitment is ongoing, with 14 patients enrolled as of January 2020. Enrollment will close in September 2020, and the study is planned to end in December 2021.

CONCLUSIONS

This randomized controlled trial will determine if rituximab is safe and effective in patients with anti-paranodal antibodies. An open-label study will provide additional data on the effects of rituximab in patients with antibody-negative CIDP. The results of the RECIPE trial are expected to provide evidence for the positioning of rituximab as a pathogenesis-based therapeutic for refractory CIDP.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03864185, https://clinicaltrials.gov/ct2/show/NCT03864185 ; The Japan Registry of Clinical Trials jRCT2041180037, https://jrct.niph.go.jp/en-latest-detail/jRCT2041180037.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/17117.

Combined intravenous immunoglobulin and methylprednisolone as induction treatment in chronic inflammatory demyelinating polyneuropathy (OPTIC protocol): a prospective pilot study

BACKGROUND AND PURPOSE

We hypothesized that combining intravenous immunoglobulin (IVIg) and intravenous methylprednisolone (IVMP) leads to more frequent remission compared with IVIg alone while maintaining the fast efficacy of IVIg. In this uncontrolled pilot study, we evaluated remission, rate of improvement and safety in patients with chronic inflammatory demyelinating polyradiculoneuropathy receiving induction treatment with combined IVIg and IVMP.

METHODS

Consecutive treatment-naive patients with chronic inflammatory demyelinating polyradiculoneuropathy were treated with IVIg infusions, consisting of a 2 g/kg loading dose and 1 g/kg maintenance treatment every 3 weeks, combined with 3-weekly 1-g IVMP infusions, for a total of 18 weeks. The cumulative steroid dose was 7 g. Primary outcome was remission at 1 year in patients who completed the treatment schedule. Remission was defined as improvement at 18 weeks without the need for further immune treatment between end of the treatment schedule and 1-year follow-up. Improvement was defined as a minimal clinically important difference on the Inflammatory Rasch-Built Overall Disability Scale and/or an increase of ≥8 kPa in grip strength between baseline and week 18.

RESULTS

A total of 20 patients were included; 17 completed the treatment schedule. A total of 13 (76%) of these patients improved at 18 weeks after start of treatment and 10 (59%) patients were in remission at 1 year. Serious adverse events were found in four patients.

CONCLUSIONS

Short-term combined induction treatment with IVIg and IVMP induced remission in almost 60% of patients who completed the treatment schedule. Combined induction therapy was generally well tolerated. A randomized controlled trial is currently running to confirm efficacy and safety of IVMP as add-on treatment to IVIg.

Comparison of Lewis-Sumner syndrome with chronic inflammatory demyelinating polyradiculoneuropathy patients in a tertiary care centre

BACKGROUND AND PURPOSE

Whether the Lewis-Sumner syndrome (L-SS) is a distinct entity from other types of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP-ot) remains controversial.

METHOD

The clinical/electrophysiological characteristics and long-term outcomes of 45 L-SS and 35 CIDP-ot patients were retrospectively compared.

RESULTS

The CIDP-ot group was composed of 11 patients with a typical CIDP, 17 with a pure sensory form, four with a distal form and three with a pure motor form. In the L-SS group, asymmetric (P < 0.001) and monomelic involvement (P = 0.04) of the upper limbs (P < 0.001) was significantly more frequent; paucisymptomatic forms (Overall Neuropathy Limitations Scale ≤ 1) were less frequent (P < 0.001); electroneuromyography showed that conduction block in intermediate nerve segments was the main demyelinating feature, with frequent F-wave abnormalities on nerves without conduction block (44%). Long-term prognosis was globally poorer in the L-SS group with more frequent aggravation during treatment (P = 0.02), less frequent treatment withdrawal (P = 0.03) and longer time to achieve successful withdrawal (39 vs. 15 months).

CONCLUSIONS

Our study suggests that L-SS patients have a less favourable therapeutic response rate and long-term outcomes. Rapid differentiation of L-SS from other forms of CIDP is important in order to anticipate a more complicated disease course management, with from one side the inefficacy or even harmfulness of corticosteroids and from the other side a difficult weaning procedure. A prospective study is necessary to confirm these results.

Serial nerve ultrasound and motor nerve conduction studies in chronic inflammatory demyelinating polyradiculoneuropathy

INTRODUCTION

The objective of this study was to evaluate the correlation between cross-sectional area (CSA) and nerve conduction studies (NCS) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and to determine how CSA changes over time after standard treatment.

METHODS

Fifty-four patients with CIDP were recruited prospectively, and 21 patients were followed for more than 6 months. Ultrasonography and motor NCS were performed in the median and ulnar nerves.

RESULTS

No or weak correlation was observed between the maximum CSA and motor conduction velocity. There were segmental nerve enlargements at 61% of sites with conduction block or temporal dispersion. Among 19 patients with clinical improvement after immunotherapy, CSA decreased to normal in 5, increased in 10, and were unchanged in 4.

DISCUSSION

Different patterns of CSA and motor NCS changes after immune treatment may indicate different CIDP pathologic mechanisms. Exploration of these pathologic mechanisms could guide treatment choices in the future. Muscle Nerve, 2019.

One-year follow-up study of neuropathic pain in chronic inflammatory demyelinating polyradiculoneuropathy

We sought to gather information about frequency and features of neuropathic pain (NeP) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and to investigate course of NeP during 1-year follow-up. Study included 105 patients diagnosed with CIDP. Patients with diabetes (N = 26) were excluded. NeP was diagnosed by the official guidelines and painDETECT questionnaire (PD-Q). Medical Research Council Sum Score (MRC-SS), INCAT disability and sensory scores, and Beck Depression Inventory were also measured. PD-Q showed presence of NeP in 16 (20%) of 79 CIDP patients and their mean pain was moderate (5.1 ± 3.0 of 10). Diagnostic delay in CIDP patients with NeP was prolonged compared to CIDP patients without NeP (21 ± 28 vs 9 ± 12 months, P < .05). Slowly progressive course of the disease was more frequent in patients with NeP (81% vs 52%, P < .05). Patients with NeP had worse INCAT sensory score (P < .01), INCAT disability score (P < .05), MRC-SS, as well as worse disease outcome at time of testing (P < .05). Depression was more common in patients with NeP (69% vs 17%, P < .01). During 1-year follow-up, majority of our CIDP patients had good control of NeP with gabapentinoids or amitriptyline. NeP was common in our cohort of non-diabetic CIDP patients. It was associated with worse functional disability, worse sensory deficit, and depression. Special attention should be paid to CIDP patients with NeP because they request additional symptomatic therapy that appeared efficacious in our cohort.

Atypical Clinical Presentations of Pediatric Acute Immune-Mediated Polyneuropathy

Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis in children. During the acute phase, the disorder can be life-threatening by involving the respiratory muscles and the autonomic nervous system. Nevertheless, the prognosis is good, and most children achieve full recovery. The aim of this study was to characterize the clinical and electrophysiologic findings in children with Guillain-Barré syndrome referred to a tertiary center in Israel. A retrospective database review from 2009 to 2015 identified 39 children. Data on clinical presentation, respiratory complications, and long-term neurologic outcomes were collected. Atypical clinical findings at admission included asymmetric weakness in 23%, nonascending weakness in 30%, and normal deep tendon reflexes in 28%. Eight children were later diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Electrophysiologic findings, available in 12 patients with Guillain-Barré syndrome, revealed acute inflammatory demyelinating polyradiculoneuropathy (AIDP) in 4 (33.5%), AIDP with secondary axonal changes in 3 (25%), and acute motor axonal neuropathy (AMAN) subtype in 4 (33.5%); 8% had no abnormal findings. On follow-up, 71% of the children with Guillain-Barré syndrome fully recovered compared to 14% of the children with CIDP. Corresponding rates of neurologic sequelae were 29% and 86%. Clinicians should be alert to the atypical presenting symptoms of Guillain-Barré syndrome, which occur in a significant proportion of children.

Peripheral Demyelinating Diseases: From Biology to Translational Medicine

Demyelinating diseases represent a spectrum of disorders that impose significant burden on global economy and society. Generally, the prognosis of these diseases is poor and there is no available cure. In recent decades, research has shed some light on the biology and physiology of Schwann cells and its neuroprotective effects in the peripheral nervous system (PNS). Insults to the PNS by various infectious agents, genetic predisposition and immune-related mechanisms jeopardize Schwann cell functions and cause demyelination. To date, there are no effective and reliable biomarkers for PNS-related diseases. Here, we aim to review the following: pathogenesis of various types of peripheral demyelinating diseases such as Guillain-Barre syndrome, Chronic Inflammatory Demyelinating Polyradiculoneuropathy, Anti-Myelin Associated Glycoprotein Neuropathy, POEMS syndrome, and Charcot-Marie-Tooth disease; emerging novel biomarkers for peripheral demyelinating diseases, and Schwann cell associated markers for demyelination.

Onion-bulb patterns predict acquired or inherited demyelinating polyneuropathy

INTRODUCTION

Onion-bulbs (OB) are concentrically layered Schwann-cell processes, surrounding nerve fibers, occurring in both inherited and acquired demyelinating polyneuropathies. We investigated whether OB patterns (generalized, mixed, or focal) correlate with acquired or inherited neuropathies.

METHODS

One hundred thirty-one OB-rich nerve biopsies were graded for OB pattern and inflammation without knowledge of clinical history. We classified inherited (n = 49) or acquired (n = 82) neuropathies based solely on clinical history.

RESULTS

Fifty-one biopsies had generalized (34 inherited vs. 17 acquired, P < 0.001), 54 mixed (48 acquired vs. 6 inherited, P < 0.001), and 26 focal/multifocal (inherited [n = 9], acquired [n = 17]) OB. Inflammation occurred more frequently in acquired (n = 54) than inherited (n = 14) neuropathy (P = 0.004).

DISCUSSION

Generalized OB correlates with inherited neuropathy; mixed OB with acquired. Inflammation occurs more in acquired neuropathy cases. OB patterns are best explained by ubiquitous Schwann-cell involvement in inherited and multifocal Schwann-cell involvement in acquired neuropathies and predict the electrophysiology of uniform demyelination in inherited and unequal demyelination in acquired neuropathies. Muscle Nerve 59:665-670, 2019.