European Federation of Neurological Societies/Peripheral Nerve Society guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy: report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society - first revision

Early therapy initiation is crucial in chronic inflammatory demyelinating polyneuropathy: prospective multimodal data from the German INHIBIT registry

BACKGROUND

Diagnosing chronic inflammatory demyelinating polyneuropathy (CIDP) can be challenging, leading to delays in initiating therapy. As disability in CIDP is mainly dependent on axonal damage, the impact of delayed immunotherapy remains unclear. We multimodally investigated the clinical outcomes of patients with early CIDP regarding different treatment strategies and time points.

METHODS

Patients with CIDP diagnosis within 1 year before study inclusion were systematically selected from the prospective Immune-mediated Neuropathies Biobank (INHIBIT) registry. Clinical and therapeutic data, and findings from nerve conduction study (NCS), and nerve and muscle ultrasound were correlated at inclusion and 12 months later. The patient outcomes were compared between immunotherapies. The effect of timing immunotherapy on clinical outcomes was determined using regression analysis.

RESULTS

In total, 30 patients were included (time from diagnosis to inclusion 22 ± 19 weeks). Low amplitudes of compound muscle potential were significantly associated with pathological spontaneous activity (PSA, r = 0.467) and correlated with the Heckmatt scale (rSp = 0.391). All three parameters were significantly associated with higher overall disability sum scores (NCS score rSp = 0.581, PSA r = 0.385, Heckmatt scale rSp = 0.472). The delays in initiating therapy resulted in progression of axonal damage (rSp = 0.467) and disability (R2 = 0.200). The combination of first-line therapies led to reduced disability progression (r = 0.773), while second-line therapies resulted in improved overall axonal damage (r = 0.467).

CONCLUSIONS

Axonal damage occurs early and is the main cause of clinical disabilities. Prompt initiation of therapy is crucial to prevent axonal damage and thereby disability progression. A comprehensive therapeutic approach, including a combination of first- or second-line therapies, may improve long-term outcomes.

The overlap of diabetic and inflammatory neuropathies: Epidemiology, possible mechanisms, and treatment implications

Diabetic polyneuropathy is the common neuropathy of diabetes. However, several inflammatory neuropathies may occur during diabetes. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents the most treatable example. There has been uncertainty about a higher risk of CIDP in subjects with diabetes. Contradicting earlier reports, subsequent epidemiological studies failed to confirm an association. However, more recent studies from different populations have shown a two-fold relative risk of concurrent diabetes with CIDP. Recognition of CIDP is important in diabetes as treatment response rates have been reported as comparable with or without diabetes. However, with diabetes, the clinical presentation of CIDP and the resulting disability may be more severe due to additional axonal loss from pre-existing diabetic polyneuropathy and delayed diagnosis. An association of nodo-paranodopathy has similarly been described with a three-fold relative risk of concurrent diabetes in seropositive subjects, particularly those harbouring anti-contactin 1 antibodies. Although rare, recognition of nodo-paranodopathy, with characteristic clinical features, in the context of diabetes is likewise important in view of treatment implications. Other inflammatory neuropathies in diabetes are the painful or painless, cervical, or lumbar, radiculoplexus neuropathies. These need distinguishing from variant, multifocal forms of CIDP, as are not treatable, although remit spontaneously over months or years. There are reports of possible association of Guillain-Barré syndrome (GBS), and particularly of greater GBS severity, with diabetes. Finally, vasculitic neuropathy may also occur in diabetes and requires early suspicion, urgent investigations and immunosuppressant treatment. As the worldwide prevalence of diabetes rises, prompt recognition of its concurrent inflammatory neuropathies, is essential.

Novel therapies in CIDP

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous but clinically well-described disease within circumscribed parameters. It is immunologically mediated through several poorly understood mechanisms. First-line therapies with steroids, intravenous immunoglobulin (IVIG) or plasma exchange are each effective in about two-thirds of patients. These treatments are seldom associated with complete resolution or cure, and often pose considerable practical, financial and medical implications.Our understanding of many of the key pathological processes in autoimmune diseases is expanding, and novel targeted therapeutics are being developed with promise in several autoimmune neurological disorders.This narrative review looks first at detailing key pathogenic mechanisms of disease in CIDP, followed by an in-depth description of potential novel therapies and the current evidence of their application in clinical practice.

Assessing axonal pathology and disease progression in chronic inflammatory demyelinating polyneuropathy using corneal confocal microscopy

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune neuropathy characterized by progressive or relapsing-remitting weakness and sensory deficits. This study aims to evaluate the utility of corneal confocal microscopy (CCM) in diagnosing and monitoring CIDP.

METHODS

We analysed 100 CIDP patients and 31 healthy controls using CCM to measure corneal nerve fiber density (CNFD), length (CNFL), and branch density (CNBD). Standardized clinical and electroneurographic evaluation were conducted, and statistical analyses were performed to compare CCM parameters between groups and across disease stages.

RESULTS

CIDP patients and subgroups exhibited significant reduction in CNFD, CNFL, and CNBD compared to controls. This reduction was observed in late disease stages and severe overall disability sum score (ODSS), and Inflammatory Neuropathy Cause and Treatment Sensory Sum Score (ISS). CCM parameters correlated with axonal pathology in electroneurography of sensory, but not motor nerves. Despite the significant differences, the diagnostic sensitivity (41%) and specificity (77%) of CCM parameters were limited.

CONCLUSION

While CCM effectively differentiates CIDP patients from healthy controls and was associated with disease severity, its diagnostic accuracy for routine clinical use is a posteriori. However, CCM shows promise as a non-invasive tool for monitoring sensory axonal pathology in CIDP.

Case report: Chronic inflammatory demyelinating polyradiculoneuropathy with severe central nervous system demyelination: a clinicopathological study

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated disease that mainly affects the peripheral nerves and nerve roots and typically presents with distal dominant motor and sensory disturbances as clinical symptoms. Central nervous system (CNS) demyelination with inflammation occurs infrequently in patients with CIDP. Here, we present a unique autopsy report of CIDP causing severe demyelination along the entire spinal cord. A Japanese woman exhibited progressive muscle weakness, muscle atrophy, sensory disturbances, and tremors in her upper and lower extremities, which began in her 60s. A nerve conduction study revealed a marked prolongation of distal latencies and very low or no compound muscle action potential amplitudes, and cerebrospinal fluid protein levels were prominently elevated. Following the diagnosis of CIDP, a combination of methylprednisolone pulse therapy, high-dose intravenous immunoglobulin therapy, and plasma exchange mildly improved her symptoms. The patient died of septic shock at the age of 74 years. Neuropathological examination revealed demyelinating lesions with inflammation in the peripheral regions of the anterior, lateral, and posterior funiculi along the entire spinal cord (from the cervical to the sacral cord), and axons and neurons were well preserved in these lesions. The nerve roots in the cervical and lumbar plexuses, cauda equina, sciatic nerve, and sural nerve showed prominent swelling and edema with infiltration of inflammatory cells. Many onion bulbs were visible in the fascicles of the sciatic and sural nerves. Our results suggest that demyelination with inflammation can occur in the CNS and peripheral nervous system in CIDP, especially in patients with specific conditions, such as severe intrathecal inflammation.

Animal models of immune-mediated demyelinating polyneuropathies

Immune-mediated demyelinating polyneuropathies (IMDPs) are rare disorders in which dysregulated adaptive immune responses cause peripheral nerve demyelinating inflammation and axonal injury in susceptible individuals. Despite significant advances in understanding IMDP pathogenesis guided by patient data and representative mammalian models, specific therapies are lacking. Significant knowledge gaps in IMDP pathogenesis still exist, e.g. precise antigen(s) and mechanisms that initially trigger immune system activation and identification of large population disease susceptibility factors. The initial directional cues for antigen-specific effector or autoreactive leukocyte trafficking into peripheral nerves are also unknown. An overview of current animal models, with emphasis on the experimental autoimmune neuritis and spontaneous autoimmune peripheral polyneuropathy models, is provided. Insights on the initial directional cues for peripheral nerve tissue specific autoimmunity using a novel Major Histocompatibility Complex class II conditional knockout mouse strain are also discussed, suggesting an essential research tool to study cell- and time-dependent adaptive immunity in autoimmune diseases.

Long-term safety and tolerability of hyaluronidase-facilitated subcutaneous immunoglobulin 10% as maintenance therapy for chronic inflammatory demyelinating polyradiculoneuropathy: Results from the ADVANCE-CIDP 3 trial

BACKGROUND AND AIMS

Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) consists of subcutaneous human immunoglobulin G (IgG) 10% with recombinant human hyaluronidase (rHuPH20) and can be administered at the same dose and interval as intravenous IgG (IVIG). fSCIG recently received US approval as maintenance therapy for adults with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and European approval for adults and children with CIDP after stabilization with IVIG.

METHODS

ADVANCE-CIDP 3 (NCT02955355) was an open-label long-term extension of the Phase 3 double-blind randomized placebo-controlled ADVANCE-CIDP 1 study (NCT02549170) that examined fSCIG safety and efficacy as maintenance CIDP therapy. Primary outcomes were safety, tolerability, and immunogenicity. Efficacy was an exploratory outcome.

RESULTS

The study provided 220 patient-years of follow-up data from 85 patients. Median (range) exposure was 33 (0-77) months. Patients received fSCIG every 4 weeks (88.2%) or every 3 weeks (11.8%). Median (range) 4-weekly IgG dose equivalent was 64.0 (28.0-200.0) g. Mean (standard deviation) infusion duration was 135.5 (62.8) minutes. Most adverse events (AEs) were mild or moderate and self-limiting. Of the 1406 AEs, only 48 were severe and 30 were serious. fSCIG-related AEs (n = 798) included infusion site reactions such as pain, redness, and pruritus. Three infusions (0.1%) were reduced in rate, interrupted, or stopped due to intolerability. Relapse occurred in 10 of 77 patients (13.0%); annual relapse rate was 4.5%. An anti-rHuPH20 antibody titer ≥1:160 was detected in 14 of 84 patients (16.7%); patients who tested positive (≥1:160) had similar relapse rates versus those who tested negative (16.7% vs. 12.3%, respectively).

INTERPRETATION

ADVANCE-CIDP 3 demonstrated favorable fSCIG long-term safety and tolerability consistent with its established safety profile, and a low relapse rate, supporting use as maintenance CIDP treatment.

The relevance of combined testing of cerebrospinal fluid glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 in multiple sclerosis and peripheral neuropathy

INTRODUCTION

This study investigates the significance of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCHL-1) in cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and peripheral neuropathy (PN).

METHODS

We included 41 MS patients, 35 PN patients, and 36 controls across 5 sites. MS patient data included lesion counts, disease activity, albumin quotient, and Expanded Disability Status Scale (EDSS) scores. PN patients included those with acute and chronic inflammatory demyelinating polyneuropathy and sensorimotor neuropathy based on nerve conduction studies. CSF concentrations of GFAP and UCHL-1 were measured using the MILLIPLEX Map Human Neuroscience Magnetic Bead Panel 1.

RESULTS

Both GFAP and UCHL-1 levels were significantly higher in the two patient groups compared to controls. In the MS group, GFAP showed a strong correlation with disease duration, EDSS score, non-enhancing lesions, and the CSF/blood albumin quotient. UCHL-1 levels were significantly higher in patients with active disease (gadolinium-enhancing lesions). The combination of UCHL-1 and GFAP improved diagnostic accuracy (AUC 0.895, 95% CI 0.780-1.000) compared to the independent measurement of either marker for indicating Gd-negative lesions. In the PN group, CSF GFAP levels were significantly lower in patients with purely demyelinating neuropathy compared to those with axonal or mixed neuropathy.

CONCLUSION

GFAP serves as a sensitive marker for axonal damage in PN, while UCHL-1 closely correlates with disease activity in MS patients.

Treatment response in patients with clinical and supportive laboratory features of chronic inflammatory demyelinating polyneuropathy without demyelinative findings on nerve conduction studies: A retrospective study

INTRODUCTION/AIMS

Not all patients with chronic inflammatory demyelinating polyneuropathy (CIDP) have evidence of demyelination on nerve conduction studies (NCS). Patients with "supportive" evidence of CIDP on cerebrospinal fluid (CSF), magnetic resonance imaging (MRI), ultrasound (US), or nerve biopsy but not on NCS, often receive immunomodulating therapy. We evaluated the treatment response of patients with clinical and supportive features of CIDP lacking NCS evidence of demyelination.

METHODS

Retrospective chart review was conducted on 232 patients who met CIDP clinical criteria and were treated with disease-modifying therapy. Patients included did not have NCS criteria of demyelination, but did have supportive CSF, MRI, or US findings consistent with CIDP. A positive treatment response was defined as at least a one-point improvement in the modified Rankin scale (mRS), or a four-point increase in the Medical Research Council sum score (MRCSS).

RESULTS

Twenty patients met criteria: 17 of the 18 (94%) patients with CSF protein >45 mg/dL, 6 of the 14 (43%) with MRI lumbosacral root or plexus enhancement, and 4 of the 6 (67%) with enlarged proximal nerves on US. Eighteen patients received intravenous immunoglobulin, 10 corticosteroids, one plasma exchange, and six other immunomodulatory therapies. Twelve patients had a positive treatment response on the MRCSS or mRS. The presence of MRI lumbosacral root or plexus enhancement was associated with a positive treatment response.

DISCUSSION

A trial of immunomodulating treatment should be considered for patients with clinical features of CIDP in the absence of NCS evidence of demyelination, particularly when there is MRI lumbosacral root or plexus enhancement.

Subcutaneous immunoglobulins (SCIG) for chronic inflammatory demyelinating polyneuropathy (CIDP): A comprehensive systematic review of clinical studies and meta-analysis

BACKGROUND

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) presents significant treatment challenges due to its chronic nature, varied clinical presentations, and rarity. Subcutaneous immunoglobulin (SCIG) has emerged as a maintenance therapy, offering potential advantages in administration and patient experience over the previously recognized intravenous immunoglobulin (IVIG).

METHODS

We included all clinical studies involving CIDP patients treated with SCIG from eleven databases up to March 2024.

RESULTS

50 clinical studies were included in the systematic review, with 22 involved in the meta-analysis. These studies offer clinical data on around 1400 CIDP patients. Almost all studies considered SCIG a maintenance therapy, with the majority of results suggesting it as a viable substitute that may offer comparable or enhanced advantages. Studies covered aspects such as efficacy, safety, quality of life, practicality, economic evaluation, and patient preference. Meta-analysis showed SCIG significantly improved muscle strength and sensory function, had fewer and milder side effects, reduced relapse rates, and received a strong preference.

CONCLUSIONS

Findings suggest that SCIG for CIDP maintenance not only provides a more feasible alternative, with economic evaluations showing considerable cost reductions over time, and patient preference for SCIG being pronounced, but may also deliver comparable or superior health outcomes. Ongoing research lines on formulations, techniques, and direct comparative studies are critical to further illuminate, enhance, and expand SCIG's role in treatment.

The difference in nerve ultrasound and motor nerve conduction studies between autoimmune nodopathy and chronic inflammatory demyelinating polyneuropathy

INTRODUCTION/AIMS

Nerve enlargement has been described in autoimmune nodopathy and chronic inflammatory demyelinating polyneuropathy (CIDP). However, comparisons of the distribution of enlargement between autoimmune nodopathy and CIDP have not been well characterized. To fill this gap, we explored differences in the ultrasonographic and electrophysiological features between autoimmune nodopathy and CIDP.

METHODS

Between March 2015 and June 2023, patients fulfilling diagnostic criteria for CIDP were enrolled; among them, those with positive antibodies against nodal-paranodal cell-adhesion molecules were distinguished as autoimmune nodopathy. Nerve ultrasound and nerve conduction studies (NCS) were performed.

RESULTS

Overall, 114 CIDP patients and 13 patients with autoimmune nodopathy were recruited. Cross-sectional areas (CSA) at all sites were larger in patients with CIDP and autoimmune nodopathy than in healthy controls. CSAs at the roots and trunks of the brachial plexus were significantly larger in patients with anti-neurofascin-155 (NF155), anti-contactin-1 (CNTN1), and anti-contactin-associated protein 1 (CASPR1) antibodies than in CIDP patients. The patients with anti-NF186 antibody did not have enlargement in the brachial plexus. NCS showed more frequent probable conduction block at Erb's point in autoimmune nodopathy than in CIDP (61.9% vs. 36.6% for median nerve, 52.4% vs. 39.5% for ulnar nerve). Markedly prolonged distal motor latencies were also present in autoimmune nodopathy.

DISCUSSION

Patients with autoimmune nodopathies had distinct distributions of peripheral nerve enlargement revealed by ultrasound, as well as distinct NCS patterns, which were different from CIDP. This suggests the potential utility of nerve ultrasound and NCS to supplement clinical characteristics for distinguishing nodopathies from CIDP.

Proteinuria is a key to suspect autoimmune nodopathies

BACKGROUND AND PURPOSE

Reports of patients who have autoimmune nodopathies concurrent with nephrotic syndrome are increasing. We investigated whether proteinuria could be a biomarker of autoimmune nodopathies.

METHODS

Qualitative urinalysis results were retrospectively obtained from 69 patients who were diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) at a hospital in Japan. Proteinuria was graded as mild to severe (i.e., mild, 30-99; moderate, 100-299; severe, 300 mg/dL or more) according to the results of the urine dipstick test. Autoantibodies against the paranodal proteins contactin 1 (CNTN1), neurofascin 155 (NF155), and contactin-associated protein 1 (Caspr1) and the nodal protein neurofascin 186 (NF186) were measured, and the predominant IgG subclass was determined by enzyme-linked immunosorbent assay in sera from the 69 patients.

RESULTS

Four patients (6%), five patients (7%), and one (1%) patient were positive for anti-CNTN1, anti-NF155, and anti-Caspr1 IgG4 antibodies, respectively. No patients had IgG4 antibodies against NF186. Proteinuria of mild or greater levels was found in three patients with anti-CNTN1 IgG4 and two patients with anti-NF155 IgG4 antibodies. The autoantibody-positive patients more frequently had proteinuria of mild or greater levels than the seronegative patients (p = 0.01).

CONCLUSIONS

Proteinuria is a possible biomarker of autoimmune nodopathies associated with autoantibodies targeting CNTN1 or NF155. Urinalysis results should be carefully checked for quick differentiation of autoimmune nodopathies from CIDP. Patients who present with nephrotic syndrome should be tested for anti-CNTN1 IgG4 antibodies, and patients who exhibit mild proteinuria should be tested for anti-NF155 IgG4 antibodies.

Safety, tolerability, and efficacy of subcutaneous efgartigimod in patients with chronic inflammatory demyelinating polyradiculoneuropathy (ADHERE): a multicentre, randomised-withdrawal, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune disease of the peripheral nervous system that can lead to severe disability from muscle weakness and sensory disturbances. Around a third of patients do not respond to currently available treatments, and many patients with a partial response have residual neurological impairment, highlighting the need for effective alternatives. Efgartigimod alfa, a human IgG1 antibody Fc fragment, has demonstrated efficacy and safety in patients with generalised myasthenia gravis. We evaluated the safety, tolerability, and efficacy of subcutaneous efgartigimod PH20 in adults with CIDP.

METHODS

ADHERE, a multistage, double-blind, placebo-controlled trial, enrolled participants with CIDP from 146 clinical sites from Asia-Pacific, Europe, and North America. Participants with evidence of clinically meaningful deterioration entered an open-label phase of weekly 1000 mg subcutaneous efgartigimod PH20 for no longer than 12 weeks (stage A). Those with confirmed evidence of clinical improvement (ECI; treatment responders) entered a randomised-withdrawal phase of 1000 mg subcutaneous efgartigimod PH20 weekly treatment versus placebo for a maximum of 48 weeks (stage B). Participants were randomised (1:1) through interactive response technology and stratified by their adjusted Inflammatory Neuropathy Cause and Treatment (aINCAT) score change during stage A and their most recent CIDP medication within 6 months before screening. Investigators, the clinical research organisation, and participants were masked to the treatment. The primary endpoint in stage A, evaluated in the stage A safety population, was confirmed ECI (≥1 points aINCAT decrease, ≥4 points [centile metric] Inflammatory Rasch-built Overall Disability Scale increase, or ≥8 kPa grip strength increase after four injections and two consecutive visits). The primary endpoint in stage B, evaluated in the modified intention-to-treat population, was the risk of relapse (time to first aINCAT increase of ≥1 points). ADHERE is registered with ClinicalTrials.gov (NCT04281472) and EudraCT (2019-003076-39) and is completed.

FINDINGS

Between April 15, 2020, and May 11, 2023, 629 participants were screened; 322 (114 female, 208 male) entered stage A, of whom 214 (66%, 95% CI 61·0-71·6) had confirmed ECI. In stage B, 221 participants were randomised (79 female, 142 male; 111 to subcutaneous efgartigimod PH20, 110 to placebo). Subcutaneous efgartigimod PH20 significantly reduced the risk of relapse versus placebo (hazard ratio 0·39 [95% CI 0·25-0·61]; p<0·0001). 31 (27·9% [19·6-36·3]) participants given subcutaneous efgartigimod PH20 had a relapse versus 59 (53·6% [44·3-63·0]) given placebo. In stage A, treatment-emergent adverse events (TEAEs) occurred in 204 (63%) participants and serious TEAEs in 21 (7%). In stage B, TEAEs occurred in 71 (64%) participants on subcutaneous efgartigimod PH20 and 62 (56%) participants on placebo, and serious TEAEs in six (5%) on subcutaneous efgartigimod PH20 and six (5%) on placebo. Three deaths occurred: two in stage A (one non-related and one unlikely related to treatment) and one in stage B (placebo group).

INTERPRETATION

ADHERE showed the efficacy of subcutaneous efgartigimod PH20 in reducing the risk of relapse versus placebo in people with CIDP who responded to treatment. Further studies are needed to provide data on the longer-term effects of efgartigimod alfa and how it compares with currently available treatment options.

FUNDING

argenx.

Differentiating recurrent Guillain-Barre syndrome and acute-onset chronic inflammatory polyneuropathy: literature review

Guillain-Barre syndrome (GBS) is an acute-onset immune-mediated polyneuropathy characterized by ascending symmetrical muscle weakness, diminished reflexes, and sensory symptoms. While GBS typically follows a monophasic course, some patients experience treatment-related fluctuations or recurrences, posing diagnostic challenges in distinguishing GBS from acute-onset chronic inflammatory polyneuropathy (A-CIDP). A-CIDP, may present acutely, simulating GBS, with a nadir in less than 8 weeks, subsequently evolving into a chronic or relapsing course. The distinction between recurrent GBS and A-CIDP is crucial, as A-CIDP necessitates long-term immunosuppression. A PubMed search was conducted using the search terms 'recurrent Guillain Barre syndrome' and 'acute onset CIDP' focusing on studies in the English language, published between January 1, 2004 and April 30, 2023. Overlapping clinical features, particularly in the early stages, complicate differentiation between recurrent GBS and CIDP. Electrophysiological studies, ultrasonography, and immunological markers have been explored for discrimination; however, definitive criteria for differentiation remain elusive. Recent follow-up studies have further blurred the boundaries between recurrent GBS and A-CIDP, suggesting the persistence of underlying immune processes even in GBS patients without clinical deterioration. This emphasizes the necessity of reevaluating diagnostic criteria and treatment strategies. In conclusion, distinguishing recurrent GBS from A-CIDP remains an ongoing challenge. Existing evidence questions the categorization of recurrent GBS as a distinct entity, challenging its very existence. Continued research is necessary to refine diagnostic criteria and deepen our understanding of these conditions, ultimately advancing patient care. This review delves into the intricacies of recurrent GBS and A-CIDP differentiation and highlights the need for a reevaluation of the recurrent GBS concept.

Proteomics analysis of immune response-related proteins in Guillain-Barré Syndrome (GBS) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

The objective is to characterize differentially expressed proteins (DEPs) in Guillain-Barré Syndrome (GBS) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) through high-throughput analysis. Sera from 11 healthy controls (HCs), 21 GBS and 19 CIDP patients were subjected to Olink Proteomics Analysis. In the comparison between CIDP and GBS groups, up-regulation of ITM2A and down-regulation of NTF4 were observed. Comparing GBS with HCs revealed 18 up-regulated and 4 down-regulated proteins. Comparing CIDP with the HCs identified 15 up-regulated and 4 down-regulated proteins. Additionally, the correlation between clinical characteristics and DEPs were uncovered. In conclusion, the DEPs have significant potential to advance our understanding of the pathogenesis in these debilitating neurological disorders.

Risk of peripheral neuropathy in patients with psoriasis and psoriatic arthritis. A prospective cohort study

INTRODUCTION/AIMS

Laboratory and clinical data suggest a link between neurologically mediated inflammation and psoriasis, but the risk and features of peripheral neuropathy in psoriasis or psoriatic arthritis remain unknown. The aim of this exploratory study was to evaluate the risk and to describe the features of peripheral neuropathy in patients with psoriasis and psoriatic arthritis.

METHODS

One hundred patients with psoriasis and/or psoriatic arthritis and 100 control subjects were consecutively enrolled. Diagnostic confirmation included electrophysiological examination, skin biopsy, and nerve ultrasound for confirmed polyneuropathy.

RESULTS

Nine patients were diagnosed with confirmed polyneuropathy, while none of the control subjects had the condition (relative risk [RR] = 19.00, 95% confidence interval [CI] = 1.12-322.11). Specific relative risks for polyneuropathy were 22.09 (95% CI = 1.17-416.43) in psoriasis patients and 18.75 (95% CI = 1.07-327.62) in psoriatic arthritis patients. The observed polyneuropathy in all nine patients was length-dependent, symmetrical, and predominantly sensory, with minimal or no disability. Comorbidities and exposure to therapies known to increase the risk of polyneuropathy were more frequent in psoriasis and/or psoriatic arthritis patients compared to controls (42% vs. 4%, p = .0001). Analyzing data after excluding possible contributory causes, the risk of polyneuropathy in patients with psoriasis and/or psoriatic arthritis was not significant.

DISCUSSION

Psoriasis and psoriatic arthritis appear to be associated with an increased risk of polyneuropathy. This increased risk seems to be linked to the higher prevalence of contributing factors for polyneuropathy, rather than a direct increase in neuropathy risk specifically related to psoriasis and psoriatic arthritis.

Incidence of cancer in chronic inflammatory demyelinating polyneuropathy: a nationwide cohort study in South Korea

Background

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare disease, and the potential risk of cancer in patients with CIDP remains an important concern during treatment. However, a comprehensive epidemiological study examining this association is yet to be conducted. This study aimed to investigate the incidence of cancer in patients with CIDP in South Korea using data from the Korean Health Insurance Review and Assessment Service (HIRA) database.

Methods

Data from the HIRA database between January 2016 and June 2021 were analyzed. The actual incidence of cancer in patients with CIDP was compared with the expected incidence based on the general population statistics in South Korea, with adjustments for age.

Results

In total, 888 patients with CIDP were included in the analysis, of whom 50 (5.63% of malignancy incidence) were newly diagnosed with cancer during the study period. Among the patients with CIDP diagnosed with cancer, 32 (64.00%) were aged 60 years or older, and 36 (72.00%) were male. The observed number of cancer diagnoses corresponded to an incidence rate of 5.63%, with a standardized incidence ratio (SIR) of 2.83 (95% confidence interval [CI]: 1.89-4.39) compared to the expected cancer incidence rate of 2.00%. Notably, the SIR for malignancies of lymphoid, hematopoietic, and related tissues, excluding malignant immunoproliferative diseases, multiple myeloma, and plasma cell neoplasms (C81-96, except C88 and C90), was the highest at 8.51 (95% CI: 4.18-19.83).

Conclusion

Our study shows a potential association between CIDP and an increased risk of hematological malignancies, which is consistent with previous investigations. Further studies are required to better understand the relationship between CIDP and cancer.

Chronic inflammatory demyelinating polyneuropathy. A case description

Patients affected by chronic inflammatory demyelinating polyradiculoneuropathy require close follow up due to the neuronal demyelination along with axonal degeneration associated with the disease process, giving the opportunity to the medical team of adequating therapeutics and other medical interventions, according to the evolution of the symptoms, to prevent irreversible axonal degeneration.

Anti-neurofascin-155 antibody mediated a distinct phenotype of chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

To investigate Ranvier's autoantibodies prevalence and isotypes in various peripheral neuropathy variants, compare clinical features between seronegative and seropositive patients, and elucidate immune mechanisms underlying antibody generation.

METHODS

Antibodies against anti-neurofascin-155 (NF155), NF186, contactin-1 (CNTN1), CNTN2, contactin-associated protein 1 (CASPR1), and CASPR2 were identified through cell-based assays. Plasma cytokines were analyzed in anti-NF155 antibody-positive chronic inflammatory demyelinating polyneuropathy (NF155+ CIDP) and Ranvier's antibodies-negative CIDP (Ab- CIDP) patients using a multiplexed fluorescent immunoassay, validated in vitro in a cell culture model.

RESULTS

In 368 plasma samples, 50 Ranvier's autoantibodies were found in 45 individuals, primarily in CIDP cases (25 out of 69 patients) and in 10 out of 122 Guillain-Barré syndrome patients. Anti-NF155 and CNTN1-IgG were exclusive to CIDP. Fourteen samples were NF155-IgG, primarily IgG4 subclass, linked to CIDP features including early onset, tremor, sensory disturbance, elevated CSF protein, prolonged motor latency, conduction block, and poor treatment response. NF155-IgG had low sensitivity (20.28%) but high specificity (100%) for CIDP, rising to 88.88% with tremor and prolonged motor latency. Cytokine profiling in NF155+ CIDP revealed distinct immune responses involving helper T cells, toll-like receptor pathways. Some NF155+ CIDP patients had circulating NF155-specific B cells producing NF155-IgG without antigen presence, suggesting therapeutic potential.

CONCLUSION

The study emphasizes the high specificity and sensitivity of NF155-IgG for diagnosing CIDP characterized by distinctive features. Further investigation into circulating NF155-specific B cell phenotypes may pave the way for B cell directed therapy.

The multiple roles of nerve biopsy in the diagnosis and prognosis of suspected immune neuropathies

INTRODUCTION

The value of a sural nerve biopsy for the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is controversial. Evidence-based recommendations for its implementation are lacking. We investigated factors leading to biopsy and analyzed biopsy outcomes and consequences, assessed the predictability of biopsy outcomes through clinical parameters to avoid unnecessary biopsies, and compared results with electrophysiological and clinical severity to determine their prognostic value.

METHODS

190 sural nerve biopsies were analyzed in two cohorts. One consisted of 163 biopsies and the second of 72 biopsies from the prospective Immune-mediated Neuropathies Biomaterial and Data registry (INHIBIT). Both have an intersection of 45 patients. 75 data sets from patients without biopsy were used. Analysis of nerve conduction studies, treatment, overall disability sum score (ODSS), biopsy outcomes, and diagnosis was performed.

RESULTS

51% of biopsied patients received the diagnosis CIDP (77% fulfilled EFNS/PNS criteria), 21% were not CIDP typical, and 27% were unspecific. Biopsied patients responded less frequently to immunotherapies at time of biopsy than non-biopsied patients (p = 0.003). Immunotherapy was initiated more frequently after biopsy (p < 0.001) and more often with intravenous immunoglobulins (p < 0.0001). 76% of all biopsied patients met the electrophysiological criteria for CIDP. Sensory nerve action potential amplitudes of 0 µV still provide 73% of histological diagnostic value. Histologic signs of degeneration predicted ODSS worsening after 1 year (p = 0.028) but disease severity did not correlate with histological damage severity.

DISCUSSION

The main indication for nerve biopsy was the treatment of refractory cases of autoimmune neuropathies with the therapeutic consequence of treatment initiation or escalation. Sural biopsy also provided prognostic information. Even with extinguished sural SNAP, the biopsy can still have diagnostic value.

Successful treatment of relapsed and refractory CIDP with ofatumumab: a first case report

Background

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous but treatable immune-mediated neuropathy. Ofatumumab (OFA) is a fully human anti-CD20 monoclonal antibody that has shown promising efficacy in central demyelinating diseases, such as multiple sclerosis (MS). However, there is a lack of studies on the usage of OFA in peripheral demyelinating diseases, particularly CIDP. A case of relapsed and refractory CIDP with an ineffective response to conventional immunotherapy and intolerance to rituximab (RTX) but a positive response to subcutaneous injections of OFA is presented.

Case presentation

The patient, a 46-year-old man diagnosed with CIDP, received high-dose intravenous methylprednisolone, intravenous immunoglobulin (IVIG), and plasma exchange(PE) during the acute phase of the disease, and long-term oral administration of prednisone, azathioprine (AZA), and mycophenolate mofetil (MMF) during the remission phase. However, the patient suffered six relapses over a five-year period, and because of these, along with an ineffective response to conventional immunotherapy, and intolerance to RTX, subcutaneous injections of OFA were selected as a prophylactic treatment against relapses. After a total of six injections of OFA, CD19+B cells were substantially depleted. The patient has been followed for more than 23 months without relapse.

Conclusions

This case demonstrates the effectiveness and good tolerability of OFA in the treatment of relapsed and refractory CIDP. Further studies are needed to investigate the efficacy and safety of OFA in patients with relapsed and refractory CIDP, especially in those who have shown an ineffective response to conventional immunotherapy and are intolerant to RTX.

Central involvement in peripheral disease: melanopsin pathway impairment in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) compromises functions of the peripheral nervous system (PNS). Recently, however, symptoms such as cognitive deficits, visual dysfunction and circadian disorders were reported, compatible with additional involvement of the central nervous system (CNS) in CIDP. Against this background, we were interested in the functional state of melanopsin-expressing retinal ganglion cells (mRGCs) as a potential biomarker for sleep-wake abnormalities and CNS involvement in CIDP. Based on a chromatic pupillometry protocol, we examined the integrity of the melanopsin system in a prospective case-control study in 20 persons with CIDP compared to 20 controls without CIDP. The results were referred to clinical measures of disease severity and sleep behaviour. Patients with CIDP had a significantly reduced melanopsin-mediated post-illumination pupil response (PIPR) compared to healthy controls (25% versus 36%; P < 0.01). This reduction correlated with disease severity (r = 0.478, P < 0.05). Further, patients with CIDP reported diminished sleep quality (P < 0.05); however, there was no significant correlation with the melanopsin-mediated PIPR. The results demonstrate an impairment of mRGC function related to CIDP. Since the PIPR reduction correlated with disease severity, it could be an easily available biomarker for CNS affection in CIDP, a condition defined as PNS disorder.

Proximity extension assay-based discovery of biomarkers for disease activity in chronic inflammatory demyelinating polyneuropathy

BACKGROUND

Objective disease activity biomarkers are lacking in chronic inflammatory demyelinating polyneuropathy (CIDP), impacting treatment decisions in clinical care and outcomes in clinical trials. Using a proximity extension assay, we aimed to identify candidate serum protein biomarkers for disease activity in CIDP.

METHOD

We collected clinical data and serum of 106 patients with CIDP. Patients starting induction treatment (n=53) and patients on maintenance treatment starting treatment withdrawal (n=40) were assessed at baseline and at 6 months (or at relapse). Patients in remission (n=13) were assessed once. Clinical disease activity was defined based on improvement or deterioration by the minimal clinically important difference on the inflammatory Rasch-built Overall Disability Scale in combination with either grip strength or the Medical Research Council sum score. Using a proximity extension assay (Olink Explore platform), 1472 protein levels were analysed in serum. Candidate proteins were selected based on fold change>0.5 or <-0.5 and p<0.05 between clinically active and inactive disease. Longitudinal changes of candidate proteins between baseline and follow-up were analysed.

RESULTS

We identified 48 candidate proteins that differed between clinically active and inactive disease on cross-sectional comparison. Five of these proteins (SUGT1, IRAK4, DCTN1, 5'-nucleotidase cytosolic IIIA (NT5C3A), glutaredoxin (GLRX)) also showed longitudinal changes consistent with disease activity changes. IRAK4 was also identified in a sensitivity analysis, using another definition for disease activity.

CONCLUSION

Our results indicate that IRAK4 and possibly SUGT1, DCTN1, NT5C3A and GLRX are candidate biomarkers for monitoring clinical disease activity in CIDP.

Increased Cerebrospinal Fluid Adenosine 5'-Triphosphate Levels in Patients with Guillain-Barré Syndrome and Chronic Inflammatory Demyelinating Polyneuropathy

Background

Extracellular adenosine 5'-triphosphate (ATP) acts as a signaling molecule in the peripheral nerves, regulating myelination after nerve injury. The present study examined whether the cerebrospinal fluid (CSF) ATP levels in patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are related to disease severity.

Methods

CSF ATP levels in 13 patients with GBS and 18 patients with CIDP were compared with those in a control group of 16 patients with other neurological diseases (ONDs). In patients with CIDP, CSF ATP levels were compared before and after treatment. The correlations between CSF ATP levels and other factors, including clinical data and CSF protein levels, were also evaluated.

Results

Median CSF ATP levels were significantly higher in patients with GBS and CIDP than in those with ONDs. When patients with CIDP were classified into two groups depending on their responsiveness to immunotherapy, median CSF ATP levels were significantly higher in good responders than in ONDs. CSF ATP levels tended to decrease after treatment in patients with CIDP. In patients with CIDP, there is a negative correlation between CSF ATP and CSF protein levels.

Conclusions

CSF ATP levels were increased in patients with GBS and CIDP. In particular, CSF ATP levels tended to decrease following treatment in patients with CIDP. CSF ATP levels may be useful biomarkers for the diagnosis or monitoring of therapeutic effects in patients with GBS and CIDP.

Neurological autoimmunity in melanoma patients: a comparison between those exposed and non-exposed to immune checkpoint inhibitors

BACKGROUND

The clinical spectrum of melanoma-associated neurological autoimmunity, whether melanoma-associated paraneoplastic neurological syndromes (PNS) or induced by immune checkpoint inhibitors (ICI), is not well characterized. We aim to describe the clinical spectrum of melanoma-associated neurological autoimmunity.

METHODS

A systematic review of the literature combined with patients from French databases of paraneoplastic neurological syndromes was conducted. All melanoma patients with a possible immune-mediated neurologic syndrome were included and classified according to whether they had previously been exposed to ICI (ICI-neurotoxicity) or not (ICI-naïve) at first neurological symptoms.

RESULTS

Seventy ICI-naïve (literature: n = 61) and 241 ICI-neurotoxicity patients (literature: n = 180) were identified. Neuromuscular manifestations predominated in both groups, but peripheral neuropathies were more frequent in ICI-neurotoxicity patients (39.4% vs 21.4%, p = 0.005) whereas myositis was more frequent in ICI-naïve patients (42.9% vs 18.7%, p < 0.001). ICI-naïve patients had also more frequent central nervous system (CNS) involvement (35.7% vs 23.7%, p = 0.045), classical paraneoplastic syndrome (25.7% vs 5.8%, p < 0.001), and more frequently positive for anti-neuron antibodies (24/32, 75.0% vs 38/90, 42.2%, p = 0.001). Although more ICI-neurotoxicity patients died during the acute phase (22/202, 10.9% vs 1/51, 2.0%, p = 0.047), mostly myositis patients (14/22, 63.6%), mortality during follow-up was higher in ICI-naïve patients (58.5% vs 29.8%, p < 0.001). There was no significant difference in the frequency of life independence (mRS ≤ 2) in the surviving patients in both groups (95.5% vs 91.0%, p = 0.437).

CONCLUSIONS

Melanoma-associated PNS appear remarkably rare. The clinical similarities observed in neurological autoimmunity between ICI-treated and ICI-naïve patients, characterized predominantly by demyelinating polyradiculoneuropathy and myositis, suggest a potential prior immunization against melanoma antigens contributing to ICI-related neurotoxicity.

An Unusual Case of Neurofascin 186 Neuropathy

Among the diverse array of neuropathies, autoimmune neuropathy stands out as a distinctive subset, where the body's immune system mistakenly attacks its nerve tissues, triggering inflammation and nerve damage. NF 186, also known as neurofascin 186, is a cell adhesion molecule crucial for the integrity and functioning of the peripheral nervous system. This case report highlights the clinical presentation specific to NF 186-positive autoimmune neuropathy and also the treatment modalities.

Recurrent CNTN1 antibody-positive nodopathy: a case report and literature review

Background

Contactin-1 (CNTN1) antibody-positive nodopathy is rare and exhibits distinct clinical symptoms such as tremors and ataxia. However, the mechanisms of these symptoms and the characteristics of the cerebral spinal fluid (CSF) remain unknown.

Case presentation

Here, we report a case of recurrent CNTN1 antibody-positive nodopathy. Initially, a 45-year-old woman experiencing numbness in the upper limbs and weakness in the lower limbs was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Eleven years later, her symptoms worsened, and she began to experience tremors and ataxia. Tests for serum CNTN1, GT1a, and GQ1b antibodies returned positive. Subsequently, she was diagnosed with CNTN1 antibody-positive nodopathy and underwent plasmapheresis therapy, although the treatment's efficacy was limited. To gain a deeper understanding of the disease, we conducted a comprehensive literature review, identifying 52 cases of CNTN1 antibody-positive nodopathy to date, with a tremor prevalence of 26.9%. Additionally, we found that the average CSF protein level in CNTN1 antibody-positive nodopathy was 2.57 g/L, with 87% of patients exhibiting a CSF protein level above 1.5 g/L.

Conclusion

We present a rare case of recurrent CNTN1 antibody-positive nodopathy. Our findings indicate a high prevalence of tremor (26.9%) and elevated CSF protein levels among patients with CNTN1 antibody-positive nodopathy.

Long-term follow-up of relapse and remission of CIDP in a Chinese cohort

Objective

We aim to describe the long-term outcome of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) after immune treatment in a Chinese cohort.

Methods

Between March 2015 and March 2023, 89 patients fulfilling the criteria for CIDP were followed up for a median of 22 months after treatment. Nine had positive antibodies against nodal-paranodal cell-adhesion molecules. Patients were treated according to clinical requirements with prednisone, intravenous immunoglobulin (IVIg) and/or immunosuppressant.

Results

A total of 78/89 patients had decreased inflammatory neuropathy cause and treatment (INCAT) scores at the last follow-up. For CIDP patients treated with steroids, 35 were stable without relapse after cessation or with a small maintenance dose; 2 relapsed at a high dose (20 mg/day); 15 relapsed at a low dosage (<20 mg/day) and 11 did not respond. The INCAT before treatment was significantly lower in those without relapse (median INCAT 2 vs 3, p=0.030). IVIg was effective in 37/52 CIDP patients. 28 CIDP patients and 4 autoimmune nodopathy patients were treated with immunosuppressants. The average INCAT was 3.3±1.9 before and 1.9±1.3 after immunosuppressant treatment (p=0.001) in CIDP.

Conclusion

The long-term prognosis of CIDP patients was generally favourable. Nearly half of our patients treated with steroid were stable without relapse after cessation or with a small maintenance dose. The risk of relapse was higher in those with high INCAT. We recommend slowly tapering prednisone based on clinical judgement.

A study on the role of serum uric acid in differentiating acute inflammatory demyelinating polyneuropathy from acute-onset chronic inflammatory demyelinating polyneuropathy

BACKGROUND AND PURPOSE

Clinical symptoms and laboratory indices for acute inflammatory demyelinating polyneuropathy (AIDP), a variant of Guillain-Barré syndrome, and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) were analyzed to identify factors that could contribute to early differential diagnosis.

METHODS

A retrospective chart review was performed on 44 AIDP and 44 A-CIDP patients looking for any demographic characteristics, clinical manifestations or laboratory parameters that might differentiate AIDP from acutely presenting CIDP.

RESULTS

In Guillain-Barré syndrome patients (N = 63), 69.84% (N = 44) were classified as having AIDP, 19.05% (N = 12) were found to have acute motor axonal neuropathy, 6.35% (N = 4) were found to have acute motor and sensory axonal neuropathy, and 4.76% (N = 3) were found to have Miller Fisher syndrome. Serum uric acid (UA) was higher in A-CIDP patients (329.55 ± 72.23 μmol/L) than in AIDP patients (221.08 ± 71.32 μmol/L) (p = 0.000). Receiver operating characteristic analyses indicated that the optimal UA cutoff was 283.50 μmol/L. Above this level, patients were more likely to present A-CIDP than AIDP (specificity 81.80%, sensitivity 81.80%). During the follow-up process, serum samples were effectively collected from 19 AIDP patients during the rehabilitation phase and 28 A-CIDP patients during the remission stage, and it was found that UA levels were significantly increased in A-CIDP (remission) (298.9 ± 90.39 μmol/L) compared with AIDP (rehabilitation) (220.1 ± 108.2 μmol/L, p = 0.009).

CONCLUSION

These results suggest that serum UA level can help to differentiate AIDP from A-CIDP with high specificity and sensitivity, which is helpful for early diagnosis and guidance of treatment.

Chronic inflammatory demyelinating polyneuropathy and HEV antibody status: A case-control study from Lazio, Italy

INTRODUCTION

Few studies have pointed to the possible role of infectious diseases in triggering Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). Given the association of Hepatitis E Virus (HEV) with Guillain Barrè syndrome, we conducted a case-control study to determine the possible association of HEV infection with CIDP, analyzing possible risk factors for acquiring HEV infection in both CIDP patients and controls.

MATERIALS AND METHODS

82 CIDP and 260 from the general population have provided some personal information (demographics, anamnestic data and recognized risk factors for HEV infection) and underwent venipuncture blood sampling for virological assays testing for anti-HEV IgG and IgM with ELISA and RNA-HEV performing RT-PCR.

RESULTS

Anti-HEV IgG seropositivity resulted in 32 CIDP patients (39.0%) and in 45 controls (17.3%), indicating a significant association between anti-HEV IgG positivity and CIDP (OR 3.04; 95% CI 1.70-5.43, p-value <0.001), but in multivariate logistic regression the only significant associations with anti-HEV positivity were eating pork liver sausages (OR 10.443, 95% CI 2.268-60.12, p-value 0.004) and IVIg/SCIg administration (OR 31.32, 95% CI 7.914-171.7, p-value <0.001).

DISCUSSION

The higher prevalence of anti-HEV IgG in CIDP patients than in controls could be justified by chronically administering IVIg/SCIg with a passive acquisition of anti-HEV antibodies. Furthermore, all the 20 CIDP patients who underwent IVIg/SCIg administration reported HEV risk factors, so that they could have acquired the infection.

CONCLUSIONS

Further studies in a larger CIDP patient sample in treatment with therapy other than IVIg/SCIg are necessary to rule out the possible confounding effect of IVIg/SCIg.

Case report: Chronic inflammatory demyelinating polyneuropathy superimposed on Charcot-Marie-tooth type 1A disease after SARS-CoV-2 vaccination and COVID-19 infection

Background

There is growing evidence that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or COVID-19 infection is associated with the development of immune mediated neuropathies like chronic inflammatory demyelinating polyneuropathy (CIDP), but the impact of SARS-CoV-2 vaccination and COVID-19 infection on genetic disorders such as Charcot-MarieTooth (CMT) remains unclear.

Case presentation

A 42-year-old male with occulted CMT neuropathy type lA (CMT1A) who developed limb numbness and weakness after the second SARS-CoV-2-vaccination was confirmed by identifying characteristic repeats in the p11.2 region of chromosome 17. Due to the progressive deterioration of muscle strength over 8 weeks, limb atrophy, moderately elevated protein counts in the cerebrospinal fluid, and significant improvement with intravenous human immunoglobulin, which were characteristic of acquired inflammatory neuropathies, he was eventually diagnosed with CIDP superimposed on CMT1A. However, after a three-month plateau, the patient contracted COVID-19, which led to repeated and worsening symptoms of limb weakness and atrophy, thus was diagnosed with a recurrence of CIDP and treated with Intravenous immunoglobulin and methylprednisolone 500 mg/d for 5 consecutive days, followed by oral prednisone and mycophenolate mofetil tablets. On 2 month follow-up, he exhibited remarkable clinical improvement and could walk independently with rocking gait. After 1 year of follow-up, the patient's condition was stable without further change.

Conclusion

Our case indicates that CMT1A can deteriorate after SARS-CoV-2 vaccination. Thus, SARS-CoV-2 vaccination should be considered a potential predisposing factor for CMT1A worsening. The possible superposition of CMTIA and CIDP in the context of SARS-CoV-2 infection or immunity suggests that any clinical exacerbation in patients with CMT1A should be carefully evaluated to rule out treatable superposition inflammation. In addition, electrophysiological and imaging examination of the proximal nerves, such as the axillary nerve, is helpful for the diagnosis of CIDP.

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.

Prevalence, Clinical Profiles, and Prognosis of CIDP in Japanese Nationwide Survey: Analyses of 1,257 Diagnosis-Confirmed Patients

BACKGROUND AND OBJECTIVES

To investigate the current epidemiology, clinical profile, and treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) using a nationwide survey in Japan.

METHODS

We conducted a nationwide survey using an epidemiologic method established in 2021. Questionnaire sheets were sent to the hospital departments of neurology and pediatric neurology throughout Japan. A primary questionnaire was used to determine the number of patients and their prevalence, and a second questionnaire was used to collect detailed clinical information.

RESULTS

The primary survey showed that the estimated number of patients with CIDP was 4,180, with a prevalence of 3.3 per 100,000 persons. In the secondary survey, detailed clinical data were available for 1,257 patients. The male-to-female ratio was 1.5:1, and the median age at onset was 52 years. Typical CIDP was the most frequent subtype (52%), followed by distal (17%) and multifocal/focal CIDP (17%). Initial treatments included immunoglobulin therapy (72%), corticosteroids (15%), and others (13%). Among patients with CIDP, 78% had a progressive/relapsing course, 14% did not respond to first-line treatments, and 18% could not walk independently at the last visit. Among the subtypes, typical CIDP had the most severe disability before treatment (44% of patients could not walk independently). However, they showed a more favorable response to treatment than those with distal or multifocal CIDP. In the subgroup analyses, logistic regression analyses showed that younger age at onset, no muscle atrophy, and abnormal median-normal sural sensory nerve responses were associated with a higher probability of independent walking.

DISCUSSION

Our study represents the largest cohort study on CIDP to demonstrate the current epidemiologic and clinical status of CIDP in Japan. Clinical subtypes seem to be associated with different treatment responses and outcomes; therefore, an appropriate treatment strategy according to the pathophysiology of each subtype is required to improve the prognosis of CIDP.

Autoantibodies Against Dihydrolipoamide S-Acetyltransferase in Immune-Mediated Neuropathies

BACKGROUND AND OBJECTIVES

This study aimed to identify disease-related autoantibodies in the serum of patients with immune-mediated neuropathies including chronic inflammatory demyelinating polyneuropathy (CIDP) and to investigate the clinical characteristics of patients with these antibodies.

METHODS

Proteins extracted from mouse brain tissue were used to react with sera from patients with CIDP by western blotting (WB) to determine the presence of common bands. Positive bands were then identified by mass spectrometry and confirmed for reactivity with patient sera using enzyme-linked immunosorbent assay (ELISA) and WB. Reactivity was further confirmed by cell-based and tissue-based indirect immunofluorescence assays. The clinical characteristics of patients with candidate autoantibody-positive CIDP were analyzed, and their association with other neurologic diseases was also investigated.

RESULTS

Screening of 78 CIDP patient sera by WB revealed a positive band around 60-70 kDa identified as dihydrolipoamide S-acetyltransferase (DLAT) by immunoprecipitation and mass spectrometry. Serum immunoglobulin G (IgG) and IgM antibodies' reactivity to recombinant DLAT was confirmed using ELISA and WB. A relatively high reactivity was observed in 29 of 160 (18%) patients with CIDP, followed by patients with sensory neuropathy (6/58, 10%) and patients with MS (2/47, 4%), but not in patients with Guillain-Barré syndrome (0/27), patients with hereditary neuropathy (0/40), and healthy controls (0/26). Both the cell-based and tissue-based assays confirmed reactivity in 26 of 33 patients with CIDP. Comparing the clinical characteristics of patients with CIDP with anti-DLAT antibodies (n = 29) with those of negative cases (n = 131), a higher percentage of patients had comorbid sensory ataxia (69% vs 37%), cranial nerve disorders (24% vs 9%), and malignancy (20% vs 5%). A high DLAT expression was observed in human autopsy dorsal root ganglia, confirming the reactivity of patient serum with mouse dorsal root ganglion cells.

DISCUSSION

Reactivity to DLAT was confirmed in patient sera, mainly in patients with CIDP. DLAT is highly expressed in the dorsal root ganglion cells, and anti-DLAT antibody may serve as a biomarker for sensory-dominant neuropathies.

Quantitative magnetic resonance neurography in chronic inflammatory demyelinating polyradiculoneuropathy: A longitudinal study over 6 years

OBJECTIVE

To evaluate magnetic resonance neurography (MRN) for the longitudinal assessment of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

Prospective examination of twelve CIDP patients by neurological assessment, MRN, and nerve conduction studies in 2016 and 6 years later in 2022. Imaging parameters were compared with matched healthy controls and correlated with clinical and electrophysiological markers. The MRN protocol included T2-weighted imaging, diffusion tensor imaging (DTI), T2 relaxometry, and magnetization transfer imaging (MTI).

RESULTS

Nerve cross-sectional area (CSA) was increased in CIDP patients compared to controls (plexus: p = 0.003; sciatic nerve: p < 0.001). Over 6 years, nerve CSA decreased in CIDP patients, most pronounced at the lumbosacral plexus (p = 0.015). Longitudinally, changes in CSA correlated with changes in the inflammatory neuropathy cause and treatment validated overall disability sum score (INCAT/ODSS) (p = 0.006). High initial nerve CSA was inversely correlated with changes in the INCAT/ODSS over 6 years (p < 0.05). The DTI parameter fractional anisotropy (FA) showed robust correlations with electrodiagnostic testing both cross-sectionally and longitudinally (p < 0.05). MTI as a newly added imaging technique revealed a significantly reduced magnetization transfer ratio (MTR) in CIDP patients (p < 0.01), suggesting underlying changes in macromolecular tissue composition, and correlated significantly with electrophysiological parameters of demyelination (p < 0.05).

INTERPRETATION

This study provides evidence that changes in nerve CSA and FA reflect the clinical and electrophysiological course of CIDP patients. Initial nerve hypertrophy might predict a rather benign course or better therapy response.

Tendon-Sparing Extraocular Muscle Enlargement Associated With Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory, sensorimotor polyneuropathy. It has presented with a variety of orbital and neuro-ophthalmic manifestations, including cranial nerve hypertrophy and a single case of extraocular muscle enlargement. The authors present a second case of tendon-sparing, extraocular muscle enlargement, resulting in new-onset diplopia and strabismus in a teenager with CIDP. The workup ruled out alternative causes of extraocular muscle enlargement, such as hyperthyroidism, inflammation, or malignancy. As with other cases of CIDP, management involved a combination of immunoglobulin therapy and anti-inflammatory medications. The patient experienced resolution of his symptoms, and radiologic improvement was noted in the muscle enlargement. As many CIDP patients have a favorable treatment response and long-term prognosis, awareness of this rare disease with an early and accurate diagnosis is important.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Current Therapeutic Approaches and Future Outlooks

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable autoimmune disorder, for which different treatment options are available. Current first-line evidence-based therapies for CIDP include intravenous and subcutaneous immunoglobulins, corticosteroids and plasma exchanges. Despite lack of evidence, cyclophosphamide, rituximab and mycophenolate mofetil are commonly used in circumstances of refractoriness and, more debatably, of perceived overdependence on first-line therapies. Rituximab is currently the object of a randomized controlled trial for CIDP. Based on case series, and although rarely considered, haematopoietic autologous stem cell transplants may be effective in refractory disease, with low mortality and high remission rates. A new therapeutic option has appeared with efgartigimod, a neonatal Fc receptor blocker, recently shown to significantly lower relapse rate versus placebo, after withdrawal from previous immunotherapy. Other neonatal Fc receptor blockers, nipocalimab and batoclimab, are under study. The C1 complement-inhibitor SAR445088, acting in the proximal portion of the classical complement system, is currently the subject of a new study in treatment-responsive, refractory and treatment-naïve subjects. Finally, Bruton Tyrosine Kinase inhibitors, which exert anti-B cell effects, may represent another future research avenue. The widening of the therapeutic armamentarium enhances the need for improved evaluation of treatment effects and reliable biomarkers in CIDP.

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, which lasts for at least two months. Uncontrolled studies have suggested that intravenous immunoglobulin (IVIg) could help to reduce symptoms. This is an update of a review first published in 2002 and last updated in 2013.

OBJECTIVES

To assess the efficacy and safety of intravenous immunoglobulin in people with chronic inflammatory demyelinating polyradiculoneuropathy.

SEARCH METHODS

We searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, and two trials registers on 8 March 2023.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) and quasi-RCTs that tested any dose of IVIg versus placebo, plasma exchange, or corticosteroids in people with definite or probable CIDP.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was significant improvement in disability within six weeks after the start of treatment, as determined and defined by the study authors. Our secondary outcomes were change in mean disability score within six weeks, change in muscle strength (Medical Research Council (MRC) sum score) within six weeks, change in mean disability score at 24 weeks or later, frequency of serious adverse events, and frequency of any adverse events. We used GRADE to assess the certainty of evidence for our main outcomes.

MAIN RESULTS

We included nine RCTs with 372 participants (235 male) from Europe, North America, South America, and Israel. There was low statistical heterogeneity between the trial results, and the overall risk of bias was low for all trials that contributed data to the analysis. Five trials (235 participants) compared IVIg with placebo, one trial (20 participants) compared IVIg with plasma exchange, two trials (72 participants) compared IVIg with prednisolone, and one trial (45 participants) compared IVIg with intravenous methylprednisolone (IVMP). We included one new trial in this update, though it contributed no data to any meta-analyses. IVIg compared with placebo increases the probability of significant improvement in disability within six weeks of the start of treatment (risk ratio (RR) 2.40, 95% confidence interval (CI) 1.72 to 3.36; number needed to treat for an additional beneficial outcome (NNTB) 4, 95% CI 3 to 5; 5 trials, 269 participants; high-certainty evidence). Since each trial used a different disability scale and definition of significant improvement, we were unable to evaluate the clinical relevance of the pooled effect. IVIg compared with placebo improves disability measured on the Rankin scale (0 to 6, lower is better) two to six weeks after the start of treatment (mean difference (MD) -0.26 points, 95% CI -0.48 to -0.05; 3 trials, 90 participants; high-certainty evidence). IVIg compared with placebo probably improves disability measured on the Inflammatory Neuropathy Cause and Treatment (INCAT) scale (1 to 10, lower is better) after 24 weeks (MD 0.80 points, 95% CI 0.23 to 1.37; 1 trial, 117 participants; moderate-certainty evidence). There is probably little or no difference between IVIg and placebo in the frequency of serious adverse events (RR 0.82, 95% CI 0.36 to 1.87; 3 trials, 315 participants; moderate-certainty evidence). The trial comparing IVIg with plasma exchange reported none of our main outcomes. IVIg compared with prednisolone probably has little or no effect on the probability of significant improvement in disability four weeks after the start of treatment (RR 0.91, 95% CI 0.50 to 1.68; 1 trial, 29 participants; moderate-certainty evidence), and little or no effect on change in mean disability measured on the Rankin scale (MD 0.21 points, 95% CI -0.19 to 0.61; 1 trial, 24 participants; moderate-certainty evidence). There is probably little or no difference between IVIg and prednisolone in the frequency of serious adverse events (RR 0.45, 95% CI 0.04 to 4.69; 1 cross-over trial, 32 participants; moderate-certainty evidence). IVIg compared with IVMP probably increases the likelihood of significant improvement in disability two weeks after starting treatment (RR 1.46, 95% CI 0.40 to 5.38; 1 trial, 45 participants; moderate-certainty evidence). IVIg compared with IVMP probably has little or no effect on change in disability measured on the Rankin scale two weeks after the start of treatment (MD 0.24 points, 95% CI -0.15 to 0.63; 1 trial, 45 participants; moderate-certainty evidence) or on change in mean disability measured with the Overall Neuropathy Limitation Scale (ONLS, 1 to 12, lower is better) 24 weeks after the start of treatment (MD 0.03 points, 95% CI -0.91 to 0.97; 1 trial, 45 participants; moderate-certainty evidence). The frequency of serious adverse events may be higher with IVIg compared with IVMP (RR 4.40, 95% CI 0.22 to 86.78; 1 trial, 45 participants, moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Evidence from RCTs shows that IVIg improves disability for at least two to six weeks compared with placebo, with an NNTB of 4. During this period, IVIg probably has similar efficacy to oral prednisolone and IVMP. Further placebo-controlled trials are unlikely to change these conclusions. In one large trial, the benefit of IVIg compared with placebo in terms of improved disability score persisted for 24 weeks. Further research is needed to assess the long-term benefits and harms of IVIg relative to other treatments.

Challenges in the Early Diagnosis and Treatment of Chronic Inflammatory Demyelinating Polyradiculoneuropathy in Adults: Current Perspectives

Diagnosing Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) poses numerous challenges. The heterogeneous presentations of CIDP variants, its mimics, and the complexity of interpreting electrodiagnostic criteria are just a few of the many reasons for misdiagnoses. Early recognition and treatment are important to reduce the risk of irreversible axonal damage, which may lead to permanent disability. The diagnosis of CIDP is based on a combination of clinical symptoms, nerve conduction study findings that indicate demyelination, and other supportive criteria. In 2021, the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) published a revision on the most widely adopted guideline on the diagnosis and treatment of CIDP. This updated guideline now includes clinical and electrodiagnostic criteria for CIDP variants (previously termed atypical CIDP), updated supportive criteria, and sensory criteria as an integral part of the electrodiagnostic criteria. Due to its many rules and exceptions, this guideline is complex and misinterpretation of nerve conduction study findings remain common. CIDP is treatable with intravenous immunoglobulins, corticosteroids, and plasma exchange. The choice of therapy should be tailored to the individual patient's situation, taking into account the severity of symptoms, potential side effects, patient autonomy, and past treatments. Treatment responses should be evaluated as objectively as possible using disability and impairment scales. Applying these outcome measures consistently in clinical practice aids in recognizing the effectiveness (or lack thereof) of a treatment and facilitates timely consideration of alternative diagnoses or treatments. This review provides an overview of the current perspectives on the diagnostic process and first-line treatments for managing the disease.

French protocol for the diagnosis and management of hematopoietic stem cell transplantation in autoimmune diseases

Hematopoietic stem cell transplantation (HSCT) for severe ADs was developed over the past 25years and is now validated by national and international medical societies for severe early systemic sclerosis (SSc) and relapsing-remitting multiple sclerosis (MS) and available as part of routine care in accredited center. HSCT is also recommended, with varying levels of evidence, as an alternative treatment for several ADs, when refractory to conventional therapy, including specific cases of connective tissue diseases or vasculitis, inflammatory neurological diseases, and more rarely severe refractory Crohn's disease. The aim of this document was to provide guidelines for the current indications, procedures and follow-up of HSCT in ADs. Patient safety considerations are central to guidance on patient selection and conditioning, always validated at the national MATHEC multidisciplinary team meeting (MDTM) based on recent (less than 3months) thorough patient evaluation. HSCT procedural aspects and follow-up are then carried out within appropriately experienced and Joint Accreditation Committee of International Society for Cellular Therapy and SFGM-TC accredited centres in close collaboration with the ADs specialist. These French recommendations were performed according to HAS/FAI2R standard operating procedures and coordinated by the Île-de-France MATHEC Reference Centre for Rare Systemic Autoimmune Diseases (CRMR MATHEC) within the Filière FAI2R and in association with the Filière MaRIH. The task force consisted of 3 patients and 64 clinical experts from various specialties and French centres. These data-derived and consensus-derived recommendations will help clinicians to propose HSCT for their severe ADs patients in an evidence-based way. These recommendations also give directions for future clinical research in this area. These recommendations will be updated according to newly emerging data. Of note, other cell therapies that have not yet been approved for clinical practice or are the subject of ongoing clinical research will not be addressed in this document.

Insights into refractory chronic inflammatory demyelinating polyneuropathy: a comprehensive real-world study

Background

Refractory chronic inflammatory demyelinating polyneuropathy (CIDP) is a challenging subset of CIDP. It does not respond well to immune therapy and causes substantial disability. A comprehensive understanding of its clinical profile, electrophysiological characteristics and potential risk factors associated with refractoriness remains to be further elucidated.

Methods

Data in this cross-sectional study was collected and reviewed from the Huashan Peripheral Neuropathy Database (HSPN). Included patients were categorized into refractory CIDP and non-refractory CIDP groups based on treatment response. The clinical and electrophysiological characteristics were compared between refractory and non-refractory CIDP groups. Potential risk factors associated with refractory CIDP were explored with a multivariate logistic regression model.

Results

Fifty-eight patients with CIDP were included. Four disease course patterns of refractory CIDP are described: a relapsing-remitting form, a stable form, a secondary progressive form and a primary progressive form. Compared to non-refractory CIDP patients, refractory CIDP exhibited a longer disease duration (48.96 ± 33.72 vs. 28.33 ± 13.72 months, p = 0.038) and worse functional impairment (MRC sum score, 46.08 ± 12.69 vs. 52.81 ± 7.34, p = 0.018; mRS, 2.76 ± 0.93 vs. 2.33 ± 0.99, p = 0.082; INCAT, 3.68 ± 1.76 vs. 3.03 ± 2.28, p = 0.056, respectively). Electrophysiological studies further revealed greater axonal impairment (4.15 ± 2.0 vs. 5.94 ± 2.77 mv, p = 0.011, ulnar CMAP) and more severe demyelination (5.56 ± 2.86 vs. 4.18 ± 3.71 ms, p = 0.008, ulnar distal latency, 7.94 ± 5.62 vs. 6.52 ± 6.64 ms, p = 0.035, median distal latency; 30.21 ± 12.59 vs. 37.48 ± 12.44 m/s, p = 0.035, median conduction velocity; 58.66 ± 25.73 vs. 42.30 ± 13.77 ms, p = 0.033, median F-wave latency), compared to non-refractory CIDP. Disease duration was shown to be an independent risk factor for refractory CIDP (p < 0.05, 95%CI [0.007, 0.076]).

Conclusion

This study provided a comprehensive description of refractory CIDP, addressing its clinical features, classification of clinical course, electrophysiological characteristics, and prognostic factors, effectively elucidating its various aspects. These findings contribute to a better understanding of this challenging subset of CIDP and might be informative for management and treatment strategies.

Waldenström Macroglobulinemia-Associated Peripheral Neuropathy in the Brachial Plexus With Bing-Neel Syndrome Diagnosed Through Repeated Cerebrospinal Tests

In Waldenström macroglobulinemia (WM), confirming the presence of Bing-Neel syndrome (BNS) is important because drugs that penetrate the central nervous system (CNS) must be selected. We report the case of a 75-year-old man for whom tirabrutinib, a second-generation Bruton's tyrosine kinase inhibitor (BTKi), was useful in treating WM-associated peripheral neuropathy (PN) with BNS. Numbness and muscle weakness in the fingers occurred three years after the initial treatment of WM. WM-associated PN due to demyelinating disease was diagnosed based on the results of a nerve conduction study and magnetic resonance imaging showing bilateral symmetric swelling of the brachial plexus. The cerebrospinal fluid (CSF) cytology results were initially negative; however, the CSF test was repeated because of extremely high protein levels (984 mg/dL) and slightly elevated leukocyte counts (14/µL). The second test revealed abnormal lymphoplasmacytic cells (189/µL), indicating BNS. Rituximab and high-dose methotrexate-containing chemotherapy were administered. Despite the subsequent negative CSF cytology results, his neurological symptoms persisted but subsided soon after the initiation of tirabrutinib. The therapeutic effects of tirabrutinib persisted for 25 months. This case suggested that a careful search for concurrent BNS is important when lesions are close to the CNS or when atypical CSF findings are obtained in patients with WM-associated PN, especially when BTKi options are available.

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.

Theory of mind and executive dysfunction in chronic inflammatory demyelinating polyneuropathy

BACKGROUND AND PURPOSE

Although chronic inflammatory demyelinating polyneuropathy (CIDP) is understood as a disease affecting the peripheral nervous system, mild cognitive dysfunction, particularly in the executive domain, has been described to form part of the condition. Here our interest lay in CIDP-related theory of mind (ToM) capacities as an aspect of social cognition relevant for many aspects of everyday life.

METHODS

Twenty-nine patients with CIDP and 23 healthy controls participated in this study. They were subjected to overview cognitive testing, different executive function (EF) tasks, as well as to the Faux Pas Recognition Task (FPRT) for assessing cognitive ToM and the Reading the Mind in the Eyes Test (RMET) with respect to affective ToM.

RESULTS

Persons with CIDP and controls did not differ with respect to their overall cognitive state. However, in the German verbal fluency standard, the digit span forward and the digit span backward tests used as EF tasks patients performed significantly worse than controls. Further, performance was abnormally low in the FPRT, whilst the groups did not differ with respect to RMET results. The FPRT and digit span backward results correlated with each other.

CONCLUSIONS

Patients with CIDP showed deficits in cognitive ToM performance together with EF dysfunction, whilst affective ToM was preserved. Altogether, the results suggest that low cognitive ToM capacities in patients with CIDP arise as a particular aspect of disease-related executive dysfunction.

Immunomodulatory effects of intravenous and subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy: An observational study

BACKGROUND AND PURPOSE

It is not known whether the route of administration affects the mechanisms of action of therapeutic immunoglobulin in chronic inflammatory demyelinating polyneuropathy (CIDP). The aim of this study, therefore, was to compare the immunomodulatory effects of intravenous (IVIg) and subcutaneous immunoglobulin (SCIg) in patients with CIDP and in IVIg-treated common variable immunodeficiency (CVID) patients.

METHODS

Serum and peripheral blood mononuclear cell samples were obtained from 30 CIDP patients receiving IVIg, 10 CIDP patients receiving SCIg, and 15 patients with CVID receiving IVIg. Samples and clinical data were obtained prior to IVIg/SCIg and at 3 days, 7 days, and, in CIDP patients receiving IVIg, 21 days post-administration. Serum cytokines were assessed by Luminex-based multiplex assay and enzyme-linked immunosorbent assay. Immune cells were characterized by flow cytometry.

RESULTS

Immune cell profiles of CIDP and CVID patients differed in frequencies of myeloid dendritic cells and cytotoxic natural killer cells. During treatment with IVIg or SCIg in CIDP patients, cellular immunomarkers were largely similar. CIDP patients receiving IVIg had higher macrophage inflammatory protein (MIP)-1α (p = 0.01), interleukin (IL)-4 (p = 0.04), and IL-33 (p = 0.04) levels than SCIg recipients. IVIg treatment more broadly modulated cytokines in CIDP than SCIg treatment.

CONCLUSIONS

Our study demonstrates that the modulation of cellular immunomarkers in CIDP is independent of the application route of therapeutic immunoglobulin. Minor differences were observed between CIDP and CVID patients. In contrast, cytokines were differentially modulated by IVIg and SCIg in CIDP.

[Modern aspects of diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy in children]

OBJECTIVE

Analysis of demographic, clinical, laboratory, electrophysiological and neuroimaging data and pathogenetic therapy of pediatric patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

MATERIAL AND METHODS

Patients (n=30) were observed in a separate structural unit of the Russian Children's Clinical Hospital of the Russian National Research Medical University named after. N.I. Pirogova Ministry of Health of the Russian Federation in the period from 2006 to 2023. The examination was carried out in accordance with the recommendations of the Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society on the Management of CIDP (2021). All patients received immunotherapy, including intravenous immunoglobulin (IVIG) (n=1), IVIG and glucocorticosteroids (GCS) (n=17, 56.7%), IVIG+GCS+plasmapheresis (n=12, 40.0%). Alternative therapy included cyclophosphamide (n=1), cyclophosphamide followed by mycophenolate mofetil (n=1), rituximab (n=2, 6.6%), azathioprine (n=3), mycophenolate mofetil (n=2, 6.6%).

RESULTS

In all patients, there was a significant difference between scores on the MRCss and INCAT functional scales before and after treatment. At the moment, 11/30 (36.6%) patients are in clinical remission and are not receiving pathogenetic therapy. The median duration of remission is 48 months (30-84). The longest remission (84 months) was observed in a patient with the onset of CIDP at the age of 1 year 7 months.

CONCLUSION

Early diagnosis of CIDP is important, since the disease is potentially curable; early administration of pathogenetic therapy provides a long-term favorable prognosis.

CSF CXCL13 is elevated in patients with CIDP and may reflect higher disease activity

To evaluate B-cell involvement in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), 11 patients with CIDP, 8 patients with Guillain-Barré syndrome and 13 patients with idiopathic normal pressure hydrocephalus (iNPH) were studied. CSF cytokine and chemokine (IL-10, IL-15, TNF-α, TGF-β1, GM-CSF, BAFF, CXCL10, and CXCL13) levels were measured by ELISA. The CSF CXCL13 level was significantly higher in patients with CIDP than in those with iNPH. The CSF CXCL13 level was significantly higher in CIDP patients with higher annualized relapse rates and higher modified Rankin scale scores. The CSF CXCL13 level is elevated in CIDP, especially in those with higher disease activity.

Clinical relevance of distinguishing autoimmune nodopathies from CIDP: longitudinal assessment in a large cohort

BACKGROUND

The aim of this study was to determine treatment response and whether it is associated with antibody titre change in patients with autoimmune nodopathy (AN) previously diagnosed as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and to compare clinical features and treatment response between AN and CIDP.

METHODS

Serum IgG antibodies to neurofascin-155 (NF155), contactin-1 (CNTN1) and contactin-associated protein 1 (CASPR1) were detected with cell-based assays in patients diagnosed with CIDP. Clinical improvement was determined using the modified Rankin scale, need for alternative and/or additional treatments and assessment of the treating neurologist.

RESULTS

We studied 401 patients diagnosed with CIDP and identified 21 patients with AN (10 anti-NF155, 6 anti-CNTN1, 4 anti-CASPR1 and 1 anti-NF155/anti-CASPR1 double positive). In patients with AN ataxia (68% vs 28%, p=0.001), cranial nerve involvement (34% vs 11%, p=0.012) and autonomic symptoms (47% vs 22%, p=0.025) were more frequently reported; patients with AN improved less often after intravenous immunoglobulin treatment (39% vs 80%, p=0.002) and required additional/alternative treatments more frequently (84% vs 34%, p<0.001), compared with patients with CIDP. Antibody titres decreased or became negative in patients improving on treatment. Treatment withdrawal was associated with a titre increase and clinical deterioration in four patients.

CONCLUSIONS

Distinguishing CIDP from AN is important, as patients with AN need a different treatment approach. Improvement and relapses were associated with changes in antibody titres, supporting the pathogenicity of these antibodies.