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 axonal polyneuropathy

OBJECTIVES

Chronic inflammatory axonal polyneuropathy (CIAP) is defined on the basis of the clinical, electrophysiological and nerve biopsy findings and therapeutic responses of 'immunotherapy responding chronic axonal polyneuropathy (IR-CAP)'.

METHODS

The diagnosis of IR-CAP was made when all of three of the following mandatory criterion were met: (1) acquired, chronic progressive or relapsing symmetrical or asymmetrical polyneuropathy with duration of progression >2 months; (2) electrophysiological evidence of axonal neuropathy in at least two nerves without any evidence of 'strict criteria of demyelination'; and (3) definite responsiveness to immunotherapy.

RESULTS

Thirty-three patients with IR-CAP showed similar clinical features of chronic inflammatory demyelinating polyneuropathy (CIDP) except 'motor neuropathy subtype'. High spinal fluid protein was found in 27/32 (78%) cases. 'Inflammatory axonal neuropathy' was proven in 14 (45%) of 31 sural nerve biopsies.

DISCUSSIONS

IR-CAP could well be 'axonal CIDP' in view of clinical similarity, but not proven as yet. Thus, IR-CAP is best described as CIAP, a distinct entity that deserves its recognition in view of responsiveness to immunotherapy.

CONCLUSION

Diagnosis of CIAP can be made by additional documentation of 'inflammation' by high spinal fluid protein or nerve biopsy in addition to the first two diagnostic criteria of IR-CAP.

Enlarged Brachial Plexus Nerve Found During Ultrasound-Guided Peripheral Nerve Block Diagnosed as Charcot-Marie-Tooth Disease: A Case Report

Ultrasound-guided peripheral nerve block (PNB) has become a popular anesthetic procedure. We report a case of an enlarged brachial plexus nerve noted on ultrasonographic images, as part of PNB, which was diagnosed postoperatively as Charcot-Marie-Tooth disease (CMTD), an inherited neurological disorder of the peripheral nerves. Although nerve enlargement is characteristic of demyelinating diseases such as CMTD, the use of ultrasonography in the diagnosis of neurological disorders is a developing area for neurologists and anesthesiologists can lack knowledge in this emerging field. Unusual nerve presentation on ultrasonographic images during PNB anesthetic procedures should be recognized as being indicative of underlying neurologic disorders. This case highlights that increased awareness of the diagnosis of underlying neurologic disorders by ultrasonography would assist the general practice of PNB in anesthetic medicine. This is especially important as underlying neurological conditions can have important consequences for patient-appropriate anesthesia and may inform best anesthetic practice. A new category, “neurological disorder on ultrasound image”, should be introduced to PNB knowledge in anesthetic field.

Optic, trigeminal, and facial neuropathy related to anti-neurofascin 155 antibody

OBJECTIVE

To characterize the frequency and patterns of optic, trigeminal, and facial nerve involvement by neuroimaging and electrophysiology in IgG4 anti-neurofascin 155 antibody-positive (NF155⁺ ) chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

Thirteen IgG4 NF155⁺ CIDP patients with mean onset age of 34 years (11 men) were subjected to neurological examination, blink reflex, and visual-evoked potential (VEP) testing, and axial and/or coronal T2-weighted head magnetic resonance imaging (MRI).

RESULTS

Among 13 patients, facial sensory impairment, facial weakness, and apparent visual impairment were observed in three (23.1%), two (15.4%), and two (15.4%) patients, respectively. All 12 patients tested had blink reflex abnormalities: absent and/or delayed R1 in 11 (91.7%), and absent and/or delayed R2 in 10 (83.3%). R1 latencies had strong positive correlations with serum anti-NF155 antibody levels (r = 0.9, P ≤ 0.0001 on both sides) and distal and F wave latencies of the median and ulnar nerves. Absent and/or prolonged VEPs were observed in 10/13 (76.9%) patients and 17/26 (65.4%) eyes. On MRI, hypertrophy, and high signal intensity of trigeminal nerves were detected in 9/13 (69.2%) and 10/13 (76.9%) patients, respectively, whereas optic nerves were normal in all patients. The intra-orbital trigeminal nerve width on coronal sections showed a significant positive correlation with disease duration.

INTERPRETATION

Subclinical demyelination frequently occurs in the optic, trigeminal, and facial nerves in IgG4 NF155⁺ CIDP, suggesting that both central and peripheral myelin structures of the cranial nerves are involved in this condition, whereas nerve hypertrophy only develops in myelinated peripheral nerve fibers.

Ultra-high-frequency ultrasound imaging of sural nerve: A comparative study with nerve biopsy in progressive neuropathies

INTRODUCTION

Nerve ultrasound has been used increasingly in clinical practice as a complementary test for diagnostic assessment of neuropathies, but nerve biopsy remains invaluable in certain cases. The aim of this study was to compare ultra-high-frequency ultrasound (UHF-US) to histologic findings in progressive polyneuropathies.

METHODS

Ten patients with severe, progressive neuropathies underwent ultrasound evaluation of the sural nerve before nerve biopsy. Ultrasound data were compared with histologic results in a retrospective manner.

RESULTS

Sural nerves were easily identified on UHF-US. Nerve hyperechogenicity correlated with inflammatory infiltrates on biopsy. Nerve fascicles could be identified and measured on ultrasound in the majority of patients.

DISCUSSION

Hyperechogenicity on UHF-US may be a marker of nerve inflammation in neuropathies. Furthermore, the UHF-US probe allows for evaluation of sensory nerves in spite of their small size, providing valuable information on their size and on their internal structure.

Electrophysiological testing in chronic inflammatory demyelinating polyneuropathy patients treated with subcutaneous immunoglobulin: The Polyneuropathy And Treatment with Hizentra (PATH) study

OBJECTIVE

To assess electrophysiology parameters that can reflect patients' clinical status and show changes in nerve function with treatment, in a study of subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy.

METHODS

Nerve conduction studies (latency, conduction velocity, conduction block and compound muscle action potential [CMAP] on upper limb median, ulnar, and lower limb peroneal motor nerves) were conducted in the placebo-controlled PATH (Polyneuropathy And Treatment with Hizentra) study of two doses of maintenance subcutaneous immunoglobulin (SCIG) IgPro20 in CIDP.

RESULTS

Averaged proximal latency substantially increased with placebo (+1.1 ms) indicating electrophysiologic deterioration but remained stable with IgPro20 (0.2 g/kg bodyweight [bw]: +0.1 ms; 0.4 g/kg bw: -0.1 ms). Distal latencies were also more prolonged with placebo versus IgPro20. Averaged motor nerve conduction velocity substantially decreased with placebo (-1.6 m/s) versus increasing in both IgPro20 groups (+0.2 m/s and +1.0 m/s, respectively). Conduction block and CMAP amplitudes did not change substantially.

CONCLUSION

These findings support the effectiveness of maintenance IgPro20, as nerve function changed in the direction of increasing nerve dysfunction with placebo but remained stable with ongoing IgPro20 therapy.

SIGNIFICANCE

Electrophysiology testing can support assessment of clinical status in CIDP to determine treatment efficacy.

The comparison of MRN, electrophysiology and progression among typical CIDP and atypical CIDP subtypes

We aimed to compare the electrophysiology and magnetic resonance neurography (MRN) results of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) subtypes and to explore the progression from atypical CIDP to typical CIDP. We collected the medical records of 45 CIDP patients to analyse the rate of progression from atypical CIDP to typical CIDP subtypes. The cerebrospinal fluid (CSF) protein (p = 0.024) and overall disability sum score (ODSS) (p = 0.000) differed among patients with typical CIDP, distal acquired demyelinating symmetric neuropathy (DADS) and Lewis-Sumner syndrome (LSS). The compound motor action potential (CMAP) of typical CIDP was lower than that of the other subtypes (p = 0.016, p = 0.022 and p = 0.012). The cross-sectional area (CSA) of nerve roots in typical CIDP was significantly thicker than that of nerve roots in DADS and LSS. There were fewer DADS and LSS patients who progressed to typical CIDP than those who progressed to pure motor and pure sensory CIDP (p = 0.000), and the progression from pure motor to typical CIDP required a significantly longer time than the progression from pure sensory to typical CIDP (p = 0.007). Typical CIDP was more severe than the other subtypes not only in terms of clinical and electrophysiology factors but also in terms of MRN factors.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Its Variants

PURPOSE OF REVIEW

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and its variants comprise a group of immune-mediated neuropathies with distinctive clinical presentations and electrodiagnostic features. Prompt recognition of these treatable disorders is mandatory as delays result in significant disability and morbidity. This article highlights the clinical presentation, pathophysiology, diagnostic evaluation, and treatment approach of these polyneuropathies.

RECENT FINDINGS

The spectrum of CIDP is expanding with the recent characterization of neuropathies associated with nodal and paranodal antibodies. These neuropathies are distinguished by their unique presentations and are often refractory to IV immunoglobulin (IVIg) therapy. Subcutaneous immunoglobulins have recently been approved as a treatment option for CIDP and join corticosteroids, IVIg, and plasma exchange as first-line treatment.

SUMMARY

CIDP is characterized by progressive symmetric proximal and distal weakness, large fiber sensory loss, and areflexia, with clinical nadir reached more than 8 weeks after symptom onset. Autoimmune demyelinating neuropathies fall on a continuum, with differences in the type of nerve fibers affected and pattern of deficits. Distinguishing between typical CIDP and its variants allows for selection of the most appropriate treatment.

Randomized trial of intravenous immunoglobulin maintenance treatment regimens in chronic inflammatory demyelinating polyradiculoneuropathy

Background and purpose

High peak serum immunoglobulin G (IgG) levels may not be needed for maintenance intravenous immunoglobulin (IVIg) treatment in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and such high levels may cause side effects. More frequent lower dosing may lead to more stable IgG levels and higher trough levels, which might improve efficacy. The aim of this trial is to investigate whether high frequent low dosage IVIg treatment is more effective than low frequent high dosage IVIg treatment.

Methods

In this randomized placebo‐controlled crossover trial, we included patients with CIDP proven to be IVIg‐dependent and receiving an individually established stable dose and interval of IVIg maintenance treatment. In the control arm, patients received their individual IVIg dose and interval followed by a placebo infusion at half the interval. In the intervention arm, patients received half their individual dose at half the interval. After a wash‐out phase patients crossed over. The primary outcome measure was handgrip strength (assessed using a Martin Vigorimeter). Secondary outcome indicators were health‐related quality of life (36‐item Short‐Form Health Survey), disability (Inflammatory Rasch‐built Overall Disability Scale), fatigue (Rasch‐built Fatigue Severity Scale) and side effects.

Results

Twenty‐five patients were included and were treated at baseline with individually adjusted dosages of IVIg ranging from 20 to 80 g and intervals ranging from 14 to 35 days. Three participants did not complete the trial; the main analysis was therefore based on the 22 patients completing both treatment periods. There was no significant difference in handgrip strength change from baseline between the two treatment regimens (coefficient −2.71, 95% CI −5.4, 0.01). Furthermore, there were no significant differences in any of the secondary outcomes or side effects.

Conclusions

More frequent lower dosing does not further improve the efficacy of IVIg in stable IVIg‐dependent CIDP and does not result in fewer side effects.

Small Fibre Involvement in Multifocal Motor Neuropathy Explored with Sudoscan: A Single-Centre Experience

Objective: Multifocal motor neuropathy (MMN) is a rare inflammatory neuropathy, clinically characterized by exclusive motor involvement. We wished to evaluate the possible presence of sensory dysfunction, including the evaluation of small fibres, after a long-term disease course. Patients and methods: seven MMN patients, regularly followed in our Neurology Department, underwent clinical evaluation, neurophysiological examination by nerve conduction studies (NCSs), and Sudoscan. We compared neurophysiological data with a group of patients with other disorders of the peripheral nervous system. Results: NCSs showed a reduction of sensory nerve action potential amplitude in 2/7 MMN patients. Sudoscan showed borderline electrochemical skin conductance (ESC) values in 3/7 MMN patients (two of them with abnormal sensory NCSs). Conclusions: Our results confirm that sensory involvement may be found in some MMN after a long-term disease course, and it could also involve the small fibres.

Dramatic clinical response to ultra-high dose IVIg in otherwise treatment resistant inflammatory neuropathies

BACKGROUND

Intravenous immunoglobulin (IVIg) has short and long-term efficacy in both chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy with conduction block (MMNCB). There is potential for under and over-treatment if trial regimens are strictly adhered to in clinical practice where titrating dose to clinical response is recommended.

METHODS

We report the response to high-dose IVIg (>2 g/kg/6 weeks) in a subgroup of patients with definite CIDP or MMNCB who were unresponsive to 'usual' dosing. IVIg frequency and dosing was determined for each individual by subjective and objective outcome measures for impairment, grip strength, and activity and participation.

RESULTS

Six patients (three with chronic inflammatory demyelinating polyneuropathy (CIDP), three with MMN) were included. Two patients (one CIDP and one MMNCB) returned to full-time work on fractionated IVIg doses of 5 g/kg/month and 9 g/kg/month. Patient three (CIDP) failed numerous other immunosuppressants but responded to short-term fractionated 4 g/kg/month of IVIg. Patient four has severe, refractory, childhood-onset CIDP, remains stable but dependent currently on 6.9 g/kg/month of IVIg. Patients five and six, both with MMNCB, required short term 4.5-5 g/kg/month to recover significant bilateral hand strength. No IVIg-related adverse events occurred in any individual.

CONCLUSIONS

These six cases demonstrate the safety and effectiveness of a treatment approach that includes individualised but evidence-based clinical assessment and, when necessary, high-doses of IVIg to restore patients' strength and ability to participate in activities of daily activities. Careful patient selection is important.

Efficacy and safety of high infusion rate IVIG in CIDP

BACKGROUND

We aimed to determine the safety and tolerance of higher rates of infusion of intravenous immunoglobulin (IVIG) in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

Patients began infusions with 10% IVIG at the standard rate of 0.08 mL/kg/min. If tolerated, infusion rates were incrementally increased to 0.14 mL/kg/min. We considered the frequency of infusions with adverse events (AEs) as the primary outcome.

RESULTS

Nineteen of 25 patients safely tolerated the maximum rate of 0.14 mL/kg/min. We observed 25 treatment-related AEs (TAEs) over 13 infusions at standard or transitional rates, across seven patients. We observed no TAEs associated with the maximum infusion rate.

CONCLUSIONS

We found that 10% IVIG can be safely administered at a high infusion rate (0.14 ml/kg/min) in most CIDP patients, reducing the treatment time and burden on healthcare resources.

Fatigue in chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

In this study we aimed to better understand fatigue in chronic inflammatory demyelinating polyneuropathy (CIDP) as it relates to disease activity status.

METHODS

Patients with probable or definite CIDP were stratified into active CIDP or CIDP in remission. Assessments of fatigue, physical impairment, disability, sleepiness, sleep quality, and depression were collected.

RESULTS

Of the 85 patients included in the study, 46 (54%) had active disease, whereas 39 (46%) were in remission. Fatigue was substantial in both groups, but was more severe in the active group. Use of sedating medications was a major contributor to fatigue. Sleep quality was poor in both groups, whereas depression more commonly affected those with active CIDP. Inflammatory Neuropathy Cause and Treatment disability, poor sleep quality, and higher level of depression had the greatest effect on fatigue severity.

DISCUSSION

Fatigue is common in CIDP regardless of the disease activity state. Minimizing sedating medications, improving sleep quality, and managing depression may improve CIDP-associated fatigue.

Refractory Chronic Immune-mediated Demyelinating Polyneuropathy

Please verify term, "alternative". Chronic immune-mediated demyelinating polyneuropathy (CIDP) is a treatable immune-related demyelinating polyneuropathy. Approximately 20% of cases do not respond to first-line therapies; most of these cases are due to alternative diagnoses, although some of them are due to severe CIDP. Unfortunately, a lack of universally accepted diagnostic criteria complicates the course of diagnosis and treatment. This article discusses videos of cases referred to a tertiary medical center for "refractory CIDP" and pitfalls in the diagnosis and management of this condition.

Nerve ultrasound for diagnosing chronic inflammatory neuropathy: A multicenter validation study

OBJECTIVE

To validate the diagnostic accuracy of a previously described short sonographic protocol to identify chronic inflammatory neuropathy (CIN), including chronic inflammatory demyelinating polyneuropathy (CIDP), Lewis Sumner syndrome, and multifocal motor neuropathy (MMN), and to determine the added value of nerve ultrasound to detect treatment-responsive patients compared to nerve conduction studies (NCS) in a prospective multicenter study.

METHODS

We included 100 consecutive patients clinically suspected of CIN in 3 centers. The study protocol consisted of neurologic examination, laboratory tests, NCS, and nerve ultrasound. We validated a short sonographic protocol (median nerve at forearm, upper arm, and C5 nerve root) and determined its diagnostic accuracy using the European Federation of Neurological Societies/Peripheral Nerve Society criteria of CIDP/MMN (reference standard). In addition, to determine the added value of nerve ultrasound in detecting treatment-responsive patients, we used previously published diagnostic criteria based on clinical, NCS, and sonographic findings and treatment response (alternative reference standard).

RESULTS

Sensitivity and specificity of the sonographic protocol for CIN according to the reference standard were 87.4% and 67.3%, respectively. Sensitivity and specificity of this protocol according to the alternative reference standard were 84.6% and 72.8%, respectively, and of NCS 76.1% and 93.4%. With addition of nerve ultrasound, 44 diagnoses of CIN were established compared to 33 diagnoses with NCS alone.

CONCLUSIONS

A short sonographic protocol shows high diagnostic accuracy for detecting CIN. Nerve ultrasound is able to detect up to 25% more patients who respond to treatment.

CLASSIFICATION OF EVIDENCE

This multicenter study provides Class IV evidence that nerve ultrasound improves diagnosis of CIN.

Diagnosis of peripheral neuropathy

Introduction

Peripheral neuropathy represents a spectrum of diseases with different etiologies. The most common causes are diabetes, exposure to toxic substances including alcohol and chemotherapeutics, immune-mediated conditions, and gene mutations. A thorough workup including clinical history and examination, nerve conduction studies, and comprehensive laboratory tests is warranted to identify treatable causes.

First steps

The variability of symptoms allows distinguishing characteristic clinical phenotypes of peripheral neuropathy that should be recognized in order to stratify the diagnostic workup accordingly. Nerve conduction studies are essential to determine the phenotype (axonal versus demyelinating) and severity. Laboratory tests, including genetic testing, CSF examination, nerve imaging, and nerve biopsy, represent additional clinical tests that can be useful in specific clinical scenarios.

Comments

We propose a flow chart based on five common basic clinical patterns of peripheral neuropathy. Based on these five clinical phenotypes, we suggest differential diagnostic pathways in order to establish the underlying cause.

Conclusions

The recognition of characteristic clinical phenotypes combined with nerve conduction studies allows pursuing subsequent diagnostic pathways that incorporate nerve conduction studies and additional diagnostic tests. This two-tiered approach promises higher yield and better cost-effectiveness in the diagnostic workup in patients with peripheral neuropathy.

MRI quantifies lumbosacral nerve root and sciatic nerve hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy

PURPOSE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable, immune-mediated condition characterised by progressive or relapsing motor and sensory neurological deficits. The diagnosis is based on a combination of clinical, neurophysiological and supportive criteria, but can be challenging. In this study, we quantified the diameter and cross-sectional area of the lumbosacral nerve roots, and explored the imaging characteristics of the sciatic nerves, in patients with CIDP versus healthy controls using MRI.

METHODS

MRI of the lumbosacral plexus and both thighs was performed at 3 T. Orthogonal diameter and cross-sectional area of the lumbosacral nerve roots were measured, along with sciatic nerve cross-sectional area at the mid-thigh level. The MRI appearance of the sciatic nerves was also evaluated qualitatively. All measurements were performed by an observer blinded to the diagnosis.

RESULTS

10 patients with CIDP and 10 healthy controls (age and sex-matched) were studied. Lumbosacral nerve root diameter and cross-sectional area were significantly increased in patients with CIDP compared to controls (mean diameter 6.0 ± 1.1 mm vs 4.8 ± 0.3 mm; p = 0.006), with a high sensitivity (89 %) and specificity (90 %) on ROC analysis. Sciatic nerve cross sectional area was also significantly increased in the CIDP group, and was accompanied by qualitative MRI changes.

CONCLUSIONS

Quantitative MRI reveals significant hypertrophy of the lumbosacral nerve roots and sciatic nerves in patients with CIDP compared to controls. This study provides further evidence for the inclusion of lumbosacral nerve root and sciatic nerve hypertrophy on MRI as a supportive feature in the diagnostic criteria for CIDP.

Immunoadsorption and Plasma Exchange in Seropositive and Seronegative Immune-Mediated Neuropathies

The inflammatory neuropathies are disabling conditions with diverse immunological mechanisms. In some, a pathogenic role for immunoglobulin G (IgG)-class autoantibodies is increasingly appreciated, and immunoadsorption (IA) may therefore be a useful therapeutic option. We reviewed the use of and response to IA or plasma exchange (PLEx) in a cohort of 41 patients with nodal/paranodal antibodies identified from a total of 573 individuals with suspected inflammatory neuropathies during the course of routine diagnostic testing (PNAb cohort). 20 patients had been treated with PLEx and 4 with IA. Following a global but subjective evaluation by their treating clinicians, none of these patients were judged to have had a good response to either of these treatment modalities. Sequential serology of one PNAb+ case suggests prolonged suppression of antibody levels with frequent apheresis cycles or adjuvant therapies, may be required for effective treatment. We further retrospectively evaluated the serological status of 40 patients with either Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinating polyneuropathy (CIDP), and a control group of 20 patients with clinically-isolated syndrome/multiple sclerosis (CIS/MS), who had all been treated with IgG-depleting IA (IA cohort). 32 of these patients (8/20 with CIDP, 13/20 with GBS, 11/20 with MS) were judged responsive to apheresis despite none of the serum samples from this cohort testing positive for IgG antibodies against glycolipids or nodal/paranodal cell-adhesion molecules. Although negative on antigen specific assays, three patients' pre-treatment sera and eluates were reactive against different components of myelinating co-cultures. In summary, preliminary evidence suggests that GBS/CIDP patients without detectable IgG antibodies on routine diagnostic tests may nevertheless benefit from IA, and that an unbiased screening approach using myelinating co-cultures may assist in the detection of further autoantibodies which remain to be identified in such patients.

Phenotypes of Late-Onset Transthyretin Amyloid Neuropathy: A Diagnostic Challenge

Hereditary transthyretin amyloidosis (hATTR) is a rare cause of severe neuropathy, typically with progressive sensorimotor and autonomic manifestations. The clinical course is marked by progressive worsening with typical survival of 7-11 years following the onset of symptoms. The phenotype may resemble other types of neuropathy, and dysautonomia may be absent at onset delaying the diagnosis. Two medications were recently approved for treatment of hATTR neuropathy in the United States and more may follow. Three major phenotypes of hATTR include neuropathic, cardiac, and mixed. Diagnostic clues include "red-flag" symptoms reflecting typical multisystem involvement, often presenting with cardiomyopathy, gastrointestinal dysmotility, or kidney insufficiency. We present a case series of 4 patients with late-onset hATTR neuropathy who were initially diagnosed with vasculitic neuropathy and chronic inflammatory demyelinating polyneuropathy to illustrate diagnostic challenges encountered with hATTR. Early diagnosis is even more urgent now given the availability of disease modifying treatments.

Pathological Findings in Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Single-Center Experience

Objective: Segmental demyelination is the pathological hallmark of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but other elementary lesions are frequently observed, configuring a series of different pathological pictures. In this article, we review the pathological findings of a large series of sural nerve biopsies from our cohort of CIDP patients. Patients and Methods: Patients with CIDP who underwent nerve biopsy were retrospectively selected from those referred to the Institute of Neurology of the “Università Cattolica del Sacro Cuore” in Rome, Italy, from 1982 to February 2020. Sural nerve biopsy was performed according to standard protocols. Results: Sural nerve biopsy was performed in 43/130 CIDP patients. Demyelinating abnormalities and axonal loss were found in 67.4% and 83.7% of biopsies, respectively. Conversely, onion bulbs and inflammatory infiltrates were rare (18.6% and 4.7%, respectively). In three cases, we observed normal pathological findings. Conclusions: A pathognomonic pathological finding of CIDP cannot be established, but we confirm the utility of nerve biopsy in this setting to confirm the diagnosis (also in atypical phenotypes) and to elucidate pathogenic mechanisms.

Home monitoring of maintenance intravenous immunoglobulin therapy in patients with chronic inflammatory neuropathy

To evaluate the utility of different outcome measures to monitor dose adjustment of intravenous immunoglobulin (IVIg) therapy in patients with chronic inflammatory neuropathy (CIN). We assessed the adjustment of IVIg maintenance therapy in 20 patients (10 CIDP and 10 MMN) by regularly monitoring grip strength (GS) using a Martin Vigorimeter, RODS, and quality of life using the SF-36 questionnaire. These measures were regularly performed by the patient at home. We also assessed the extended MRC sumscore (eMRC sumscore) at each outpatient visit for IVIg infusion. We also enrolled 30 healthy controls to measure any possible training effect of GS with time and to analyze random fluctuation of GS. Clinically relevant change was detected by eMRC sumscore in 14 (93%) patients, by RODS in 11 (73%) patients, and by GS in 8 (53%) patients. Early sensitivity was greatest for RODS (73%), followed by GS (53%), and eMRC sumscore (27%). This differed from CIDP, with an early change in RODS in 100% of patients, and MMN with an early change in GS in 75%. None of the outcome measures alone was sufficient to detect clinically significant changes in all patients. Home monitoring of outcome measures objectively assisted clinical decision during individualization of IVIg treatment. We recommend a multimodal approach using different outcome measures to monitor the individual patient with CIN.

Electrodiagnostic accuracy in polyneuropathies: supervised learning algorithms as a tool for practitioners

OBJECTIVE

The interpretation of electrophysiological findings may lead to misdiagnosis in polyneuropathies. We investigated the electrodiagnostic accuracy of three supervised learning algorithms (SLAs): shrinkage discriminant analysis, multinomial logistic regression, and support vector machine (SVM), and three expert and three trainee neurophysiologists.

METHODS

We enrolled 434 subjects with the following diagnoses: chronic inflammatory demyelinating polyneuropathy (99), Charcot-Marie-Tooth disease type 1A (124), hereditary neuropathy with liability to pressure palsy (46), diabetic polyneuropathy (67), and controls (98). In each diagnostic class, 90% of subjects were used as training set for SLAs to establish the best performing SLA by tenfold cross validation procedure and 10% of subjects were employed as test set. Performance indicators were accuracy, precision, sensitivity, and specificity.

RESULTS

SVM showed the highest overall diagnostic accuracy both in training and test sets (90.5 and 93.2%) and ranked first in a multidimensional comparison analysis. Overall accuracy of neurophysiologists ranged from 54.5 to 81.8%.

CONCLUSIONS

This proof of principle study shows that SVM provides a high electrodiagnostic accuracy in polyneuropathies. We suggest that the use of SLAs in electrodiagnosis should be exploited to possibly provide a diagnostic support system especially helpful for the less experienced practitioners.

Contactin-1 autoimmunity: Serologic, neurologic, and pathologic correlates

OBJECTIVE

To determine serologic characteristics, frequency, phenotype, paraneoplastic associations, and electrodiagnostic and histopathologic features accompanying contactin-1 autoimmunity.

METHODS

Archived sera known to produce synaptic tissue-based immunofluorescence patterns were reevaluated, and contactin-1 specificity was confirmed by recombinant protein assays. Screening of 233 chronic/relapsing demyelinating neuropathies for additional cases was performed.

RESULTS

We identified 10 contactin-1 IgG seropositive cases. Frequency of contactin-1 immunoglobulin (Ig) G among tested Mayo Clinic chronic/relapsing demyelinating neuropathies was 2%. Sensory predominant presentations (n = 9, 90%), neuropathic pain (n = 6, 60%), and subacute progression (n = 5, 50%) were commonly encountered among contactin-1 neuropathies. Two patients had chronic immune sensory polyradiculopathy-like phenotype at presentation. Electrodiagnostic studies were consistent with demyelination (slowed conduction velocities and/or prolonged distal latencies) without conduction block. Markedly elevated CSF protein (median 222 mg/dL, range 69-960 mg/dL), thickening/gadolinium enhancement of nerve roots (4/5), and subperineural edema on nerve biopsy (4/4) were other characteristic features. Three cases were diagnosed with paraneoplastic demyelinating neuropathies (thymoma, n = 1; breast cancer, n = 1; plasmacytoma, n = 1). Four of the 9 patients treated with IV immunoglobulin demonstrated initial clinical improvement, but the favorable response was sustained in only 1 case (median follow-up, 60 months). Sustained clinical stabilization or improvement was observed among 3 of the 6 cases in whom second-line therapies (rituximab, cyclophosphamide, and azathioprine) were used.

CONCLUSION

Contactin-1 IgG has a distinct sensory predominant presentation commonly associated with neuropathic pain, with demyelinating changes on electrophysiologic studies. A paraneoplastic cause should be considered. Testing of contactin-1 IgG among cases with similar presentations may guide immunotherapy selection, especially second-line immunotherapy consideration.

Long-term treatment with subcutaneous immunoglobulin in patients with chronic inflammatory demyelinating polyradiculoneuropathy: a follow-up period up to 7 years

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a rare and heterogeneous acquired sensory-motor polyneuropathy with autoimmune pathogenesis. Intravenous immunoglobulins (IVIG) are a well-established therapy for CIDP: it is well known that at least two-thirds of these patients need these infusions for several years. More recently, Subcutaneous Immunoglobulins (SCIg) have been proved to be effective: this finding has been confirmed either in isolated cases or in few randomized trials. However, it appeared that the longest SCIg treatment follow up lasted no longer than 48 months. We report herein the results of a long-term SCIg treatment with a follow up period up to 7 years (84 months), considering safety, tolerability and patients’ perception of SCIg treatment in a CIDP population. We studied 17 patients (10 M; 7 F) with a diagnosis of CIDP, defined according to the EFNS/PNS criteria, successfully treated with IVIG every 4/6 weeks before being switched to SCIg treatment. Clinical follow-up included, apart from a routinely clinical assessment, the administration of Medical Research Council (MRC) sum-score, the Overall Neuropathy Limitation Scale (ONLS) and the Life Quality Index questionnaire (LQI). The results showed that, in the majority of this pre-selected group of CIDP patients (16/17), SCIg were well tolerated and were preferred over IVIG. Strength and motor functions remained stable or even improved during the long term follow-up (up to 84 months) with benefits on walking capability and resistance, manual activity performances and fatigue reduction.

Daily grip strength response to intravenous immunoglobulin in chronic immune neuropathies

INTRODUCTION

Monitoring grip strength at home may detect improvement between intravenous immunoglobulin (IVIg) treatments in patients with chronic inflammatory neuropathies (CINs).

METHODS

Fifteen patients recorded grip strength each day, from one IVIg treatment until the next. We analyzed grip strength changes comparing thresholds of 8 kPa and 14 kPa. "Random" fluctuations of grip strength were distinguished from treatment response by smoothing the data.

RESULTS

"Random" fluctuations of at least 8 kPa occurred in 27% of patients. Smoothed daily grip strength increased by at least 8 kPa above baseline in 11 (73%) patients. Grip strength increased by at least 8 kPa for 3 consecutive days in 9 (60%) patients, and 5-day block mean increased by at least 8 kPa in 10 (67%) patients.

DISCUSSION

Home monitoring of grip strength confirmed treatment response in most patients with CINs on IVIg. To detect improvement in an individual patient, we suggest a threshold of at least 8 kPa on 3 consecutive days or on 5-day block mean.

Sustained response to subcutaneous immunoglobulins in chronic ataxic neuropathy with anti-disialosyl IgM antibodies (CANDA): report of two cases and review of the literature

INTRODUCTION

Chronic ataxic neuropathy with anti-disialosyl IgM antibodies (CANDA) is a rare disorder for which the pathological, neurophysiological, and therapeutic evidence remains anecdotal and controversial.

METHODS

This report on CANDA focuses on the neurophysiological patterns and treatment responses shared by two cases. One patient underwent nerve ultrasound follow-up. A comprehensive review of the literature highlighted the diverse experiences with different treatment options.

RESULTS

Response to different therapies was similar in both patients: intravenous immunoglobulins achieved a favorable response albeit with significant wearing-off fluctuations; treatment with subcutaneous immunoglobulins (SCIg) was an effective alternative leading to a clinical response for at least 2 years. Rituximab, which was trialed in both patients, was not continued long enough to determine its efficacy in modifying the disease course and/or modulating responsiveness to immunoglobulins. Steroids caused clinical worsening in both patients.

CONCLUSIONS

Immunoglobulin therapy appeared as the most effective in the treatment of these two patients. SCIg provided an effective treatment option for the long-term management of CANDA.

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.

Dose Adjustment of Subcutaneous IgG in Chronic Inflammatory Demyelinating Polyneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated neuropathy that is characterized by a slowly progressive sensory and motor involvement lasting at least 2 months. We present a CIDP patient on subcutaneous Ig (SCIg). Upon fine-tuning his dose from 24 to 28 g/week, this showed a dramatic improvement in both hand grip (13-25%) and dorsiflexion (73-278%). Follow-up nerve conduction studies also demonstrated significant improvements in latencies, motor amplitudes, and conduction velocities. Ongoing surveillance of CIDP patients receiving SCIg therapy is therefore necessary to ensure therapeutic optimization.

[Chronic dysimmune hypertrophic plexopathy as a variant of atypical chronic inflammatory demyelinating polyneuropathy]

The authors report the clinical case of a 7-year-old child with gradual development in left leg weakness considering by the neurologist as the unknown lesion of the sciatic nerve. According to the results of clinical and instrumental examinations, the diagnosis was established as a focal form of chronic inflammatory demyelinating polyneuropathy (CIDP). The dysimmune cause of the disease was confirmed by MRI of the lumbosacral plexus with contrast enhancement of neural structures and response to therapy with high-dose intravenous immunoglobulin in combination with corticosteroids.

Nerve ultrasound improves detection of treatment-responsive chronic inflammatory neuropathies

OBJECTIVE

To examine the diagnostic accuracy of nerve ultrasound in a prospective cohort of consecutive patients with a clinical suspicion of chronic inflammatory neuropathies, including chronic inflammatory demyelinating polyneuropathy, Lewis-Sumner syndrome, and multifocal motor neuropathy, and to determine the added value in the detection of treatment-responsive patients.

METHODS

Between February 2015 and July 2018, we included 100 consecutive incident patients with a clinical suspicion of chronic inflammatory neuropathy. All patients underwent nerve ultrasound, extensive standardized nerve conduction studies (NCS), and other relevant diagnostic investigations. We evaluated treatment response using predefined criteria. A diagnosis of chronic inflammatory neuropathy was established when NCS were abnormal (fulfilling criteria of demyelination of the European Federation of Neurological Societies/Peripheral Nerve Society) or when the degree of nerve enlargement detected by sonography was compatible with chronic inflammatory neuropathy and there was response to treatment.

RESULTS

A diagnosis of chronic inflammatory neuropathy was established in 38 patients. Sensitivity and specificity of nerve ultrasound and NCS were 97.4% and 69.4% and 78.9% and 93.5%, respectively. The added value of nerve ultrasound in detection of treatment-responsive chronic inflammatory neuropathy was 21.1% compared to NCS alone.

CONCLUSIONS

Nerve ultrasound and NCS are complementary techniques with superior sensitivity in the former and specificity in the latter. Addition of nerve ultrasound significantly improves the detection of chronic inflammatory neuropathies. Therefore, it deserves a prominent place in the diagnostic workup of chronic inflammatory neuropathies.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that nerve ultrasound is an accurate diagnostic tool to detect chronic inflammatory neuropathies.

Antibodies to neurofascin, contactin-1, and contactin-associated protein 1 in CIDP: Clinical relevance of IgG isotype

OBJECTIVE

To assess the prevalence and isotypes of anti-nodal/paranodal antibodies to nodal/paranodal proteins in a large chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) cohort, compare clinical features in seronegative vs seropositive patients, and gather evidence of their isotype-specific pathogenic role.

METHODS

Antibodies to neurofascin-155 (Nfasc155), neurofascin-140/186 (Nfasc140/186), contactin-1 (CNTN1), and contactin-associated protein 1 (Caspr1) were detected with ELISA and/or cell-based assay. Antibody pathogenicity was tested by immunohistochemistry on skin biopsy, intraneural injection, and cell aggregation assay.

RESULTS

Of 342 patients with CIDP, 19 (5.5%) had antibodies against Nfasc155 (n = 9), Nfasc140/186 and Nfasc155 (n = 1), CNTN1 (n = 3), and Caspr1 (n = 6). Antibodies were absent from healthy and disease controls, including neuropathies of different causes, and were mostly detected in patients with European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) definite CIDP (n = 18). Predominant antibody isotypes were immunoglobulin G (IgG)4 (n = 13), IgG3 (n = 2), IgG1 (n = 2), or undetectable (n = 2). IgG4 antibody-associated phenotypes included onset before 30 years, severe neuropathy, subacute onset, tremor, sensory ataxia, and poor response to intravenous immunoglobulin (IVIG). Immunosuppressive treatments, including rituximab, cyclophosphamide, and methotrexate, proved effective if started early in IVIG-resistant IgG4-seropositive cases. Five patients with an IgG1, IgG3, or undetectable isotype showed clinical features indistinguishable from seronegative patients, including good response to IVIG. IgG4 autoantibodies were associated with morphological changes at paranodes in patients' skin biopsies. We also provided preliminary evidence from a single patient about the pathogenicity of anti-Caspr1 IgG4, showing their ability to penetrate paranodal regions and disrupt the integrity of the Nfasc155/CNTN1/Caspr1 complex.

CONCLUSIONS

Our findings confirm previous data on the tight clinico-serological correlation between antibodies to nodal/paranodal proteins and CIDP. Despite the low prevalence, testing for their presence and isotype could ultimately be part of the diagnostic workup in suspected inflammatory demyelinating neuropathy to improve diagnostic accuracy and guide treatment.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that antibodies to nodal/paranodal proteins identify patients with CIDP (sensitivity 6%, specificity 100%).

[A women with aplastic anemia developed chronic inflammatory demyelinating polyneuropathy]

A 66-year-old female developed chronic inflammatory demyelinating polyneuropathy (CIDP) one year after the diagnosis of aplastic anemia. High-dose intravenous immunoglobulin (IVIg) therapy, followed by IVIg maintenance therapy, rapidly improved her weakness and hyperesthesia in four extremities. In addition, pancytopenia caused by aplastic anemia also improved following IVIg treatment in parallel. This is the first report to show the co-existence of CIDP and aplastic anemia, and a common pathomechanism may be present in these two rare autoimmune disorders.

Unique HLA haplotype associations in IgG4 anti-neurofascin 155 antibody-positive chronic inflammatory demyelinating polyneuropathy

To clarify the immunogenetic background of patients with immunoglobulin G (IgG)4 anti-neurofascin 155 (NF155) antibody-positive chronic inflammatory demyelinating polyneuropathy (CIDP), we genotyped the extended human leukocyte antigen (HLA) haplotypes in 22 Japanese patients with this disorder and compared them with those of healthy Japanese controls. All IgG4 anti-NF155 antibody-positive CIDP patients exclusively carried either HLA-DRB1*15:01-DRB5*01:01-DQA1*01:02-DQB1*06:02 or -(A*24:02)-B*52:01-C*12:02-DRB1*15:02-DRB5*01:02-DQA1*01:03-DQB1*06:01, resulting in significantly increased HLA-DRB1*15, -DRB1*15:01, -DQB1*06:01/06:02, -DQB1*06:02, and -DRB1*15:01-DQB1*06:02 frequencies compared with healthy Japanese controls. These findings indicate the involvement of specific HLA class II molecules in the pathomechanisms of IgG4 anti-NF155 antibody-positive CIDP.

Improving Intravenous Immunoglobulin Dosing in Autoimmune Neuropathies

This symposium took place on Monday 24th June 2019, as part of the 2019 Peripheral Nerve Society (PNS) Annual Meeting in Genoa, Italy. Immune-mediated neuropathies such as Guillain–Barré Syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and multifocal motor neuropathy (MMN) are diverse inflammatory peripheral nerve disorders. International consensus guidelines recommend intravenous Ig (IVIG) as Level A for the treatment of GBS, CIDP, and MMN. Suggested induction doses of IVIG are 2 g/kg divided over 2–5 days, but maintenance doses are purposely less clearly defined and left up to the judgement of the clinician, depending upon the specific needs of the individual patient. Community-based neurologists treating patients with these rare inflammatory neuropathies may be unaware of optimal dosing regimens and patient response to treatment may therefore be inadequate. In this symposium, world-renowned experts in GBS, CIDP, and MMN shared their expertise and review of the literature to provide reasonable dosing regimens for neurologists who may rarely encounter these conditions.

Distinctive patterns of peripheral neuropathy across the spectrum of plasma cell disorders

Many patients with plasma cell disorders suffer from peripheral neuropathy, but differential diagnosis with chronic inflammatory demyelinating polyneuropathy (CIDP) is difficult. We aimed to (1) identify factors useful for differential diagnosis between peripheral neuropathy associated with plasma cell disorders versus CIDP and (2) determine whether neuropathy presentations and severity varied across the spectrum of different plasma cell disorders. A retrospective chart review of 18 monoclonal gammopathy of unknown significance (MGUS) patients, 15 POEMS syndrome patients and 34 CIDP patients between January 2005 and December 2016 was conducted. The peripheral neuropathy associated with plasma cell disorders seemed to be more sensory oriented compared to CIDP. MGUS patients were significantly older than CIDP patients (median age 70 vs. 59, respectively, p = 0.027). POEMS syndrome patients showed significantly higher platelet count at the time of neuropathy presentation compared to CIDP (p = 0.028). Lambda type MGUS patients were associated with less severe symptoms compared to POEMS syndrome patients despite harboring lambda monoclonal gammopathy as a common denominator. Kappa type MGUS patients showed predominantly axonal type neuropathy compared to its counterpart and POEMS syndrome. Careful inspection of clinical profiles and symptoms of patients presenting with neuropathy can help to discriminate those with underlying plasma cell disorders. The phenotype of neuropathy, platelet count and age at presentation seem to be the most useful indicators.

Serum CXCL13 reflects local B-cell mediated inflammatory demyelinating peripheral neuropathy

Immune damages on the peripheral myelin sheath under pro-inflammatory milieu result in primary demyelination in inflammatory demyelinating neuropathy. Inflammatory cytokines implicating in the pathogenesis of inflammatory demyelinating neuropathy have been used for the development of potential biomarkers for the diagnosis of the diseases. In this study, we have found that macrophages, which induce demyelination, expressed a B-cell-recruiting factor CXC chemokine ligand 13 (CXCL13) in mouse and human inflammatory demyelinating nerves. The serum levels of CXCL13 were also higher in inflammatory demyelinating neuropathic patients but not in acute motor axonal neuropathy or a hereditary demyelinating neuropathy, Charcot-Marie-Tooth disease type 1a. In addition, CXCL13-expressing macrophages were not observed in the sciatic nerves after axonal injury, which causes the activation of innate immunity and Wallerian demyelination. Our findings indicate that the detection of serum CXCL13 will be useful to specifically recognize inflammatory demyelinating neuropathies in human.

Prognostic factor of poor outcome in anti-MAG neuropathy: clinical and electrophysiological analysis of a French Cohort

BACKGROUND

Anti-MAG polyneuropathy (anti-MAG PN) is an immune-mediated peripheral sensorimotor neuropathy characterized by distal demyelination and ataxia. However, this disorder, unlike other immune-mediated neuropathies, is difficult to treat in most cases.

METHOD

We retrospectively collected all anti-MAG PN patients followed in two hospitals for a period of 12 years to determine prognostic factors, especially those that indicated a good response to the various therapeutic strategies used.

RESULTS

Forty-seven patients were included in the study; of these, 61% had a classical 'distal demyelinating pattern', 34.2% had a 'CIDP-like pattern', and the others had an 'axonal pattern'. The most commonly used treatments were intravenous immunoglobulin (IVIg) as the first-line treatment and rituximab as the second- or third-line treatment. No prognostic factor was identified for IVIg, but electrophysiological parameters at onset were better in patients with a good response to rituximab than in non-responder patients, even though mild or high disability was observed in nearly half the patients at last examination.

CONCLUSION

Even though disability seems to progress in most cases despite the treatments used, our results suggest that an early electrophysiological reduction in sensory nerves could be considered a 'red flag' for the prompt initiation of rituximab to try to delay long-term disability.

Immunoglobulin administration for the treatment of CIDP: IVIG or SCIG?

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired neurological disorder characterized clinically by weakness and impaired sensory function evolving over 2 months or more, loss or significant decrease in deep tendon reflexes, and by electrophysiological evidence of peripheral nerve demyelination. Expeditious diagnosis and treatment of CIDP early in the disease course is critical such that irreversible disability can be avoided. Intravenous immunoglobulin (IVIG) is one first-line and maintenance therapy option for CIDP. The US Food & Drug Administration's (FDA's) approval of subcutaneous immunoglobulin (SCIG) in 2018 provides patients with CIDP more treatment options for maintenance therapy. The different options for administration of IG treatment create the need for information to assist clinicians and patients in choosing the optimal therapeutic approach. Considerations for pharmacokinetics, administration procedures, adverse events, patient variables, and cost will all be discussed in this article.

Intrathecal cytokine profile in neuropathy with anti-neurofascin 155 antibody

Objective

To characterize the CSF cytokine profile in chronic inflammatory demyelinating polyneuropathy (CIDP) patients with IgG4 anti‐neurofascin 155 (NF155) antibodies (NF155⁺ CIDP) or those lacking anti‐NF155 antibodies (NF155⁻ CIDP).

Methods

Twenty‐eight CSF cytokines/chemokines/growth factors were measured by multiplexed fluorescent immunoassay in 35 patients with NF155⁺ CIDP, 36 with NF155⁻ CIDP, and 28 with non‐inflammatory neurological disease (NIND).

Results

CSF CXCL8/IL‐8, IL‐13, TNF‐α, CCL11/eotaxin, CCL2/MCP‐1, and IFN‐γ were significantly higher, while IL‐1β, IL‐1ra, and G‐CSF were lower, in NF155⁺ CIDP than in NIND. Compared with NF155⁻ CIDP, CXCL8/IL‐8 and IL‐13 were significantly higher, and IL‐1β, IL‐1ra, and IL‐6 were lower, in NF155⁺ CIDP. CXCL8/IL‐8, IL‐13, CCL11/eotaxin, CXCL10/IP‐10, CCL3/MIP‐1α, CCL4/MIP‐1β, and TNF‐α levels were positively correlated with markedly elevated CSF protein, while IL‐13, CCL11/eotaxin, and IL‐17 levels were positively correlated with increased CSF cell counts. IL‐13, CXCL8/IL‐8, CCL4/MIP‐1β, CCL3/MIP‐1α, and CCL5/RANTES were decreased by combined immunotherapies in nine NF155⁺ CIDP patients examined longitudinally. By contrast, NF155⁻ CIDP had significantly increased IFN‐γ compared with NIND, and exhibited positive correlations of IFN‐γ, CXCL10/IP‐10, and CXCL8/IL‐8 with CSF protein. Canonical discriminant analysis of cytokines/chemokines revealed that NF155⁺ and NF155⁻ CIDP were separable, and that IL‐4, IL‐10, and IL‐13 were the three most significant discriminators.

Interpretation

Intrathecal upregulation of type 2 helper T (Th2) cell cytokines is characteristic of IgG4 NF155⁺ CIDP, while type 1 helper T cell cytokines are increased in CIDP regardless of the presence or absence of anti‐NF155 antibodies, suggesting that overproduction of Th2 cell cytokines is unique to NF155⁺ CIDP.

Chronic inflammatory demyelinating polyneuropathy with anti-NF155 IgG4 in China

Patients with chronic inflammatory demyelinating polyneuropathy (CIDP) seropositive for autoantibodies against nodal and paranodal proteins display distinct clinical presentations. We herein tested for autoantibodies against neurofascin (NF) 155, NF186, contactin-associated protein 1 and contactin-1 and investigated the autoantibody-related clinical features in 29 patients with CIDP from China. Six patients with anti-NF155 IgG4 antibodies displayed younger age of onset and poor response to intravenous immunoglobulin than seronegative patients. One patient had anti-NF186 IgG antibody and no patients had anti-contactin-associated protein 1 or anti-contactin-1 antibodies. Clinical features of CIDP patients with anti-NF155 antibodies in China were similar to those reported in other countries.

Human leukocyte antigens class II in CIDP spectrum neuropathies

CIDP spectrum encompasses several clinical variants and the reasons of the heterogeneous clinical expression and the variable response to therapy are scarcely known. HLA associations are common in dysimmune conditions. In CIDP, few studies reported no associations or HLA-DR13/DQ6 association in some populations but, to date, a clear confirmed association is lacking. We analyzed expression of HLA-DR and DQ haplotypes in 24 CIDP patients and 216 healthy subject. HLA-DR3 and DR3/DQ2 were significantly more frequent in CIDP patients than in the control group. The DR3 and DR3/DQ2 positive patients present with more frequent relapsing course, worse response to IVIg, higher inflammatory neuropathy sensory sumscore (ISS) and Rotterdam Inflammatory Neuropathy Cause and Treatment Scale (INCAT) than negative patients.