Chronic inflammatory demyelinating polyneuropathy: clinical features and response to treatment in 67 consecutive patients with and without a monoclonal gammopathy

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.

Diagnostic value of nerve conduction study in NOTCH2NLC-related neuronal intranuclear inclusion disease

BACKGROUND AND AIMS

Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disorder mainly caused by abnormally expanded GGC repeats within the NOTCH2NLC gene. Most patients with NIID show polyneuropathy. Here, we aim to investigate diagnostic electrophysiological markers of NIID.

METHODS

In this retrospective dual-center study, we reviewed 96 patients with NOTCH2NLC-related NIID, 94 patients with genetically confirmed Charcot-Marie-Tooth (CMT) disease, and 62 control participants without history of peripheral neuropathy, who underwent nerve conduction studies between 2018 and 2022.

RESULTS

Peripheral nerve symptoms were presented by 53.1% of patients with NIID, whereas 97.9% of them showed peripheral neuropathy according to electrophysiological examinations. Patients with NIID were characterized by slight demyelinating sensorimotor polyneuropathy; some patients also showed mild axonal lesions. Motor nerve conduction velocity (MCV) of the median nerve usually exceeded 35 m/s, and were found to be negatively correlated with the GGC repeat sizes. Regarding the electrophysiological differences between muscle weakness type (n = 27) and non-muscle weakness type (n = 69) of NIID, nerve conduction abnormalities were more severe in the muscle weakness type involving both demyelination and axonal impairment. Notably, specific DWI subcortical lace sign was presented in only 33.3% of muscle weakness type, thus it was difficult to differentiate them from CMT. Combining age of onset, distal motor latency, and compound muscle action potential of the median nerve showed the optimal diagnostic performance to distinguish NIID from major CMT (AUC = 0.989, sensitivity = 92.6%, specificity = 97.4%).

INTERPRETATION

Peripheral polyneuropathy is common in NIID. Our study suggest that nerve conduction study is useful to discriminate NIID.

Clinical and pathophysiological implications of autoantibodies in autoimmune neuropathies

Autoimmune neuropathies are a heterogeneous group of rare and disabling diseases in which the immune system targets peripheral nervous system antigens and that respond to immune therapies. This review focuses on Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, polyneuropathy associated with IgM monoclonal gammopathy, and autoimmune nodopathies. Autoantibodies targeting gangliosides, proteins in the node of Ranvier, and myelin-associated glycoprotein have been described in these disorders, defining subgroups of patients with similar clinical features and response to therapy. This topical review describes the role of these autoantibodies in the pathogenesis of autoimmune neuropathies and their clinical and therapeutic importance.

Outcome in chronic inflammatory demyelinating polyneuropathy: A systematic review and meta-analysis

INTRODUCTION/AIMS

Outcomes in chronic inflammatory demyelinating polyneuropathy (CIDP) have been reported in longitudinal and cross-sectional studies. A considerable variation in long-term disease outcome has appeared in those reports. To overcome this uncertainty, a systematic review and meta-analysis was conducted on CIDP outcomes, including the parameters of case fatality rate, ambulation, physical ability, and remission.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search was conducted in PubMed and EMBASE (OVID) for reports with at least 2 years of follow-up on patients with active or previously active CIDP that were published no later than May 12, 2022. Studies were appraised for quality using the Joanna Briggs Institute Critical Appraisal Checklist for studies reporting prevalence data. Pooled analyses were conducted and the results were visualized using forest plots. The study protocol was registered prospectively on PROSPERO (CRD42021266903).

RESULTS

A total of 1290 titles were identified. Sixty-nine full-text articles were screened and 21 studies with 1199 patients were selected for the data analysis. The pooled case fatality rate was 3.3% (95% confidence interval [CI], 1.9% to 5.7%). The pooled fraction of nonambulatory patients was 8.2% (95% CI, 5.7% to 11.6%) and, overall, 47.1% (95% CI, 39.5% to 54.9%) of CIDP patients had a good outcome without disability. The pooled rate of remission was 40.8% (95% CI, 30.6% to 51.8%).

DISCUSSION

Future research is warranted on how to prevent long-term impairment in CIDP. Care should be taken in developing clinical strategies to avoid immunomodulating therapy in the many patients in remission.

Unclassified clinical presentations of chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

To assess the ability of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) clinical criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) to include within their classification the whole spectrum of clinical heterogeneity of the disease and to define the clinical characteristics of the unclassifiable clinical forms.

METHODS

The 2021 EAN/PNS clinical criteria for CIDP were applied to 329 patients fulfilling the electrodiagnostic (and in some cases also the supportive) criteria for the diagnosis of CIDP. Clinical characteristics were reviewed for each patient not strictly fulfilling the clinical criteria ('unclassifiable').

RESULTS

At study inclusion, 124 (37.5%) patients had an unclassifiable clinical presentation, including 110 (89%) with a typical CIDP-like clinical phenotype in whom some segments of the four limbs were unaffected by weakness ('incomplete typical CIDP'), 10 (8%) with a mild distal, symmetric, sensory or sensorimotor polyneuropathy confined to the lower limbs with cranial nerve involvement ('cranial nerve predominant CIDP') and 4 (1%) with a symmetric sensorimotor polyneuropathy limited to the proximal and distal areas of the lower limbs ('paraparetic CIDP'). Eighty-one (65%) patients maintained an unclassifiable presentation during the entire disease follow-up while 13 patients progressed to typical CIDP. Patients with the unclassifiable clinical forms compared with patients with typical CIDP had a milder form of CIDP, while there was no difference in the distribution patterns of demyelination.

CONCLUSIONS

A proportion of patients with CIDP do not strictly fulfil the 2021 EAN/PNS clinical criteria for diagnosis. These unclassifiable clinical phenotypes may pose diagnostic challenges and thus deserve more attention in clinical practice and research.

Vision Loss as a Presenting Feature of Chronic Inflammatory Demyelinating Polyneuropathy: A Case Series

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired, immune-mediated, and clinically heterogeneous demyelinating disease affecting the nerve roots and peripheral nerves. We report a series of 4 patients who presented with early and progressive vision loss in the context of new-onset CIDP: 3 due to papilledema and 1 due to optic neuropathy without papilledema.

METHODS

This was a retrospective case series of 4 patients with vision loss as a presenting feature of CIDP evaluated at the Hospital of the University of Pennsylvania from January 2016 to August 2021. Demographic, clinical, diagnostic, and treatment data were collected via retrospective medical record review.

RESULTS

Case 1 was a 51-year-old man with 2 months of progressive bilateral papilledema associated with reduced visual acuity (count fingers at 1 foot in each eye) and severely constricted visual fields. Case 2 was a 36-year-old man with 4 months of worsening headaches, reduced visual acuity (count fingers at 1 foot in each eye), severely constricted visual fields, and papilledema. Case 3 was a 39-year-old man with papilledema causing progressive vision loss (20/80 in both eyes), headaches, and relapsing limb sensorimotor deficits. Case 4 was a 19-year-old man with 3 months of progressive bilateral visual decline (20/400 in the right eye, 20/600 in the left eye), central scotoma, and optic disc pallor consistent with optic neuropathy without papilledema. All 4 patients met clinical and electrodiagnostic criteria of CIDP. Cases 3 and 4 each tested positive for serum neurofascin-155 IgG4 antibodies. All patients were managed with immunomodulatory therapy. Cases 1 and 2 also each required surgical intervention with bilateral optic nerve sheath fenestration and cerebrospinal fluid (CSF) shunting procedures.

CONCLUSION

Vision loss from optic neuropathy with or without papilledema has rarely been reported in CIDP, and typically has been described in the context of longstanding disease. Our cases highlight how CIDP can present with early vision loss that may be profound and challenging to manage if diagnosis is delayed. CIDP should be considered in any patient with new progressive vision loss when associated with peripheral sensorimotor symptoms and elevated CSF protein. The small subgroup of CIDP patients with neurofascin-155 antibodies may be at particular risk of optic nerve involvement.

Metabolic disorder and intestinal microflora dysbiosis in chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare acquired immune-mediated neuropathy. Although microbial infection is potentially a contributing factor, a causative link between CIDP and microbial infection remains unclear. There is also no definitive biomarker for CIDP diagnostics and therapies. The present study aimed to characterize the serum metabolic profile and gut microbiome structure in CIDP.

METHODS

Targeted metabolomics profiling of serum, using liquid chromatography-mass spectrometry, and metagenomics sequencing of stool samples from a cohort of CIDP and non-CIDP subjects were performed to evaluate serum metabolic profiles and gut microbiome structure in CIDP subjects relative to healthy controls.

RESULTS

Metabolome data revealed that the bile acids profile was perturbed in CIDP with bile acids and arachidonic acid enriched significantly in CIDP versus non-CIDP controls. Metagenome data revealed that opportunistic pathogens, such as Klebsiella pneumonia and Megamonas funiformis, and genes involved in bacterial infection were notably more abundant in CIDP subjects, while gut microbes related to biotransformation of secondary bile acids were abnormal in CIDP versus non-CIDP subjects. Correlation analysis revealed that changes in secondary bile acids were associated with altered gut microbes, including Bacteroides ovatus, Bacteroides caccae, and Ruminococcus gnavus.

CONCLUSION

Bile acids and arachidonic acid metabolism were disturbed in CIDP subjects and might be affected by the dysbiosis of gut microbial flora. These findings suggest that the combination of bile acids and arachidonic acid could be used as a CIDP biomarker and that modulation of gut microbiota might impact the clinical course of CIDP.

Acute/chronic inflammatory polyradiculoneuropathy

Autoimmune neuropathy may present acutely or with a more progressive and/or relapsing and remitting course. Acute inflammatory neuropathy or Guillain-Barré syndrome (GBS) has variable presentations but by far the most common is acute inflammatory demyelinating polyradiculoneuropathy which is characterized by rapidly progressive proximal and distal symmetric weakness, sensory loss, and depressed reflexes. The most common chronic autoimmune neuropathy is chronic inflammatory demyelinating polyradiculoneuropathy, which in its most typical form is clinically similar to acute inflammatory demyelinating polyradiculoneuropathy (proximal and distal symmetric weakness, sensory loss, and depressed reflexes) but differs in that onset is much more gradual, i.e., over at least 8 weeks. While the majority of GBS cases result from a postinfectious activation of the immune system, presumably in a genetically susceptible host, less is understood regarding the etiopathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy. Both acute and chronic forms of these inflammatory neuropathies are driven by some combination of innate and adaptive immune pathways, with differing contributions depending on the neuropathy subtype. Both disorders are largely clinical diagnoses, but diagnostic tools are available to confirm the diagnosis, prognosticate, detect variant forms, and rule out mimics. Given the autoimmune underpinnings of both disorders, immunosuppressive and immunomodulating treatments are typically given in both diseases; however, they differ in their response to treatment.

Monoclonal gammopathies of clinical significance (MGCS): In pursuit of optimal treatment

Monoclonal gammopathy of clinical significance (MGCS) represents a new clinical entity referring to a myriad of pathological conditions associated with the monoclonal gammopathy of undetermined significance (MGUS). The establishment of MGCS expands our current understanding of the pathophysiology of a range of diseases, in which the M protein is often found. Aside from the kidney, the three main organ systems most affected by monoclonal gammopathy include the peripheral nervous system, skin, and eye. The optimal management of these MGUS-related conditions is not known yet due to the paucity of clinical data, the rarity of some syndromes, and limited awareness among healthcare professionals. Currently, two main treatment approaches exist. The first one resembles the now-established therapeutic strategy for monoclonal gammopathy of renal significance (MGRS), in which chemotherapy with anti-myeloma agents is used to target clonal lesion that is thought to be the culprit of the complex clinical presentation. The second approach includes various systemic immunomodulatory or immunosuppressive options, including intravenous immunoglobulins, corticosteroids, or biological agents. Although some conditions of the MGCS spectrum can be effectively managed with therapies aiming at the etiology or pathogenesis of the disease, evidence regarding other pathologies is severely limited to individual patient data from case reports or series. Future research should pursue filling the gap in knowledge and finding the optimal treatment for this novel clinical category.

French recommendations for the management of adult & pediatric chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare autoimmune disorder of the peripheral nervous system, primarily affecting the myelin sheath. The pathophysiology of CIDP is complex, involving both humoral and cellular immunity. The diagnosis of CIDP should be suspected in patients with symmetrical proximal and distal motor weakness and distal sensory symptoms of progressive onset, associated with decreased/abolished tendon reflexes. Treatments include intraveinous immunoglobulins, steroids and plasma exchange, with usually an induction phase followed by a maintenance therapy with progressive weaning. Treatment should be rapidly initiated to prevent axonal degeneration, which may compromise recovery. CIDP outcome is variable, ranging from mild distal paresthesiae to complete loss of ambulation. There have been several breakthroughs in the diagnosis and management of CIDP the past ten years, e.g. discovery of antibodies against the node of Ranvier, contribution of nerve ultrasound and magnetic resonance imaging to diagnosis, and demonstration of subcutaneous immunoglobulins efficiency. This led us to elaborate French recommendations for the management of adult & pediatric CIDP patients. These recommendations include diagnosis assessment, treatment, and follow-up.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy in Association With Concomitant Diseases: Identification and Management

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare, heterogeneous, but treatable autoimmune-mediated peripheral neuropathy characterized by demyelination. CIDP can occur independently or simultaneously with a variety of diseases such as diabetes, monoclonal gammopathy of undetermined significance (MGUS), connective tissue disease, and HIV. It is important to identify CIDP and specific peripheral neuropathies caused by these diseases; this review aims to summarize the CIDP literatures related to diabetes, MGUS, SLE, and HIV, and to be helpful for the management of such patients.

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

INTRODUCTION/AIMS

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

METHODS

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

RESULTS

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

DISCUSSION

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

Atypical chronic inflammatory demyelinating polyradiculoneuropathy: recent advances on classification, diagnosis, and pathogenesis

PURPOSE OF REVIEW

In recent years, there has been an intense debate in literature regarding the definition of the individual variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), their possible pathogenetic mechanisms, and impact in the diagnosis of CIDP.

RECENT FINDINGS

The 2021 European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) guidelines revised the definition of the individual CIDP variants and implemented their diagnostic criteria. Diagnosis of atypical CIDP is challenging and misdiagnosis is frequent, leading to diagnostic delay and consequent greater accumulation of disability and treatment dependency. Recent studies suggest that patients with typical CIDP have an antibody-mediated mechanism of neuropathy whereas in those with Lewis--Sumner syndrome (LSS) neuropathy is preferentially mediated by macrophages and T cells.

SUMMARY

Although the validity of the 2021 EFNS/PNS diagnostic criteria for atypical CIDP is unknown, they will hopefully lead to greater uniformity in the selection of patients to be enrolled in future studies and to a greater diagnostic accuracy. New data are emerging on the possible pathological mechanisms of individual variants and this could result in the discovery of specific diagnostic biomarkers and new therapies.

Antecedent infections and vaccinations in chronic inflammatory demyelinating polyneuropathy: A European collaborative study

INTRODUCTION/AIMS

Chronic inflammatory demyelinating polyneuropathy (CIDP) may be rarely preceded by infection. A causative link remains unproven, in contrast to Guillain-Barré syndrome (GBS), which is commonly postinfectious with well-demonstrated pathophysiological mechanisms of molecular mimicry following Campylobacter jejuni enteritis. Uncommonly, infections are reported before the onset of CIDP. In this study we aimed to determine the frequency and characteristics of CIDP occurring after antecedent infections or vaccinations in two large European cohorts.

METHODS

We reviewed the records of 268 subjects with "definite" or "probable" CIDP from the Inflammatory Neuropathy Clinic, Birmingham, UK (129 subjects), and from the Serbian national CIDP database (139 subjects).

RESULTS

Twenty-five of 268 (9.3%) subjects had a respiratory or gastrointestinal infection in the 6 weeks preceding CIDP onset, and 3 of 268 (1.1%) had received an influenza vaccination. CIDP disease onset occurred at a younger age (mean [standard deviation], 44.25 [17.36] years vs 54.05 [15.19] years; P < .005) and acute-onset CIDP was more common (42.9% vs 12.1%; odds ratio, 5.46; 95% confidence interval, 2.35-12.68; P < .001) in subjects with preceding infections or vaccinations. No differences in CIDP subtype, rates of cerebrospinal fluid protein level elevation, disability, or likelihood of treatment response, were observed.

DISCUSSION

Antecedent infections or vaccinations may precede about 10% of cases of CIDP and are more common in younger subjects. Acute-onset CIDP is more frequent after antecedent events. These findings may suggest specific pathophysiological mechanisms in such cases.

Chronic inflammatory demyelinating polyneuropathy with hypoglossal nerve involvement and inverted Beevor's sign: case report

Background

Cranial nerve involvement is not commonly encountered in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP); this is especially true for involvement of the hypoglossal nerve. Neither Beevor's sign nor its inverted form has previously been described in CIDP.

Case presentation

A 28-year-old man presented with distal-predominant limb weakness and numbness at the age of 18. A diagnosis of CIDP was made, which was confirmed by electrodiagnostic evidence of demyelination. He responded well to intravenous immunoglobulin and glucocorticoid treatment and achieved remission for 5 years. However, the same symptoms relapsed at the age of 28 and lasted for 10 months. On examination, in addition to limb sensory impairment and muscle weakness, mild bilateral facial paresis, tongue atrophy and fasciculations, and inverted Beevor's sign were also observed. A brief literature review of cranial nerve involvements in CIDP and Beevor's sign or its inverted form were also performed.

Conclusions

Cranial nerves may be affected in patients with CIDP. Facial palsy is most frequently present, while hypoglossal nerve involvement is rare. Inverted Beevor's sign can appear in CIDP patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02287-5.

The Cost Effectiveness of Immunoglobulin vs. Hematopoietic Stem Cell Transplantation for CIDP

Background: Intravenous immunoglobulin (IVIG) is effective as standard first line therapy for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but some patients remain dependent on its long-term use. Recently, we have reported that autologous non-myeloablative hematopoietic stem cell transplantation (HSCT) is an effective second line therapy for CIDP. Objectives: To compare the cost of chronic IVIG vs. autologous HSCT (a one-time therapy), we collected data on patients with CIDP undergoing HSCT between 2017 and 2019. This was compared with published literature on the costs and efficacy defined by the Inflammatory Neuropathy Cause And Treatment (INCAT) disability score, Medical Research Council (MRC) sum score, hand grip strength, and SF-36 quality of life (QOL) for CIDP. Methods: Between 2017 and 2019, nineteen patients with chronic CIDP (mean disease treatment duration prior to HSCT of 6 years) underwent autologous HSCT with mean cost of $108,577 per patient (range $56,327-277,119, standard deviation $53,092). After HSCT, 80% of patients remain IVIG and immune treatment free for up to 5 years. In comparison, published cost of IVIG treatment in the USA for an average CIDP patient exceeds $136,000 per year. Despite remaining treatment free, HSCT demonstrated greater improvement in efficacy compared to immunoglobulins. Recommendations: Given the long-term treatment-free remission and better outcome measurements, autologous HSCT is more cost effective than long-term IVIG treatment in patients with chronic CIDP. However, costs will depend on patient selection, the HSCT regimen, and regional variations. Further analysis of the health economics, i.e., cost/outcome ratio, of HSCT as therapy for chronically IVIG dependent CIDP is warranted.

Autologous Hematopoietic Stem Cell Transplantation for Chronic Inflammatory Demyelinating Polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) refractory to conventional therapy can lead to marked disability and represents a therapeutic challenge.

OBJECTIVE

To report five cases of treatment-refractory disabling CIDP treated with autologous hematopoietic stem cell transplantation (AHSCT).

METHODS

This was a retrospective cohort study from a tertiary care referral center for both neuromuscular disease and AHSCT. Patients with CIDP treated with AHSCT between 2008 and 2020 were included. All patients had major persistent and disabling neuropathic deficits despite combinations of intensive immunosuppressive therapy. The primary outcome measures were: Medical Research Council sum score, Overall Neuropathy Limitations Scale and requirement for ongoing CIDP immunotherapy after transplantation. We also analyzed safety outcomes by documenting all severe AHSCT-related complications.

RESULTS

Five patients with refractory CIDP underwent AHSCT. Three were classified as manifesting a typical syndrome, two were classified as the multifocal Lewis Sumner variant. The mean age at time of CIDP diagnosis was 33.4 years (range 24-46 years), with a median delay of 46 months (range 21-135 months) between diagnosis and AHSCT. The median follow-up period was 41 months. All five patients were able to wean off CIDP-related immunotherapy. Marked improvements in Medical Research Council scale and overall Neuropathy Limitations Scale were noted in 4/5 patients. One patient with longstanding neurogenic atrophy showed no improvement in disability scales. There were no treatment-related deaths or critical illnesses.

CONCLUSIONS

AHSCT can achieve marked sustained clinical improvement of refractory CIDP and may allow for weaning off long-term complex immunotherapies.

New evidence for secondary axonal degeneration in demyelinating neuropathies

Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.

Frequency of diabetes and other comorbidities in chronic inflammatory demyelinating polyradiculoneuropathy and their impact on clinical presentation and response to therapy

OBJECTIVES

To determine the prevalence of different comorbidities in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and their impact on outcome, treatment choice and response.

METHODS

Using a structured questionnaire, we collected information on comorbidities from 393 patients with CIDP fulfilling the European Federation of Neurological Societies and Peripheral Nerve Society criteria included in the Italian CIDP database.

RESULTS

One or more comorbidities were reported by 294 patients (75%) and potentially influenced treatment choice in 192 (49%) leading to a less frequent use of corticosteroids. Response to treatment did not differ, however, from that in patients without comorbidities. Diabetes (14%), monoclonal gammopathy of undetermined significance (MGUS) (12%) and other immune disorders (16%) were significantly more frequent in patients with CIDP than expected in the general European population. Patients with diabetes had higher disability scores, worse quality of life and a less frequent treatment response compared with patients without diabetes. Patients with IgG-IgA or IgM MGUS had an older age at CIDP onset while patients with other immune disorders had a younger age at onset and were more frequently females. IgM MGUS was more frequent in patients with motor CIDP than in patients with typical CIDP.

CONCLUSIONS

Comorbidities are frequent in patients with CIDP and in almost 50% of them have an impact on treatment choice. Diabetes, MGUS and other immune diseases are more frequent in patients with CIDP than in the general population. Only diabetes seems, however, to have an impact on disease severity and treatment response possibly reflecting in some patients a coexisting diabetic neuropathy.

Refractory CIDP: Clinical characteristics, antibodies and response to alternative treatment

OBJECTIVE

To review the clinical characteristics, antibodies, and response to alternative treatments in a cohort of patients with refractory CIDP.

METHODS

We reviewed the charts of all CIDP patients seen at the Oregon Health & Science University neuromuscular clinic between 2017 and 2019. We collected demographics, clinical characteristics, antibodies, and response to treatments.

RESULTS

Among 45 CIDP patients studied, 34 (76%) showed improvement with first-line therapy (steroids, IVIG and/or plasmapheresis) and 11 (24%) were considered refractory to first line therapy. Of the latter, 7 of 11 patients (64%) responded to alternative treatment (cyclophosphamide or rituximab). Three were refractory to all treatment. Most patients were ambulatory without aid and a few were in remission. One patient died from complications of alcoholic liver cirrhosis. Thrombosis was seen in three patients receiving IVIG. Six patients (13%) tested positive for Neurofascin (NF) antibodies. Four tested positive for NF155 IgM antibodies only and of those, one responded to IVIG, two partially responded to IVIG and one was refractory. One patient tested positive for NF155 IgG4. Another tested positive for NF155 IgG4 and NF155 IgM. Both patients with IgG4 antibodies were refractory to IVIG, one responded to rituximab and one was refractory to all treatment.

CONCLUSION

Less than a quarter of our CIDP patients did not respond to steroids, IVIG, and/or plasmapheresis. Most of the refractory patients responded to rituximab or cyclophosphamide. Patients with IgG4 NF antibodies were resistant to IVIG. The majority of refractory CIDP patients were seronegative and disease management relied on clinical judgement.

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.

Motor chronic inflammatory demyelinating polyneuropathy (CIDP) in 17 patients: Clinical characteristics, electrophysiological study, and response to treatment

Motor chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare and poorly described subtype of CIDP. We aimed to study their clinical and electrophysiological characteristics and response to treatment. From a prospective database of CIDP patients, we included patients with definite or probable CIDP with motor signs and without sensory signs/symptoms at diagnosis. Patients were considered to have pure motor CIDP (PM-CIDP) if sensory conductions were normal or to have motor predominant CIDP (MPred-CIDP) if ≥2 sensory nerve action potential amplitudes were abnormal. Among the 700 patients with CIDP, 17 (2%) were included (PM-CIDP n = 7, MPred-CIDP n = 10); 71% were male, median age at onset was 48 years (range: 13-76 years), 47% had an associated inflammatory or infectious disease or neoplasia. At the more severe disease stage, 94% of patients had upper and lower limb weakness, with distal and proximal weakness in 4 limbs for 56% of them. Three-quarters (75%) responded to intravenous immunoglobulins (IVIg) and four of five patients to corticosteroids including three of three patients with MPred-CIDP. The most frequent conduction abnormalities were conduction blocks (CB, 82%) and F-wave abnormalities (88%). During follow up, 4 of 10 MPred-CIDP patients developed mild sensory symptoms; none with PM-CIDP did so. Patients with PM-CIDP had poorer outcome (median ONLS: 4; range: 22-5) compared to MPred-CIDP (2, range: 0-4; P = .03) at last follow up. This study found a progressive clinical course in the majority of patients with motor CIDP as well as frequent associated diseases, CB, and F-wave abnormalities. Corticosteroids might be considered as a therapeutic option in resistant IVIg patients with MPred-CIDP.

Electrodiagnostic data-driven clustering identifies a prognostically different subgroup of patients with chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

This study aimed to explore the correlations between electrodiagnostic (EDX) features in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and to investigate whether EDX data-driven clustering can identify a distinct subgroup regarding clinical phenotype and treatment response.

METHODS

We reviewed clinical and EDX data of 56 patients with definite CIDP fulfilling the 2010 European Federation of Neurological Societies and Peripheral Nerve Society criteria at two teaching hospitals. A hierarchical agglomerative clustering algorithm with complete linkage was used to partition the patients into subgroups with similar EDX features. A stepwise logistic regression analysis was performed to evaluate predictors of the long-term outcome.

RESULTS

EDX data-driven clustering partitioned the patients into two clusters, identifying a distinct subgroup characterised by coexistence of prominent conduction slowing and markedly reduced distally evoked compound muscle action potential (CMAP) amplitudes. This cluster of patients was significantly over-represented by an atypical subtype (distal acquired demyelinating symmetric polyneuropathy) compared with the other cluster (70% vs 26.1%, p=0.042). Furthermore, patients in this cluster invariably showed favourable long-term treatment outcome (100% vs 63%, p=0.023). In logistic regression analyses, the initial disability (OR 6.1, 95% CI 2.4 to 25.4), F-wave latency (OR 0.93, 95% CI 0.86 to 0.98) and distal CMAP duration (OR 0.96, 95% CI 0.91 to 0.99) were significant predictors of the poor long-term outcome.

CONCLUSION

Our results show that EDX data-driven clustering could differentiate a pattern of EDX features with prognostic implication in patients with CIDP. Reduced distally evoked CMAPs may not necessarily predict poor responses to treatment, and active treatment is warranted when prominent slowing of conduction is accompanied in the distal segments.

Atypical CIDP: diagnostic criteria, progression and treatment response. Data from the Italian CIDP Database

OBJECTIVES

A few variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) have been described, but their frequency and evolution to typical CIDP remain unclear. To determine the frequency and characteristics of the CIDP variants, their possible evolution to typical CIDP, and treatment response.

METHODS

We applied a set of diagnostic criteria to 460 patients included in a database of Italian patients with CIDP. Clinical characteristics and treatment response were reviewed for each patient. The Kaplan-Meier curve was used to estimate the progression rate from atypical to typical CIDP.

RESULTS

At the time of inclusion, 376 (82%) patients had a diagnosis of typical CIDP while 84 (18%) had atypical CIDP, including 34 (7%) with distal acquired demyelinating symmetric neuropathy (DADS), 17 (4%) with purely motor, 17 (4%) with Lewis-Sumner syndrome (LSS) and 16 (3.5%) with purely sensory CIDP. Based on retrospective review of the symptoms and signs present at onset and for at least 1 year, 180 (39%) patients had an initial diagnosis compatible with atypical CIDP that in 96 (53%) patients evolved to typical CIDP. Mean disease duration was longer in patients evolving to typical CIDP than in those not evolving (p=0.0016). Patients with DADS and LSS had a less frequent response to immunoglobulin than those with typical CIDP, while patients with purely motor and sensory CIDP had a similar treatment response.

CONCLUSIONS

The proportion of patients with atypical CIDP varies during the disease course. DADS and LSS have a less frequent response to intravenous immunoglobulin compared with typical CIDP, raising the possibility of a different underlying pathogenetic mechanism.

Incidence and Prevalence of Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Systematic Review and Meta-Analysis

BACKGROUND

Prevalence and incidence rates of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are required to determine the impact of CIDP on society. We aimed to estimate the prevalence and incidence of CIDP worldwide and to determine the effect of diagnostic criteria on prevalence and incidence.

METHOD

A systematic review was conducted for all published incidence and prevalence studies on CIDP until May 18, 2017. Methodological quality was assessed using the Methodological Evaluation of Observational Research checklist. We performed a random effect meta-analysis to estimate pooled prevalence and incidence rates.

RESULTS

Of the 907 studies, 11 were included in the systematic review, 5 in the meta-analysis of incidence (818 cases; 220,513,514 person-years) and 9 in the meta-analysis of prevalence (3,160 cases; 160,765,325 population). These studies had a moderate quality. The pooled crude incidence rate was 0.33 per 100,000 person-years (95% CI 0.21-0.53; I2 = 95.7%) and the pooled prevalence rate was 2.81 per 100,000 (95% CI 1.58-4.39; I2 = 99.1%). Substantial heterogeneity in incidence and prevalence across studies seems to be partly explained by using different diagnostic criteria.

CONCLUSION

These findings provide a starting point to estimate the social burden of CIDP and demonstrate the need to reach consensus on diagnostic criteria for CIDP.

Differences between acute-onset chronic inflammatory demyelinating polyneuropathy and acute inflammatory demyelinating polyneuropathy in adult patients

Acute inflammatory demyelinating polyneuropathy (AIDP) and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) are conditions presenting overlapping clinical features during early stages (first 4 weeks), although the latter may progress after 8 weeks. The aim of this study was to identify predictive factors contributing to their differential diagnosis. Clinical records of adult patients with AIDP or A-CIDP diagnosed at our institution between January 2006 and July 2017 were retrospectively reviewed. Demographic characteristics, clinical manifestations, cerebrospinal-fluid (CSF) findings, treatment and clinical evolution were analyzed. Nerve conduction studies were performed in all patients with at least 12 months follow-up. A total of 91 patients were included (AIDP, n = 77; A-CIDP, n = 14). The median age was 55.5 years in patients with A-CIDP vs 43 years in AIDP (P = .07). The history of diabetes mellitus was more frequent in A-CIDP (29% vs 8%, P = .04). No significant differences between groups were observed with respect to: human immunodeficiency virus (HIV) status, presence of auto-immune disorder or oncologic disease. Cranial, motor and autonomic nerve involvement rates were similar in both groups. Patients in the A-CIDP group showed higher frequency of proprioceptive disturbances (83% vs 28%; P < .001), sensory ataxia (46% vs 16%; P = .01), and the use of combined immunotherapy with corticoids (29% vs 3%; P = .005). There were no significant differences in CSF findings, intensive care unit (ICU) admission, or mortality rates. During the first 8 weeks both entities are practically indistinguishable. Alterations in proprioception could suggest A-CIDP. Searching for markers that allow early differentiation could favor the onset of corticotherapy without delay.

Transthyretin amyloid polyneuropathies mimicking a demyelinating polyneuropathy

OBJECTIVE

To clearly define transthyretin familial amyloid polyneuropathies (TTR-FAPs) fulfilling definite clinical and electrophysiologic European Federation of Neurological Societies/Peripheral Nerve Society criteria for chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

From a cohort of 194 patients with FAP, 13 of 84 patients (15%) of French ancestry had late-onset demyelinating TTR-FAP. We compared clinical presentation and electrophysiology to a cohort with CIDP and POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes) syndrome. We assessed nerve histology and the correlation between motor/sensory amplitudes/velocities. Predictors of demyelinating TTR-FAP were identified from clinical and electrophysiologic data.

RESULTS

Pain, dysautonomia, small fiber sensory loss above the wrists, upper limb weakness, and absence of ataxia were predictors of demyelinating TTR-FAP (p < 0.01). The most frequent demyelinating features were prolonged distal motor latency of the median nerve and reduced sensory conduction velocity of the median and ulnar nerves. Motor axonal loss was severe and frequent in the median, ulnar, and tibial nerves (p < 0.05) in demyelinating FAP. Ulnar nerve motor amplitude <5.4 mV and sural nerve amplitude <3.95 μV were distinguishing characteristics of demyelinating TTR-FAP. Nerve biopsy showed severe axonal loss and occasional segmental demyelination-remyelination.

CONCLUSION

Misleading features of TTR-FAP fulfilling criteria for CIDP are not uncommon in sporadic late-onset TTR-FAP, which highlights the limits of European Federation of Neurological Societies/Peripheral Nerve Society criteria. Specific clinical aspects and marked electrophysiologic axonal loss are red flag symptoms that should alert to this diagnosis and prompt TTR gene sequencing.

Plasma-exchange in Chronic Peripheral Neurological Disorders

We investigated 19 patients affected by chronic peripheral neurological disorders treated with therapeutic plasma exchange (TPE) to verify the efficacy of the therapeutic protocol used in these diseases.

Every patient was clinically considered after 5 TPE. Those who showed an improvement started chemotherapy and continued TPE at the rate of 2 procedures/week for 2 weeks, then 1 procedure/week for 1 month and finally 1 procedure every 2 weeks for 2 months. Intravenous immunoglobulins (IVIg) were infused at the end of apheretic treatment in one of the patients affected by neurological disorders due to monoclonal gammopathy undetermined significance. HCV-positive patients with cryoglobulins were treated with α-interferon (α-IFN) for 6 months before TPE. Eleven patients (58%) had a symptomatic improvement, 2 (1.5%) stopped TPE treatment owing to side effects and 6 (31.5%) did not respond to apheretic therapy.

In order to improve the advantages of TPE we suggest using IVIg at the end of apheretic therapy, while in HCV-positive patients, at least one year of α-IFN therapy is required before initiating TPE.

Are neurological complications of monoclonal gammopathy of undetermined significance underestimated?

Objectives

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignancy preceding multiple myeloma (MM) or related disorders. Neurological symptoms caused by the monoclonal immunoglobulins or free light-chains are often associated with a high morbidity. We analyzed the prevalence of neuropathy, clinical features and the long-term outcome in 223 patients (pts.) with MGUS.

Patients and Methods

Between 1/2005 and 3/2015, 223 adult pts. with MGUS were identified in our database.

Results

In36/223 pts. (16%) a neuropathy was diagnosed (MGUS associated neuropathy, MGUS-N). 20 pts. (55%) had a distal symmetric axonal neuropathy, 10 pts. (28%) had a chronic inflammatory demyelinating polyneuropathy and 6 pts (17%) a distal acquired demyelinating symmetric polyneuropathy. In MGUS-NN (without neuropathy) and in MGUS-N, progression to smoldering MM, MM or Waldenstrom's macroglobulinemia (WM) occurred in 17% of the pts. The Immunoglobulin subtype was predominantly IgG in MGUS-NN and IgM in MGUS-N and ≥5.5% plasma cells in the bone-marrow predicted progression to MM and AL-amyloidosis in MGUS-NN and to WM in MGUS-N (p<0.05).

Conclusion

Due to the substantial prevalence of neuropathies, MGUS pts. should be monitored carefully and referred to a specialized center if neurological symptoms occur.

Chronic inflammatory demyelinating polyradiculoneuropathy and anesthesia: a case series

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired autoimmune demyelinating polyneuropathy characterized by symmetrical diffuse weakness that also can rarely affect bulbar and respiratory muscles. The study objective was to describe perioperative outcomes of patients with CIDP who received general anesthesia. This retrospective observational study evaluated patients with active (diagnosed or treated within the previous year) CIDP who underwent general anesthesia at our institution between January 1, 2010, and December 31, 2015. Medical records were reviewed for perioperative outcomes with emphasis on respiratory complications or unexpected reactions to muscle relaxants. Seventeen patients with CIDP underwent general anesthesia, of whom 16 had muscle weakness. Succinylcholine was used in 5 cases (29.4%) and nondepolarizing muscle relaxants in 11 cases (64.7%). Two patients required postoperative mechanical ventilation; one was critically ill and the other had open heart surgery. One patient had aspiration on the second postoperative day and required endotracheal intubation and mechanical ventilation for 3 days. Three patients had worsening CIDP symptoms: 1 acutely after surgery; 1 several months later; and 1 who died in the hospital. The patient who died underwent lengthy abdominal exploration, had acute worsening of neurologic symptoms, and died after 46 days of malnutrition. Anesthetic concerns of patients with CIDP include frailty, bulbar dysfunction, and the effects of immunosuppressive therapy. Although our patients tolerated neuromuscular drugs, substantial theoretical concerns with these medications in patients with demyelinating neuropathies preclude safety in this population without further study.

Early predictive factors of disability in CIDP

The objective of this study was to identify early clinical, biochemical and electrophysiological prognostic factors of disability in CIDP. We evaluated a dataset from 60 CIDP patients that included sex, age of onset, type of onset, phenotype, disease duration, response to treatment, disability at the time of diagnosis assessed using the modified Rankin Scale (baseline mRS), cerebrospinal fluid protein levels and electrophysiological data. All patients had clinical assessment of disability through the mRS within the last 6 months (last mRS) before enrollment in the study. Stepwise forward logistic regression model was applied to evaluate the impact of clinical, biochemical and electrophysiological parameters on the last mRS, considered as binary outcome (absence or presence of severe disability, i.e., <4/≥4 mRS). Moreover, we used Spearman's rank correlation coefficient to evaluate the relationship between disease duration and last mRS. We observed a significant relationship between last mRS and baseline mRS [p = 0.015, z = 2.44, OR 5.15 (CI 1.38-19.22)] and age of onset [p = 0.017, z = 2.39, OR 1.13 (CI 1.02-1.27) per additional year of age of onset]. There was no correlation between disease duration and last mRS. Our data suggest that a worse clinical status at the beginning of disease and an older age at onset may be negative prognostic factors of long-term disability independent from disease duration.

Diagnosis and management of neuropathies associated with plasma cell dyscrasias

Neuropathies associated with plasma cell dyscrasias are a major cause of morbidity for patients managed by medical oncologists. Because of similarities in clinical presentation and on nerve conduction studies, identifying the underlying disease leading to a paraproteinemic neuropathy can often be difficult. In addition, the degree of neurologic deficit does not strictly correlate with the extent of abnormalities on common clinical laboratory testing. Fortunately, with increasing understanding into the biologic mechanisms of underlying hematologic diseases, additional biomarkers have recently been developed, thus improving our diagnostic capacity. Neuropathies associated with plasma cells dyscrasias are seen with Monoclonal gammopathy of undetermined significance (MGUS) particularly IgM subtype, followed by IgG and IgA MGUS, multiple myeloma, Waldenström's macroglobulinemia, amyloid, Castleman's disease, and POEMS syndrome. The mechanisms of neuronal injury associated with plasma cell dyscrasia vary based on underlying diagnosis and include malignant infiltration, immune-mediated antibody deposition, or local compression of nerve roots. The polyneuropathies are frequently demyelinating, although axonal and mixed neuropathies can also be seen. As demonstrated by the cases included in this review, patients frequently present with symmetric sensory disturbance, followed by progressive motor weakness. Unfortunately, because of the complexity of diagnostic testing, patients are frequently examined late, often after receiving several ineffective therapies. The aim of this case-based review is to provide clinicians with insight on how to properly recognize these atypical neuropathies and send the appropriate diagnostic work, increasing the likelihood of accurately classify the patient's underlying hematologic disorder.

Cerebrospinal fluid findings in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathies

The classic immunologic alteration of the cerebrospinal fluid (CSF) in Guillain-Barré syndrome (GBS), albuminocytologic dissociation, has been known since the original paper by Guillain, Barré, and Strohl. Albuminocytologic dissociation has been also described in other forms of the GBS spectrum, such as axonal motor or motor-sensory forms (AMAN, AMSAN), the anti-GQ1b spectrum of Miller Fisher syndrome, and Bickerstaff brainstem encephalitis. Cytokines, chemokines, antibodies, complement components, and molecules with a putative neuroprotective role or indicating axonal damage have also been examined using different methods. Besides these candidate approaches, proteomics has been recently applied to discover potential biomarkers. The overall results support the immunopathogenesis of GBS, but albuminocytologic dissociation remained the only consistent CSF biomarker supporting the diagnosis of GBS. Chronic inflammatory neuropathies also comprise a heterogeneous group of diseases. Increased protein in the CSF is a supportive factor of chronic inflammatory demyelinating polyneuropathy, especially in the absence of definite electrophysiologic criteria. A number of other markers have also been investigated in the CSF of patients with chronic inflammatory neuropathies, similar to GBS. However, none has been used in supporting diagnosis, differentiating among syndromes, or predicting the clinical course and treatment responses.

Two years' long-term follow up in chronic inflammatory demyelinating polyradiculoneuropathy: efficacy of intravenous immunoglobulin treatment

BACKGROUND

Administration of intravenous immunoglobulins (IVIgs) is established for long-term treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Prevention of secondary axonal loss going along with permanent clinical disability and muscular atrophy is a major aim in CIDP therapy. To assess long-term clinical efficacy of IVIg treatment despite heterogenous disease course and variable complaints reported by the patients, long-term electrophysiological monitoring was performed for systematic evaluation of therapeutic efficacy of IVIg.

METHODS

A total of 21 patients with CIDP treated with IVIg 1 g/kg bodyweight every 3-6 weeks were examined electrophysiologically every 12 months over a period of 2 years.

RESULTS

Assessment of clinical symptoms, using the Inflammatory Neuropathy Cause and Treatment (INCAT) and Hughes functional grading score (F-score) revealed improvement of motor and sensory symptoms over a period of 2 years. As electrophysiological results remained stable, IVIg treatment seems to be suitable to prevent axonal loss in CIDP.

CONCLUSIONS

This study confirms efficacy of IVIg as firstline therapy in CIDP. Doses and frequency of IVIg application should be adapted based on clinical evaluation and analysis of long-term electrophysiological findings.

Immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated peripheral neuropathies

BACKGROUND

Serum monoclonal anti-myelin-associated glycoprotein (anti-MAG) antibodies may be pathogenic in some people with immunoglobulin M (IgM) paraprotein and demyelinating neuropathy. Immunotherapies aimed at reducing the level of these antibodies might be expected to be beneficial. This is an update of a review first published in 2003 and previously updated in 2006 and 2012.

OBJECTIVES

To assess the effects of immunotherapy for IgM anti-MAG paraprotein-associated demyelinating peripheral neuropathy.

SEARCH METHODS

On 1 February 2016 we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase for randomised controlled trials (RCTs). We also checked trials registers and bibliographies, and contacted authors and experts in the field.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs involving participants of any age treated with any type of immunotherapy for anti-MAG antibody-associated demyelinating peripheral neuropathy with monoclonal gammopathy of undetermined significance and of any severity.Our primary outcome measures were numbers of participants improved in disability assessed with either or both of the Neuropathy Impairment Scale (NIS) or the modified Rankin Scale (mRS) at six months after randomisation. Secondary outcome measures were: mean improvement in disability, assessed with either the NIS or the mRS, 12 months after randomisation; change in impairment as measured by improvement in the 10-metre walk time, change in a validated linear disability measure such as the Rasch-built Overall Disability Scale (R-ODS) at six and 12 months after randomisation, change in subjective clinical scores and electrophysiological parameters at six and 12 months after randomisation; change in serum IgM paraprotein concentration or anti-MAG antibody titre at six months after randomisation; and adverse effects of treatments.

DATA COLLECTION AND ANALYSIS

We followed standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified eight eligible trials (236 participants), which tested intravenous immunoglobulin (IVIg), interferon alfa-2a, plasma exchange, cyclophosphamide and steroids, and rituximab. Two trials of IVIg (22 and 11 participants, including 20 with antibodies against MAG), had comparable interventions and outcomes, but both were short-term trials. We also included two trials of rituximab with comparable interventions and outcomes.There were very few clinical or statistically significant benefits of the treatments used on the outcomes predefined for this review, but not all the predefined outcomes were used in every included trial and more responsive outcomes are being developed. A well-performed trial of IVIg, which was at low risk of bias, showed a statistical benefit in terms of improvement in mRS at two weeks and 10-metre walk time at four weeks, but these short-term outcomes are of questionable clinical significance. Cyclophosphamide failed to show any benefit in the single trial's primary outcome, and showed a barely significant benefit in the primary outcome specified here, but some toxic adverse events were identified.Two trials of rituximab (80 participants) have been published, one of which (26 participants) was at high risk of bias. In the meta-analysis, although the data are of low quality, rituximab is beneficial in improving disability scales (Inflammatory Neuropathy Cause and Treatment (INCAT) improved at eight to 12 months (risk ratio (RR) 3.51, 95% confidence interval (CI) 1.30 to 9.45; 73 participants)) and significantly more participants improve in the global impression of change score (RR 1.86, 95% CI 1.27 to 2.71; 70 participants). Other measures did not improve significantly, but wide CIs do not preclude some effect. Reported adverse effects of rituximab were few, and mostly minor.There were few serious adverse events in the other trials.

AUTHORS' CONCLUSIONS

There is inadequate reliable evidence from trials of immunotherapies in anti-MAG paraproteinaemic neuropathy to form an evidence base supporting any particular immunotherapy treatment. IVIg has a statistically but probably not clinically significant benefit in the short term. The meta-analysis of two trials of rituximab provides, however, low-quality evidence of a benefit from this agent. The conclusions of this meta-analysis await confirmation, as one of the two included studies is of very low quality. We require large well-designed randomised trials of at least 12 months' duration to assess existing or novel therapies, preferably employing unified, consistent, well-designed, responsive, and valid outcome measures.

Nivolumab-induced chronic inflammatory demyelinating polyradiculoneuropathy mimicking rapid-onset Guillain-Barré syndrome: a case report

Nivolumab, an anti-programmed death-1-specific monoclonal antibody, has demonstrated a durable response and effect on overall survival and has become one of the standard treatments for patients with advanced melanoma. Reported herein is a case of nivolumab-induced chronic inflammatory demyelinating polyradiculoneuropathy, in which an 85-year-old woman with stage IV melanoma developed grade 1 paresthesia 2 weeks after the initial dose of nivolumab was administered. With continued treatment, the neurological deficiency deteriorated rapidly, mimicking Guillain-Barré syndrome, causing such a dramatic decrease in her activities of daily living that she could no longer function in daily life. Thus, nivolumab treatment was discontinued. A course of intravenous immunoglobulin infusion yielded a dramatic clinical improvement; in particular, improved motor control was observed within a few days. Her initial presentation was suggestive of acute inflammatory demyelinating polyradiculoneuropathy, a subtype of Guillain-Barré syndrome; however, the good response to steroids and exacerbation 8 weeks after the onset were suggestive of chronic inflammatory demyelinating polyradiculoneuropathy induced by nivolumab. This is the first case of Guillain-Barré syndrome-like autoimmune polyradiculoneuropathy induced by programmed death-1/programmed death-ligand 1 inhibitors. Although neurological adverse events related to nivolumab are rare, they can become severe, requiring early diagnosis and intervention. Intravenous immunoglobulin may be considered as an effective initial treatment for patients who develop acute autoimmune nervous system disorders due to nivolumab.

Long-term disability and prognostic factors in polyneuropathy associated with anti-myelin-associated glycoprotein (MAG) antibodies

AIM OF THE STUDY

Neuropathy associated with IgM monoclonal gammopathy (MGUS) represents distinctive clinical syndrome, characterized by male predominance, late age of onset, slow progression, predominantly sensory symptoms, deep sensory loss, ataxia, minor motor impairment. More than 50% of patients with neuropathy-associated MGUS possess antibodies against myelin-associated glycoprotein (MAG). Purpose of our study was to assess effects on disease progression of demographic, clinical and neurophysiological variables in our large cohort of patients.

MATERIALS AND METHODS

Forty-three Caucasians patients were followed every eight months for median duration time of 93 months. Extremity strength was assessed with Medical Research Council (MRC) Scale, disability with overall disability status scale (ODSS), modified Rankin Scale and sensory function with Inflammatory Neuropathy Cause and Treatment (INCAT) sensory scale (ISS). Statistical analyses were conducted with parametric or non-parametric measures as appropriate. Survival analysis was used to test predictive value of clinical, demographical and neurophysiological variables. Variance analysis was conducted to explain difference on MRC between patients and groups at different time from onset.

RESULTS

Results showed that demyelinating pattern, older age and absence of treatment were significant risk factors for disability worsening. No other factors emerged as predictors including gender, ataxia and tremor at baseline, level of anti-MAG and IgM protein concentration in serum. Despite worsening of all outcome measures between first and last visit, quality of life (HRQol) judged by patients did not vary significantly.

CONCLUSIONS

Our study provides evidence that electrophysiologic pattern, age of onset and absence of treatment are strong predictor of prognosis in anti-MAG polyneuropathy.

Improving the management of chronic inflammatory demyelinating polyradiculoneuropathy

This article considers several issues of current interest relating to the management of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), including diagnostic pitfalls, differences between CIDP patients with and without concurrent diabetes mellitus and how to best measure treatment response in daily practice. Despite the availability of diagnostic criteria, many patients diagnosed with CIDP do not meet these criteria; reasons for misdiagnosis are discussed. There are no definitive predictors of treatment response in CIDP; however, certain clinical and electrophysiological characteristics may be helpful. Patients with CIDP and concurrent diabetes present an additional diagnostic challenge; the differences between these groups, including possible differences in response predictors are discussed. Finally, the most appropriate outcome measures for use in daily practice are considered.

Treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is one of the acquired demyelinating neuropathies and is considered to be immune mediated. Diagnosis is typically based on clinical history, neurologic examination, electrophysiologic studies, CSF studies, and pathologic examination. Early diagnosis and treatment is important to prevent irreversible axonal loss and optimize improvement in function. The first-line agents for treatment are intravenous immunoglobulin (IVIg), corticosteroids, and plasmapheresis, which have all been demonstrated to be effective in controlled studies. Studies have not shown a significant difference between these three treatments, and the initial choice of therapy is often based on availability, cost, ease of administration, and side effect profile. If patients do not respond to one of these agents, they may respond to one of the others and sometimes in combination. If the first-line agents are not effective, chemotherapeutic or immunosuppressive agents may be considered. There are limited controlled studies of these modalities, and they are often used in conjunction with a first-line treatment. The majority of patients require long-term therapy to maintain a response and to prevent relapse.

Novel immunotherapeutic strategies in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic immune-mediated neuropathy: it is clinically heterogeneous (relapsing-remitting form, chronic progressive form, monophasic form or CIDP having a Guillain-Barré syndrome-like onset), but potentially treatable. Although its pathophysiology remains largely unknown, CIDP is considered an immune-mediated neuropathy. Therefore, many immunotherapies have been proposed in this peripheral nervous system disorder, the most known efficient treatments being intravenous immunoglobulin, corticosteroids and plasma exchange. However, these therapies remain unsatisfactory for many patients, so numerous other immunotherapeutic strategies have been evaluated, based on their immunosuppressant or immunomodulatory potency. We have performed a large review of the literature about treatment in CIDP, with a special emphasis on novel and alternative immunotherapeutic strategies.