Pulsed high-dose dexamethasone versus standard prednisolone treatment for chronic inflammatory demyelinating polyradiculoneuropathy (PREDICT study): a double-blind, randomised, controlled trial

Treatment response amplitude and timing in chronic inflammatory demyelinating polyneuropathy with routine care: Study of a UK cohort

BACKGROUND AND PURPOSE

The amplitude, timing, and determinants of improvement with available treatments are uncertain in chronic inflammatory demyelinating polyneuropathy (CIDP). Our primary objective was to quantify categorized outcomes with routine care.

METHODS

We retrospectively studied treatment response within 36 months from initiation in 112 consecutive subjects with CIDP. Response was classified into a proposed new "CIDP treatment-response category" (CT-RC), based on achieved endpoints. Determinants of the CT-RC, of timing of maximum improvement, and of treatment discontinuation were ascertained.

RESULTS

The CT-RC demonstrated high concurrent validity with current outcome measures. Thirty-six subjects (32.1%) achieved a "complete response," 37 (33%) a "good partial response," 10 (8.9%) a "moderate partial response," and 15 (13.4%) a "poor partial response." Fourteen subjects (12.5%) were "nonresponsive." The CT-RC was independently predicted only by age. Mean time to maximum improvement was 12.1 months (range = 1-36) and was not associated with any pretreatment covariate. Treatment discontinuation occurred in 24 of 62 (38.2%) partial responders and was only associated with shorter pretreatment disease duration. Nonresponders were older and received a similar number of treatments compared to responders.

CONCLUSIONS

CT-RC classification indicates persistent disability in >60% of treatment responders in CIDP. Timing of maximum improvement is variable, frequently delayed, and unpredictable. Treatment withdrawal without deterioration is achievable in approximately 40% of subjects and may be more likely with prompt treatment. Treatment withdrawal in partial responders and limited escalation in nonresponders suggest implication of physician- and patient-related factors in suboptimal response. More effective treatments/treatment methods and better understanding of other factors influencing response are needed in CIDP.

[Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)]

Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common chronic autoimmune disease of the peripheral nervous system. It is often difficult to diagnose, but severaly therapeutic options are nowadays available to reduce neurological deficits and to improve the disease course. This article exemplifies the management of CIDP by a typical case study.

Prospective open-label trial with rituximab in patients with chronic inflammatory demyelinating polyradiculoneuropathy not responding to conventional immune therapies

BACKGROUND

To evaluate the efficacy of rituximab in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients not responding to conventional immune therapies.

METHODS

An open-label, prospective exploratory study was conducted with intravenous rituximab on 17 CIDP patients who had not responded to at least two first-line therapies. The primary endpoint was to determine the proportion of patients who showed improvement 6 months after rituximab therapy. The percentage of responders to rituximab, along with a 95% CI, was reported and compared with the 30% response rate after other immunosuppressive drugs previously documented in the literature.

RESULTS

13 of the 17 treated patients (76.5%) showed improvement at 6 months (95% CI 50.1 to 93.2). Among the 14 patients who completed the 12-month follow-up (2 were lost to follow-up after showing improvement at months 8 and 10, and 1 deteriorated at 6 months), 13 (92.9%) demonstrated improvement at 12 months (95% CI 66.1 to 99.8). Nerve conduction parameters improved by at least 20% in two nerves in 6 out of 15 (40%) patients at 6 months and in 7 out of 13 (53.9%) at 12 months. None of the treated patients withdrew from the study due to side effects. There was a significant reduction of circulating CD19+ cells 15 days, 2, 6 and 12 months after treatment.

CONCLUSION

Rituximab seems to be a safe therapy in most patients with CIDP not responding to conventional immune therapies. The high percentage of patients who improved in this study suggests a possible positive effect of rituximab which is worth investigating in future randomised controlled clinical trials.

TRIAL REGISTRATION NUMBER

NCT05877040.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Current Therapeutic Approaches and Future Outlooks

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

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

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

Cerebrospinal Fluid Analysis in Rheumatological Diseases with Neuropsychiatric Complications and Manifestations: A Narrative Review

The analysis of cerebrospinal fluid (CSF) remains a valuable diagnostic tool in the evaluation of inflammatory and infectious conditions involving the brain, spinal cord, and meninges. Since many rheumatic inflammatory diseases can involve the central and peripheral nervous system, the aims of this narrative review were to summarize the latest evidence on the use of CSF analysis in the field of neuropsychiatric manifestations of rheumatic diseases. Routine CSF parameters were taken into consideration for this review: appearance; total protein and cellular content (pleocytosis); lactate and/or glucose; CSF/serum albumin quotient; intrathecal synthesis of IgG. Data regarding the role of CSF analysis in the clinical management of neuropsychiatric systemic lupus erythematosus, primary Sjogren's syndrome, rheumatoid arthritis, and Behçet's syndrome are presented. Although no disease-specific picture has been identified, CSF analysis remains a useful diagnostic tool to confirm the presence of a neuro-inflammatory state or, conversely, to exclude the concomitant presence of other inflammatory/infectious diseases affecting the CNS in the context of systemic rheumatologic conditions.

Beneficial effects and safety of traditional Chinese medicine for chronic inflammatory demyelinating polyradiculoneuropathy: A case report and literature review

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated neuropathy. First-line treatments for CIDP include corticosteroids, intravenous immunoglobulin, and plasma exchange. However, the application is always limited by high costs, effectiveness, and adverse events. This study investigated a new potentially effective and safe therapeutic treatment to alleviate CIDP symptoms and improve the quality of life. In the present case, a 47-year-old rural woman presented with weakness and numbness of progressive extremities. She was diagnosed with CIDP based on abnormal cerebrospinal fluid and electromyography. The patient was treated with intravenous dexamethasone for 1 week and with Huangqi-Guizhi-Wuwu and Bu-Yang-Huan-Wu decoctions for 90 days. Surprisingly, after the treatment, the weakness and numbness were eliminated, and the quality of life improved. The varying INCAT, MRC, and BI scores also reflected the treatment effects. After 8 months of discharge, the symptoms did not relapse during the follow-up. We also searched “traditional Chinese medicine (TCM)” and “CIDP” in PubMed, EMBASE, the Web of Science, the Cochrane Library, the Chinese National Knowledge Infrastructure Databases, Wanfang Data, and the Chongqing Chinese Science and Technology Periodical Database. Finally, only ten studies were included in the literature review. Three studies were randomized controlled trials, and seven were case reports or case series. There were 419 CIDP patients, but all study sites were in China. Nine TCM formulas involving 44 herbs were reported, with Huang Qi (Astragalus membranaceus) being the most important herb. In conclusion, the case and literature demonstrated that TCM treatment might be a more effective, low-cost, and safe option for treating CIDP. Although these preliminary findings are promising, a larger sample size and higher-quality randomized clinical trials are urgently required to confirm our findings.

B-cell and T-cell receptor repertoire in chronic inflammatory demyelinating polyneuropathy, a prospective cohort study

The immunopathophysiological mechanisms underlying chronic inflammatory demyelinating polyneuropathy (CIDP) in an individual patient are largely unknown. Better understanding of these mechanisms may aid development of biomarkers and targeted therapies. Both B- and T-cell dominant mechanisms have been implicated. We therefore investigated whether B-cell and T-cell receptor (BCR/TCR) repertoires might function as immunological biomarkers in CIDP. In this prospective cohort study, we longitudinally sampled peripheral blood of CIDP patients in three different phases of CIDP: starting induction treatment (IT), starting withdrawal from IVIg maintenance treatment (MT), and patients in remission (R). BCR and TCR repertoires were analyzed using RNA based high throughput sequencing. In baseline samples, the number of total clones, the number of dominant BCR and TCR clones and their impact on the repertoire was similar for patients in the IT, MT, and remission groups compared with healthy controls. Baseline samples in the IT or MT did not predict treatment response or potential relapse at follow-up. Treatment responders in the IT group showed a potential IVIg-induced increase in the number of dominant BCR clones and their impact at follow-up (baseline1.0 [IQR 1.0-2.8] vs. 6 m 3.5 [0.3-6.8]; P < .05, Wilcoxon test). Although the BCR repertoire changed over time, the TCR repertoire remained robustly stable. We conclude that TCR and BCR repertoire distributions do not predict disease activity, treatment response or response to treatment withdrawal.

Treatment of CIDP

Chronic inflammatory demyelinating polyneuropathy is a disabling but treatable disorder. However, misdiagnosis is common, and it can be difficult to optimise its treatment. Various agents are used both for first and second line. First-line options are intravenous immunoglobulin, corticosteroids and plasma exchange. Second-line therapies may be introduced as steroid-sparing agents or as more potent escalation therapy. It is also important to consider symptomatic treatment of neuropathic pain and non-pharmacological interventions. We discuss the evidence for the various treatments and explain the practicalities of the different approaches. We also outline strategies for monitoring response and assessing the ongoing need for therapy.

On the path to evidence-based therapy in neuromuscular disorders

Neuromuscular disorders encompass a diverse group of acquired and genetic diseases characterized by loss of motor functionality. Although cure is the goal, many therapeutic strategies have been envisioned and are being studied in randomized clinical trials and entered clinical practice. As in all scientific endeavors, the successful clinical translation depends on the quality and translatability of preclinical findings and on the predictive value and feasibility of the clinical models. This chapter focuses on five exemplary diseases: childhood spinal muscular atrophy (SMA), Charcot-Marie-Tooth (CMT) disorders, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), acquired autoimmune myasthenia gravis (MG), and Duchenne muscular dystrophy (DMD), to illustrate the progress made on the path to evidenced-based therapy.

Update on therapy of chronic immune-mediated neuropathies

Chronic immune-mediated neuropathies, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), neuropathies associated with monoclonal gammopathy, and multifocal motor neuropathy (MMN), are a group of disorders deemed to be caused by an immune response against peripheral nerve antigens. Several immune therapies have been reported to be variably effective in these neuropathies including steroids, plasma exchange, and high-dose intravenous (IVIg) or subcutaneous (SCIg) immunoglobulins. These therapies are however far from being invariably effective and may be associated with a number of side effects leading to the use of immunosuppressive agents whose efficacy has not been so far confirmed in randomized trials. More recently, new biological agents, such as rituximab, have proved to be effective in patients with neuropathy associated with IgM monoclonal gammopathy and are currently tested in CIDP.

Efficacy of rituximab in anti-myelin-associated glycoprotein demyelinating polyneuropathy: Clinical, hematological and neurophysiological correlations during 2 years of follow-up

BACKGROUND AND PURPOSE

We evaluated the clinical and neurophysiological efficacy of rituximab (RTX) in a neurophysiologically homogeneous group of patients with monoclonal gammopathy and immunoglobulin M (IgM) anti-myelin-associated glycoprotein antibody (anti-MAG) demyelinating polyneuropathy.

METHODS

Twenty three anti-MAG-positive polyneuropathic patients were prospectively evaluated before and for 2 years after treatment with RTX 375 mg/m² . The Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale (INCAT-ds), modified INCAT sensory score (mISS), Medical Research Council sum score, Patients' Global Impression of Change scale were used, IgM levels were assessed and extensive electrophysiological examinations were performed before (T0) and 1 year (T1) and 2 years (T2) after RTX treatment.

RESULTS

At T1 and T2 there was a significant reduction from T0 both in mISS and in INCAT-ds, with a p value < 0.001 in the inferential Friedman's test overall analysis. Ulnar nerve Terminal Latency Index and distal motor latency significantly changed from T0 to T1 and in the overall analysis (p = 0.001 and p = 0.002), and ulnar nerve sensory nerve action potential (SNAP) amplitude was significantly increased at T2 from T1, with a p value < 0.001 in the overall analysis. Analysis of the receiver-operating characteristic curves showed that a 41.8% increase in SNAP amplitude in the ulnar nerve at T2 from T0 was a fair predictor of a mISS reduction of ≥2 points (area under the curve 0.85; p = 0.005; sensitivity: 90.9%, specificity: 83.3%).

CONCLUSIONS

This study suggests that RTX is effective in patients with clinically active demyelinating anti-MAG neuropathy over 2 years of follow-up, and that some neurophysiological variables might be useful for monitoring this efficacy.

A first case of childhood chronic inflammatory demyelinating polyneuropathy associated with alopecia universalis

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired demyelinating disease of the peripheral nervous system with unknown etiology. Alopecia universalis, an advanced form of alopecia areata (AA), is a condition characterized by complete hair loss. Here we report the first case of childhood CIDP associated with AA who was successfully treated with a combination of intravenous immunoglobulin (IVIg) and corticosteroids. CASE REPORT: This case describes a nine-year-old Japanese girl who developed alopecia, progressive muscle weakness, and eventually loss of walking ability (at ages 2, 4, and 7, respectively). She was treated with IVIg and prednisolone combination therapy, which improved muscle weakness and alopecia. She was positive for serum IgG-GM2 type anti-glycolipid antibodies, which may be associated with this rare combination of diseases.

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.

Treatment of Chronic Inflammatory Demyelinating Polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic peripheral polyneuropathy that results in disability through immune mediated nerve injury, but which not uncommonly has residual and irreversible neurologic deficits after the active inflammatory component of the disorder has been treated. Management of the condition entails addressing both the abnormal immune activity that drives ongoing or active deficits while also managing residual symptoms through supportive interventions. Immune based treatments are grounded in several important principles. First, early treatment is guided by evidence-based proven effective therapies that sequentially escalate depending on the response. Second, optimization or personalization of first line treatments is needed in order to understand the ideal dose for any given patient, and whether long term treatment is needed at all. Third, although many immunosuppressive agents may be utilized in non-responding patients or when intravenous immunoglobulin (IVIG)/corticosteroid sparing intervention is desired, all are unproven and require a delicate balance between risk, cost, and unknown likelihood of benefit that is tailored to each individual patient's unique circumstances. There is no reliable disease activity biomarker that can be used to guide treatment - a reality that makes it very challenging to optimize treatment to individual patient needs. Serial clinical assessments are key to understanding the value of continued immunotherapy or if long-term therapy is needed at all. Regardless of the immunotherapy status of a patient, equally important is addressing residual deficits through supportive interventions including physical therapy, adaptive equipment, pain management, and emotional support. This article is protected by copyright. All rights reserved.

Relevance of Nerve Biopsy in the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy—A Systematic Review

Chronic Inflammatory Demyelinating Polyneuropathy is an immune-mediated pathology of the peripheral nerves and nerve roots that leads to weakness and sensory symptoms. Given its clinical heterogeneity, often times diagnosis is challenging. Even though nerve conduction studies and clinical features are the main criteria used for diagnosis, supplementary investigations, such as nerve biopsies, cerebral spinal fluid examination and magnetic resonance studies, may be used in order to confirm the diagnosis. Given the fact that the hallmark in CIDP physiopathology is the demyelination process, nerve biopsies are used to demonstrate and assess the magnitude of the phenomenon. The question and the main interest of this review is whether histopathological findings are relevant for the diagnosis and can be useful in disease assessment.

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): Current Therapies and Future Approaches

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated polyradiculoneuropathy leading to disability via inflammatory demyelination of peripheral nerves. Various therapeutic approaches with different mechanisms of action are established for the treatment of CIDP. Of those, corticosteroids, intravenous or subcutaneous immunoglobulin, or plasma exchange are established first-line therapies as suggested by the recently revised EAN/PNS guidelines for the management of CIDP. In special cases, immunosuppressants or rituximab may be used. Novel therapeutic approaches currently undergoing clinical studies include molecules or monoclonal antibodies interacting with Fc receptors on immune cells to alleviate immune-mediated neuronal damage. Despite various established therapies and the current development of novel therapeutics, treatment of CIDP remains challenging due to an inter-individually heterogeneous disease course and the lack of surrogate parameters to predict the risk of clinical deterioration.

Contemporary challenges in the diagnosis and management of chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

Despite extensive research, multiple inter-related diagnostic and management challenges remain for chronic inflammatory demyelinating polyneuropathy (CIDP).

AREAS COVERED

A literature review was performed on diagnosis and treatment in CIDP. The clinical features and disease course were evaluated. Investigative techniques, including electrophysiology, cerebrospinal fluid examination, neuropathology, imaging and neuroimmunology, were considered in relation to technical aspects, sensitivity, specificity, availability and cost. Available evidenced-based treatments and those with possible efficacy despite lack of evidence, were considered, as well as current methods for evaluation of treatment effects.

EXPERT OPINION

CIDP remains a clinical diagnosis, supported first and foremost by electrophysiology. Other investigative techniques have limited impact. Most patients with CIDP respond to available first-line treatments and immunosuppression may be efficacious in those who do not. Consideration of the natural history and of the high reported remission rate, of under-recognised associated disabling features, of treatment administration modalities and assessment methods, require enhanced attention.

Efficacy of intravenous immunoglobulin in autoimmune neurological diseases. Literature systematic review and meta-analysis

BACKGROUND

Corticosteroids are the first-line treatment for several common autoimmune neurological diseases. Other therapeutic approaches, including intravenous immunoglobulin (IVIg) and plasmapheresis, have shown mixed results in patient improvement.

OBJECTIVE

To compare the efficacy of IVIg administration with that of corticosteroids, plasmapheresis, and placebo in autoimmune neurological diseases like Guillain-Barré syndrome, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy, optic neuritis, and multiple sclerosis.

METHODS

A systematic review was performed on the databases PubMed, MEDLINE, Embase, and Cochrane. Controlled, randomized studies comparing the efficacy of IVIg with placebo, plasmapheresis, and/or glucocorticoid administration were selected. Only studies reporting the number of patients who improved after treatment were included, irrespective of language or publication year. In total, 23 reports were included in the meta-analysis study.

RESULTS

Our meta-analysis showed a beneficial effect of IVIg administration on patient improvement over placebo (OR = 2.79, CI [95%] = 1.40-5.55, P = 0.01). Meanwhile, IVIg administration showed virtually identical effects to plasmapheresis (OR = 0.83, CI [95%] = 0.45-1.55, P < 0.01). Finally, no significant differences were found in the efficacy of IVIg and glucocorticoid administration (OR = 0.98, Cl [95%] = 0.58-1.68, P = 0.13).

CONCLUSION

IVIg can be regarded as a viable therapeutic approach, either as a first- or second-line therapy, and as an adjuvant therapy for autoimmune neurological diseases.

Immunoglobulin shortage: Practice modifications and clinical outcomes in a reference centre

BACKGROUND

Growing numbers of indications for intravenous immunoglobulins (IVIg) in recent years has resulted in an increase in the consumption of these products. A lack of raw material has led to IVIg shortage. The objective of this work was to evaluate the impact of this situation on patient care in one French referral centre considering practice modifications and clinical impact.

METHODS

All patients treated with IVIg for chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy and myasthenia gravis from October 2017 to October 2018 were included.

RESULTS

Out of 142 patients, 111 (78%) had a modification of their IVIg treatment. We noted that 75 (68%) patients had a delay in IVIg treatment, 41 (37%) patients had a decrease in IVIg doses and 31 (28%) experienced IVIg treatment interruption. Thirty percent of patients for whom IVIg treatment was discontinued were switched to other treatments mainly plasma exchange (16%) or corticosteroids (13%). Switches to plasma exchange or corticosteroids were carried out in order to save immunoglobulins for patients who had no other alternatives. Fifty-eight (52%) patients presented a deterioration of their clinical score after IVIg treatment changes including 31 (28%) patients who had a moderate or a clinically significant deterioration. Concerning practice modifications, we noted a substantial though not significant decrease in median IVIg dose for myasthenia gravis and a significant increase in the delay between IVIg courses for chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy (P=0.011 and P=0.018 respectively).

CONCLUSION

Our study showed a rather important number of changes in IVIg treatment related to IVIg shortage during the period considered. These changes had a negative impact on the clinical status of some patients.

An approach to assessing immunoglobulin dependence in chronic inflammatory demyelinating inflammatory polyneuropathy

Regular immunoglobulin treatment maintains strength and prevents disability in chronic inflammatory demyelinating polyneuropathy (CIDP). Discrimination between active disease, with optimum symptom control on treatment, and disease in remission not requiring treatment is essential for therapeutic decision-making and clinical trial design. To compare treatment cessation versus gradual dose reduction in assessment of disease activity (immunoglobulin dependence) in a cohort of stable CIDP patients on maintenance immunoglobulin treatment. An approach to restabilization of immunoglobulin-dependent individuals is also described. Retrospective review of IVIg cessation or gradual reduction in 33 patients with stable CIDP on maintenance IVIg. Demographic, clinical and treatment data were collected; clinical monitoring data were recorded prospectively as part of routine clinical practice. A total of 21/33 patients (62.6%) were immunoglobulin dependent, (gradual dose reduction:11, cessation:10). Mean change in Inflammatory Rasch-built Overall Disability Scale (I-RODS) (-15, standard deviation [SD] 16) and Medical Research Council Sum Score (MRC-SS) (-4, SD: 4) was clinically and statistically meaningful (>75% exceeded minimum clinically important differences). Mean time to deterioration was 5.0 (SD: 4.6) months, shorter in cessation group (3.5 months) than gradual reduction group (8.8 months). All patients were restabilized to previous baseline (M: 2.3, SD: 4.3 months), half within 1 week of retreatment. A total of 12 patients (37.4%) remained stable without treatment for ≥2 years (remission). A total of 50% were identified rapidly by cessation and 50% by gradual dose reduction requiring mean 4.8 (SD: 2.8) years follow-up and costing £113 623 per person Ig spend. No predictors of disease activity were identified. A treatment cessation trial with close clinical monitoring is an efficient, cost-effective and safe approach to assessing disease activity in CIDP.

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision

OBJECTIVE

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs).

RESULTS

Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

Subcutaneous immunoglobulin treatment for chronic inflammatory demyelinating polyneuropathy

Immunoglobulin G (IgG) therapy is an established long‐term treatment in chronic inflammatory demyelinating polyneuropathy (CIDP) that is commonly administered intravenously (IVIg). The subcutaneous immunoglobulin (SCIg) administration route is a safe and effective alternative option, approved by the United States Food and Drug Administration (FDA) in 2018, for maintenance treatment of adults with CIDP. Physicians and patients alike need to be aware of all their treatment options in order to make informed decisions and plan long‐term treatment strategies. In this review, we collate the evidence for SCIg in CIDP from all published studies and discuss their implications and translation to clinical practice. We also provide guidance on the practicalities of how and when to transition patients from IVIg to SCIg and ongoing patient support. Evidence suggests that IVIg and SCIg have comparable long‐term efficacy in CIDP. However, SCIg can provide additional benefits for some patients, including no requirement for venous access or premedication, and reduced frequency of systemic adverse events. Local‐site reactions are more common with SCIg than IVIg, but these are mostly well‐tolerated and abate with subsequent infusions. Data suggest that many patients prefer SCIg following transition from IVIg. SCIg preference may be a result of the independence and flexibility associated with self‐infusion, whereas IVIg preference may be a result of familiarity and reliance on a healthcare professional for infusions. In practice, individualizing maintenance dosing based on disease behavior and determining the minimally effective IgG dose for individuals are key considerations irrespective of the administration route chosen.

Nerve Pathology Distinguishes Focal Motor Chronic Inflammatory Demyelinating Polyradiculoneuropathy From Multifocal Motor Neuropathy

OBJECTIVES

The objective of the study is to distinguish the mechanisms of disease for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN), which we believe to be fundamentally different. However, distinguishing the mechanisms is more difficult when the presentation of CIDP is motor-predominant, focal, or asymmetric.

METHODS

We describe 3 focal, motor-predominant, representative cases that could be interpreted on clinical and/or electrophysiological grounds as either MMN or focal CIDP, and present pathological findings.

RESULTS

We highlight pathological differences in these cases, and provide an argument that CIDP and MMN are distinct entities with different pathophysiological mechanisms-chronic demyelination for CIDP, and an immune-mediated attack on paranodal motor axons for MMN.

CONCLUSIONS

Based on clinical evaluation, electrophysiology, and nerve biopsy pathology, we can divide the conditions into inflammatory demyelinating neuropathy (focal CIDP) versus chronic axonal neuropathy (MMN). The divergent pathological findings provide further evidence that CIDP and MMN are fundamentally different disorders.

Outcome measures and biomarkers in chronic inflammatory demyelinating polyradiculoneuropathy: from research to clinical practice

Introduction: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated syndrome characterized clinically by weakness and/or numbness that evolves over 2 months or more. The heterogeneity of clinical features necessitates an individualized approach to disease monitoring that takes lessons learned from clinical trials and applies them to clinical practice.Areas covered: This review discusses the importance of clinimetrics and biomarkers in CIDP diagnosis and disease monitoring. Highlighted are the challenges of defining responses to immunotherapy, the usefulness, and limitations of utilizing evidence-based clinical outcome measures during routine clinical care, and the evolving understanding of how diagnostic and disease activity biomarkers may reshape our treatment and disease monitoring paradigms.Expert opinion: Although disability and impairment outcome measures are commonly used in CIDP to indicate disease status, the nonspecific nature of these metrics limits the ability to attribute a change in any given metric to a change in CIDP. This interpretive challenge may be magnified by inconsistencies in the direction of change as well as a strong placebo effect. There is a need to improve our understanding of minimally important changes in existing outcome measures as a means to personalize treatment and to better assess disease activity status with biomarker discovery.

Clinical outcome of CIDP one year after start of treatment: a prospective cohort study

OBJECTIVE

To assess clinical outcome in treatment-naive patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

We included adult treatment-naive patients participating in the prospective International CIDP Outcome Study (ICOS) that fulfilled the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria for CIDP. Patients were grouped based on initial treatment with (1) intravenous immunoglobulin (IVIg), (2) corticosteroid monotherapy or (3) IVIg and corticosteroids (combination treatment). Outcome measures included the inflammatory Rasch-built overall disability scale (I-RODS), grip strength, and Medical Research Council (MRC) sum score. Treatment response, treatment status, remissions (improved and untreated), treatment changes, and residual symptoms or deficits were assessed at 1 year.

RESULTS

Forty patients were included of whom 18 (45%) initially received IVIg, 6 (15%) corticosteroids, and 16 (40%) combination treatment. Improvement on ≥ 1 of the outcome measures was seen in 31 (78%) patients. At 1 year, 19 (48%) patients were still treated and fourteen (36%) patients were in remission. Improvement was seen most frequently in patients started on IVIg (94%) and remission in those started on combination treatment (44%). Differences between groups did not reach statistical significance. Residual symptoms or deficits ranged from 25% for neuropathic pain to 96% for any sensory deficit.

CONCLUSIONS

Improvement was seen in most patients. One year after the start of treatment, more than half of the patients were untreated and around one-third in remission. Residual symptoms and deficits were common regardless of treatment.

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs). Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

Clinical management of chronic inflammatory demyelinating polyneuropathy (CIDP) in Europe and India: An exploratory study

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disorder causing inflammatory demyelination of peripheral nerves and consecutive disability. Diagnostic criteria and treatments are well established, but it is unknown how clinical practice may differ in different geographical regions. In this multicentre study, clinical management of CIDP was compared in 44 patients from Germany, India and Norway regarding diagnostic and therapeutic procedures. All centres used EFNS/PNS diagnostic criteria for CIDP but diagnostic workup varied regarding screening for infectious diseases, genetic testing and nerve biopsy. Intravenous immunoglobulin and prednisolone were the most common therapies in all centres with differences in indication and dosage. Patients from the Indian cohort were the most severely affected with less diverse therapeutic approaches, whereas psychological strain did not differ significantly from the two other cohorts. Our exploratory study discloses an unaddressed issue in management of CIDP that should be further investigated to optimise standard of care for CIDP worldwide.

Borrelia burgdorferi sensu lato seroconversion after intravenous immunoglobulin treatment: A cohort study

Objective

Intravenous immunoglobulin (IVIg) consists of pooled donor immunoglobulins (IgG), possibly including anti‐Borrelia burgdorferi (Bbsl) antibodies. Apparent IVIg‐related Bbsl seroconversion could lead to incorrect diagnosis of Lyme borreliosis. This cohort study was designed to determine how often IVIg treatment leads to apparent Bbsl seroconversion and whether antibodies disappear post‐treatment.

Methods

Sera from chronic inflammatory demyelinating polyneuropathy (CIDP) and myositis patients were analyzed, drawn pre‐treatment and 6–12 weeks after the start of IVIg. In patients with apparent seroconversion, follow‐up samples after treatment withdrawal were analyzed, if available. Patients treated with corticosteroids were included as controls. A two‐tier protocol was used for serological testing consisting of the C6 Lyme ELISA (Oxford Immunotec) and confirmation by immunoglobulin M (IgM) and immunoglobulin G (IgG) immunoblot (Mikrogen^®).

Results

We included 61 patients: 51 patients were treated with IVIg and 10 with dexamethasone. Of the patients treated with IVIg, 42 had CIDP (82%) and were treated with Nanogam^® (Sanquin Plasma Products). Nine patients had myositis (18%) and were treated with Privigen^® (CSL Behring). Anti‐Bbsl IgG seroprevalence pre‐treatment was 3% (2/61). Apparent seroconversion during IVIg treatment occurred in 39% (20/51) of patients, all treated with Nanogam. Post‐treatment seroreversion occurred in 92% (12/13) of patients with available follow‐up samples; in 78% (7/9) seroreversion was observed within 3 months.

Conclusions

Transient presence of anti‐Bbsl IgG antibodies after IVIg is regularly observed. This effect appears to be dependent on the IVIg brand, probably reflecting variation in Bbsl exposure of plasma donors. Lyme borreliosis serological testing during, and weeks to months after, IVIg is therefore of limited utility.

Intravenous immunoglobulin and intravenous methylprednisolone as optimal induction treatment in chronic inflammatory demyelinating polyradiculoneuropathy: protocol of an international, randomised, double-blind, placebo-controlled trial (OPTIC)

Background

International guidelines recommend either intravenous immunoglobulin (IVIg) or corticosteroids as first-line treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). IVIg treatment usually leads to rapid improvement and is generally safe, but does not seem to lead to long-term remissions. Corticosteroids act more slowly and are associated with more side effects, but may induce long-term remissions. The hypothesis of this study is that combined IVIg and corticosteroid induction treatment will lead to more frequent long-term remissions than IVIg treatment alone.

Methods

An international, randomised, double-blind, placebo-controlled trial, in adults with ‘probable’ or ‘definite’ CIDP according to the EFNS/PNS 2010 criteria. Three groups of patients are included: (1) treatment naïve, (2) known CIDP patients with a relapse after > 1 year without treatment, and (3) patients with CIDP who improved within 3 months after a single course of IVIg, who subsequently deteriorate at any interval without having received additional treatment. Patients are randomised to receive 7 courses of IVIg and 1000 mg intravenous methylprednisolone (IVMP) (in sodium chloride 0.9%) or IVIg and placebo (sodium chloride 0.9%), every 3 weeks for 18 weeks. IVIg treatment consists of a loading dose of 2 g/kg (over 3–5 days) followed by 6 courses of IVIg 1/g/kg (over 1–2 days). The primary outcome is remission at 1 year, defined as improvement in disability from baseline, sustained between week 18 and week 52 without further treatment. Secondary outcomes include changes in disability, impairment, pain, fatigue, quality of life, care use and costs and (long-term) safety.

Discussion

In case of superiority of the combined treatment, patients will experience the advantages of two proven efficacious treatments, namely rapid improvement due to IVIg and long-term remission due to corticosteroids. Long-term remission would reduce the need for maintenance IVIg treatment and may decrease health care costs. Additionally, we expect that the combined treatment leads to a higher proportion of patients with improvement as some patients who do not respond to IVIg will respond to corticosteroids. Risks of short and long-term additional adverse events of the combined treatment need to be assessed.

Trial registration

ISRCTN registry ISRCTN15893334. Prospectively registered on 12 February 2018.

Clinical practice guidance for Sjögren's syndrome in pediatric patients (2018) - summarized and updated

There are a considerable number of pediatric patients with Sjögren's syndrome (SS); however, SS is generally considered rare among children. Pediatric patients with SS report fewer sicca symptoms; therefore, many are under-diagnosed and cannot access appropriate medical management. Therefore, we propose a newly developed guidance for the diagnosis, treatment, and management of pediatric SS, including epidemiology, clinical features, and diagnostic examination methodology. The aim of this guidance was to standardize the medical care of pediatric SS in Japan, and we published the Japanese version by YODOSHA in 2018. This article is the English version, which is summarized and updated. This guidance will need to be revised in the near future as additional clinical data become available.

Chronic inflammatory demyelinating polyradiculoneuropathy-Diagnostic pitfalls and treatment approach

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is characterized by progressive weakness and sensory loss, often affecting patients' ability to walk and perform activities of daily living independently. With the lack of a diagnostic biomarker, the diagnosis relies on clinical suspicion, clinical findings, and the demonstration of demyelinating changes on electrodiagnostic (EDx) testing and nerve pathology. As a result, patients can often be misdiagnosed with CIDP and unnecessarily treated with immunotherapy. Interpreting the EDx testing and cerebrospinal fluid findings in light of the clinical phenotype, recognizing atypical forms of CIDP, and screening for CIDP mimickers are the mainstays of the approach to patients suspected of having CIDP, and are detailed in this review. We also review the currently available treatment options, including intravenous immunoglobulin (IVIg), corticosteroids (CCS), and plasma exchange (PE), and discuss how to approach treatment-refractory cases. Finally, we emphasize the need to adopt objective outcome measures to monitor treatment response.

Outcome measures for chronic inflammatory demyelinating polyneuropathy in research: relevance and applicability to clinical practice

Outcome measures are recommended in the management of chronic inflammatory demyelinating polyneuropathy (CIDP). Various scales have been proposed in recent years, some now commonly utilized in daily clinical practice. The available evidence base relies itself on randomized controlled trial data obtained over the past 30 years, with several studies using different primary and secondary outcomes. We here review the different outcome measures used in CIDP research in relation to those currently recommended for clinical management. We consider the evidence base for CIDP treatment from the primary and secondary outcomes used in these studies and attempt to assess how this may relate to current clinical practice of routine evaluation of treatment effects and long-term monitoring.

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.

Systematic literature review of burden of illness in chronic inflammatory demyelinating polyneuropathy (CIDP)

Background

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder characterised by muscle weakness and impaired sensory function. The present study provides a comprehensive literature review of the burden of illness of CIDP.

Methods

Systematic literature search of PubMed, Embase, and key conferences in May 2019. Search terms identified studies on the epidemiology, humanistic burden, current treatment, and economic burden of CIDP published since 2009 in English.

Results

Forty-five full texts and nineteen conference proceedings were identified on the epidemiology (n = 9), humanistic burden (n = 7), current treatment (n = 40), and economic burden (n = 8) of CIDP. Epidemiological studies showed incidence and prevalence of 0.2–1.6 and 0.8–8.9 per 100,000, respectively, depending on geography and diagnostic criteria. Humanistic burden studies revealed that patients experienced physical and psychosocial burden, including impaired physical function, pain and depression. Publications on current treatments reported on six main types of therapy: intravenous immunoglobulins, subcutaneous immunoglobulins, corticosteroids, plasma exchange, immunosuppressants, and immunomodulators. Treatments may be burdensome, due to adverse events and reduced independence caused by treatment administration setting. In Germany, UK, France, and the US, CIDP economic burden was driven by direct costs of treatment and hospitalisation. CIDP was associated with indirect costs driven by impaired productivity.

Conclusions

This first systematic review of CIDP burden of illness demonstrates the high physical and psychosocial burden of this rare disease. Future research is required to fully characterise the burden of CIDP, and to understand how appropriate treatment can mitigate burden for patients and healthcare systems.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-09998-8) contains supplementary material, which is available to authorized users.

Management challenges for chronic dysimmune neuropathies during the COVID-19 pandemic

Since March 2020, the COVID-19 pandemic has led to the need to re-think the delivery of services to patients with chronic dysimmune neuropathies. Telephone/video consultations have become widespread but have compounded concerns about objective evaluation. Therapeutic decisions need, more than ever before, to be considered in the best interests of both patients, and society, while not denying function-preserving/restoring treatment. Immunoglobulin therapy and plasma exchange, for those treated outside of the home, expose patients to the hazards of hospital or outpatient infusion centers. Steroid therapy initiation and continuation pose increased infectious risk. Immunosuppressant therapy similarly becomes highly problematic, with the risks of treatment continuation enhanced by uncertainties regarding duration of the pandemic. The required processes necessitate considerable time and effort especially as resources and staff are re-deployed to face the pandemic, but are essential for protecting this group of patients and as an integral part of wider public health actions.

Rituximab in refractory chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a disorder in which early effective treatment is important to minimize disability from axonal degeneration. It has been suggested that some patients with CIDP may benefit from rituximab therapy, but there is no definitive evidence for this.

METHODS

Baseline and post-rituximab-therapy neuromuscular Medical Research Council (MRC) sum scores, Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, and functional status were assessed in 11 patients with refactory CIDP.

RESULTS

The MRC sum score, INCAT disability score, and functional status improved in all patients after rituximab therapy.

DISCUSSION

Our study provides evidence of the efficacy of rituximab therapy in at least some patients with CIDP. A placebo-controlled study to assess the effectiveness of rituximab therapy in CIDP with and without nodal antibodies is required to identify disease markers that predict responsiveness.

Inflammatory polyradiculoneuropathies: Clinical and immunological aspects, current therapies, and future perspectives

Inflammatory polyradiculoneuropathies are heterogeneous disorders characterized by immune-mediated leukocyte infiltration of peripheral nerves and nerve roots leading to demyelination or axonal degeneration or both. Inflammatory polyradiculoneuropathies can be divided into acute and chronic: Guillain–Barré syndrome and chronic inflammatory demyelinating polyneuropathy and their variants. Despite major advances in immunology and molecular biology have been made in the last years, the pathogenesis of these disorders is not completely understood. This review summarizes the current literature of the clinical features and pathogenic mechanisms of inflammatory polyradiculoneuropathies and focuses on current therapies and new potential treatment for the future.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Randomized, controlled crossover study of IVIg for demyelinating polyneuropathy and diabetes

OBJECTIVE

To determine whether IV immunoglobulin (IVIg) is more effective than placebo at reducing disability in patients with diabetes and demyelinating polyneuropathy features.

METHODS

This is a double-blinded, single-center, randomized, controlled crossover trial of IVIg treatment vs placebo. The primary outcome measure was the mean change in Overall Neuropathy Limitation Scale (ONLS) scores during the IVIg phasecompared with the placebo phase. Secondary outcomes include changes in the Rasch-built Overall Disability Scale, Medical Research Council sum scores, grip strength, electrophysiologic measurements, quality of life, and adverse effects.

RESULTS

Twenty-five subjects were recruited between March 2015 and April 2017. The mean change in ONLS scores was -0.2 points during the IVIg phase and 0.0 points during the placebo phase (p = 0.23). Secondary outcomes did not show significant differences between IVIg and placebo.

CONCLUSIONS

IVIg did not reduce disability, improve strength, or quality of life in patients with demyelinating polyneuropathy features and diabetes after 3 months of treatment in comparison with placebo. Therefore, careful consideration of the primary diagnosis is required before immunomodulatory therapy.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for patients with diabetes and demyelinating polyneuropathy features, IVIg did not significantly reduce disability.

Risk of osteoporosis in patients with chronic inflammatory neuropathy- a population-based cohort study

The risk of osteoporosis in patients with chronic inflammatory neuropathy (CIN) has not been evaluated in detail. We conducted a population-based case-control study nested in a retrospective cohort to analyze osteoporosis risk among patients with CIN using a nationwide database. Patients with CIN based on the Korean Classification of Disease diagnostic code were included and were matched to controls. A Cox proportional hazards regression model was used to evaluate the effect of CIN on osteoporosis. After propensity score matching, 585 CIN patients and 585 controls were selected. Patients with CIN had an increased osteoporosis risk (hazard ratio [HR] = 2.293, 95% confidence interval [CI] 1.460-3.601) compared with controls. The osteoporosis risk was higher among male patients with CIN than among male controls (HR = 5.404, 95% CI 2.252-12.969), while there were no significant differences among women. Among the CIN patients, the average daily dose of corticosteroids was higher in those who developed osteoporosis (19.6 mg [10.8-49.3]) than those who did not (16.2 mg [7.2-29.1], p = 0.001). The osteoporosis risk among CIN patients is higher than among controls. High risk of osteoporosis in male patients may indicate that osteoporosis in CIN patients results from the disease itself or related treatments.