An update on the management of chronic inflammatory demyelinating polyneuropathy

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ultramicronized Palmitoylethanolamide in the Management of Neuropathic Pain Related to Chronic Inflammatory Demyelinating Polyneuropathy: A Proof-of-Concept Study

Background/Objectives: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune disease. Neuropathic pain (NP), related to peripheral inflammation, is among its earliest manifestations. This preliminary open-label investigation aimed to evaluate the efficacy of ultramicronized Palmitoylethanolamide (umPEA) in the management of NP. Methods: A total of 14 patients with CIDP, already undergoing immunoglobulin (Ig) therapy, were divided into two groups: Group A received umPEA 600 mg twice daily in addition to Ig for 60 days, followed by Ig alone until the end of the observation (180 days); Group B received Ig alone for 120 days and subsequently umPEA + Ig in the last 60 days of the study. Painful symptom intensity and quality of life were assessed by the Numeric Rating Scale, Neuropathic Pain Symptoms Inventory, and Five Dimensions Health Questionnaire. The safety umPEA profile was evaluated. Results: UmPEA in addition to immunoglobulins allowed for a significant improvement over time in all NP symptoms intensity (p = 0.0007) and in patients' quality of life (p = 0.0036). Conclusions: This study suggests umPEA as a safe and effective treatment in addition to immunoglobulins to improve NP, ameliorating the patient's health status. These results highlight the importance of neuroinflammation modulation in the management of CIDP's painful symptoms, drawing attention to umPEA's potential use also in neuropathies of different etiologies.

Intravenous Immunoglobulin Treatment Patterns and Outcomes in Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A US Claims Database Analysis

INTRODUCTION

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare progressive or relapsing inflammatory disease. Intravenous immunoglobulin (IVIG) is recommended as a first-line therapy. The aim of this study was to describe real-world treatment patterns and outcomes of patients with CIDP in the Define initiating IVIG treatment.

METHODS

This cohort study used health insurance claims data from the Merative MarketScan Research Databases (2008-2018). Adult patients (≥ 18 years old) with CIDP without prior immunoglobulin treatment were identified using International Statistical Classification of Diseases and Related Health Problems (ICD) codes, and patients subsequently initiating IVIG were included in the analysis. Real-world IVIG treatment patterns and treatment and safety outcomes (assessed via ICD codes) were described.

RESULTS

In total, 3975 patients (median age 58 years) with CIDP who initiated IVIG were identified. After the initial IVIG loading period, patients received IVIG at a median dosing interval of 21 days (quartile [Q]1, Q3: 7, 28), and continued treatment for a median of 129 days (Q1, Q3: 85, 271). After the 2-year follow-up period, 55% of patients had discontinued all IVIG treatment; more than one-half of these discontinuations occurred within 4 months. Diagnoses of impaired functional status were evident in more than 30% of patients at baseline, but at lower rates during follow-up. Rates of new-onset safety outcomes after IVIG treatment were low.

CONCLUSION

This real-world analysis of IVIG treatment patterns and treatment and safety outcomes of patients with CIDP who initiated IVIG highlights the unmet need for improved long-term management. Further research is needed to evaluate the use of functional status measures as endpoints for immunoglobulin treatment effectiveness.

Chronic inflammatory demyelinating polyradiculoneuropathy in patients with diabetes mellitus - treatment with intravenous immunoglobulins: A systematic review

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare disease, but it is one of the most common inflammatory neuropathies in the population. It is particularly common among patients with diabetes mellitus. This raises many problems, both with the differential diagnosis of diabetic and inflammatory neuropathy, as well as the choice of treatment. Intravenous immunoglobulin (IVIG) is one of the therapeutic options. There is evidence for the effectiveness of IVIG in treating about two-thirds of patients. However, no review has been published to date systematising studies evaluating the response to IVIG treatment in patients with CIDP and coexisting diabetes.

METHODS

The present study is based on the PRISMA statement and is registered at PROSPERO (CRD42022356180). The study included searches of the databases of MEDLINE, ERIC, CINAHL Complete, Academic Search Ultimate and Health Source: Nursing/Academic Edition, finally including seven original papers evaluating a total of 534 patients in the review. The main inclusion criteria were the presence of a group of patients with CIDP and comorbid diabetes in the study.

RESULTS

The systematic review showed a lower efficacy of IVIG treatment among patients with coexisting diabetes compared with idiopathic CIDP (61 % vs 71 %). In addition, the presence of conduction blocks on neurography and shorter disease duration proved to be significant factors improving response to treatment.

CONCLUSIONS

Current scientific data do not allow for strong recommendations on the choice of treatment for CIDP. A randomised, multicentre study evaluating the efficacy of different therapeutic approaches to this disease entity needs to be planned.

Immunoglobulin Use for the Management of Painful Peripheral Neuropathy: A Systematic Review and Meta-Analysis

BACKGROUND

Immunoglobulins (IG) are widely used for the treatment of a variety of immune-mediated diseases. The exact mechanism of action remains unknown, but IG modulate the expression and function of Fc receptors, interfere with complement activation and production of cytokines, neutralize pathogenic autoantibodies, and affect the activation and effector functions of B and T lymphocytes. Immunoglobulins are usually delivered intravenously, and are effective in ameliorating motor symptoms, and/or preventing disease progression in immune-mediated neuropathies, including Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy.

OBJECTIVE

The aim of this systematic review and meta-analysis was to study the potential of IG for the treatment of painful peripheral neuropathy (PPN). The outcome of interest was the percentage of patients with PPN who achieved pain relief following IG administration.

METHODS

We performed a systematic literature search on March 17, 2022, in the PubMed database without any publication date restrictions. We also looked for unpublished or ongoing trials in clinicaltrials.org. Pain reduction following IG treatment had to be within the aims (primary or secondary).

RESULTS

The aforementioned literature search strategy revealed five studies (two open-label, three randomized placebo-controlled) eligible to be included. The pooled estimate of the percentage of patients with PPN who received immunoglobulins and reported pain relief was found to be 65% (95% CI 58-71%). The likelihood of achieving pain relief with immunoglobulin treatment was 2.9 times higher (95% CI 1.6-5.2) compared to placebo (p = 0.0003).

CONCLUSION

The use of IG for the treatment of pain due to peripheral neuropathy has a potential therapeutic benefit. Further studies across patients with different types of painful peripheral neuropathy are needed to better characterize this effect. Registration number on PROSPERO: CRD42022319614.

Estimation of the latent therapeutic demand for immunoglobulin therapies in autoimmune neuropathies in the United States

BACKGROUND AND OBJECTIVES

The use of immunoglobulin (IG) solutions as an immunomodulatory therapy in certain neurological conditions has become an established modality and represents a significant proportion of total IG use. The estimation of the evidence-based potential demand designated as the latent therapeutic demand (LTD) for IG in these diseases is required for adequate planning of the plasma supply required to manufacture the product.

MATERIALS AND METHODS

The diseases studied included chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barré syndrome (GBS) and multifocal motor neuropathy (MMN). The LTD for IG was assessed using a decision analysis model, using Microsoft Excel. The model analysed the epidemiological and clinical factors contributing to IG usage. One-way sensitivity analysis and probabilistic sensitivity analysis derived the LTD in grams per 1000 inhabitants. The key variables included the treatment schedule and the prevalence of the disease.

RESULTS

The model estimates that an average annual IG demand and standard deviation for CIDP, GBS and MMN in the United States is 83.05 ± 24.5, 6.1 ± 3.2 and 36.1 ± 25.5 g/1000 inhabitants, respectively.

CONCLUSION

Together with previous work on the LTD for IG in immunodeficiencies, these results indicate that current IG usage reflects the estimated LTD for the main indications for IG in the United States The wide range of LTD found in all these studies emphasizes the need for more precise assessment of the underlying variables, particularly disease prevalence and dosage. Further studies on other indications such as secondary immunodeficiencies will augment these results and will assist in guiding demand planning for IG use and plasma collection in the United States and inform blood policy in other countries.

Association between chronic inflammatory demyelinating polyneuropathy and gastrointestinal malignancies

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an uncommon and under-recognized immune-mediated disorder of the peripheral nervous system. It is associated with both infectious and non-infectious etiologies and presents in several variant forms. In rare instances, CIDP has been reported in association with gastrointestinal (esophageal, hepatic, colorectal, and pancreatic) malignancies. The diagnosis of malignancy is typically preceded by weeks to months by that of CIDP, though the inverse may also be seen. As with other etiologies of CIDP, cases associated with gastrointestinal malignancies are often treated with corticosteroids, intravenous immunoglobulins, and/or plasma exchange, with improvement or resolution of neurological symptoms in the majority of cases. In this review, we provide a practical overview of CIDP, with an emphasis on recognizing the clinical association between CIDP and gastrointestinal malignancies.

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

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

Expanding the Role of the Pharmacist: Immunoglobulin Therapy and Disease Management in Neuromuscular Disorders

Immunoglobulin G (IgG) is a commonly used treatment for chronic neuromuscular disorders (NMDs), such as chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy. IgG therapy has also shown promise in treating other NMDs including myasthenia gravis, polymyositis, and dermatomyositis. IgG is administered as either intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg), with SCIg use becoming more popular due to the treatment burden associated with IVIg. IVIg requires regular venous access; long infusions (typically 4-6 hours); and can result in systemic adverse events (AEs) for some patients. In contrast, SCIg can be self-administered at home with shorter infusions (approximately 1 hour) and fewer systemic AEs. As patient care shifts toward home-based settings, the role of the pharmacist is paramount in providing a continuation of care and acting as the bridge between patient and clinic. Pharmacists with a good understanding of current recommendations, dosing strategies, and administration routes for IgG therapy are best placed to support patients. The aims of this review are to highlight the evidence supporting IgG therapy in the treatment of NMDs and provide practical information on patient management and IVIg/SCIg dosing in order to guide pharmacists on optimizing clinical outcomes and patient care.

Subcutaneous Immunoglobulin Therapy for Chronic Inflammatory Demyelinating Polyneuropathy: A Nursing Perspective

Chronic inflammatory demyelinating polyneuropathy (CIDP), an immune-mediated peripheral neuropathy, is frequently treated with long-term maintenance intravenous immunoglobulin (IVIG). However, disadvantages of IVIG are the systemic adverse reactions, lengthy infusions, and need for vascular access. Subcutaneous immunoglobulin (SCIG) addresses many of the issues encountered by those unable, or unwilling, to tolerate the treatment burden of long-term IVIG. Subcutaneous immunoglobulin, a 20% solution stabilized with L-proline, is US Food and Drug Administration-approved for CIDP maintenance therapy in patients after being stabilized with IVIG. Approval was based on a randomized, double-blind, placebo-controlled trial where SCIG demonstrated superiority over placebo and was safe and efficacious in maintaining function. In addition to reviewing the primary efficacy results from the clinical trial, this article aims to update the neurology nursing community on a new option for long-term management of CIDP, including the practicalities of initiating and maintaining patients on SCIG therapy.

Rare Occurrence of PLA2R-Positive Membranous Nephropathy in a Patient with Sjogren's Syndrome and CIDP

Membranous nephropathy is known to be associated with number of autoimmune diseases. Occurrence of PLA2R positive membranous nephropathy with sjogren's syndrome and chronic inflammatory demyelinating neuropathy (CIDP) is quite rare. Role of PLA2R antigen in autoimmune diseases like sjogren's syndrome and CIDP is largely unknown. Choice and initiation of immunosuppression if required may also be governed by the presence of other autoimmune diseases along with PLA2R positive membranous nephropathy

Chronic inflammatory demyelinating polyneuropathy: Plasmapheresis or cyclosporine can be good treatment options in refractory cases

Childhood chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare condition, and the optimal treatment strategy is not well established, especially in refractory cases. We analyzed the clinical features and treatment outcomes of 14 cases of childhood CIDP with more than 12 months of follow-up. Of the 14 cases, 10 cases were considered refractory to the conventional first-line treatment. In the monophasic group (n = 6), plasmapheresis resulted in a better treatment response than did IVIG. Monophasic refractory cases (n = 4) were especially responsive to plasmapheresis. In the polyphasic group (n = 8), IVIG and plasmapheresis had comparable effects. Among them six polyphasic patients were refractory to the first-line treatment options and received additional immunosuppressants. Four treatment-refractory polyphasic patients received cyclosporine and achieved successful disease control. With regard to the long-term outcomes, six patients showed minimal symptoms and no relapse within 6 months. Our results suggest that early administration of plasmapheresis in a monophasic course and cyclosporine in a polyphasic course may be effective treatment options for refractory childhood CIDP.

Treatment Patterns and Costs of Chronic Inflammatory Demyelinating Polyneuropathy: A Claims Database Analysis

BACKGROUND

Corticosteroids, plasma exchange, and intravenous immunoglobulin (IVIG) have been standard-of-care treatments for chronic inflammatory demyelinating polyneuropathy (CIDP) for more than 2 decades. Despite guideline recommendations for best clinical practices, heterogeneity in patient presentation and the course of treatment for CIDP remains. There is limited literature regarding the real-world treatment patterns of and costs associated with CIDP.

OBJECTIVE

To analyze and describe the real-world treatment patterns of and economic burden associated with CIDP.

METHODS

This retrospective cohort study evaluated the treatment patterns and CIDP-related healthcare costs over a 2-year follow-up period for patients with newly diagnosed CIDP who had commercial insurance, using claims data from the IMS LifeLink PharMetrics Plus Claims database between 2009 through 2014. Treatment-naïve patients with newly diagnosed CIDP were evaluated for 2 years postdiagnosis, which captured the treatments used and the resource utilization. The patients were defined as receiving active CIDP therapy (ie, IVIG, immunosuppressants, oral or intravenous steroids, or plasma exchange) or active surveillance.

RESULTS

Of the 525 patients identified with newly diagnosed CIDP, 55.2% of patients were prescribed only steroid therapy, and 25.3% of patients were prescribed an IVIG therapy during the 2-year follow-up. The median time to the initial treatment was shortest for patients receiving plasma exchange alone (0.03 months) or in combination with a steroid (0.03 months), followed by IVIG plus another therapy (0.53 months), and then IVIG alone (0.71 months). Initiating therapy with steroids alone took the longest mean time (6.51 months) to start the treatment. The median length of time to receive therapy was longest for the steroid plus plasma exchange cohort (21.8 months), followed by the steroid plus immunosuppressant cohort (10.1 months), and the 2 IVIG cohorts (9.04 months for IVIG alone and 9.82 months for IVIG plus another therapy). The mean total CIDP-specific 2-year follow-up costs were highest for the cohort that received IVIG alone ($119,928) or with an additional therapy ($133,334) and lowest for patients who received active surveillance ($3723) or steroids alone ($3101).

CONCLUSIONS

Steroid therapy was initiated later and resulted in a shorter duration of treatment than other treatment options for patients with CIDP, which may reflect diagnostic uncertainty, disease severity or remission, therapeutic challenge to determine diagnosis, or the side-effect profile of steroids. The use of steroids alone was the most common prescribed treatment for CIDP. Further research is needed to understand the rationale for treatment decisions in this patient population and their potential impact on patients and health plans.

Efficacy and Safety of Octagam® in Patients With Chronic Inflammatory Demyelinating Polyneuropathy

Introduction

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a debilitating autoimmune neuropathy that is treated with intravenous immunoglobulin (IVIG). The aim of this retrospective study was to investigate the efficacy and safety of the sucrose-free IVIG Octagam® (Octapharma AG, Lachen, Switzerland) in patients with CIDP.

Methods

Data from 47 patients who received at least one dose of Octagam were collected from the records of 11 centres in France. Efficacy was assessed using Overall Neuropathy Limitation Scale (ONLS). Safety was evaluated using adverse event rates.

Results

Data from 24 patients who were IVIG naïve (n = 11) or had stopped IVIG ≥ 12 weeks before   initiation of Octagam therapy (washout group; n  = 13) were included in the efficacy analysis. At 4 months post-initiation of Octagam treatment, 41.7% of patients had improved their functional status (decrease of ≥ 1 ONLS score) with a significant change   in the ONLS score from baseline (– 0.42; p = 0.04; signed test). Functional status was reduced in only two patients: one patient in the IVIG-naïve group and one patient in the IVIG-washout group. All 47 patients were included in the safety analysis, which showed that Octagam was well tolerated, with a frequency of 0.04 adverse events per Octagam course. The most common adverse drug reaction was headache.

Conclusions

These real-life results are consistent with the efficacy and safety of IVIG reported in randomised controlled studies. A long-term prospective study of Octagam in patients with CIDP is warranted.

Funding

Octapharma, France SAS.

Two comparative assessments of intravenous immunoglobulin therapy switching patterns in the treatment of chronic inflammatory demyelinating polyneuropathy in the US

Purpose: For chronic inflammatory demyelinating polyneuropathy (CIDP) patients, each branded intravenous immunoglobulin (IVIG) treatment differs in production processes, virus elimination, formulation, and composition. Given the limited availability of real-world data comparing IVIGs for CIDP, this study evaluated switching patterns between IVIG products in 2 separate retrospective databases. Patients and methods: Two independent analytic teams retrospectively evaluated IVIG treatment-naïve patients with an ICD diagnosis code for CIDP. Study 1 used integrated healthcare claims from IMS LifeLink PharMetrics Plus™ and Study 2 used the Truven MarketScan® Database. All analyses were descriptive, with outcomes assessed during the 2-year post-index period. Results: One-quarter of IVIG patients switched therapies within the 2-year study period. In both studies, switching rates were lowest for IVIG-G (Gamunex®-C) (Study 1: 9.8%, Study 2: 8.9%), followed by IVIG-F (Flebogamma®) (Study 1: 25.0%, Study 2: 18.2%), and highest for IVIG-other (Octagam®/Gammaplex®) (Study 1: 50.0%, Study 2: 33.3%). When patients were switched, most switched to IVIG-G (Study 1: 51.6%, Study 2: 54.3%). Conclusion: The small proportion of CIDP switchers in 2 independent studies suggests that IVIG therapy is generally well tolerated. However, differences existed in switch rates for different IVIG products. The reason for low switching rates could not be assessed in this study; therefore, further studies are required to detect possible relevant differences in effectiveness and tolerability.

Spinal Manifestations of Systemic Disease

The spine is frequently involved in systemic diseases, including those with neuropathic, infectious, inflammatory, rheumatologic, metabolic, and neoplastic etiologies. This article provides an overview of systemic disorders that may affect the spine, which can be subdivided into disorders predominantly involving the musculoskeletal system (including bones, joints, disks, muscles, and tendons) versus those predominantly involving the nervous system. By identifying the predominant pattern of spine involvement, a succinct, appropriate differential diagnosis can be generated. The importance of reviewing the medical record, as well as prior medical imaging (including nonspine imaging), which may confer greater specificity to the differential diagnosis, is stressed.

The economic burden of CIDP in the United States: A case-control study

Background

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder of the peripheral nervous system. The economic burden of CIDP is not well understood.

Objectives

To assess the economic and clinical burden of CIDP and to compare the incremental burden relative to a matched control group without CIDP.

Methods

This retrospective case-control analysis was conducted using data from the IQVIA Real-World Data Adjudicated Claims. Adults newly diagnosed with CIDP between 7/1/2010 and 6/30/2014 were identified and direct matched to controls without CIDP. Baseline characteristics were assessed and compared over a 6-month pre-index period. Healthcare resource use, costs and clinical characteristics were assessed and compared over a 2-year follow-up. Total cost differences over the 2-year follow-up were compared between matched cohorts using a generalized estimating equation model.

Results

The final sample comprised a total of 790 cases matched to 790 controls. Over the 2-year follow-up, cases more frequently experienced neuropathic pain, back pain and osteoarthritis and more commonly utilized opioids, anti-convulsants and anti-depressants. Compared to controls, more cases had ≥1 hospitalization (26.2% vs. 9.0%), and cases had a higher mean number of outpatient prescription fills (62.8 vs. 32.0) and physician office visits (34.7 vs. 13.0) (all p<0.0001). Cases had 7.5x higher mean total costs ($116,330 vs. $15,586, p<0.0001). Important cost drivers were costs for outpatient ancillary, radiology and HCPCS drugs (mean $76,366 vs. $4,292) and costs for inpatient care (mean $16,357 vs. $2,862) (both p<0.0001). Among cases, CIDP therapy (inclusive of both outpatient pharmacy and medical claims) accounted for 51.2% of mean total costs. After further adjusting for baseline clinical characteristics, cases were associated with a 6.1x increase in total costs compared to controls (p<0.0001).

Conclusions

Our findings suggest a substantial clinical and economic burden among patients with CIDP relative to matched controls over a 2-year follow-up.

Pharmacokinetics and Pharmacodynamics of Intravenous Immunoglobulin G Maintenance Therapy in Chronic Immune-mediated Neuropathies

The regimen for IVIg maintenance treatment varies considerably between patients with chronic immune-mediated neuropathies. Although it is widely recognized that treatment regimens should be improved, detailed pharmacokinetics (PK) of IVIg have not yet been established. We aimed to determine the PK of IVIg maintenance treatment in patients with clinically stable, treatment-dependent, chronic immune-mediated neuropathy. Patients received a median IVIg dose of 30 g (range, 15-70 g) every 14 days (range, 7-28 days) resulting in high IgG peak levels (median, 25.9 g/L; range, 16.7-41.0 g/L) and trough levels (median, 16.1 g/L; range, 9.7-23.6 g/L). IgG PK parameters, including half-life (median, 23.1 days; range, 11-60 days), were constant during subsequent courses in the same patients, but varied considerably between patients. The IgG levels at 1 week after infusion correlated with grip strength. These results provide insight into the PK of IVIg maintenance treatment in patients with chronic immune-mediated neuropathies.

Disease activity in chronic inflammatory demyelinating polyneuropathy

INTRODUCTION

Evaluation of disease status in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) is often done by a combination of clinical evaluation and electrodiagnostic studies. A CIDP disease activity status (CDAS) was developed to standardize outcomes in CIDP patients. We aimed to determine if the CDAS was concordant with classical evaluation and whether CDAS enables benchmarking of CIDP.

METHODS

We performed a retrospective chart review of 305 CIDP patients and identified 206 patients with >1 visit and applied the CDAS to this cohort. We examined relationships between the CDAS and classical evaluation as to outcomes and compared our cohort to other CIDP cohorts who had CDAS.

RESULTS

We found that the CDAS mirrored disease severity as measured by electrophysiology and vibration perception thresholds in that CDAS class 5 had more severe neuropathy. Our results are similar to other cohorts in the middle CDAS strata with the exception of fewer subjects in CDAS 1 and more in CDAS 5. The only demographic factor predicting CDAS 5 in our cohort was age, and the overall treatment response rate using the CDAS classification was 79.3%.

CONCLUSIONS

CDAS appears to have sufficient face-validity as a grading system to assess disease activity in relation to treatment status. The use of CDAS appears to allow benchmarking of patients with CIDP that may be useful in subject selection for clinical trials and also to highlight differences in practice.

Stance Postural Strategies in Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Introduction

Polyneuropathy leads to postural instability and an increased risk of falling. We investigated how impaired motor impairment and proprioceptive input due to neuropathy influences postural strategies.

Methods

Platformless bisegmental posturography data were recorded in healthy subjects and patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Each subject stood on the floor, wore a head and a hip electromagnetic tracker. Sway amplitude and velocity were recorded and the mean direction difference (MDD) in the velocity vector between trackers was calculated as a flexibility index.

Results

Head and hip postural sway increased more in patients with CIDP than in healthy controls. MDD values reflecting hip strategies also increased more in patients than in controls. In the eyes closed condition MDD values in healthy subjects decreased but in patients remained unchanged.

Discussion

Sensori-motor impairment changes the balance between postural strategies that patients adopt to maintain upright quiet stance. Motor impairment leads to hip postural strategy overweight (eyes open), and prevents strategy re-balancing when the sensory context predominantly relies on proprioceptive input (eyes closed).

Paraproteinemic neuropathy: a practical review

The term paraproteinemic neuropathy describes a heterogeneous set of neuropathies characterized by the presence of homogeneous immunoglobulin in the serum. An abnormal clonal proliferation of B-lymphocytes or plasma cells, which may or may not occur in the context of a hematologic malignancy, produces the immunoglobulins in excess. If malignancy is identified, treatment should be targeted to the neoplasm. Most cases, however, occur as monoclonal gammopathy of undetermined significance. Few prospective, randomized, placebo-controlled trials are available to inform the management of paraproteinemic neuropathies. Clinical experience combined with data from smaller, uncontrolled studies provide a basis for recommendations, which depend on the specific clinical setting in which the paraprotein occurs. In this review, we provide a clinically practical approach to diagnosis and management of such patients.

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.

AAV1.NT-3 gene therapy attenuates spontaneous autoimmune peripheral polyneuropathy

The spontaneous autoimmune peripheral polyneuropathy (SAPP) model in B7-2 knockout non-obese diabetic mice shares clinical and histological features with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Secondary axonal loss is prominent in the progressive phase of this neuropathy. Neurotrophin 3 (NT-3) is an important autocrine factor supporting Schwann cell survival and differentiation and stimulates neurite outgrowth and myelination. The anti-inflammatory and immunomodulatory effects of NT-3 raised considerations of potential efficacy in the SAPP model that could be applicable to CIDP. For this study, scAAV1.tMCK.NT-3 was delivered to the gastrocnemius muscle of 25-week-old SAPP mice. Measurable NT-3 levels were found in the serum at 7-week postgene delivery. The outcome measures included functional, electrophysiological and histological assessments. At week 32, NT-3-treated mice showed increased hind limb grip strength that correlated with improved compound muscle action potential amplitude. Myelinated fiber density was 1.9 times higher in the NT-3-treated group compared with controls and the number of demyelinated axons was significantly lower. The remyelinated nerve fiber population was significantly increased. These improved histopathological parameters from scAAV1.tMCK.NT-3 treatment occurred in the setting of reduced sciatic nerve inflammation. Collectively, these findings suggest a translational application to CIDP.

Current and future immunotherapy targets in autoimmune neurology

Randomized controlled treatment trials of autoimmune neurologic disorders are generally lacking and data pertaining to treatment are mostly derived from expert opinion, large case series, and anecdotal reports. The treatment of autoimmune neurologic disorders comprises oncologic therapy (where appropriate) and immunotherapy. In this chapter, we first describe the standard acute and chronic immunotherapies and provide a practical overview of their use in the clinic (mechanisms of action, dosing, monitoring, and side effects). Novel approaches to treatment of autoimmune neurologic disorders, through new drug discovery or repurposing, are dependent on improved mechanistic understanding of immunopathology. Such approaches, with emphasis on monoclonal antibodies, are discussed using the paradigm of three autoimmune neurologic disorders whose immunopathogenesis is better understood, specifically myasthenia gravis, neuromyelitis optica, and chronic inflammatory demyelinating polyradiculoneuropathy. It is important to realize that the treatment strategy and management plan must be individualized for each patient. In general these are influenced by the following: clinical severity, antibody type, presence or absence of cancer, and prior treatment response, if known.

Chronic inflammatory demyelinating polyradiculoneuropathy with cholesterol deposits in a dog

Chronic inflammatory demyelinating polyradiculoneuropathy occurred in an 11-year-old Labrador Retriever dog. Spinal cord compression resulted from massive radiculitis with prominent cholesterol granulomas. Cholesterol deposition and associated granuloma formation is unique in chronic inflammatory demyelinating polyradiculoneuropathy, in both its human and canine expressions.

CIDP variants in diabetes: measuring treatment response with a small nerve fiber test

INTRODUCTION

Chronic inflammatory demyelinating polyneuropathy (CIDP) is eleven times more common among people with diabetes than the general population and is treatable with appropriate immunotherapy. Treatment response is usually measured clinically (symptomatic and functional improvement). We present a case of a patient with type 2 diabetes (T2D) and CIDP whose treatment response was measurable with the Sudoscan sudomotor function test. This test may represent a new objective evaluation of the treatment of CIDP.

CASE DESCRIPTION

The patient is a 60year old male initially referred to our center in August 2012, at which time he was diagnosed with CIDP based on AAN electrodiagnostic criteria (NCS). Autonomic functions were significant for low heart rate variability response to expiration/inspiration (E/I), Valsalva maneuver and the ratio of the RR interval for the 30th to the 15th beat upon standing (1.08, 1.12, 1.05 respectively), and frequency analysis of the total spectral power, the standard deviation of the normal RR intervals (sdNN) and their root mean squared (rmsSD). Sudoscan electrochemical skin conductances (ESC), measuring small nerve fiber function on the palms and soles, were very low: 23 μS in the feet and 32 μS in the hands. After one cycle of intravenous immunoglobulin (IVIG: 6 doses total, 75g each) the patient had no change in symptoms of burning, numbness, shooting pains, and gait impairment. However, E/I, Valsalva, and 30:15 ratios (1.19, 1.36, 1.39 respectively) were improved, as were NCS. Sudoscan scores for feet and hands were unchanged (23 μS and 32 μS). In March 2013, the patient's autonomic functions worsened (E/I, Valsalva, and 30:15 ratios 1.1, 1.07, 1.12 respectively), but feet and hand ESC started to show improvement (35 μS and 52 μS respectively). Azathioprine was started. Eight days after a second cycle of IVIG in January 2014, the patient reported for the first time less burning, shooting pains and tingling. E/I, Valsalva, and 30:15 ratios remained low (1.03, 1.07, and not analyzable, respectively), while foot and hand ESC scores continued to improve (43 μS and 55 μS respectively).

DISCUSSION

CIDP diagnosis and treatment response are difficult in the diabetic patient. We found that NCS and autonomic function tests did not correlate well with clinical status while numerical Sudoscan scores matched closely symptomatic changes. ESC have been found to correlate well with peripheral small fiber function and neuropathic symptoms in DPN. The findings in this patient warrant further investigation of the use of Sudoscan to monitor CIDP response to therapy.

A case of chronic inflammatory demyelinating polyneuropathy presented with unilateral ptosis

Chronic Inflammatory Demyelinating Polyneuropathy is an autoimmune disease with progressive and relapsing courses. The main clinical presentations are diffuse deep tendon hyporeflexia or areflexia and symmetric proximal-distal muscles weakness. Myasthenia gravis is also an immune mediated disease with fluctuating ocular and bulbar symptoms and sometimes weakness. Although both myasthenia gravis and chronic inflammatory demyelinating polyneuropathy are immune mediated disorders, clinical presentations are obviously different in the two diseases. Herein, we will report a case of chronic inflammatory demyelinating polyneuropathy who presented with isolated unilateral ptosis. Initially, the patient was managed as ocular type of myasthenia gravis, but after progression to general limb weakness and areflexia, the diagnosis of chronic inflammatory demyelinating polyneuropathy was made. Although unilateral ptosis is a typical feature of myasthenia gravis, it may be seen as the first presentation of chronic inflammatory demyelinating polyneuropathy as well which mimics myasthenia gravis disease.

A review of the use of biological agents for chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a group of idiopathic, acquired, immune-mediated inflammatory demyelinating diseases of the peripheral nervous system. A majority of patients with CIDP respond to "first-line" treatment with IVIG, plasmapheresis and/or corticosteroids. There exists insufficient evidence to ascertain the benefit of treatment with "conventional" immunosuppressive drugs. The inconsistent efficacy, long-term financial burden and health risks of non-specific immune altering therapy have drawn recurrent attention to the possible usefulness of a variety of biological agents that target key aspects in the CIDP immunopathogenic pathways. This review aims to give an updated account of the scientific rationale and potential use of biological therapeutics in patients with CIDP. No specific treatment recommendations are given. The discovery, development and application of biological markers by modern molecular diagnostic techniques may help identify drug-naïve or treatment-resistant CIDP patients most likely to respond to targeted immunotherapy.