Subcutaneous versus intravenous immunoglobulin in multifocal motor neuropathy: a randomized, single-blinded cross-over trial

Patient-reported preferences for subcutaneous or intravenous administration of parenteral drug treatments in adults with immune disorders: a systematic review and meta-analysis

Aim: Several studies have found subcutaneous (SC) and intravenous (IV) administration of similar drugs for long-lasting immunological and autoimmune diseases to have similar clinical effectiveness, meaning that what patients report they prefer is, or should be, a major factor in treatment choices. Therefore, it is important to systematically compile evidence regarding patient preferences, treatment satisfaction and health-related quality of life (HRQL) using SC or IV administration of the same drug. Materials & methods: PubMed database searches were run on 15 October 2021. Studies involving patients with experience of both home-based SC and hospital-based IV administration of immunoglobulins or biological therapies for the treatment of any autoimmune disease or primary immunodeficiencies (PIDs) were included. The outcomes assessed were patient preferences, treatment satisfaction and HRQL. Preference data were meta-analyzed using a random-effects model. Results: In total, 3504 citations were screened, and 46 publications describing 37 studies were included in the review. There was a strong overall preference for SC over IV administration, with similar results seen for PIDs and autoimmune diseases: PID, 80% (95% confidence interval [CI], 64-94%) preferred SC; autoimmune diseases, 83% (95% CI: 73-92%); overall, 82% (95% CI: 75-89%). The meta-analysis also found that 84% (95% CI: 75-92%) of patients preferred administration at home to treatment in hospital. Analysis of treatment satisfaction using the life quality index found consistently better treatment interference and treatment setting scores with SC administration than with IV administration. Conclusion: Compared with IV infusions in hospital, patients tend to prefer, to be more satisfied with and to report better HRQL with SC administration of the same drug at home, primarily due to the greater convenience. This study contributes to evidence-based care of patients with autoimmune diseases or PIDs.

Effects of Intravenous Immunoglobulins on Human Innate Immune Cells: Collegium Internationale Allergologicum Update 2024

BACKGROUND

Intravenous immunoglobulin (IVIg) has been used for almost 40 years in the treatment of autoimmune and systemic inflammatory diseases. Numerous cells are involved in the innate immune response, including monocytes/macrophages, neutrophils, dendritic cells, mast cells, basophils, eosinophils, natural killer cells, and innate lymphoid cells. Many studies have investigated the mechanisms by which IVIg down-modulates inflammatory and autoimmune processes of innate immune cells. However, questions remain regarding the precise mechanism of action in autoimmune or inflammatory conditions. The aim of this work was to review the immunomodulatory effect of IVIg on only human innate immune cells. A narrative review approach was chosen to summarize key evidence on the immunomodulatory effects of commercially available and unmodified IVIg on human innate immune cells.

SUMMARY

Numerous different immunomodulatory effects of IVIg have been reported, with some very different effects depending on the immune cell type and disease. Several limitations of the different studies were identified. Of the 77 studies identified and reviewed, 29 (37.7%) dealt with autoimmune or inflammatory diseases. Otherwise, the immunomodulatory effects of IVIg were studied only in healthy donors using an in vitro experimental approach. Some of the documented effects showed disease-specific effects, such as in Kawasaki disease. Various methodological limitations have also been identified that may reduce the validity of some studies.

KEY MESSAGE

As further insights have been gained into the various inflammatory cascades activated in immunological diseases, interesting insights have also been gained into the mechanism of action of IVIg. We are still far from discovering all the immunomodulatory mechanisms of IVIg.

A Practical Guide to Identify Patients With Multifocal Motor Neuropathy, a Treatable Immune-Mediated Neuropathy

Multifocal motor neuropathy (MMN) is a rare immune-mediated motor neuropathy characterized by asymmetric weakness that preferentially affects distal upper limb muscles. The clinical features of MMN may be difficult to differentiate from motor neuron disease. Other conditions that may be mistaken for MMN include inclusion body myositis, chronic inflammatory demyelinating polyradiculoneuropathy, hereditary neuropathy with liability to pressure palsy, focal neuropathies, and radiculopathies. A key distinguishing electrophysiologic feature of MMN is the motor nerve conduction block located at noncompressible sites. MMN is a treatable neuropathy; therefore it is important that primary care physicians are aware of the features of the disease to identify potential patients and make referrals to a neuromuscular specialist in a timely manner. This review provides an overview of the disease, highlights key differential diagnoses, and describes available treatment options for patients with MMN.

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.

Immune-Mediated Neuropathies: Pathophysiology and Management

Dysfunction of the immune system can result in damage of the peripheral nervous system. The immunological mechanisms, which include macrophage infiltration, inflammation and proliferation of Schwann cells, result in variable degrees of demyelination and axonal degeneration. Aetiology is diverse and, in some cases, may be precipitated by infection. Various animal models have contributed and helped to elucidate the pathophysiological mechanisms in acute and chronic inflammatory polyradiculoneuropathies (Guillain-Barre Syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, respectively). The presence of specific anti-glycoconjugate antibodies indicates an underlying process of molecular mimicry and sometimes assists in the classification of these disorders, which often merely supports the clinical diagnosis. Now, the electrophysiological presence of conduction blocks is another important factor in characterizing another subgroup of treatable motor neuropathies (multifocal motor neuropathy with conduction block), which is distinct from Lewis-Sumner syndrome (multifocal acquired demyelinating sensory and motor neuropathy) in its response to treatment modalities as well as electrophysiological features. Furthermore, paraneoplastic neuropathies are also immune-mediated and are the result of an immune reaction to tumour cells that express onconeural antigens and mimic molecules expressed on the surface of neurons. The detection of specific paraneoplastic antibodies often assists the clinician in the investigation of an underlying, sometimes specific, malignancy. This review aims to discuss the immunological and pathophysiological mechanisms that are thought to be crucial in the aetiology of dysimmune neuropathies as well as their individual electrophysiological characteristics, their laboratory features and existing treatment options. Here, we aim to present a balance of discussion from these diverse angles that may be helpful in categorizing disease and establishing prognosis.

A Budget Impact Model of Maintenance Treatment of Chronic Inflammatory Demyelinating Polyneuropathy with IgPro20 (Hizentra) Relative to Intravenous Immunoglobulin in the United States

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, progressive autoimmune disease causing peripheral nervous system dysfunction. Guidelines recommend immunoglobulin (IG) therapy as an immunomodulatory agent in CIDP. Drawbacks and unmet needs with intravenous immunoglobulin (IVIG) include adverse effects and wear-off effects, along with the burden of administration based on site of care. Subcutaneous administration of Hizentra, a subcutaneous immunoglobulin (SCIG) reduces patient burden by allowing self-administration outside the hospital setting and has fewer adverse events (AEs).

OBJECTIVE

We aimed to compare the expected cost of treatment and the budget impact of Hizentra compared with IVIG for maintenance treatment of CIDP in the United States.

METHODS

A decision tree model was developed to estimate the expected budget impact of maintenance treatment with Hizentra for US stakeholders. The model adopts primarily a US integrated delivery network perspective and, secondarily, a commercial perspective over a 1-year time horizon. Pharmacy costs were based on a payment mix of average sales price (73%), wholesale acquisition cost (2%), and average wholesale price (25%). Costs in the model reflect 2022 US dollars. In accordance with the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines and recommendations for budget impact modeling, no discounting was performed. The PATH clinical study of Hizentra maintenance in CIDP was used to determine clinical inputs for relapse rates at initial assessment (24 weeks) and at 52 weeks for Hizentra. The ICE clinical study of Gamunex maintenance in CIDP was the basis of relapse rates for Gamunex (and other IVIGs). Literature-based estimates were obtained for infusion costs by site of care, costs of IVIG infusion-related complications, and significant IVIG AE rates. Hizentra AE rates from the US Hizentra prescribing information were assessed but were not included in the model as the AEs in CIDP were mild, easily treated, and self-limited. Sensitivity analyses and scenario analyses were conducted to evaluate variations from the base case.

RESULTS

The model showed that a Hizentra starting dose of 0.2 g/kg is expected to result in annual cost savings of US$32,447 per patient compared with IVIG. For a hypothetical 25-million-member plan, the budget impact of a 10% market share shift from IVIG to Hizentra is expected to result in savings of US$2,296,235.

CONCLUSION

This analysis projects that Hizentra is likely associated with favorable economic benefit compared with IVIG in managing CIDP.

Autoimmune polyneuropathies

The autoimmune peripheral neuropathies with prominent motor manifestations are a diverse collection of unusual peripheral neuropathies that are appreciated in vast clinical settings. This chapter highlights the most common immune-mediated, motor predominant neuropathies excluding acute, and chronic inflammatory demyelinating polyradiculoneuropathy (AIDP and CIDP, respectively). Other acquired demyelinating neuropathies such as distal CIDP and multifocal motor neuropathy will be covered. Additionally, the radiculoplexus neuropathies, resulting from microvasculitis-induced injury to nerve roots, plexuses, and nerves, including diabetic and nondiabetic lumbosacral radiculoplexus neuropathy and neuralgic amyotrophy (i.e., Parsonage-Turner syndrome), will be included. Finally, the motor predominant peripheral neuropathies encountered in association with rheumatological disease, particularly Sjögren's syndrome and rheumatoid arthritis, are covered. Early recognition of these distinct motor predominant autoimmune neuropathies and initiation of immunomodulatory and immunosuppressant treatment likely result in improved outcomes.

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.

Immunoglobulin for multifocal motor neuropathy

BACKGROUND

Multifocal motor neuropathy (MMN) is a rare, probably immune-mediated disorder characterised by slowly progressive, asymmetric, distal weakness of one or more limbs with no objective loss of sensation. It may cause prolonged periods of disability. Treatment options for MMN are few. People with MMN do not usually respond to steroids or plasma exchange. Uncontrolled studies have suggested a beneficial effect of intravenous immunoglobulin (IVIg). This is an update of a Cochrane Review first published in 2005, with an amendment in 2007. We updated the review to incorporate new evidence.

OBJECTIVES

To assess the efficacy and safety of intravenous and subcutaneous immunoglobulin in people with MMN.

SEARCH METHODS

We searched the following databases on 20 April 2021: the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and WHO ICTRP for randomised controlled trials (RCTs) and quasi-RCTs, and checked the reference lists of included studies.

SELECTION CRITERIA

We considered RCTs and quasi-RCTs examining the effects of any dose of IVIg and subcutaneous immunoglobulin (SCIg) in people with definite or probable MMN for inclusion in the review. Eligible studies had to have measured at least one of the following outcomes: disability, muscle strength, or electrophysiological conduction block. We used studies that reported the frequency of adverse effects to assess safety.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the literature searches to identify potentially relevant trials, assessed risk of bias of included studies, and extracted data. We followed standard Cochrane methodology.

MAIN RESULTS

Six cross-over RCTs including a total of 90 participants were suitable for inclusion in the review. Five RCTs compared IVIg to placebo, and one compared IVIg to SCIg. Four of the trials comparing IVIg versus placebo involved IVIg-naive participants (induction treatment). In the other two trials, participants were known IVIg responders receiving maintencance IVIg at baseline and were then randomised to maintenance treatment with IVIg or placebo in one trial, and IVIg or SCIg in the other. Risk of bias was variable in the included studies, with three studies at high risk of bias in at least one risk of bias domain. IVIg versus placebo (induction treatment): three RCTs including IVIg-naive participants reported a disability measure. Disability improved in seven out of 18 (39%) participants after IVIg treatment and in two out of 18 (11%) participants after placebo (risk ratio (RR) 3.00, 95% confidence interval (CI) 0.89 to 10.12; 3 RCTs, 18 participants; low-certainty evidence). The proportion of participants with an improvement in disability at 12 months was not reported. Strength improved in 21 out of 27 (78%) IVIg-naive participants treated with IVIg and one out of 27 (4%) participants who received placebo (RR 11.00, 95% CI 2.86 to 42.25; 3 RCTs, 27 participants; low-certainty evidence). IVIg treatment may increase the proportion of people with resolution of at least one conduction block; however, the results were also consistent with no effect (RR 7.00, 95% CI 0.95 to 51.70; 4 RCTs, 28 participants; low-certainty evidence). IVIg versus placebo (maintenance treatment): a trial that included participants on maintenance IVIg treatment reported an increase in disability in 17 out of 42 (40%) people switching to placebo and seven out of 42 (17%) remaining on IVIg (RR 2.43, 95% CI 1.13 to 5.24; 1 RCT, 42 participants; moderate-certainty evidence) and a decrease in grip strength in 20 out of 42 (48%) participants after a switch to placebo treatment compared to four out of 42 (10%) remaining on IVIg (RR 0.20, 95% CI 0.07 to 0.54; 1 RCT, 42 participants; moderate-certainty evidence). Adverse events, IVIg versus placebo (induction or maintenance): four trials comparing IVIg and placebo reported adverse events, of which data from two studies could be meta-analysed. Transient side effects were reported in 71% of IVIg-treated participants versus 4.8% of placebo-treated participants in these studies. The pooled RR for the development of side effects was 10.33 (95% CI 2.15 to 49.77; 2 RCTs, 21 participants; very low-certainty evidence). There was only one serious side effect (pulmonary embolism) during IVIg treatment. IVIg versus SCIg (maintenance treatment): the trial that compared continuation of IVIg maintenance versus SCIg maintenance did not measure disability. The evidence was very uncertain for muscle strength (standardised mean difference 0.08, 95% CI -0.84 to 1.00; 1 RCT, 9 participants; very low-certainty evidence). The evidence was very uncertain for the number of people with side effects attributable to treatment (RR 0.50, 95% CI 0.18 to 1.40; 1 RCT, 9 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Low-certainty evidence from three small RCTs shows that IVIg may improve muscle strength in people with MMN, and low-certainty evidence indicates that it may improve disability; the estimate of the magnitude of improvement of disability has wide CIs and needs further studies to secure its significance. Based on moderate-certainty evidence, it is probable that most IVIg responders deteriorate in disability and muscle strength after IVIg withdrawal. SCIg might be an alternative treatment to IVIg, but the evidence is very uncertain. More research is needed to identify people in whom IVIg withdrawal is possible and to confirm efficacy of SCIg as an alternative maintenance treatment.

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.

Long-term follow-up of facilitated subcutaneous immunoglobulin therapy in multifocal motor neuropathy

OBJECTIVE

To assess the feasibility, efficacy and patient satisfaction of long-term facilitated subcutaneous immunoglobulin therapy (fSCIG) in multifocal motor neuropathy (MMN).

METHODS

Twelve patients previously participating in a randomized trial investigating the short-term efficacy of fSCIG were offered to switch to fSCIG maintenance therapy following a variable interval on conventional subcutaneous immunoglobulin.

RESULTS

Eight patients were switched to fSCIG maintenance therapy, seven of whom were invited for a follow-up assessment after 18 months (range 13-23 months) of treatment. The age at follow-up was 57 years (range 45-70 years) and patients received a median weekly dose immunoglobulin G of 32.5 g (range 20.0-50.0 g), the dose being unaltered compared to baseline values following completion of the fSCIG trial. In five patients the infusion was biweekly, whereas two patients were infused weekly. The follow-up mean isometric strength normalized to pre-trial values was 107.7% (95% CI 86.4-129.0%) being non-inferior to baseline values (104.7%, 95% CI 97.6-111.8%, P = 0.015). The mean ODSS was 2.0 (95% CI 0.8-3.2) which is identical to the baseline score following completion of the fSCIG trial, the P-value for non-inferiority being <0.0001. The secondary variables of impairment, function and quality of life at follow-up all were non-inferior to baseline values (P ≤ 0.046).

CONCLUSION

fSCIG seems feasible and effective for long-term maintenance treatment in patients with MMN.

Long-term treatment with subcutaneous immunoglobulin in multifocal motor neuropathy

Multifocal motor neuropathy (MMN) is a rare disease with a prevalence of less than 1 per 100,000 people. Intravenous immunoglobulin (IVIG) therapy, performed for a long-term period, has been demonstrated able to improve the clinical picture of MMN patients, ameliorating motor symptoms and/or preventing disease progression. Treatment with subcutaneous immunoglobulin (SCIg) has been shown to be as effective as IVIG. However, previously published data showed that follow-up of MMN patients in treatment with SCIg lasted no more than 56 months. We report herein the results of a long-term SCIg treatment follow up (up to 96 months) in a group of 8 MMN patients (6 M; 2F), previously stabilized with IVIG therapy. Clinical follow-up included the administration of Medical Research Council (MRC) sum-score, the Overall Neuropathy Limitation Scale (ONLS) and the Life Quality Index questionnaire (LQI) at baseline and then every 6 months. Once converted to SCIg, patients’ responsiveness was quite good. Strength and motor functions remained stable or even improved during this long-term follow-up with benefits on walking capability, resistance to physical efforts and ability in hand fine movements.

Patient Preferences for Subcutaneous versus Intravenous Administration of Treatment for Chronic Immune System Disorders: A Systematic Review

BACKGROUND

For many chronic immune system disorders, the available treatments provide several options for route of administration. The objective of this systematic literature review is to inform discussions about therapy choices for individual patients by summarizing the available evidence regarding the preferences of patients with chronic immune system disorders for intravenous (IV) or subcutaneous (SC) administration.

METHODS

Searches of the MEDLINE, Embase and Cochrane Library databases were conducted using terms designed to capture studies reporting patient preferences between IV and SC therapy published in English. Relevant studies were limited to those in which mode of administration, including treatment frequency and setting, was the main difference between comparators.

RESULTS

In total, 49 studies were included in the review. Among 18 studies that compared IV and SC immunoglobulin therapy, 16 found patients to prefer the SC administration route. The results of the 31 studies comparing IV infusion and SC injection of non-immunoglobulin therapies were mixed, with patients favoring SC administration in 20, IV infusion in seven, and having no overall preference in four. Patient experience had a strong effect on preferences, with treatment-experienced patients preferring their current administration route in most studies. Patients preferring SC administration tended also to prefer treatment at home, mainly due to the convenience and comfort of home treatment and the avoidance of having to attend hospital. By contrast, patients preferring IV infusion tended to cite the lower treatment frequency and a dislike of self-injecting, and preferred hospital treatment, mainly due to the presence of healthcare professionals and resulting feelings of safety.

CONCLUSION

In general patients with chronic immune system disorders tend to be more likely to choose SC administration than IV infusion, but preferences may vary according among individuals. These findings may assist discussions around appropriate treatment choices for each patient.

Pattern of muscle strength improvement after intravenous immunoglobulin therapy in multifocal motor neuropathy

Introduction

In multifocal motor neuropathy (MMN), knowledge about the pattern of treatment response in a wide spectrum of muscle groups, distal as well as proximal, after intravenous immunoglobulin (IVIg) initiation is lacking.

Methods

Hand‐held dynamometry data of 11 upper and lower limb muscles, from 47 patients with MMN was reviewed. Linear mixed models were used to determine the treatment response after IVIg initiation and its relationship with initial muscle weakness.

Results

All muscle groups showed a positive treatment response after IVIg initiation. Changes in SD scores ranged from +0.1 to +0.95. A strong association between weakness at baseline and the magnitude of the treatment response was found.

Discussion

Improved muscle strength in response to IVIg appears not only in distal, but to a similar degree also in proximal muscle groups in MMN, with the largest response in muscle groups that show the greatest initial weakness.

Clinical outcomes in multifocal motor neuropathy: A combined cross-sectional and follow-up study

OBJECTIVE

To assess the clinical course of multifocal motor neuropathy (MMN) in a large cohort of patients and to identify predictive factors of a progressive disease course.

METHODS

Between May 2015 and February 2016, we collected clinical data from 100 patients with MMN, of whom 60 had participated in a nationwide cross-sectional cohort study in 2007. We documented clinical characteristics using standardized questionnaires and performed a standardized neurologic examination. We used multiple linear regression analysis to identify factors that correlated with worse outcome.

RESULTS

We found that age at diagnosis (45.2 vs 48.6 years, p < 0.02) was significantly increased between 2007 and 2015-2016, whereas diagnostic delay decreased by 15 months. Seven out of 10 outcome measures deteriorated over time (all p < 0.01). Patients who had a lower Medical Research Council (MRC) sumscore and absence of 1 or more reflexes at the baseline visit showed a greater functional loss at follow-up (p = 0.007 and p = 0.016).

CONCLUSIONS

Our study shows that MMN is a progressive disease. Although 87% of patients received maintenance treatment, muscle strength, reflexes, vibration sense, and the Self-Evaluation Scale score significantly deteriorated over time. Lower MRC sumscore and absence of reflexes predicted a more progressive disease course.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that lower MRC sumscore and the absence of reflexes predict a more progressive disease course in patients with MMN.

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.

Immune-Mediated Neuropathies

The immune-mediated neuropathies are a broad category of diseases differentiated by time course, affected nerve fibers, and disease associations. This article spans the common, well-defined inflammatory demyelinating polyradiculoneuropathies (Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy) to the rarer, acquired demyelinating neuropathy variants (Miller-Fisher syndrome and multifocal motor neuropathy), vasculitic neuropathies, and sensory neuronopathies (dorsal root ganglionopathies). These case studies illustrate the characteristic clinical patterns of the immune-mediated neuropathies encountered in neurologic practice. Recommendations for diagnostic evaluation and treatment approach accompany each case. Prompt recognition of these disorders is imperative; delays in treatment may result in prolonged morbidity and permanent disability.

An Eye for an Eye: A Randomized Placebo-Controlled Trial of IVIG in Antibody-Mediated Encephalitis

Randomized Placebo-Controlled Trial of Intravenous Immunoglobulin in Autoimmune LGI1/CASPR2 Epilepsy Dubey D, Britton J, Mckeon A, et al. Ann Neurol . 2019;87(2):313-323. doi:10.1002/ana.25655 . Objective: Drug-resistant seizures are common in patients with leucine-rich, glioma-inactivated 1 (LGI1) immunoglobulin (IgG)-associated and contactin-associated protein-like 2 (CASPR2)-IgG associated encephalitis. We performed the first randomized double-blind placebo-controlled trial to evaluate efficacy of intravenous immunoglobulin (IVIG) in reducing seizure frequency. Methods: Our enrollment goal was 30 LGI1/CASPR2-IgG-seropositive adult patients with ≥2 seizures per week. Patients were randomized to receive IVIG (0.5 g/kg, day 1; 1 g/kg, day 2; 0.6 g/kg weeks 3 and 5) or volume-matched IV normal saline. Following the blinded phase, the nonresponders in the placebo group received IVIG. The primary clinical outcome was 50% reduction in seizure frequency from baseline to 5 weeks. Results: After enrollment of 17 patients (LGI1-IgG, 14; CASPR2-IgG, 3) over 34 months, the study was terminated due to slow enrollment. Six of 8 patients in the IVIG group were responders, compared to 2 of 9 in the placebo group (P = .044, odds ratio = 10.5, 95% confidence interval = 1.1-98.9). For the LGI1-IgG seropositive subgroup, 6 of 8 patients in the IVIG group were responders, compared to 0 of 6 in the placebo group. Two LGI1-IgG-seropositive patients receiving IVIG, but none receiving placebo, were seizure-free at the end of the blinded phase. Four of the 6 patients entering the open-label IVIG arm reported ≥50% reduction in seizure frequency. There were no correlations with LGI1/CASPR2-IgG1-4 subclasses. Interpretation: Superiority of IVIG to placebo reached statistical significance for the primary end point for all patients and the subset with LGI1-IgG. These results have to be interpreted with the caveat that the study did not reach its originally selected sample size.

Multifocal motor neuropathy: controversies and priorities

Despite 30 years of research there are still significant unknowns and controversies associated with multifocal motor neuropathy (MMN) including disease pathophysiology, diagnostic criteria and treatment. Foremost relates to the underlying pathophysiology, specifically whether MMN represents an axonal or demyelinating neuropathy and whether the underlying pathophysiology is focused at the node of Ranvier. In turn, this discussion promotes consideration of therapeutic approaches, an issue that becomes more directed in this evolving era of precision medicine. It is generally accepted that MMN represents a chronic progressive immune-mediated motor neuropathy clinically characterised by progressive asymmetric weakness and electrophysiologically by partial motor conduction block. Anti-GM1 IgM antibodies are identified in at least 40% of patients. There have been recent developments in the use of neuromuscular ultrasound and MRI to aid in diagnosing MMN and in further elucidation of its pathophysiological mechanisms. The present Review will critically analyse the knowledge accumulated about MMN over the past 30 years, culminating in a state-of-the-art approach to therapy.

Human immune globulin 10% with recombinant human hyaluronidase in multifocal motor neuropathy

Objective

The primary aim was to determine the safety of treatment with human immune globulin 10% with recombinant human hyaluronidase (fSCIg) compared to intravenous immunoglobulin (IVIg) in a prospective open-label study in patients with multifocal motor neuropathy (MMN).

Methods

Our study consisted of two phases: the IVIg phase (visits 1–3; 12 weeks), in which patients remained on IVIg treatment, and the fSCIg phase (visits 4–7; 36 weeks), in which patients received fSCIg treatment. After visit 3, IVIg was switched to an equivalent dose and frequency of fSCIg. Outcome measures were safety, muscle strength, disability and treatment satisfaction.

Results

Eighteen patients were enrolled in this study. Switching to fSCIg reduced the number of systemic adverse events (IVIg 11.6 vs. fSCIg 5.0 adverse events/per person-year, p < 0.02), and increased the number of local reactions at the injection site (IVIg 0 vs. fSCIg 3.3 local reactions/per person-year, p < 0.01). Overall, no significant differences in muscle strength and disability between fSCIg and IVIg were found. Treatment with fSCIg was perceived as optimal treatment option by 8 of the 17 patients (47.1%) and they continued with fSCIg after study closure because of improved independence and flexibility to administer treatment.

Conclusion

Treatment with fSCIg can be considered a safe alternative for patients with MMN on IVIg treatment. fSCIg could be a favorable option in patients who prefer self-treatment and more independency, and in patients who experience systemic adverse events on IVIg or have difficult intravenous access.

Electronic supplementary material

The online version of this article (10.1007/s00415-019-09475-x) contains supplementary material, which is available to authorized users.

Immunoglobulin Treatment in Neuromuscular Medicine

Intravenous immunoglobulin (IVIg) is used in the treatment of autoimmune diseases, including immune-mediated central and peripheral nervous system disorders. This article will review the indications, proposed mechanism of actions, and administration of immunoglobulin treatment in various neuropathies, neuromuscular junction disorders, and myopathies. IVIg may have more than one mechanism of action to alter the pathogenesis of underlying neuromuscular disease. IVIg treatment has been used as a first-line treatment in Guillain-Barre syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy, and second-line off-label treatment in medically refractory cases of polymyositis, dermatomyositis, and myasthenia gravis. IVIg is a well-tolerated and effective treatment for these neuromuscular diseases. With this review article, we hope to increase clinicians' awareness of the indications and efficiencies of IVIg in a broad spectrum of neuromuscular diseases.

Immune-mediated neuropathies

Since the discovery of an acute monophasic paralysis, later coined Guillain-Barré syndrome, almost 100 years ago, and the discovery of chronic, steroid-responsive polyneuropathy 50 years ago, the spectrum of immune-mediated polyneuropathies has broadened, with various subtypes continuing to be identified, including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). In general, these disorders are speculated to be caused by autoimmunity to proteins located at the node of Ranvier or components of myelin of peripheral nerves, although disease-associated autoantibodies have not been identified for all disorders. Owing to the numerous subtypes of the immune-mediated neuropathies, making the right diagnosis in daily clinical practice is complicated. Moreover, treating these disorders, particularly their chronic variants, such as CIDP and MMN, poses a challenge. In general, management of these disorders includes immunotherapies, such as corticosteroids, intravenous immunoglobulin or plasma exchange. Improvements in clinical criteria and the emergence of more disease-specific immunotherapies should broaden the therapeutic options for these disabling diseases.

IgPro20, the Polyneuropathy and Treatment with Hizentra® study (PATH), and the treatment of chronic inflammatory demyelinating polyradiculoneuropathy with subcutaneous IgG

Subcutaneous IgG (SCIG) administration may be preferred over the intravenous route (IVIG) in chronic inflammatory demyelinating polyneuropathy (CIDP) because it minimizes ‘end of cycle’ treatment-related fluctuations, reduces systemic adverse effects, improves convenience/quality of life and potentially lowers overall costs. Early reports of the use of highly concentrated SCIG preparations suggested they were effective and well-tolerated in chronic inflammatory demyelinating polyneuropathy. This was confirmed in the Polyneuropathy and Treatment with Hizentra® study of 172 subjects randomized to receive maintenance therapy with placebo or one of two doses of IgPro20 (20% IgG stabilized with L-Proline) for 6 months. Risk of relapse was reduced by SCIG in a dose-related manner as compared with placebo. A total of 88% of polyneuropathy and treatment with hizentra subjects felt the subcutaneous method was ‘easy to learn’. Local adverse events were mostly mild or moderate, and systemic adverse events were infrequent. Some patients may prefer maintenance therapy with SCIG over IVIG.

Efficacy and patient satisfaction in the use of subcutaneous immunoglobulin immunotherapy for the treatment of auto-immune neuromuscular diseases

We reviewed the efficacy of SCIg administration in terms of muscle strength maintenance and patient satisfaction comparing with IVIg in the treatment of auto-immune neuromuscular diseases. A systematic review was conducted, and identified studies from databases (PUBMED, EMBASE, EBSCO, Web of Science and Google Scholar) which were analyzed. The methodological quality of the selected publications was evaluated using the Newcastle-Ottawa Scale. Data were extracted from a total of 11 studies Fixed and random-effect model meta-analyses were performed. For the maintenance of muscle strength, Overall Neuropathy Limitations Scale (ONLS) data from 100 patients diagnosed with multifocal mononeuropathy (MMN) or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) were pooled together. Switching to subcutaneous immunoglobulin administration led to a significant improvement (fixed effects model, p = 0.002). In data collected using the Medical Research Council Scale for Muscle Strength data from 140 patients with a wider range of disorders, a small but significant improvement in overall strength was observed in the SCIg group (p < 0.0001). In addition, the results of two studies measuring health-related quality of life and patient satisfaction were pooled. Data from 49 patients suffering from MMN, CIDP, and a variety of different myopathies demonstrated a small but significant increase in the mean 36-Item Short Form Survey (SF-36) scores (p < 0.0001). A highly significant difference was revealed when comparing data from 119 patients' responses to the Life Quality Index questionnaire (LQI) assessing patient satisfaction (p < 0.0001). This is the first analysis showing that SCIg is more effective than IVIg in improving Patient Reported Outcomes in auto-immune neuromuscular disease. These results should permit a broad range of patients to self-administer immunoglobulin treatments at home, potentially improving patient acceptability while reducing hospital visits and healthcare costs for the treatment of chronic auto-immune neuropathies.

Maintenance IV immunoglobulin treatment in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients treated with intravenous immunoglobulin (IVIg) usually start with a standard dosage of 2 g/kg bodyweight. Only a minority of patients has a sustained improvement, and most require ongoing maintenance treatment. Preferred IVIg regimens, however, vary considerably between doctors and at present it is unknown which is optimal. As there are also large differences in IVIg dosage and interval requirements between patients, optimal IVIg maintenance treatment of CIDP is even more complex. The lack of evidence-based guidelines on how IVIg maintenance treatment should be administered may potentially lead to under- or overtreatment of this expensive therapy. We provide an overview of published practical IVIg maintenance treatment regimens, IVIg maintenance schedules used in randomized controlled trials and one based upon our own long-term experience on how this treatment could be given in CIDP.

Comparisons in fluctuation of muscle strength and function in patients with immune-mediated neuropathy treated with intravenous versus subcutaneous immunoglobulin

INTRODUCTION

Variations in muscle strength and function have not been studied in patients with chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy whose treatment regimen has been changed from intravenous to subcutaneous immunoglobulin (IVIg to SCIg).

METHODS

In a prospective, open-label study, patients were changed from monthly IVIg to weekly SCIg. The primary endpoint was variation in isokinetic muscle strength (cIKS). Secondary endpoints were variations in Medical Research Council (MRC) score, grip strength (GS), 9-hole-peg test (9-HPT), and 40-meter-walk test (40-MWT).

RESULTS

The coefficient of variance of cIKS during the IVIg and SCIg treatment periods was unchanged (mean ± SD: 6.97 ± 4.83% vs. 5.50 ± 3.13%, P = 0.21). The variations in the 9-HPT and 40-MWT were significantly lower in the SCIg group (P = 0.01 and P = 0.005, respectively).

DISCUSSION

When therapy was changed from IVIg to SCIg, fluctuation of muscle strength was unchanged, but performance fluctuations were diminished. Muscle Nerve 57: 610-614, 2018.

Subcutaneous immunoglobulin treatment in CIDP and MMN. Efficacy, treatment satisfaction and costs

Subcutaneous administration of immunoglobulin (SCIG) in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) has been reported in several case reports and in a few randomized trials during the last decade. In this review we present the studies on SCIG in CIDP and MMN with special focus on the clinical effects. Moreover, the effect on quality of life, side effects to SCIG and the health economic perspectives are reviewed. Nine case studies, three randomized trials and six long-term, follow-up studies were identified. Most of the studies are conducted in patients switched from regular IVIG to SCIG treatment; one study involves treatment-naïve patients. The review shows that none of the studies have been powered to demonstrate an effect on disability. SCIG can maintain muscle strength for a period of 1 to 2years and ability seems preserved for a similar period. Quality of life is generally unchanged or improved after switch to SCIG and generalized side-effects seem fewer, whereas local reactions at the injection site occur. Health economic analyses favour SCIG at the doses used in the reviewed studies.

Update on the use of immunoglobulin in human disease: A review of evidence

Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.

Safety and Efficacy of Subcutaneous Immunoglobulin in the Treatment of Neuromuscular Disorders

Many neuromuscular diseases may be treated with immunoglobulins. In the United States, the major form of immunoglobulin used is intravenous (IV). Recently, there has been an increased interest in research regarding the use of subcutaneous immunoglobulin (SCIg), mainly for improved patient quality of life, convenience, potential for fewer systemic adverse events, and avoiding wear-off. The widespread use of the subcutaneous formulation in neurology has been affected by some limitations, mainly the smaller volume and higher frequency of infusions compared to IV administration. Also, there are different pharmacokinetic properties that should be considered to evaluate whether they change the immunomodulatory effect. There are several formulations available that address some limitations. Several studies have assessed efficacy, safety, and quality of life of SCIg in neurology. This review article summarizes the current evidence for the use of SCIg in neuromuscular diseases. It also addresses the pharmacokinetic differences and the different formulations available. The current available preliminary evidence indicates that SCIg is at least as effective as the IV formulations.

Subcutaneous Immunoglobulin Therapy in the Chronic Management of Myasthenia Gravis: A Retrospective Cohort Study

BACKGROUND

Immunoglobulin therapy has become a major treatment option in several autoimmune neuromuscular disorders. For patients with Myasthenia Gravis (MG), intravenous immunoglobulin (IVIg) has been used for both crisis and chronic management. Subcutaneous Immunoglobulins (SCIg), which offer the advantage of home administration, may be a practical and effective option in chronic management of MG. We analyzed clinical outcomes and patient satisfaction in nine cases of chronic disabling MG who were either transitioned to, or started de novo on SCIg.

METHODS AND FINDINGS

This was a retrospective cohort study for the period of 2015-2016, with a mean follow-up period of 6.8 months after initiation of SCIg. All patients with MG treated with SCIg at the Ottawa Hospital, a large Canadian tertiary hospital with subspecialty expertise in neuromuscular disorders were included, regardless of MG severity, clinical subtype and antibody status. The primary outcome was MG disease activity after SCIg initiation. This outcome was measured by 1) the Myasthenia Gravis Foundation of America (MGFA) clinical classification, and 2) subjective scales of disease activity including the Myasthenia Gravis activities of daily living profile (MG-ADL), Myasthenia Gravis Quality-of-life (MG-QOL 15), Visual Analog (VA) satisfaction scale. We also assessed any requirement for emergency department visits or hospitalizations. Safety outcomes included any SCIg related complication. All patients were stable or improved for MGFA class after SCIg initiation. Statistically significant improvements were documented in the MG-ADL, MG-QOL and VAS scales. There were no exacerbations after switching therapy and no severe SCIg related complications.

CONCLUSIONS

SCIg may be a beneficial therapy in the chronic management of MG, with favorable clinical outcome and patient satisfaction results.

Subcutaneous immunoglobulin for maintenance treatment in chronic inflammatory demyelinating polyneuropathy (The PATH Study): study protocol for a randomized controlled trial

BACKGROUND

Subcutaneous administration of Ig (SCIg) has gained popularity as an alternative route of administration but has never been rigorously examined in chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS/DESIGN

The primary objective of the PATH study (Polyneuropathy and Treatment with Hizentra) is to determine the efficacy of two different doses of SCIg IgPro20 (0.2 g/kg bw or 0.4 g/kg bw) in a 24-week maintenance treatment of CIDP in comparison to placebo. The primary efficacy endpoint will be the proportion of patients who show CIDP relapse (1-point deterioration on the adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability score) or are withdrawn within 24 weeks after randomization for any reason. IVIg-dependent adult patients with definite or probable CIDP according to the European Federation of Neurological Societies/Peripheral Nerve Society who fulfil the inclusion and exclusion criteria will be eligible. Based on sample-size calculation and relapse assumptions in the three arms, a sample size of 58 is needed per arm (overall sample size will be 350, of which 174 will be randomized). All eligible patients will progress through three study periods: an IgG dependency period (≤12 weeks) to select those who are Ig dependent; an IVIg restabilization period (10 or 13 weeks), which will be performed using the 10 % IgPro10 product; and an SC treatment period (24 weeks, followed by a 1-week completion visit after last follow-up). Patients showing IVIg restabilization will be randomized to demonstrate the efficacy of SCIg IgPro20 maintenance treatment over placebo. After completing the study, subjects are eligible to enter a long-term, open-label, extension study of 1 year or return to their previous treatment. In case of CIDP relapse during the 24-week SC treatment period, IgPro10 rescue medication will be offered. Safety, tolerability, and patients' preference of Ig administration route will be examined.

DISCUSSION

The PATH trial, which started in March 2012, is expected to finish at the end of 2016. The results will increase knowledge about the efficacy, safety, and tolerability of SCIg in maintenance management of CIDP patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01545076 . Registered on 1 March 2012.

Outcome measures in MMN revisited: further improvement needed

The objectives of this study were to provide an overview of the outcome measures (OMs) applied in clinical trials in multifocal motor neuropathy (MMN) and to determine the responsiveness of a core set of selected OMs as part of the peripheral neuropathy outcome measures standardization (PeriNomS) study. The following OMs were serially applied in 26 patients with newly diagnosed or relapsing MMN, receiving intravenous immunoglobulin (assessments: T0/T3/T12 months): 14 muscle pairs MRC (Medical Research Council) scale, the Neuropathy Impairment Scale motor-subset, a self-evaluation scale, grip strength, and MMN-RODS© (Rasch-built overall disability scale). All data, except the grip strength, were subjected to Rasch analyses before determining responsiveness. For grip strength, responsiveness was examined using a combined anchor- (SF-36 question-2) and distribution-based (½ × SD) minimum clinically important difference (MCID) techniques, determining the proportion of patients exceeding both the identified cut-offs. For the remaining scales, the magnitude of change for each patient on each scale was determined using the MCID related to the individual SE (responder definition: MCID-SE ≥ 1.96). Overall, a great assortment of measures has been used in MMN trials with different responsiveness definitions. For the selected OMs, responsiveness was poor and only seen in one fourth to one third of the patients, the grip strength being more responsive. Despite the efforts taken to standardize outcome assessment, further clinimetric responsiveness studies are needed in MMN.

Subcutaneous immunoglobulins in the treatment of chronic immune-mediated neuropathies

Intravenous immunoglobulins represent an established therapy for the treatment of chronic immune-mediated neuropathies, specifically chronic inflammatory demyelinating polyradiculoneuropathies (CIDPs) as well as multifocal motor neuropathies (MMNs). For the treatment of antibody deficiency syndromes, subcutaneous immunoglobulins (SCIgs) have represented a mainstay for decades. An emerging body of evidence suggests that SCIg might also exhibit clinical efficacy in CIDP and MMN. This article reviews the current evidence for clinical effectiveness, as well as safety of SCIg for the treatment of immune-mediated neuropathies, and addresses remaining open questions in this context. We conclude that despite the need for controlled long-term studies to demonstrate long-term efficacy of SCIg in immune-mediated neuropathies, SCIg may already represent a potential therapeutic alternative for selected patients.

Clinical experiences in primary and secondary immunodeficiencies and immune-mediated conditions using Gammanorm(®)

Treatment for primary and secondary immunodeficiency disorders focuses on prevention and management of infections, using immunoglobulin G (IgG) replacement therapy with regular intravenous or subcutaneous IgG (SCIG) infusions. SCIG therapy has many advantages including improved efficacy and tolerability, enhanced patient satisfaction and lower costs. A number of SCIG preparations are available, including Gammanorm(®) (Octapharma AG), a ready-to-use 16.5% liquid preparation of IgG, with low viscosity, well suited to self-administration and a long history of use. Clinical experience with Gammanorm has shown that it is effective and well tolerated in children and adults, including pregnant women, for primary and secondary immunodeficiency disorders. Recent data also suggest SCIG may have a role in the treatment of certain immune-mediated conditions.

Treatment of patients with multifocal motor neuropathy with immunoglobulins in clinical practice: the SIGNS registry

OBJECTIVES

The management of patients with multifocal motor neuropathy (MMN) under everyday clinical conditions has been insufficiently studied. We therefore collected comprehensive observational data on patients with MMN who received intravenous (IV) or subcutaneous (SC) immunoglobulins (IGs) as maintenance therapy.

METHODS

This was a prospective, noninterventional study (registry) in neurological centres (hospitals and offices) throughout Germany.

RESULTS

As of 1 December 2015, 80 patients with MMN were included (mean age 55.4 ± 9.8 years, 67% males, mean disease duration 10.7 ± 10.2 years). The affected limb regions were predominantly distal muscle groups of the upper extremities. On the inflammatory neuropathy cause and treatment (INCAT) scale, 94% of the patients had some disability in the arms and 61% in the legs. At inclusion, 98.8% received IVIG and 1.3% SCIG. Substantial variation was observed between IVIG treatment intervals (every 0.7 to 17.3 weeks) and dosage (0.2-2.1 g/kg body weight received during a single administration; mean monthly dosage, 0.9 g/kg body weight). However, the mean monthly dosage was steady over time. At 1-year follow up, improvement was seen in muscle strength, INCAT and quality of life (QoL) scores (SF-36 questionnaire).

CONCLUSIONS

The management of patients with MMN in everyday clinical practice demonstrates a wide range of absolute dosages and treatment intervals of IG, supporting the recommended practice of determining treatment dose on an individual patient basis. The improvements in muscle strength and reduction in disability, accompanied by increased QoL, strengthen the case for use of IG as a maintenance treatment for MMN.