Long-term immunoglobulin therapy for chronic inflammatory demyelinating polyradiculoneuropathy

The overlap of diabetic and inflammatory neuropathies: Epidemiology, possible mechanisms, and treatment implications

Diabetic polyneuropathy is the common neuropathy of diabetes. However, several inflammatory neuropathies may occur during diabetes. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents the most treatable example. There has been uncertainty about a higher risk of CIDP in subjects with diabetes. Contradicting earlier reports, subsequent epidemiological studies failed to confirm an association. However, more recent studies from different populations have shown a two-fold relative risk of concurrent diabetes with CIDP. Recognition of CIDP is important in diabetes as treatment response rates have been reported as comparable with or without diabetes. However, with diabetes, the clinical presentation of CIDP and the resulting disability may be more severe due to additional axonal loss from pre-existing diabetic polyneuropathy and delayed diagnosis. An association of nodo-paranodopathy has similarly been described with a three-fold relative risk of concurrent diabetes in seropositive subjects, particularly those harbouring anti-contactin 1 antibodies. Although rare, recognition of nodo-paranodopathy, with characteristic clinical features, in the context of diabetes is likewise important in view of treatment implications. Other inflammatory neuropathies in diabetes are the painful or painless, cervical, or lumbar, radiculoplexus neuropathies. These need distinguishing from variant, multifocal forms of CIDP, as are not treatable, although remit spontaneously over months or years. There are reports of possible association of Guillain-Barré syndrome (GBS), and particularly of greater GBS severity, with diabetes. Finally, vasculitic neuropathy may also occur in diabetes and requires early suspicion, urgent investigations and immunosuppressant treatment. As the worldwide prevalence of diabetes rises, prompt recognition of its concurrent inflammatory neuropathies, is essential.

Immunoglobulin use in neurology: a practical approach

Human immunoglobulin, delivered either intravenously (IVIg) or subcutaneously, is used to treat a range of immune-mediated neurological disorders. It has a role in acute or subacute inflammatory disease control and as a maintenance therapy in chronic disease management. This review considers mechanisms of IVIg action and the evidence for IVIg in neurological conditions. We use Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) as frameworks to demonstrate an approach to IVIg use in acute and chronic dysimmune neurological conditions across two different healthcare systems: the UK and Australia. We highlight the benefits and limitations of IVIg and focus on practical considerations such as informed consent, managing risks and adverse effects, optimal dosing and monitoring response. We use these basic clinical practice principles to discuss the judicious use of an expensive and scarce blood product with international relevance.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Current Therapeutic Approaches and Future Outlooks

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

[Modern aspects of diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy in children]

OBJECTIVE

Analysis of demographic, clinical, laboratory, electrophysiological and neuroimaging data and pathogenetic therapy of pediatric patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

MATERIAL AND METHODS

Patients (n=30) were observed in a separate structural unit of the Russian Children's Clinical Hospital of the Russian National Research Medical University named after. N.I. Pirogova Ministry of Health of the Russian Federation in the period from 2006 to 2023. The examination was carried out in accordance with the recommendations of the Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society on the Management of CIDP (2021). All patients received immunotherapy, including intravenous immunoglobulin (IVIG) (n=1), IVIG and glucocorticosteroids (GCS) (n=17, 56.7%), IVIG+GCS+plasmapheresis (n=12, 40.0%). Alternative therapy included cyclophosphamide (n=1), cyclophosphamide followed by mycophenolate mofetil (n=1), rituximab (n=2, 6.6%), azathioprine (n=3), mycophenolate mofetil (n=2, 6.6%).

RESULTS

In all patients, there was a significant difference between scores on the MRCss and INCAT functional scales before and after treatment. At the moment, 11/30 (36.6%) patients are in clinical remission and are not receiving pathogenetic therapy. The median duration of remission is 48 months (30-84). The longest remission (84 months) was observed in a patient with the onset of CIDP at the age of 1 year 7 months.

CONCLUSION

Early diagnosis of CIDP is important, since the disease is potentially curable; early administration of pathogenetic therapy provides a long-term favorable prognosis.

IgG4 Autoantibodies in Organ-Specific Autoimmunopathies: Reviewing Class Switching, Antibody-Producing Cells, and Specific Immunotherapies

Organ-specific autoimmunity is often characterized by autoantibodies targeting proteins expressed in the affected tissue. A subgroup of autoimmunopathies has recently emerged that is characterized by predominant autoantibodies of the IgG4 subclass (IgG4-autoimmune diseases; IgG4-AID). This group includes pemphigus vulgaris, thrombotic thrombocytopenic purpura, subtypes of autoimmune encephalitis, inflammatory neuropathies, myasthenia gravis and membranous nephropathy. Although the associated autoantibodies target specific antigens in different organs and thus cause diverse syndromes and diseases, they share surprising similarities in genetic predisposition, disease mechanisms, clinical course and response to therapies. IgG4-AID appear to be distinct from another group of rare immune diseases associated with IgG4, which are the IgG4-related diseases (IgG4-RLD), such as IgG4-related which have distinct clinical and serological properties and are not characterized by antigen-specific IgG4. Importantly, IgG4-AID differ significantly from diseases associated with IgG1 autoantibodies targeting the same organ. This may be due to the unique functional characteristics of IgG4 autoantibodies (e.g. anti-inflammatory and functionally monovalent) that affect how the antibodies cause disease, and the differential response to immunotherapies of the IgG4 producing B cells/plasmablasts. These clinical and pathophysiological clues give important insight in the immunopathogenesis of IgG4-AID. Understanding IgG4 immunobiology is a key step towards the development of novel, IgG4 specific treatments. In this review we therefore summarize current knowledge on IgG4 regulation, the relevance of class switching in the context of health and disease, describe the cellular mechanisms involved in IgG4 production and provide an overview of treatment responses in IgG4-AID.

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

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

Association of serum neurofilament light chain levels with clinicopathology of chronic inflammatory demyelinating polyneuropathy, including NF155 reactive patients

OBJECTIVES

To clarify whether serum neurofilament light chains (NfLs) serve as a biomarker of axonal damage in patients with chronic inflammatory demyelinating polyneuropathy (CIDP), especially in patients with anti-neurofascin 155 (NF155) antibodies.

METHODS

The Simoa system was used to examine serum NfL levels from 58 patients with CIDP, including 13 anti-NF155 antibody-positive patients, and from 14 age- and sex-matched healthy individuals. Serum NfL levels were evaluated before and after treatment in eight patients with anti-NF155 antibodies. Clinical features, electrophysiological findings, and cerebrospinal fluid (CSF) protein levels, were evaluated. The pathological features of sural nerves from 40 patients were also examined.

RESULTS

Serum NfL levels were significantly higher in patients with CIDP than in healthy individuals (median 29.63 vs. 7.71 pg/mL, p < 0.001) and were correlated with both modified Rankin Scale scores (r = 0.584, p < 0.001) and CSF protein levels (r = 0.432, p = 0.001). The NfL levels of anti-NF155 antibody-positive patients were higher than those of antibody-negative patients (p = 0.005). Serum NfL levels were negatively correlated with compound muscle action potential amplitudes of the tibial nerves (r =  - 0.404, p = 0.004) and positively correlated with the degree of active axonal degeneration in the pathological findings (r = 0.485, p = 0.001). In the antibody-positive group, NfL levels and antibody titers decreased after treatment in all examined patients.

CONCLUSION

Serum NfL correlated with pathological indices of axonal degeneration, and may serve as a biomarker that reflects active axonal damage of CIDP.

Semi-Automatic MRI Muscle Volumetry to Diagnose and Monitor Hereditary and Acquired Polyneuropathies

With emerging treatment approaches, it is crucial to correctly diagnose and monitor hereditary and acquired polyneuropathies. This study aimed to assess the validity and accuracy of magnet resonance imaging (MRI)-based muscle volumetry.Using semi-automatic segmentations of upper- and lower leg muscles based on whole-body MRI and axial T1-weighted turbo spin-echo sequences, we compared and correlated muscle volumes, and clinical and neurophysiological parameters in demyelinating Charcot-Marie-Tooth disease (CMT) (n = 13), chronic inflammatory demyelinating polyneuropathy (CIDP) (n = 27), and other neuropathy (n = 17) patients.The muscle volumes of lower legs correlated with foot dorsiflexion strength (p < 0.0001), CMT Neuropathy Score 2 (p < 0.0001), early gait disorders (p = 0.0486), and in CIDP patients with tibial nerve conduction velocities (p = 0.0092). Lower (p = 0.0218) and upper (p = 0.0342) leg muscles were significantly larger in CIDP compared to CMT patients. At one-year follow-up (n = 15), leg muscle volumes showed no significant decrease.MRI muscle volumetry is a promising method to differentiate and characterize neuropathies in clinical practice.

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

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

Isoagglutinin reduction in intravenous immunoglobulin (IgPro10, Privigen) by specific immunoaffinity chromatography reduces its reporting rates of hemolytic reactions: an analysis of spontaneous adverse event reports

BACKGROUND

Hemolysis is an infrequent but recognized and potentially serious adverse effect of intravenous immunoglobulin (IVIG). Relatively elevated hemolysis reporting rates were seen with some IVIG products with high anti-A/B isoagglutinin content, among which IgPro10 (Privigen, CSL Behring). For IgPro10, two isoagglutinin reduction measures were successively implemented: 1) anti-A donor screening and 2) immunoaffinity chromatography (IAC; Ig IsoLo)-based isoagglutinin reduction step included in the production process. The aim of this analysis was to investigate the effects of these isoagglutinin reduction measures on the reporting rates of IgPro10 hemolysis worldwide.

STUDY DESIGN AND METHODS

Between February 2008 and December 2018, hemolysis reports from the CSL Behring Global Safety Database were analyzed in relationship to changes in IVIG IgPro10 production methods. Further analysis classified hemolysis reports by indication and blood group.

RESULTS

Median (minimum-maximum) anti-A/anti-B titers were 32 (8-64)/16 (8-32) at baseline, 32 (8-64)/16 (8-32) after donor screening, and 8 (8-32)/4 (2-8) after implementation of IAC. The reporting rate of hemolytic reactions per 1000 kg IgPro10 sold was 4.05 cases at baseline, 2.00 after donor screening, and 0.50 after implementation of IAC. In 2018, there were seven reports of hemolytic reactions; representing 0.18 cases per 1000 kg IgPro10 sold, with a reduction of 95.6% versus baseline.

CONCLUSION

Following implementation of the IAC isoagglutinin reduction step, spontaneous reports of hemolytic events with IgPro10 were significantly and consistently reduced versus IgPro10 without isoagglutinin reduction, offering patients a more favorable benefit-risk profile.

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

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

Daily grip strength response to intravenous immunoglobulin in chronic immune neuropathies

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

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

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

Current practice patterns in CIDP: A cross-sectional survey of neurologists in the United States

To evaluate how neurologists make decisions regarding chronic inflammatory demyelinating polyneuropathy (CIDP), we conducted a cross-sectional quantitative survey of 100 community neurologists in the United States. Only 13% cited using the European Federation of Neurological Societies/Peripheral Nerve Society guideline. In addition, variability in treatment approaches existed regarding the dose of IVIg used, the length of IVIg therapy before determining response, the outcome measures used to determine IVIg response, and the protocol for weaning off therapy. Forty-three percent reported giving doses that were lower than the recommended IVIg loading dose for CIDP. Many reported giving nonspecific patient education about the rationale of IVIg use and treatment duration. The finding that approximately half of community neurologists endorsed electrodiagnostic criteria that do not support CIDP diagnosis indicated difficulties relying heavily upon neurophysiologic studies in diagnostic guidelines. More education on CIDP diagnosis and treatment and a clear, actionable, clinically focused guideline would enhance best practices, particularly in the midst of high information flow and multiple guidelines.

Octagam® for chronic inflammatory demyelinating polyneuropathy: results from three observational studies

Aim:

To present data from three studies of a Post-Authorization Safety Surveillance (PASS) program for the subset of patients receiving Octagam^® 5% or 10% for chronic inflammatory demyelinating polyneuropathy (CIDP).

Methods:

Data on patients with CIDP treated with Octagam were analyzed to assess its safety and tolerability.

Results:

Of 2314 patients included in the studies, 58 patients (mean age: 64.6 years) received Octagam for CIDP, mean dose of which was 0.8 g/kg bodyweight/course. 81% of observations for clinical appearance since last observation were assessed as stable and 16.6% showed an improved clinical appearance with treatment. Adverse drug reactions were rare (<0.7% of infusions).

Conclusion:

Octagam was effective and well-tolerated in patients with CIDP.

Intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyradiculoneuropathy, a time to start and a time to stop

Intravenous immunoglobulin (IVIg) is often used as preferred treatment in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Several studies highlighted the short-term efficacy of IVIg for CIDP yet many patients need maintenance therapy. Notwithstanding the fact IVIg has been used for over 30 years in CIDP, there is only limited evidence to guide dosage and interval during maintenance treatment. The variation in disease course, lack of biomarkers, and fear of deterioration after stopping IVIg makes long-term treatment challenging. Recent studies suggest a proportion of patients receive unnecessary IVIg maintenance treatment. This review provides an overview of the use of IVIg for CIDP treatment, focusing on evidence for long-term IVIg use.

Unconventional treatments for chronic inflammatory demyelinating polyneuropathy

This article focuses on the unconventional treatments used in chronic inflammatory demyelinating polyneuropathy (CIDP). First line, evidence-based treatments for CIDP include corticosteroids, immunoglobulins and plasma exchanges. Several unproven treatments are however given in treatment-refractory disease or to reduce requirements in validated therapies for reasons of side effects/practical delivery/cost. Despite methodological issues, IFN-α, azathioprine and methotrexate have not been shown to be useful in randomized controlled trials. Cyclophosphamide, rituximab and, as final resort in highly selected cases, hematopoietic stem cell transplant may be options considered in severely disabled refractory patients. Debatably, azathioprine, methotrexate, cyclosporine and mycophenolate mofetil are still occasionally used, among others, in milder disease. Physical therapy may be of benefit in CIDP but is not systematically considered as an integral part of management strategies. Current literature relating to unconventional therapies in CIDP is reviewed here and the possible avenues that require consideration in severe refractory disease and less disabling forms are discussed.

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.

Considerations for dosing immunoglobulin in obese patients

Obesity is a very common condition; however, the effect of excess body weight on the appropriate dose of immunoglobulin has not been defined empirically. The proposed pharmacokinetic differences between lean and obese patients and the opportunity to reduce costs has led to the proposition that obese patients should receive proportionally lower doses of immunoglobulin once a certain threshold is reached. Here the theoretical factors which could affect dosing in obese patients are considered alongside the available empirical evidence. The available evidence indicates that obesity may affect the pharmacokinetics of immunoglobulin; however, the effect is likely to be too small to have a clinically important effect on dosing. Wide interpatient individuality and highly variable clinical need mean that obesity should not play a major factor in dosing considerations. However, patients who are obese are more likely to have multiple cardiovascular risk factors and their weight indicates a large dose. This puts these patients at a higher risk of adverse reactions, and therefore caution is advised.

Impact of Immunoglobulin Therapy in Pediatric Disease: a Review of Immune Mechanisms

Intravenous immunoglobulin (IVIG) provides replacement therapy in immunodeficiency and immunomodulatory therapy in inflammatory and autoimmune diseases. This paper describes the immune mechanisms underlying six major non-primary immunodeficiency pediatric diseases and the diverse immunomodulatory functions of IVIG therapy. In Kawasaki disease, IVIG plays a major, proven, and effective role in decreasing aneurysm formation, which represents an aberrant inflammatory response to an infectious trigger in a genetically predisposed individual. In immune thrombocytopenia, IVIG targets the underlying increased platelet destruction and decreased platelet production. Although theoretically promising, IVIG shows no clear clinical benefit in the prophylaxis and treatment of neonatal sepsis. Limitations in research design combined with the unique neonatal immunologic environment offer explanations for this finding. Inflammation from aberrant immune activation underlies the myelinotoxic effects of Guillain-Barré syndrome. HIV-1 exerts a broad range of immunologic effects and was found to decrease serious bacterial infections in the pre-highly active anti-retroviral therapy (HAART) era, although its practical relevance in the post-HAART era has waned. Clinical and experimental data support the role of immune mechanisms in the pathogenesis of childhood epilepsy. IVIG exerts anti-epileptic effects through targeting upregulated cytokine pathways and antibodies thought to contribute to epilepsy. Applications in six additional pediatric diseases including pediatric asthma, atopic dermatitis, cystic fibrosis, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS), autism, and transplantation will also be briefly reviewed. From autoimmunity to immunodeficiency, a dynamic immunologic basis underlies major pediatric diseases and highlights the broad potential of IVIG therapy.

What is new in 2015 in dysimmune neuropathies?

This review discusses and summarizes the concept of nodopathies, the diagnostic features, investigations, pathophysiology, and treatment options of chronic inflammatory demyelinating polyradiculoneuropathy, and gives updates on other inflammatory and dysimmune neuropathies such as Guillain-Barré syndrome, sensory neuronopathies, small-fiber-predominant ganglionitis, POEMS syndrome, neuropathies associated with IgM monoclonal gammopathy and multifocal motor neuropathy. This field of research has contributed to the antigenic characterization of the peripheral motor and sensory functional systems, as well as helping to define immune neuropathic syndromes with widely different clinical presentation, prognosis and response to therapy.

The dilemma of diabetes in chronic inflammatory demyelinating polyneuropathy

PURPOSE

We reviewed the literature on chronic inflammatory demyelinating polyneuropathy (CIDP) in diabetes mellitus (DM) and explored real-world data on the prevalence and treatment of CIDP within DM.

METHODS

A literature search of Scopus was performed for the terms chronic inflammatory demyelinating polyradiculoneuropathy, chronic inflammatory demyelinating polyneuropathy, CIDP, and prevalence, incidence, epidemiology, or diabetes; peripheral neuropathy and prevalence or diabetes. We also searched through the reference lists of the resulting publications for additional findings that may have been missed. Additional publications on guidelines for the diagnosis of CIDP and diabetic neuropathy were also included. A descriptive analysis of the 2009-2013 PharMetrics Plus™ Database was performed to estimate the prevalence and treatment of CIDP within the DM population.

RESULTS

There is an increasing body of literature suggesting that the prevalence of CIDP tends to be higher in diabetic patients, especially in those of older age. Our real-world data seem to support published findings from the literature. For the total cohort (N=101,321,694), the percent prevalence of CIDP (n=8,173) was 0.008%; DM (n=4,026,740) was 4%. The percent prevalence of CIDP without DM (n=5,986) was 0.006%; CIDP with DM (n=2,187) was 9-fold higher at 0.054%. For patients >50years old, there was a significantly higher percentage of CIDP with DM than CIDP without DM. Approximately 50% of CIDP patients were treated with IVIg, 23%-24% with steroids, 1%-2% with PE, and 20%-23% received no treatment.

CONCLUSIONS

In addition to the growing evidence of higher prevalence of CIDP in DM, our findings reinforce the need for heightened awareness of the association of CIDP and DM.

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.