Subcutaneous immunoglobulin infusion: a new therapeutic option in chronic inflammatory demyelinating polyneuropathy

[Administration of intravenous immunoglobulins in neurology. An evidence-based consensus: update 2010]

Our knowledge on the clinical efficacy of intravenous immunoglobulins (IVIg) in neurological diseases has greatly increased in the last 5 years. Liquid formulations with a higher concentration of IVIg have simplified administration. Despite a worldwide increase in plasma production it is still a valuable biological product which is why current indications must be continuously validated. Long-term efficacy of the preparation Gamunex could be demonstrated in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). In acute myasthenic worsening a dose of 1 g IVIg/kg body weight appears to be sufficient for clinical stabilization. New indications, such as the postpolio syndrome or Alzheimer's disease are being explored in clinical trials. In addition to the consensus statement from 2004 the evidence for clinical use of IVIg has been re-evaluated and recommendations are given.

Advances in the diagnosis, pathogenesis and treatment of CIDP

Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common chronic autoimmune neuropathy. Despite clinical challenges in diagnosis-owing in part to the existence of disease variants, and different views on how many electrophysiological abnormalities are needed to document demyelination-consensus criteria seem to have been reached for research or clinical practice. Current standard of care involves corticosteroids, intravenous immunoglobulin (IVIg) and/or plasmapheresis, which provide short-term benefits. Maintenance therapy with IVIg can induce sustained remission, increase quality of life and prevent further axonal loss, but caution is needed to avoid overtreatment. Commonly used immunosuppressive drugs offer minimal benefit, necessitating the development of new therapies for treatment-refractory patients. Advances in our understanding of the underlying immunopathology in CIDP have identified new targets for future therapeutic efforts, including T cells, B cells, and transmigration and transduction molecules. New biomarkers and scoring systems represent emerging tools with the potential to predict therapeutic responses and identify patients with active disease for enrollment into clinical trials. This Review highlights the recent advances in diagnosing CIDP, provides an update on the immunopathology including new target antigens, and discusses current treatments, ongoing challenges and future therapeutic directions.

Standard and escalating treatment of chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired, immune-mediated polyradiculoneuritis that is progressive or relapsing over a period of at least 8 weeks. Although the exact pathogenesis is unclear, it is thought to be mediated by both cellular and humoral immune reactions directed against the peripheral nerve myelin or axon. CIDP also involves spinal nerve roots. Early medical treatment of CIDP is important to prevent axonal loss. Only three treatment regimens for CIDP have demonstrated benefit in randomized, controlled studies: corticosteroids, plasma exchange, and intravenous immunoglobulins (IVIg). Approximately 25% of patients respond inadequately to corticosteroids, plasma exchange or IVIg. Large placebo-controlled trials with alternative immunosuppressive compounds, e.g. mycophenolate mofetil, cyclosporine, cyclophosphamide, or monoclonal antibodies, are lacking.

Current proposed mechanisms of action of intravenous immunoglobulins in inflammatory neuropathies

Intravenous immunoglobulins (IVIg) have been shown in a number of trials, to be an effective treatment for the three main types of inflammatory neuropathies: Guillain-Barré Syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and multifocal motor neuropathy (MMN). IVIg is thought to exert its immunomodulatory effects by affecting several components of the immune system including B-cells, T-cells, macrophages, complement, cytokines and cellular adhesion molecules. This article reviews the published evidence and the principal postulated mechanisms of action of intravenous immunoglobulins with special emphasis on inflammatory neuropathies.

Safety of intravenous immunoglobulin treatment

IMPORTANCE OF THE FIELD

Intravenous immunoglobulin (IVIg) is a biologic pharmaceutical that is widely used to treat immunodeficiency conditions and a variety of autoimmune conditions. It is under-recognized that IVIg can be associated with severe complications including death.

AREAS COVERED IN THIS REVIEW

This review will address common mild side effects and extensively discuss the uncommon but serious complications of IVIg. Mild constitutional reactions include headache, fever and rash and severe complications include anaphylaxis, acute renal failure, stroke and myocardial infarction. IVIg has been used to treat autoimmune illnesses for ~30 years and the literature since then is reviewed with special attention to reports in the last 10 years that detail the serious adverse events.

WHAT THE READER WILL GAIN

The reader will understand that mild side effects are common and that these can be ameliorated with pre-treatment medications. They will also become familiar with the risk factors for serious complications so that careful patient and IVIg product selection will result in fewer poor outcomes.

TAKE HOME MESSAGE

IVIg is quite safe across age groups although serious adverse reactions occur particularly in elderly individuals with multiple cardiovascular risk factors and those with preexisting renal failure.

Intravenous immunoglobulin-based immunotherapy: an arsenal of possibilities for patients and science

The use of intravenous immunoglobulin (IVIG) concentrated from pooled healthy donors' plasma has gained increasing popularity. IVIG therapy has become important as a replacement therapy in primary and acquired humoral immunodeficiencies, and it has been extended to autoimmune, neurodegenerative and inflammatory conditions and transplantation therapy. Recurrent pregnancy failure and cancer are rather new platforms, where IVIG has shown its beneficial effects. This manuscript is focused on these two off-labelled usages. The immunomodulatory mechanisms of IVIG therapy appear as a coordinated orchestration of different functions, resulting in a synergistic effect. Treatment monitoring and detailed molecular analyses reveal how such treatments may interfere with disease pathogenesis. These finding may foster the development of novel therapeutic and/or preventive strategies. Studying this field with bidirectional bench-to-bedside and bedside-to-bench approaches fit well into 'the two-way road' paradigm of translational medicine.

Can we face the challenge of expanding use of intravenous immunoglobulin in neurology?

The use of high-dose polyclonal intravenous immunoglobulin (IVIG) in the treatment of autoimmune neurological diseases has expanded over the last decade. Based on controlled clinical trials IVIG can be considered currently as the first-line treatment in Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy, and it may be used as a rescue therapy in worsening myasthenia gravis. IVIG is a second-line therapy in dermatomyositis, stiff-person syndrome and pregnancy-associated or postpartum relapses of multiple sclerosis. Although the biological efficacy of IVIG is due to multiple effects on the immune system, many mechanisms are still unknown. The awareness of risks and complications of IVIG therapy has increased, but severe side effects are still considered rare. Due to increasing costs of this treatment, careful selection of patients who will benefit from IVIG is extremely important.

Treatment in inflammatory neuropathies

This review focuses on recent developments in the treatment of inflammatory neuropathies arising from immune dysregulation, rather than from infectious causes. The dysimmune inflammatory neuropathies are diseases of the peripheral nerves that have varying etiologies and may respond to immunomodulatory therapies. They are characterized by inflammatory changes in the nerve with associated destruction of myelin and axons. The underlying immune mechanisms are better understood in some of these conditions than others. Correct diagnosis and treatment is important to prevent clinical progression. Randomized controlled trials of some treatments in the more common inflammatory neuropathies have clarified their effectiveness; however, there are still groups of patients who are resistant to currently available treatments and for whom little effective treatment is available. Newer, targeted biologics and larger controlled trials of existing and novel therapies in these conditions offer promise of improved morbidity and mortality in this group of diseases.

Overview of the pathogenesis and treatment of chronic inflammatory demyelinating polyneuropathy with intravenous immunoglobulins

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired heterogeneous disorder of immune origin affecting the peripheral nerves, causing motor weakness and sensory symptoms and signs. The precise pathophysiology of CIDP remains uncertain although B and T cell mechanisms are believed to be implicated. Intravenous immunoglobulins (IVIg) have been shown in a number of trials to be an effective treatment for CIDP. IVIg is thought to exert its immunomodulatory effects by affecting several components of the immune system including B-cells, T-cells, macrophages and complement. This article provides an overview of the pathogenesis of CIDP and of its treatment with IVIg.

Safety and pharmacokinetics of subcutaneous ceftriaxone administered with or without recombinant human hyaluronidase (rHuPH20) versus intravenous ceftriaxone administration in adult volunteers

OBJECTIVE

To compare pharmacokinetics and safety of recombinant human hyaluronidase (rHuPH20)-facilitated subcutaneous (SC) ceftriaxone administration versus SC ceftriaxone preceded by SC saline placebo or intravenous (IV) ceftriaxone administration.

RESEARCH DESIGN AND METHODS

This Phase I, two-part, placebo-controlled, crossover study was conducted in 54 healthy volunteers. In Part 1 (N = 24), subjects received 1 mL rHuPH20 (150 USP units) or placebo (0.9% sodium chloride) SC, followed by 1 or 2 g ceftriaxone (10-350 mg/mL). In Part 2 (N = 30), subjects received 1 g ceftriaxone at the Part 1 maximum tolerated concentration (MTC) administered either SC - preceded by SC rHuPH20 or placebo - or IV. Subjects were monitored for adverse events (AEs); blood samples were obtained (Part 2 only) during 48 hours post-dosing for ceftriaxone bioanalysis.

MAIN OUTCOME MEASURES

Part 1 primary endpoint was the SC ceftriaxone (with or without rHuPH20) MTC. Pharmacokinetic parameters were determined in Part 2. Bioequivalence was based on maximum concentration (C(max)) and area under plasma concentration-time curve (AUC).

RESULTS

The highest SC ceftriaxone concentration tested in Part 1 (350 mg/mL) was selected as the Part 2 MTC. In Part 2, median time to maximum concentration (t(max)) was 1 hour earlier (P < 0.0001), and C(max) was 12% higher (P < 0.0001) for ceftriaxone (350 mg/mL) administered via rHuPH20-facilitated SC versus SC preceded by placebo. IV ceftriaxone led to higher C(max) and shorter t(max) values than either SC treatment. Ceftriaxone exposure (AUC) was comparable among all three treatments. At least 1 AE was experienced by 100% of subjects after SC ceftriaxone and 76% after IV; most commonly reported AEs were infusion-site reactions.

CONCLUSIONS

Ceftriaxone AUC did not differ significantly between the three administration routes. C(max) was higher and t(max) shorter with rHuPH20-facilitated SC than SC preceded by placebo. rHuPH20-facilitated SC ceftriaxone was generally well tolerated. This study is limited by evaluation of healthy adults and absence of repeated-dose groups.

A systematic data review of the cost of rehydration therapy

Dehydration secondary to acute gastroenteritis is a commonly encountered condition among patients presenting to physicians' offices and hospital EDs. Treatment options consist of oral rehydration therapy (ORT), intravenous rehydration therapy (IVRT) and subcutaneous rehydration therapy (SCRT). Although most patients with dehydration can be effectively treated in an outpatient setting, hospitalization is frequently warranted, with estimated annual inpatient costs for dehydration therapy exceeding $US1 billion in the US in 1999 for elderly patients alone. Although most treatment guidelines recommend ORT as first-line treatment for mild to moderate dehydration, IVRT remains the predominant route of administration for rehydration fluids in the acute care setting in the US. To evaluate the current state of the literature examining costs associated with dehydration therapy, a systematic review of articles published on MEDLINE from 2000 to 2009 was conducted. A total of 20 reports containing pharmacoeconomic data on rehydration therapy were evaluated. Findings suggest that ORT and SCRT may be less costly than IVRT in the treatment of mild to moderate dehydration; however, variability in cost parameters examined or data collection methods described in the literature precluded a comprehensive comparative cost-effectiveness analysis of treatment options. Future pharmacoeconomic analyses of rehydration therapy should incorporate time-motion analyses comprising a consistent set of variables to determine the most cost-effective treatment modality for patients with mild to moderate dehydration.

Subcutaneous immunoglobulin: opportunities and outlook

Immunoglobulin (Ig) administration via the subcutaneous (s.c.) route has become increasingly popular in recent years. The method does not require venous access, is associated with few systemic side effects and has been reported to improve patients' quality of life. One current limitation to its use is the large volumes which need to be administered. Due to the inability of tissue to accept such large volumes, frequent administration at multiple sites is necessary. Most studies conducted to date have investigated the use of subcutaneous immunoglobulin (SCIg) in patients treated previously with the intravenous (i.v.) formulation. New data now support the use of s.c. administration in previously untreated patients with primary immunodeficiencies. SCIg treatment may further be beneficial in the treatment of autoimmune neurological conditions, such as multi-focal motor neuropathy; however, controlled trials directly comparing the s.c. and i.v. routes are still to be performed for this indication. New developments may further improve and facilitate the s.c. administration route. For example, hyaluronidase-facilitated administration increases the bioavailability of SCIg, and may allow for the administration of larger volumes at a single site. Alternatively, more concentrated formulations may reduce the volume required for administration, and a rapid-push technique may allow for shorter administration times. As these developments translate into clinical practice, more physicians and patients may choose the s.c. administration route in the future.

[The significance of intravenous immunoglobulin in treatment of immune-mediated polyneuropathies]

Long-term treatment of immune-mediated polyneuropathies remains difficult. For acute polyneuritis, or Guillain-Barré syndrome, the established standard therapy utilizes high doses of polyvalent intravenous immunoglobulins (IVIG). A recently published randomized placebo-controlled study of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) showed IVIG to be clinically effective also for this disorder in both short and long term. This survey presents data of this so-called ICE study ("Intravenous immune globulin for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy"). It also discusses the value of IVIG in the treatment of immune-mediated polyneuropathies.

What's new in chronic inflammatory demyelinating polyradiculoneuropathy in 2007-2008?

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)-related research has made progress in the field of pathogenesis, genetics, and treatment. The number of circulating CD4(+) CD25(+) T-regulatory cells was shown to be reduced in CIDP patients. Increased frequency of genotype GA13-16 of the SH2D2A gene encoding for a T-cell-specific adapter protein in CIDP patients may result in a defective control and elimination of autoreactive T cells. IVIg treatment has been shown to increase numbers and function of peripheral CD4(+) CD25(+) T-regulatory cell in a mouse model. These findings shed new light on the understanding of why peripheral tolerance is breached in CIDP patients and why the disease becomes chronic and adds another possible mechanism of action of intravenous immunoglobulin to the already long list. Long-term effectiveness of IVIg has now been proven. Subcutaneous immunoglobulin could be an alternative for IVIg, but this has to be explored further in well-designed trials. Autologous stem cell transplantation has been tried in refractory patients, but larger trials are necessary to assess safety and effect of this treatment.

Diagnosis and treatment in inflammatory neuropathies

The inflammatory neuropathies are a large diverse group of immune-mediated neuropathies that are amenable to treatment and may be reversible. Their accurate diagnosis is essential for informing the patient of the likely course and prognosis of the disease, informing the treating physician of the appropriate therapy and informing the scientific community of the results of well-targeted, designed and performed clinical trials. With the advent of biological therapies able to manipulate the immune response more specifically, an understanding of the pathogenesis of these conditions is increasingly important. This review presents a broad overview of the pathogenesis, diagnosis and therapy of inflammatory neuropathies, concentrating on the most commonly encountered conditions.

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

BACKGROUND AND PURPOSE

For treatment of multifocal motor neuropathy (MMN), we hypothesized that (i) infusion of equivalent dosages of subcutaneous immunoglobulin (SCIG) is as effective as intravenous immunoglobulin (IVIG) and that (ii) subcutaneous infusion at home is associated with a better quality of life.

METHODS

In a randomized single-blinded cross-over study, nine IVIG responsive patients were allocated to receive either SCIG or IVIG for a period equivalent to three IVIG treatment intervals and, subsequently, crossed over to the other treatment. Primary end-points were (i) dynamometric strength of affected muscles and (ii) the SF-36 quality of life questionnaire.

RESULTS

The two treatments were equally effective, the mean change in muscle strength after SCIG being 3.6% (95% CI -3.6% to 10.9%) vs. 4.3% (-1.3% to 10.0%) after IVIG (P = 0.86). One patient had sustained erythema and oedema at the injection sites for a few weeks. All other adverse effects during SCIG were mild and transient. No differences between treatments of health-related quality of life occurred.

CONCLUSION

In MMN, short-term subcutaneous infusion of immunoglobulin is feasible, safe and as effective as intravenous infusion. Subcutaneous administration is an alternative option that adds flexibility to the treatment schedule.

Subcutaneous administration of IgG

The availability of IgG preparations that could be administered safely by the intravenous route was finally achieved in the early to mid-1980s. Intravenous immunoglobulin (IVIG) revolutionized the treatment of primary immune deficiency diseases (PIDD) and led to the discovery of the therapeutic value of high-dose IgG in autoimmune and inflammatory diseases not associated with PIDD. Improved therapy has improved outcomes and expectations, and most PIDD patients can lead fully active and productive lives. Administration of IgG by the subcutaneous route is effective and safe and overcomes obstacles to the use of IVIG in some patients. Many patients find administration of subcutaneous IgG at home more convenient than receiving IVIG at the Doctor's office or hospital. The coming years will see increased use of subcutaneous immunoglobulin in PIDD, which will be facilitated by advances leading to higher-concentration IgG products and easier delivery.

Intravenous immunoglobulins in the treatment of immune neuropathies

PURPOSE OF REVIEW

The aim of this review is to describe the value of high-dose polyclonal intravenous immunoglobulins as a treatment option in autoimmune disorders affecting the peripheral nervous system.

RECENT FINDINGS

A randomized placebo-controlled trial in patients with chronic inflammatory demyelinating polyradiculoneuropathy revealed short-term and long-term efficacy and safety of intravenous immunoglobulins as a treatment option for the chronically inflamed peripheral nervous system. Case reports suggest that the subcutaneous administration of immunoglobulins may represent a convenient alternative.

SUMMARY

Intravenous immunoglobulin represents an effective and safe treatment option in patients with autoimmune-mediated diseases affecting the peripheral nerves.

New advances in the treatment of neurological diseases using high dose intravenous immunoglobulins

Since the incidental discovery in 1981 that intravenous immunoglobulins (IVIg) are immunomodulatory, they have been investigated in a large number of putative autoimmune diseases. This has led to licensing for idiopathic thrombocytopenic purpura, Kawasaki disease, and in neurological disorders for Guillain-Barré syndrome (GBS). Although not licensed, randomized controlled trials have also shown IVIg efficacy in other neuroimmunological diseases such as multifocal motor neuropathy (MMN), chronic inflammatory demyelinating neuropathy (CIDP), myasthenia gravis, dermatomyositis, and stiff-person syndrome. However, other indications are currently being explored including Alzheimer's disease, postpolio syndrome, and narcolepsy. There are even reports from experimental studies in stroke. The results of recently published clinical trials in both the classical neuroimmunological disorders as well as for new indications are reported and their role in clinical practice is discussed.

[Current use of immunoglobulins in neurology]

Intravenous immunoglobulins (IVIg) have been used for treating various neuroimmunological diseases. Over the past decade their efficacy could be demonstrated in placebo-controlled, double-blinded clinical trials. Use of IVIg has become the first-line treatment for Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and rapidly worsening myasthenia gravis. It is also a second-line treatment for dermatomyositis, polymyositis, stiff-person syndrome, and pregnancy- and postpartum-related relapses in multiple sclerosis. Intravenous immunoglobulin is easily available, its administration is uncomplicated, and it has an excellent safety profile. In Germany it has been approved only for GBS; for other indications it has to be used off-label. Here we review the clinical applications and recommendations for the use of IVIg in neurological diseases.