Subcutaneous immunoglobulins in the treatment of chronic immune-mediated neuropathies

Cross-Reactivity of Antibodies in Intravenous Immunoglobulin Preparation for Protection against SARS-CoV-2

Severe cases of COVID-19 continue to put pressure on medical operations by prolonging hospitalization, occupying intensive care beds, and forcing medical personnel to undergo harsh labor. The eradication of SARS-CoV-2 through vaccine development has yet to be achieved, mainly due to the appearance of multiple mutant-incorporating strains. The present study explored the utility of human intravenous immunoglobulin (IVIG) preparations in suppressing the aggravation of any COVID-19 infection using a SARS-CoV-2 pseudovirus assay. Our study revealed the existence of IgG antibodies in human IVIG preparations, which recognized the spike protein of SARS-CoV-2. Remarkably, the pretreatment of ACE2/TMPRSS2-expressing host cells (HEK293T cells) with IVIG preparations (10 mg/mL) inhibited approximately 40% entry of SARS-CoV-2 pseudovirus even at extremely low concentrations of IgG (0.16-1.25 mg/mL). In contrast, the antibody-dependent enhancement of viral entry was confirmed when SARS-CoV-2 pseudovirus was treated with some products at an IgG concentration of 10 mg/mL. Our data suggest that IVIG may contribute to therapy for COVID-19, including for cases caused by SARS-CoV-2 variants, since IVIG binds not only to the spike proteins of the virus, but also to human ACE2/TMPRSS2. An even better preventive effect can be expected with blood collected after the start of the COVID-19 pandemic.

The influence of the COVID-19 pandemic on patients with chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVES

At a time of global health crisis, fear, anxiety, and stress levels increase. The effects of protracted social isolation, and media related misinformation's about the coronavirus disease 2019 (COVID-19) resulting in increased fear/stress related to the insufficiently known illness. The aim was to assess the influence of the COVID-19 health crisis on patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

A cross-sectional study on 29 adult CIDP patients was performed. The Medical Research Council scale was used to evaluate muscle strength. The degree of functional disability was measured using the Inflammatory Neuropathy Cause and Treatment disability scale. The overall quality of life (QoL) was self-estimated on a 0-100 numeric rating scale. We also used a specifically designed 22-question-survey about COVID-19.

RESULTS

Regarding the COVID-19 pandemic, 62% of CIDP patients were concerned. The daily activities of 55% of patients were negatively influenced by the pandemic. During the COVID-19 outbreak, 21% of patients reported their CIDP got worse. In 39% of CIDP patients, the influence of the pandemic on CIDP therapy was reported (reducing the dose or time interval or even discontinuation). The mean value of the self-estimated QoL was 64 ± 19. Independent predictors of worse QoL were age of patients (beta = -0.35, p < 0.05) and fear of the COVID-19 (beta = -0.34, p < 0.05).

CONCLUSION

The COVID-19 pandemic has a significant impact on CIDP patients. Besides the direct influence of the virus and fear of the virus, restrictive measures can indirectly harm the patients with CIDP.

Individualizing Therapy in CIDP: A Mini-Review Comparing the Pharmacokinetics of Ig With SCIg and IVIg

Immunoglobulin (Ig) therapy is a first-line treatment for CIDP, which can be administered intravenously (IVIg) or subcutaneously (SCIg) and is often required long term. The differences between these modes of administration and how they can affect dosing strategies and treatment optimization need to be understood. In general, the efficacy of IVIg and SCIg appear comparable in CIDP, but SCIg may offer some safety and quality of life advantages to some patients. The differences in pharmacokinetic (PK) profile and infusion regimens account for many of the differences between IVIg and SCIg. IVIg is administered as a large bolus every 3–4 weeks resulting in cyclic fluctuations in Ig concentration that have been linked to systemic adverse events (AEs) (potentially caused by high Ig levels) and end of dose “wear-off” effects (potentially caused by low Ig concentration). SCIg is administered as a smaller weekly, or twice weekly, volume resulting in near steady-state Ig levels that have been linked to continuously maintained function and reduced systemic AEs, but an increase in local reactions at the infusion site. The reduced frequency of systemic AEs observed with SCIg is likely related to the avoidance of high Ig concentrations. Some small studies in immune-mediated neuropathies have focused on serum Ig data to evaluate its potential use as a biomarker to aid clinical decision-making. Analyzing dose data may help understand how establishing and monitoring patients' Ig concentration could aid dose optimization and the transition from IVIg to SCIg therapy.

Update on immune-mediated therapies for myasthenia gravis

With the exception of thymectomy, immune modulatory treatment strategies and clinical trials in myasthenia gravis over the past 50 y were mainly borrowed from experience in other nonneurologic autoimmune disorders. The current experimental therapy paradigm has significantly changed such that treatments directed against the pathological mechanisms specific to myasthenia gravis are being tested, in some cases as the initial disease indication. Key advances have been made in three areas: (i) the expanded role and long-term benefits of thymectomy, (ii) complement inhibition to prevent antibody-mediated postsynaptic membrane damage, and (iii) neonatal Fc receptor (FcRn) inhibition as in vivo apheresis, removing pathogenic antibodies. Herein, we discuss these advances and the potential for these newer therapies to significantly influence the current treatment paradigms. While these therapies provide exciting new options with rapid efficacy, there are anticipated challenges to their use, especially in terms of a dramatic increase in cost of care for some patients with myasthenia gravis.

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.

Evaluation of a Personalized Subcutaneous Immunoglobulin Treatment Program for Neurological Patients

BACKGROUND

Subcutaneous immunoglobulin (SCIg) treatment has been shown to control symptoms and improve overall satisfaction in patients with neurological disorders. However, a large injection volume can be overwhelming and a barrier to successful SCIg treatment. We established a nurse-led individualized approach program to facilitate a smooth and successful treatment transition from intravenous immunoglobulin (IVIg) to SCIg. The program involved a lead nurse to provide two or more individual educational sessions on SCIg administration, establish a written transition plan, and liaise care with physicians.

OBJECTIVES

We aimed to evaluate the impact of our program to a successful transition defined as SCIg retention or adherence without a need to restart IVIg by six or twelve months.

METHODS

We reviewed medical charts of all patients with immune-mediated neuromuscular disorders who were in our program during January 2010 to Dec 2016.

RESULTS

Nineteen patients were identified. Mean IVIg treatment duration was 31.5 months (range 4-98) before the transition. Mean steady state SCIg dosage was 26.2 g/week (SD 10.3). All patients were initially able to switch to SCIg, with a retention rate of 17/19 (89.5%) at six months and 15/19 (78.9%) at twelve months. Two patients reverted back to IVIg treatment due to worsening of their symptoms at two and three months, while two required supplemental IVIg infusions. There were no major adverse events reported during the twelve-month period, but one minor cutaneous adverse event (redness around the injection site).

CONCLUSIONS

Successful treatment transition may be achieved with the nurse led individualized approach program.

[Aspects of nutrition for prevention and treatment of chronic neurological diseases]

Chronic neurodegenerative and neuroinflammatory diseases, such as idiopathic Parkinson's syndrome, amyotrophic lateral sclerosis and multiple sclerosis, represent a therapeutic challenge. Their pathophysiology is not well understood and a cure for any of these diseases is not possible. Over the past decades lifestyle and nutritional habits in modern industrial nations have changed and evidence is increasing that the prevalence of chronic diseases as well their clinical presentation are also changing. Epidemiological investigations indicate that nutritional components might have an impact on the pathogenesis of chronic neurological diseases. A profound understanding of these correlations could foster a better prevention as well as treatment of such chronic disabling diseases. This continuing medical education article summarizes the current understanding of selected nutritional components and their effect on the development and clinical course of chronic neurological disorders.

Immune Globulin Subcutaneous (Human) 20% (Hizentra®): A Review in Chronic Inflammatory Demyelinating Polyneuropathy

Intravenous immunoglobulin (IVIg) is well-established in the treatment of patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Immune globulin subcutaneous (human) 20% liquid (Hizentra^®; referred to as IgPro20 hereafter) has recently been approved in a number of countries, including the USA and those of the EU, as maintenance therapy in patients with CIDP. In the pivotal phase III PATH trial in adults with CIDP who were first stabilized on IVIg therapy, maintenance therapy with IgPro20 for 24 weeks significantly reduced CIDP relapse or study withdrawal rates versus placebo. Efficacy was sustained during ≤ 48 weeks of additional treatment with IgPro20 in the open-label PATH extension study. IgPro20 was generally well tolerated, with low rates of systemic adverse events (AEs); the most common AEs were local reactions (e.g. infusion-site erythema, infusion-site swelling). In PATH, more than one-half of IgPro20 recipients preferred this therapy to their previous IVIg therapy. IgPro20 offers a convenient alternative to IVIg with a better systemic AEs profile and thus extends the options for maintenance therapy in CIDP.

High-Dose Intravenous Immunoglobulin in Skin Autoimmune Disease

The immunomodulatory potential and low incidence of severe side effects of high-dose intravenous immunoglobulin (IVIg) treatment led to its successful application in a variety of dermatological autoimmune diseases over the last two decades. IVIg is usually administered at a dose of 2 g per kg body weight distributed over 2–5 days every 4 weeks. They are most commonly used as a second- or third-line treatment in dermatological autoimmune disease (pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, dermatomyositis, systemic vasculitis, and systemic lupus erythematosus). However, first-line treatment may be warranted in special circumstances like concomitant malignancy, a foudroyant clinical course, and contraindications against alternative treatments. Furthermore, IVIg can be considered first line in scleromyxedema. Production of IVIg for medical use is strictly regulated to ensure a low risk of pathogen transmission and comparable quality of individual batches. More common side effects include nausea, headache, fatigue, and febrile infusion reactions. Serious side effects are rare and include thrombosis and embolism, pulmonary edema, renal failure, aseptic meningitis, and severe anaphylactic reactions. Regarding the mechanism of action, one can discriminate between functions of the Fcγ region and the F(ab)2 region and their effects on a cellular level. These functions are not mutually exclusive, and more than one pathway may contribute to the beneficial effects. Here, we present a historical background, details on manufacturing, hypotheses on the mechanisms of action, information on the clinical application in the abovementioned conditions, and a brief outlook on future directions of IVIg treatment in dermatology.

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.

Efficacy, safety and quality of life in patients receiving subcutaneous IgG treatment: experience in Bogotá, Colombia

AIM

Investigate efficacy, safety and quality of life of Gammanorm^® 16.5% (subcutaneous immunoglobulin [SCIG]) in patients with primary immunodeficiencies (PIDs) and safety and to lesser extent efficacy in autoimmune diseases.

PATIENTS & METHODS

Medical records were extracted from 31 pediatric and 12 adult patients who received SCIG as part of the Personalized Program at University Children's Hospital, Bogotá, Colombia.

RESULTS

Mean SCIG dose was 28.7 g/month. Serious bacterial infections were observed in 7/33 patients in the PID group, most often bacterial pneumonia (3/33). There were no serious adverse events related to SCIG treatment. Drug-related adverse reactions were reported in 2/43 patients.

CONCLUSION

Self-administration of SCIG provided effective protection, favorable tolerability and improved quality of life in patients with PIDs and autoimmune diseases from Colombia.

Subcutaneous immunoglobulin in myasthenia gravis exacerbation: A prospective, open-label trial

OBJECTIVE

To investigate the efficacy, tolerability, and safety of subcutaneous immunoglobulin (SCIg) in patients with mild to moderate myasthenia gravis (MG) exacerbation.

METHODS

We performed a prospective, open-label, phase 3 trial in patients with MG aged 18 years or older and mild to moderate worsening (transition from Myasthenia Gravis Foundation of America class I to II/III or class II to III), treated with SCIg (2 g/kg), self-administered over 4 weeks. The primary endpoint was change in quantitative MG (QMG) score from baseline to study end at 6 weeks. Secondary endpoints included change in manual muscle testing (MMT), MG activities of daily living (MG-ADL), and MG composite (MGC) scores, as well as occurrence of adverse events, and tolerability as assessed via Treatment Satisfaction Questionnaire for Medication (TSQM).

RESULTS

Twenty-two of 23 patients completed the study. QMG score decreased from 14.9 ± 4.1 to 9.8 ± 5.6 (p < 0.0001), MMT score decreased from 16.8 ± 9.5 to 5.2 ± 4.5 (p < 0.0001), MG-ADL score decreased from 9.5 ± 3.0 to 4.6 ± 3.0 (p < 0.0001), and MGC score decreased from 17.4 ± 5.0 to 5.6 ± 4.5 (p < 0.0001). Satisfaction by TSQM was high (79.6 ± 15.6%). Common adverse events included headache and injection site reactions. No serious adverse events occurred.

CONCLUSIONS

SCIg is well-tolerated, safe, and effective in mild to moderate MG exacerbation. Comparative safety and efficacy must be established with randomized controlled trials.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that in patients with mild to moderate MG exacerbation, SCIg is safe and effective in reducing MG disability measures.