Emerging treatment landscape for Guillain-Barré Syndrome (GBS): what's new?

INTRODUCTION

Guillain-Barré syndrome (GBS) is a monophasic immune neuropathic disorder characterized by acute paralysis. A significant portion of patients are left with residual deficits, which presents a considerable global healthcare challenge. The precise mechanisms underlying GBS pathogenesis are not fully elucidated. Recent studies have focused on postinfectious molecular mimicry and identified involvement of IgG autoantibodies and innate immune effectors in GBS. Intravenous immunoglobulins (IVIg) and plasma exchange (PE) are two established evidence-based immunomodulatory treatments for GBS, but a significant proportion of GBS patients fails to respond adequately to either therapy. This emphasizes an urgent need for novel and more potent treatments.

AREAS COVERED

We discuss novel immunomodulatory therapies presently at different phases of preclinical and clinical investigation. Some drugs in development target pathophysiologic mechanisms such as IgG autoantibody catabolism and complement activation, which are relevant to GBS.

EXPERT OPINION

There is an unmet need for more effective immune therapies for GBS. New immunomodulatory therapies under development may provide more potent options for GBS patients who do not respond to IVIg or PE. Future directions may include incorporating neuroprotective interventions based on evolving understanding of mechanisms underlying nerve injury and axonal degeneration.

Retrospective Evaluation of Survival and Prognostic Factors in Immune Thrombocytopenia: A Single-Center and Cross-Sectional Study

Background and Objectives: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by the autoantibody-mediated destruction of platelets. The treatment of ITP aims to maintain a sufficient platelet count to prevent bleeding. First-line treatment options include corticosteroids and intravenous immunoglobulin (IVIg), while second-line treatments include splenectomy, rituximab and other immunosuppressive agents, and thrombopoietin (TPO) receptor agonists. This study aims to discuss the treatment methods and results from 100 patients with ITP at the Muğla Training and Research Hospital through a pharmacological approach. Materials and Methods: Demographic characteristics, clinical findings, bone marrow aspiration and biopsy results, and treatments and treatment responses at the time of diagnosis of the 100 patients with ITP who were treated and followed up in the period 2015-2023 were evaluated retrospectively. Results: In the third month after treatment, the overall response percentage was 100% in patients who received steroids only and 88% in patients who received IVIg treatment alone or in combination with steroids (p > 0.05). The most preferred second-line treatments were splenectomy (41%), eltrombopag (26%), and rituximab (10%). Bone marrow biopsy was performed in 54% of patients, where 35.1% showed increased megakaryocytes, 44.4% adequate megakaryocytes, and 14.8% decreased megakaryocytes. It is noted that eltrombopag and rituximab, in particular, yield higher complete remission rates than immunosuppressive drugs. Conclusions: Considering the side effects of immunosuppressive medications, IVIg, splenectomy, and steroid therapy, the use of new agents such as eltrombopag, which are easily tolerated and have a lower risk of side effects, is expected to increase.

Treatment response in patients with clinical and supportive laboratory features of chronic inflammatory demyelinating polyneuropathy without demyelinative findings on nerve conduction studies: A retrospective study

INTRODUCTION/AIMS

Not all patients with chronic inflammatory demyelinating polyneuropathy (CIDP) have evidence of demyelination on nerve conduction studies (NCS). Patients with "supportive" evidence of CIDP on cerebrospinal fluid (CSF), magnetic resonance imaging (MRI), ultrasound (US), or nerve biopsy but not on NCS, often receive immunomodulating therapy. We evaluated the treatment response of patients with clinical and supportive features of CIDP lacking NCS evidence of demyelination.

METHODS

Retrospective chart review was conducted on 232 patients who met CIDP clinical criteria and were treated with disease-modifying therapy. Patients included did not have NCS criteria of demyelination, but did have supportive CSF, MRI, or US findings consistent with CIDP. A positive treatment response was defined as at least a one-point improvement in the modified Rankin scale (mRS), or a four-point increase in the Medical Research Council sum score (MRCSS).

RESULTS

Twenty patients met criteria: 17 of the 18 (94%) patients with CSF protein >45 mg/dL, 6 of the 14 (43%) with MRI lumbosacral root or plexus enhancement, and 4 of the 6 (67%) with enlarged proximal nerves on US. Eighteen patients received intravenous immunoglobulin, 10 corticosteroids, one plasma exchange, and six other immunomodulatory therapies. Twelve patients had a positive treatment response on the MRCSS or mRS. The presence of MRI lumbosacral root or plexus enhancement was associated with a positive treatment response.

DISCUSSION

A trial of immunomodulating treatment should be considered for patients with clinical features of CIDP in the absence of NCS evidence of demyelination, particularly when there is MRI lumbosacral root or plexus enhancement.

Successful Treatment of Severe Pemphigus Vulgaris with Reduced Side Effects Using a Novel IVIg Preparation

Pemphigus vulgaris (PV) is a rare autoimmune bullous dermatosis (AIBD) characterized by painful blistering of the skin and mucosa caused by autoantibodies that lead to loss of adhesion in the epidermis. Standard therapy for PV is corticosteroids, either alone or in combination with steroid-sparing immunosuppressants or infusions with rituximab. According to the published European guideline, high-dose intravenous immunoglobulin (IVIg) therapy with a dosage of 2 g per kg body weight distributed over 2-5 days every 4 weeks is a promising treatment option, especially for severe or refractory disease. This report describes a 73-year-old female patient with severe and recurrent disease who achieved stabilization with IVIg treatment. However, the patient experienced side effects such as headaches, nausea, and vomiting, which affected daily life. Hence, she was transitioned to a new IVIg preparation with a new manufacturing process, resulting in fewer side effects and an improved quality of life. Further follow-up is necessary to fully evaluate the effectiveness and tolerability of this new IVIg product.

Corrigendum: Low rates of headache and migraine associated with intravenous immunoglobulin infusion using a 15-minute rate escalation protocol in 123 patients with primary immunodeficiency

[This corrects the article DOI: 10.3389/fimmu.2022.1075527.].

Effect of intravenous immunoglobulin and plasmapheresis on nerve conduction parameters compared to the natural course of Guillain-Barré syndrome

BACKGROUND

Intravenous immunoglobulin (IVIg) and plasmapheresis (PLEX) are recommended in moderate to severe Guillain-Barré Syndrome (GBS), but there is paucity of studies evaluating its effect on nerve conduction studies (NCS). We report the effect of IVIg and PLEX on the NCS parameters and clinical outcomes compared to natural course (NC) of GBS patients.

METHOD

Moderate to severe GBS patients were included based on clinical, cerebrospinal fluid, and NCS finding. Six motor and sensory nerves were evaluated at admission, one month and 3 months, and NCS subtyping was done. Axonal and demyelination burden in motor nerves and early reversible conduction block (ERCB) were noted. Patients receiving IVIg, PLEX or on NC were noted. Outcome was defined at 3 months into complete, partial and poor using a 0-6 GBS Disability Scale (GBSDS).

RESULT

Seventy-two patients were included, whose median age was 36 years and 22(30.6 %) were females. 44 patients received IVIg, 9 PLEX and 19 were in NC, and they had comparable peak disability. AIDP was the dominant subtype at admission (58.3 %), which remained so at 3 months (50 %). The shift of subtypes was the highest from the equivocal group followed by AMAN and the least from AIDP. IVIg and PLEX group had more reduction in axonal burden and had ERCB compared to NC. 33(44 %) patients had complete recovery, and 40(55.5 %) patients had concordance in clinical and neurophysiological outcome.

CONCLUSION

Transition of GBS subtype may occur at follow-up from all the subtypes, the highest from the equivocal and the lowest from the AIDP group. IVIg/PLEX treatment may help in reducing conduction block and axonal burden.

Safety and tolerability of intravenous immunoglobulin infusion in Down syndrome regression disorder

Three large multi-center studies have identified the clinical utility of intravenous immunoglobulin (IVIg) in the treatment of Down syndrome regression disorder (DSRD). Yet the tolerability of infusions in individuals with DS and the safety of IVIg remains unknown in this population. This study sought to evaluate the safety and tolerability of IVIg in individuals with DSRD compared to a real-world cohort of individuals with pediatric onset neuroimmunologic disorders. A single-center, retrospective chart review evaluating clinically documented infusion reactions was performed for individuals meeting international consensus criteria for DSRD and having IVIg infusions between 2019 and 2023. Infusion reactions were evaluated for severity and need for alterations in infusion plan. This cohort was compared against an age and sex matched cohort of children with neuroimmunologic conditions who had also received IVIg infusions. In total, 127 individuals with DSRD and 186 individuals with other neuroimmunologic disorders were enrolled. There was no difference in the overall rate of adverse reactions (AEs) between the DSRD and general neuroimmunology cohorts (p = 0.31, 95% CI: 0.80-2.00), but cardiac-related AEs specifically were more common among the DSRD group (p = 0.02, 95% CI: 1.23-17.54). When AEs did occur, there was no difference in frequency of pharmacologic intervention (p = 0.12, 95% CI: 0.34-1.13) or discontinuation of therapy (p = 0.74, 95% CI: 0.06-7.44). There was a higher incidence of lab abnormalities on IVIG among the general neuroimmunology cohort (p = 0.03, 95% CI: 0.24-0.94) compared to the DSRD cohort. Transaminitis was the most common laboratory abnormality in the DSRD group. In a large cohort of individuals with DSRD, there were no significant differences in the safety and tolerability of IVIg compared to a cohort of children and young adults with neuroimmunologic conditions.

Rapid recovery in a child with febrile ulceronecrotic Mucha-Habermann disease following intravenous immunoglobulin administration

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD), a lymphocyte-mediated inflammatory skin disorder, is considered a severe variant of pityriasis lichenoides et varioliformis acuta that can lead to a fatal outcome if not managed in a timely fashion. Children with FUMHD can have systemic complications involving various organs. The scarcity of reported cases and the absence of well-designed studies or randomized clinical trials to evaluate different therapeutic modalities pose a major challenge in treating this potentially life-threatening disorder. We report a five-year-old child with FUMHD and seizures treated unsuccessfully with a combination of systemic steroids, methotrexate, dapsone, and oral erythromycin, who improved rapidly and achieved disease control with just a single infusion of low-dose intravenous immunoglobulin.

Longitudinal evaluation of serum MOG-IgG titers in MOGAD after initiation of maintenance immunoglobulin: A case series

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a distinct demyelinating disease of the central nervous system. Immunoglobulin (Ig) has been used as a maintenance therapy to prevent relapses in MOGAD, but the impact of Ig on serum MOG-IgG titers is unclear.

OBJECTIVE

To characterize the variation in serum MOG-IgG titers after initiation of Ig treatment in people with MOGAD.

METHODS

We conducted a retrospective study of 10 patients with a diagnosis of MOGAD and available serum MOG-IgG titers before and after initiation of maintenance Ig treatment.

RESULTS

We found that most of the patients remained MOG-IgG seropositive while on Ig treatment with a reduced or unchanged titer, despite a lack of disease activity.

CONCLUSIONS

This case series suggests that the mechanism of action of Ig therapy in MOGAD is not exclusively dependent on MOG-IgG titer reduction.

Burden of illness and costs in patients with myasthenia gravis currently receiving treatment in the United States

INTRODUCTION/AIMS

If myasthenia gravis (MG) symptoms are inadequately controlled, patients may experience exacerbations or life-threatening myasthenic crises. Patients with inadequately controlled MG symptoms tend to be treated with chronic intravenous immunoglobulin (IVIg) therapy and/or multiple immunosuppressant therapies (ISTs). This study aimed to examine disease burden, healthcare resource utilization, and associated costs in these patients.

METHODS

This was a retrospective observational study using a claims database. Patients with MG were classified into three cohorts based on treatment over a 1-y follow-up period: (a) treated with four or more IVIg episodes (chronic IVIg cohort); (b) received two or more non-steroidal ISTs (NSISTs) sequentially (multiple NSIST cohort); (c) received neither chronic IVIg nor multiple NSISTs (reference cohort). Incidences of crises and exacerbations and annual healthcare costs in each cohort were estimated.

RESULTS

In total, 3516 patients with MG were included in the analysis. Compared with the reference cohort (n = 2992), the MG crisis rate was approximately twice as high in both the chronic IVIg (n = 324) and multiple NSIST (n = 291) cohorts (p < 0.001); and the MG exacerbation rate was approximately four-fold higher in the chronic IVIg cohort (p < 0.001) and three-fold higher in the multiple NSIST cohort (p < 0.001). Median annual MG-related inflation-adjusted total healthcare costs were higher in the chronic IVIg ($81,900) and multiple NSIST ($30,300) cohorts than in the reference cohort ($2540).

DISCUSSION

The burden of crises/exacerbations was substantially higher and healthcare costs were considerably greater in patients with MG treated with chronic IVIg or multiple NSISTs than in patients not receiving these treatments.

The Experiences of Children with Primary Immunodeficiency Who Receive Immunoglobulin Subcutaneously Instead of Intravenously

BACKGROUND

Children with primary immunodeficiency disorder have begun receiving subcutaneous immunoglobulin (SCIg) instead of intravenous immunoglobulin (IVIg). So, we aim to explore the experiences of primary immunodeficiency children with regard to receiving SCIg instead of IVIg.

METHOD

We adopted a phenomenological approach in 2022 in Turkey using semi-structured interviews. We recruited 15 participants using the purposive sampling method.

RESULTS

The main theme was the sweetness and bitterness of living with SCIg. The first subtheme was sweetness (sense of freedom, having a normal life, saving time, ease of use, and feeling better). The second subtheme was bitterness (worries about taking responsibility for injection, impaired body image due to abdominal edema, and minimal tolerable complications).

DISCUSSION

The results show these children had more sweet experiences than bitter ones. Being flexible in choosing a method, teaching patients to apply it correctly, and providing enough time to cope are as reasons for this.

Atezolizumab Lung Toxicity: Importance of Combination Treatment On The Edge of Life, A Case Report

BACKGROUND

Lung cancer is one of the most common and mortal cancers worldwide. According to pathological and clinical groups, treatments vary, and a tailored approach is considered. Adjuvant therapies, such as chemotherapy, radiation, and immune checkpoint inhibitors (ICI), are recommended by recent guidelines for patients with locally advanced cancer.

OBJECTIVE

This study aimed to report the case of a patient with stage 2B squamous cell lung carcinoma who was managed for pulmonary toxicity after receiving adjuvant chemotherapy and atezolizumab treatment.

CASE REPORT

A 66-year-old male patient received chemotherapy and immunotherapy after surgery for squamous cell lung cancer. A diagnosis of atezolizumab-associated pneumonitis was made using laboratory tests and imaging due to the patient's worsening dyspnea after treatment. Due to the patient's rapid progression, pulse steroid and MMF therapy were administered concurrently. When Klebsiella pneumoniae growth was detected in the sputum culture during the follow-up, IVIg was used to supplement the medication. The patient showed significant clinical and radiological improvement.

CONCLUSION

In this study, we present an atezolizumab-induced pneumonitis case of a squamous cell lung cancer patient. It may be life-saving not to avoid aggressive treatment approaches by combining the steps of guideline recommendations in patients with rapidly progressive pneumonitis.

Intravenous immunoglobulin alteration in response to adverse reactions in neurological conditions: A retrospective cohort study

INTRODUCTION

Intravenous immunoglobulin (IVIg) is an important treatment in a range of neurological conditions. There is currently limited evidence regarding the frequency and management of IVIg-associated adverse reactions (AR) in neurological disorders.

METHODS

A single-centre 18-month retrospective cohort study was conducted for all patients at a single tertiary hospital receiving IVIg as an inpatient or the medical day unit. Electronic medical record AR and alerts were reviewed for entries relating to IVIg, and prescribing records associated with recent IVIg administration were reviewed for the use of premedications. Case note review was undertaken to identify AR associated with alterations in IVIg treatment (such as reduction in rate, use of premedications or cessation of IVIg). Demographic, patient, and treatment factors were analysed for associations with AR necessitating alteration in IVIg treatment.

RESULTS

This study included 98 individuals who received IVIg during the study period. Of these, 12 (12.1%) patients required an alteration in their IVIg treatment. In total, 3 (3.1%) of the 98 included patients required a reduced rate of IVIg, and 10 (10.2%) patients received premedication. The most common premedications were normal saline at the time of the infusion, cetirizine, and hydrocortisone. No demographic factors, indications or comorbidities were found to be associated with an increased likelihood of AR. However, an IVIg daily dose of >35 g and >45 g were associated with an increased likelihood of requiring IVIg treatment alteration due to AR.

CONCLUSIONS

Alterations to IVIg treatment due to AR are commonly required in neurology patients, and may be associated with higher daily doses of IVIg.

Case report: JC polyomavirus nephropathy in simultaneous heart-kidney transplantation: the role of viral-specific in situ hybridization staining

Introduction

JC polyomavirus (JCPyV) is a ubiquitous virus that can be latent in the brain and the kidney. It is the etiologic agent responsible for progressive multifocal leukoencephalopathy, a fatal, demyelinating disease of the central nervous system, and rarely causes polyomavirus nephropathy in immunocompromised kidney transplant recipients.

Case description

We present the first case of JCPyV nephropathy in a simultaneous heart-kidney transplant patient, where viral-specific in situ hybridization staining of the kidney tissue was utilized to confirm the diagnosis. The patient was diagnosed 6 years after simultaneous heart-kidney transplantation and was treated with immunosuppression reduction and intravenous immunoglobulin.

Discussion

JCPyV nephropathy should be considered in the differential diagnosis of kidney allograft injury, particularly, with suggestive light microscopy histologic features in the absence of BK polyomavirus viremia and/or viruria. In addition to obtaining JCPyV PCR in the blood, in situ hybridization staining may have a utility in confirming the diagnosis. To date, we lack effective JCPyV-specific therapies, and prompt initiation of immunosuppression reduction remains the mainstay of treatment.

Current clinical management of CIDP with immunoglobulins in France: An expert opinion

Treatment strategies in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) must be adapted on a case-to-case basis. Validated and reproducible tools for monitoring treatment response are required at diagnosis, when initiating treatment and throughout follow-up. A task force of French neurologists, experts in neuromuscular disease reference centers, was assembled to provide expert advice on the management of typical CIDP with intravenous immunoglobulins (Ig), and to harmonize treatment practices in public and private hospitals. The task force also referred to the practical experience of treating CIDP with Ig at the diagnostic, induction and follow-up stages, including the assessment and management of Ig dependence, and following the recommendations of the French health agency.

Multisystem Inflammatory Syndrome in Children (MIS-C) Related to SARS-CoV-2 and 1-Year Follow-up

OBJECTIVE

To study the demographics, clinical profile, management, outcome and 1-y follow-up of children with multisystem inflammatory syndrome in children (MIS-C).

METHODS

This was a retrospective observational study of 54 Children satisfying the WHO MIS-C criteria admitted during the study period.

RESULTS

Fifty-four children were included in the study, median age was 5.5 (IQR 8.75), 68.5% were males. PICU admissions were 77%. Most involved organ was gastrointestinal (92%), followed by cardiovascular 85%, central nervous system (CNS) 74%, respiratory 72%, mucocutaneous 59%, and renal 31%, and hypotension was the presenting symptom in 43%. Coronary artery dilatation was seen in 1 (1.8%) child. All patients presented with more than three organs involvement. Raised procalcitonin was seen in 100%, raised BNP in 31.5%, low ejection fraction in 83.3%, and abnormal radiograph in 59%. All children were positive for anti-SARS-CoV-2 antibodies and negative for cultures. Methylprednisolone or intravenous immunoglobulin (IVIg) was used in 77%, mechanical ventilation in 18.5%, and inotropic support in 77%. Aspirin was used in 48% and low molecular weight heparin (LMWH) in 54%. The median stay in hospital was 7 d (IQR 2). There was 1 mortality (1.8%). On 7-d follow-up, 98% children had a normal echocardiography; on 6 mo and 1-y follow-up, all children had normal echocardiography.

CONCLUSION

MIS-C is an important complication of COVID-19 infection. Cardiac involvement resolves completely. Coronary artery involvement is not common.

Stiff-Leg Syndrome Associated with Autoimmune Retinopathy and Its Treatment with IVIg-A Case Report and Review of the Literature

Antibodies to glutamic acid decarboxylase (GAD) have been predominantly associated with stiff-person syndrome (SPS), which is often accompanied by organ-specific autoimmune diseases, such as late-onset type 1 diabetes. Autoimmune retinal pathology in SPS has recently been suggested to coexist in patients suffering from this disease; however, evidence reporting potential treatment options for the neurological and visual symptoms these patients experience remains scarce. We provide a review of the relevant literature, presenting a rare case of a middle-aged woman with autoimmune retinopathy (AIR) followed by stiff-leg syndrome who responded to intravenous immune globulin treatment (IVIg). Our report adds to previously reported data supporting the efficacy of IVIg in SPS spectrum disorders while also proposing the potential effect of IVIg in treating SPS spectrum patients with coexisting AIR.

Efficacy and Safety of Intravenous Immunoglobulin Treatment in Selected Neurological Diseases-One Centre's Experience Based on the Therapy of 141 Patients

BACKGROUND

Intravenous immunoglobulins (IVIg) are the first-choice drugs for the treatment of certain neuroimmune diseases. The aim of this study was to evaluate the efficacy and safety of IVIg in patients with selected nervous system diseases.

METHODS

The study enrolled patients who received IVIg in programmes financed by the National Health Fund in Poland. The status of patients upon inclusion and during treatment was assessed using scales dedicated to specific neurological diseases.

RESULTS

The study enrolled 141 patients aged 56.28 ± 14.72 (51.77% female): 21 patients with myasthenia gravis (MG), 65 with chronic inflammatory demyelinating polyneuropathy (CIDP), 30 with Guillain-Barré syndrome (GBS), 12 with neuromyelitis optica spectrum disorder (NMOSD) and 13 patients with autoimmune encephalitis (AE). Neurological improvement was found in 14 (66.66%) MG patients (with a reduction of at least three points on the Quantitative Myasthenia Gravis Score (QMGS) within 14 days from the completion of the cycle), and in 34 (52.3%) GBS patients (with a reduction of at least one point on the Medical Research Council Scale within 14 days from the completion of the cycle). The parameters with the strongest effect on clinical improvement in MG patients were age [OR 1.033, CI 95% [0.09-1.09], p = 0.049] and baseline QMGS [OR 0.505; CI 95% [0.24-0.87], p = 0.038]. In the majority of CIDP patients (27, 97%) and NMOSD patients (6, 50%), neurological stabilisation was observed (without clinical improvement, defined for CIDP patients as an increase of at least two points on the Lovett Scale after three courses of IVIg were administered, and for NMOSD patients as an increase of at least one point on the Medical Research Council Scale and/or a shift of at least 0.3 logMAR after three courses of treatment). Deep-vein thrombosis was only one serious adverse event in the total group of patients treated with IVIg.

CONCLUSIONS

The use of IVIg in patients with MG and GBS mostly results in neurological improvement, while in patients with NMOSD and CIDP, it mostly results in disease stabilisation. This could indicate the predominant anti-idiotypic antibody activity of IVIg in acute neuroimmune diseases or during exacerbations in chronic autoimmune diseases. The therapy of AE in comorbid neoplastic disease is burdened with an elevated risk of failure for IVIg. The results of our study confirm the improved safety of IVIg for selected neurological diseases.

IVIg treatment increases thrombin activation of platelets and thrombin generation in paediatric patients with immune thrombocytopenia

Clinical manifestations and laboratory parameters of haemostasis were investigated in 23 children with newly diagnosed immune thrombocytopenia (ITP) before and after intravenous immunoglobulin (IVIg) treatment. ITP patients with platelet counts of less than 20 × 109 /L and mild bleeding symptoms, graded by a standardized bleeding score (BS), were compared with healthy children with normal platelet counts and children with chemotherapy-related thrombocytopenia. Markers of platelet activation and platelet apoptosis in the absence and presence of platelet activators were analysed by flow cytometry; thrombin generation in plasma was determined. ITP patients at diagnosis presented with increased proportions of platelets expressing CD62P and CD63 and activated caspases, and with decreased thrombin generation. Thrombin-induced activation of platelets was reduced in ITP compared with controls, while increased proportions of platelets with activated caspases were observed. Children with a higher BS had lower proportions of CD62P-expressing platelets compared with those with a lower BS. IVIg treatment increased the number of reticulated platelets, the platelet count to more than 20 × 109 /L and improved bleeding in all patients. Decreased thrombin-induced platelet activation, as well as thrombin generation, were ameliorated. Our results indicate that IVIg treatment helps to counteract diminished platelet function and coagulation in children with newly diagnosed ITP.

T Regulatory Cell-Associated Tolerance Induction by High-Dose Immunoglobulins in an HLA-Transgenic Mouse Model of Pemphigus

Pemphigus vulgaris (PV) is a potentially lethal autoimmune bullous skin disorder caused by IgG autoantibodies against desmoglein 3 (Dsg3) and Dsg1. During the last three decades, high-dose intravenous immunoglobulins (IVIgs) have been applied as an effective and relatively safe treatment regime in severe, therapy-refractory PV. This prompted us to study T- and B- cell polarization by IVIg in a human-Dsg3-dependent mouse model for PV. Using humanized mice transgenic for HLA-DRB1*04:02, which is a highly prevalent haplotype in PV, we employed IVIg in two different experimental approaches: in prevention and quasi-therapeutic settings. Our data show that intraperitoneally applied IVIg was systemically distributed for up to 42 days or longer. IVIg-treated Dsg3-immunized mice exhibited, in contrast to Dsg3-immunized mice without IVIg, significantly less Dsg3-specific IgG, and showed induction of T regulatory cells in lymphatic tissue. Ex vivo splenocyte analysis upon Dsg3-specific stimulation revealed an initial, temporarily reduced antigen-induced cell proliferation, as well as IFN-γ secretion that became less apparent over the course of time. Marginal-zone B cells were initially reduced in the preventive approach but re-expanded over time. In contrast, in the quasi-therapeutic approach, a robust down-regulation in both spleen and lymph nodes was observed. We found a significant down-regulation of the immature transitional 1 (T1) B cells in IVIg-treated mice in the quasi-therapeutic approach, while T2 and T3, representing a healthy stage of B-cell development, appeared to be up-regulated by IVIg. In summary, in two experimental settings employing an active PV mouse model, we demonstrate distinct alterations of T- and B-cell populations upon IVIg treatment, compatible with a tolerance-associated polarization in lymphatic tissue. Our data suggest that the clinical efficacy of IVIg is at least modulated by distinct alterations of T- and B-cell populations compatible with a tolerance-associated polarization in lymphatic tissue.

Pediatric-Onset Chronic Inflammatory Demyelinating Polyneuropathy: A Multicenter Study

BACKGROUND

To evaluate the clinical features, demographic features, and treatment modalities of pediatric-onset chronic inflammatory demyelinating polyneuropathy (CIDP) in Turkey.

METHODS

The clinical data of patients between January 2010 and December 2021 were reviewed retrospectively. The patients were evaluated according to the Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society Guideline on the management of CIDP (2021). In addition, patients with typical CIDP were divided into two groups according to the first-line treatment modalities (group 1: IVIg only, group 2: IVIg + steroid). The patients were further divided into two separate groups based on their magnetic resonance imaging (MRI) characteristics.

RESULTS

A total of 43 patients, 22 (51.2%) males and 21 (48.8%) females, were included in the study. There was a significant difference between pretreatment and post-treatment modified Rankin scale (mRS) scores (P < 0.05) of all patients. First-line treatments include intravenous immunoglobulin (IVIg) (n = 19, 44.2%), IVIg + steroids (n = 20, 46.5%), steroids (n = 1, 2.3%), IVIg + steroids + plasmapheresis (n = 1, 2.3%), and IVIg + plasmapheresis (n = 1, 2.3%). Alternative agent therapy consisted of azathioprine (n = 5), rituximab (n = 1), and azathioprine + mycophenolate mofetil + methotrexate (n = 1). There was no difference between the pretreatment and post-treatment mRS scores of groups 1 and 2 (P > 0.05); however, a significant decrease was found in the mRS scores of both groups with treatment (P < 0.05). The patients with abnormal MRI had significantly higher pretreatment mRS scores compared with the group with normal MRI (P < 0.05).

CONCLUSIONS

This multicenter study demonstrated that first-line immunotherapy modalities (IVIg vs IVIg + steroids) had equal efficacy for the treatment of patients with CIDP. We also determined that MRI features might be associated with profound clinical features, but did not affect treatment response.

Chronic inflammatory demyelinating polyradiculoneuropathy-associated tremor: Phenotype and pathogenesis

BACKGROUND AND PURPOSE

Tremor in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is underrecognized, and the pathophysiology remains incompletely understood. This study evaluated tremor in CIDP and tested the hypothesis, established in other demyelinating neuropathies, that tremor occurs due to mistimed peripheral inputs affecting central motor processing. Additionally, the tremor stability index (TSI) was calculated with the hypothesis that CIDP-related tremor is more variable than other tremor disorders.

METHODS

Consecutive patients with typical CIDP were prospectively recruited from neuromuscular clinics. Alternative causes of neuropathy and tremor were excluded. Cross-sectional clinical assessment and extensive tremor study recordings were undertaken. Pearson correlation coefficient was used to compare nerve conduction studies and tremor characteristics, and t-test was used for comparisons between groups.

RESULTS

Twenty-four patients with CIDP were included. Upper limb postural and action tremor was present in 66% and was mild according to the Essential Tremor Rating Assessment Scale. Tremor did not significantly impact disability. Surface electromyography (EMG) found high-frequency spectral peaks in deltoid (13.73 ± 0.66 Hz), biceps brachii (11.82 ± 0.91 Hz), and extensor carpi radialis (11.87 ± 0.91 Hz) muscles, with lower peaks in abductor pollicis brevis EMG (6.07 ± 0.45 Hz) and index finger accelerometry (6.53 ± 0.42 Hz). Tremor was unchanged by weight loading but correlated with ulnar nerve F-wave latency and median nerve sensory amplitude. TSI (2.3 ± 0.1) was significantly higher than essential tremor.

CONCLUSIONS

Postural tremor is a common feature in CIDP. Tremor was unaffected by weight loading, typical of centrally generated tremors, although there was a correlation with peripheral nerve abnormalities. The high beat-to-beat variability on TSI and gradation of peak frequencies further suggest a complex pathophysiology. These findings may assist clinicians with the diagnosis of neuropathic tremor.

Evaluation of immunoglobulin replacement therapy in secondary immunodeficiency at three British Columbia hospitals

BACKGROUND AND OBJECTIVES

Immunoglobulin (Ig) usage has ongoing shortage concerns. Secondary immunodeficiencies (SIDs) account for a major proportion of usage of Igs in Canada. We audited Ig usage in patients with SID at three British Columbia hospitals to determine whether more stringent local guidelines are necessary.

MATERIALS AND METHODS

A retrospective chart review was performed for patients who had Ig ordered between 1 January 2018 and 31 December 2019 for any SID indication. Cohorts were stratified into chronic and new users, and the Australian BloodSTAR guidelines were used as the benchmark at the time of conception. Having an eligible primary diagnosis, meeting SID criteria, an appropriate dosage and follow-up immunoglobulin G (IgG) levels encompassed appropriate usage.

RESULTS

There were no demographic differences between chronic (N = 81) and new (N = 33) cohorts. The new cohort had a higher rate of appropriate usage (45.7% vs. 66.7%, p = 0.06). The most common reason for inappropriate usage in both groups was the lack of follow-up IgG level at 6 or 12 months. Factors, displayed by relative risk (RR), associated with appropriateness included the dispensing hospital (RR: 6.60), use of subcutaneous Ig (RR: 3.84), having an IgG level before starting therapy (RR: 3.51) and documentation of clinical benefit (RR: 4.70).

CONCLUSION

There are high rates of inappropriate Ig usage in SID patients in both new and chronically treated groups. More stringent local guidelines and processes for assessing initial and ongoing Ig replacement are warranted.

Treatment patterns in myasthenia gravis: A United States health claims analysis

INTRODUCTION/AIMS

Limited knowledge exists on treatment patterns in clinical practice in patients with myasthenia gravis (MG). In this study we examined MG treatment patterns in the United States.

METHODS

Adult patients newly diagnosed with MG were identified from the IBM MarketScan insurance claims database. Patients with ≥2 MG International Classification of Disease diagnosis codes ≥3 months apart were retrospectively followed from the date of their first MG diagnosis record or start of treatment with acetylcholinesterase inhibitors (AChEI), intravenous (IV) or subcutaneous (SC) immunoglobulin (Ig), or plasma exchange (PLEx) therapy. Based on treatment received at any time during the follow-up period, patients were segmented into six main treatment cohorts. Exacerbations and use of IVIg, SCIg, or PLEx after the index date were identified.

RESULTS

During 2010 to 2019, 7,194 patients were followed for up to 10 (median, 2.3) years. Of 6,539 treated patients, 6,462 (99%) were ever treated with AChEI and/or corticosteroids (CS); 95% were first treated with AChEI and/or CS only; 33% received ≥1 nonsteroid immunosuppressive treatment (IST) and 2% received a biologic. During treatment with first IST (n = 2,166), patients experienced 42% and 94% higher incidence rates of exacerbations and IVIg, respectively, compared with AChEI and/or CS (n = 6,242), and 33% and 23% higher, respectively, compared with a second IST (n = 353).

DISCUSSION

Many patients experienced exacerbations and received rescue therapy despite treatment, suggesting current treatments may not provide adequate disease control for some patients and that additional treatment options should be explored.