Prognostic indicators of improvement with therapeutic plasma exchange in pediatric demyelination

Early clinical response and complications of therapeutic plasma exchange in central nervous system demyelinating diseases

Background

Appropriate treatment reduces the severity and duration of relapses in demyelinating diseases of Central Nervous System (CNS). If high-dose corticosteroids treatment fails, therapeutic plasma exchange (TPE) is considered as a rescue treatment.

Objectives

This study aimed to investigate early clinical response and complications of TPE and prognostic factors in CNS demyelinating relapses.

Design

This prospective observational study was designed in a tertiary center during one year.

Methods

All adult patients diagnosed corticosteroid-resistant Multiple Sclerosis (MS), NeuroMyelitis Optica Spectrum Disorder (NMOSD), idiotypic Transverse Myelitis or Clinical Isolated Syndrome relapses, were eligible. Clinical response is defined based on Expanded Disability Status Scale (EDSS) at discharge. Clinical and laboratory complications recorded.

Results

Seventy-two patients were analyzed which 58.3% patients were female. MS was diagnosed for 61.1% of cases. Thirty-five patients (48.6%) responded and the mean differences of EDSS significantly decreased 0.60 score (CI95%:0.44-.77). Electrolyte imbalances and thrombocytopenia occurred in 80.6% and 55.6% of cases respectively and 40.3% of patients had systemic reactions. However, 26.4% patients experienced moderate to severe complications. In patients with moderate to severe disability, responders were younger (MD: 8.42 years, CI95%: 1.67-15.17) and had lower EDSS score at admission (median:6, IQR: 5.5-6 against 7.5 IQR: 6.5-8). The risk of failure was higher in active progressive MS patients compared with RRMS patients (OR: 6.06, CI 95%:1.37-26.76). Patients with thrombocytopenia were hospitalized more than others (MD: 1.5 days, CI 95%: 0-3). Females were more prone to hypokalemia and systemic reactions (OR: 3.11, CI 95%:1.17-8.24 and OR: 6.67, CI 95%:2.14-20.81 respectively).

Conclusion

The most common indication of TPE was corticosteroid-resistant severe MS relapses. About half of the patients presented an early clinical response. Lower disability, younger age and RRMS diagnosis are prognostic factors of better response. One out of four patients experienced moderate to severe complications, mainly electrolyte imbalances and systemic reactions. Appropriate interventions against these complications should be considered during TPE, especially in females.

Clinico-radiologic Spectrum and Outcome of Pediatric Acquired Demyelinating Disorders of Central Nervous System: A Retrospective Indian Tertiary Care Hospital Cohort

BACKGROUND

 Pediatric acquired demyelinating syndrome (ADS) constitutes a group of treatable disorders with acute neurologic dysfunction. Neuroimaging has played a significant role in diagnosis of ADS. We describe clinico-radiologic spectrum, outcomes, and comparison of the groups: acute disseminated encephalomyelitis (ADEM), neuromyelitis optica spectrum disorder (NMOSD), clinically isolated syndrome (CIS), multiple sclerosis (MS), and myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).

METHODS

 Retrospective review of 70 children with ADS at a tertiary care hospital over 15 years (2008-2023) was performed. Diagnosis was assigned as per International Pediatric Multiple Sclerosis Study Group criteria 2016. Fisher's exact and chi-square tests were applied.

RESULTS

 Thirty-nine boys and 31 girls aged 8.2 ± 4.0 years with CIS (n = 27), ADEM (n = 16), NMOSD (n = 13), MS (n = 1), and MOGAD (n = 13) were included. Clinical syndromes with positive significant association included polyfocal symptoms, encephalopathy in ADEM, optic neuritis (ON) in MOGAD, brainstem, area postrema syndrome in NMOSD. MOGAD presented with atypical presentations like prolonged fever (PF; 76.9%) and aseptic meningitis (23%). Seropositivity for myelin oligodendrocyte glycoprotein immunoglobulin-G was 62% and for NMO-IgG 2.6%. Neuroimaging of MOGAD showed lesions predominantly in basal ganglia/thalami (69.2%), optic nerve (46.2%), and cerebellum (46.2%). Imaging patterns between ADEM and MOGAD were comparable except for more ON (p = 0.004), spinal cord (p = 0.01), and cerebellar lesions (p = 0.03) in MOGAD. Area postrema lesion was unique to NMOSD. All patients received immunotherapy, of whom 91.4% (n = 64) had good recovery, 8.6% (n = 6) had functional limitation on modified Rankin scale at discharge, and 12 (17.1%) relapsed.

CONCLUSION

 The largest group was CIS. Seropositivity of MOG was high with atypical presentations like PF and aseptic meningitis. Specific neuroimaging patterns correlated with ADS categories. Short-term outcome with immunotherapy was favorable in spite of relapses.

Chimeric AQP4-based immunosorbent for highly-specific removal of AQP4-IgG from blood

Anti-aquaporin-4 autoantibodies (AQP4-IgG) are implicated in the pathogenesis of neuromyelitis optica spectrum disorders (NMOSD), and their removal from the blood circulation is considered to be an effective method for acute treatment. An ideal extracorporeal AQP4-IgG removal system should have high specificity, which means that it can selectively remove AQP4-IgG without affecting normal immunoglobulins. However, the conventional tryptophan immobilized column lacks sufficient specificity and cannot achieve this goal. In this study, we successfully prepared a fusion protein chimeric AQP4, which consists of the complete antigenic epitopes of human AQP4 and the constant region of scaffold protein DARPin. Chimeric AQP4 was expressed and purified from Escherichia coli, and then immobilized on agarose gel as a ligand for selective capture of AQP4-IgG immunosorbent. The prepared immunosorbent had a theoretical maximum adsorption capacity of 20.48 mg/g gel estimated by Langmuir isotherm. In vitro plasma perfusion tests demonstrated that the chimeric AQP4 coupled adsorbent had remarkable adsorption performance, and could eliminate more than 85 % of AQP4-IgG under the gel-to-plasma ratio of 1:50. Moreover, it exhibited high specificity because other human plasma proteins were not adsorbed in the dynamic adsorption experiment. These results suggest that the chimeric AQP4 coupled immunosorbent can provide a new approach for specific immunoadsorption (IA) treatment of NMOSD.

The role of plasmapheresis in severe acute disseminated encephalomyelitis with clinical findings of transverse myelitis

INTRODUCTION

Acute disseminated encephalomyelitis is a rare acute demyelinating disease of the central nervous system (CNS). The pathogenesis remains unclear but is suspected to be autoimmune. High doses of methylprednisolone (HDMP) are currently considered standard of treatment. Plasmapheresis (PE) is typically given in steroid refractory cases. There is currently limited evidence supporting its use in ADEM.

MATERIALS AND METHODS

We report a 16-year-old girl with ADEM who improved rapidly after initiating PE.

RESULTS

The patient presented with acute onset of multifocal CNS symptoms, including encephalopathy, requiring intensive care unit management. Despite HDMP administration, her clinical condition continued to deteriorate. PE was therefore initiated on the same day as HDMP. Her clinical condition improved significantly following the first session. She was extubated and discharged from the intensive care unit the following day.

CONCLUSION

HDMP combined with PE may be an effective first-line treatment in patients with fulminant ADEM.

Myelin Oligodendrocyte Glycoprotein (MOG) Associated Diseases: Updates in Pediatric Practice

Myelin oligodendrocyte glycoprotein (MOG) is a membrane bound protein found on the surface of oligodendrocyte cells and the outermost surface of myelin sheaths. MOG is posited to play a role as a cell surface receptor or cell adhesion molecule, though there is no definitive answer to its exact function at this time. In the last few decades, there has been a recognition of anti-MOG-antibodies (MOG-Abs) in association with a variety of neurologic conditions, though primarily demyelinating and white matter disorders. In addition, MOG associated disease (MOGAD) appears to have a predilection for pediatric populations and in some patients may have a relapsing course. There has been considerable debate as to whether MOG-Abs are truly directly pathogenic or a disease biomarker associated with neuorinflammatory disease. In this manuscript we will review the current literature surrounding MOGAD, review new clinical phenotypes, discuss treatment and prognosis, and provide insight into potential future directions that studies may focus on.

Neuromyelitis optica spectrum disorders: a review with a focus on children and adolescents

Neuromyelitis optica spectrum disorder (NMOSD) is a rare and severe inflammatory disorder of the central nervous system (CNS). It is strongly associated with anti-aquaporin 4 antibodies (AQP4-IgG), and it mainly affects young women from non-white ethnicities. However, ∼ 5 to 10% of all cases have onset during childhood. Children and adolescents share the same clinical, radiologic, and laboratory presentation as adults. Thus, the same NMOSD diagnostic criteria are also applied to pediatric-onset patients, but data on NMOSD in this population is still scarce. In seronegative pediatric patients, there is a high frequency of the antibody against myelin oligodendrocyte glycoprotein (MOG-IgG) indicating another disease group, but the clinical distinction between these two diseases may be challenging. Three drugs (eculizumab, satralizumab, and inebilizumab) have been recently approved for the treatment of adult patients with AQP4-IgG-positive NMOSD. Only satralizumab has recruited adolescents in one of the two pivotal clinical trials. Additional clinical trials in pediatric NMOSD are urgently required to evaluate the safety and efficacy of these drugs in this population.

Safety and efficacy of plasma exchange treatment in children with AQP4-IgG positive neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD), a severe demyelinating disease, is rare among children. Plasma exchange (PE) is widely used as a salvage therapy for severe and corticosteroid-unresponsive patients with NMOSD. Presently, there are limited studies on the safety and efficacy of PE in children with NMOSD. Herein, we report the case of six children with NMOSD who received PE along with the outcomes and adverse events. All six children (female, age at onset 4 years 9 months-13 years 2 months) were AQP4-IgG positive and received standard PE using the COM.TEC Cell Separator. The interval between NMOSD onset and PE was 29 days (range 10-98). Only one patient (P3) who received PE 10 days after acute exacerbations exhibited clinical improvement. Her left visual acuity increased from 0.06 to 0.6 (spectacle-corrected visual acuity was 1.0) and her EDSS score decreased from 4 to 3 points. The other five patients had no clinical improvement and no EDSS scores changes after PE. Adverse events included rashes (P1, P3), acute non-occlusive thrombosis of the internal jugular vein (P1), and thrombocytopenia (P2). In conclusion, the timing of PE initiation as a rescue therapy for severe and corticosteroid-unresponsive pediatric AQP4-IgG positive NMOSD may be crucial to treatment efficacy, and early initiation of PE may be associated with a better outcome. Furthermore, PE has the potential risk for clinically significant adverse effects that should be considered before initiating the therapy and should be weighed against potential benefits.

Pediatric Acquired Demyelinating Disorders

PURPOSE OF REVIEW

This article reviews the clinical presentation, diagnostic evaluation, treatment, and prognosis of the most common monophasic and relapsing acquired demyelinating disorders presenting in childhood.

RECENT FINDINGS

Our understanding of neuroimmune disorders of the central nervous system is rapidly expanding. Several clinical and paraclinical factors help to inform the diagnosis and ultimately the suspicion for a monophasic versus relapsing course, including the age of the patient (prepubertal versus postpubertal), presence or absence of clinical encephalopathy, identification of serum autoantibodies (eg, myelin oligodendrocyte glycoprotein [MOG] and aquaporin-4), presence of intrathecally unique oligoclonal bands, and location/extent of radiologic abnormalities. Collaborative international research efforts have facilitated understanding of the safety and efficacy of currently available immunotherapies in children with acquired demyelinating disorders, particularly multiple sclerosis.

SUMMARY

Although many of the demyelinating disorders presented in this article can affect children and adults across the age spectrum, the clinical and radiologic phenotypes, treatment considerations, and long-term prognoses are often distinct in children.

Efficacy of Plasma Exchange Treatment for Demyelinating Optic Neuritis Associated with Various Serum Antibodies: A Prospective Cohort Study

INTRODUCTION

To evaluate the value of plasma exchange (PE) for patients with three subtypes of demyelinating optic neuritis (ON): aquaporin-4 (AQP4) antibody-positive ON (AQP4-ON), myelin oligodendrocyte glycoprotein (MOG) antibody-positive ON (MOG-ON), and AQP4 and MOG double-antibody-seronegative ON (D-ON).

METHODS

A single-center prospective study compared the logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) at most severe onset, 1 day before intravenous high-dose methylprednisolone (IVMP) treatment, 1 day before PE treatment, after five-cycles of PE therapy, and at 1-, 3-, and 6-month follow-up visits. The proportions of eyes in each visual outcome category were also compared. Logistic regression and a receiver operating characteristic curve were used to analyze predicted factors for VA improvement.

RESULTS

A total of 124 ON attacks of 122 patients were included. No significant differences were found in BCVA (P = 0.659) before and after PE therapy for 22 D-ON attacks, but VA improved in two of six MOG-ON patients. In 95 AQP4-ON patients suffering 96 attacks, the mean logMAR BCVA markedly improved and was steadily maintained after five-cycles of PE treatments (adjusted P < 0.001), with VA exhibiting a significantly increasing trend (adjusted P = 0.001) after PE treatment. The combination of the number of previous ON episodes and the time window to PE treatment showed accuracy of 74.7% for predicting an improvement in BCVA score ≥ 2 levels. In addition, a combination of logMAR VA before PE and the time window to PE treatment resulted in 83.4% accuracy in predicting whether VA would regain 1.0 logMAR.

CONCLUSION

PE therapy effectively improves visual outcomes for AQP4-ON patients, but offers limited value for D-ON patients. Early initiation greatly increases likelihood of achieving VA improvement.

Longitudinally Extensive Transverse Myelitis: One Disease, Variable Outcomes—A Case Series

Longitudinal extensive transverse myelitis (LETM) is a rare form of widespread inflammation of the spinal cord causing T2 hyperintensity in spinal magnetic resonance imaging (MRI) extending across three or more vertebral segments. It is an acute onset of sensory, motor, and autonomic dysfunction of variable etiology with a likely poor outcome. We present a case series of three cases wherein children between the ages of 4 and 13 years had diverse symptoms from gradual painless loss of vision in both eyes with headache, vomiting and seizure, and a normal central nervous system examination except involvement of the optic nerve to another child with abdominal pain, urinary retention and constipation for 3 days with exaggerated DTR, and patchy sensory loss without any definite sensory level, and to the third child with fever and weakness of lower limbs, hypotonia and grade 1–2/5 power in lower limbs and normal upper limb power. Contrast-enhanced MRI spine of all children showed long segment T2 hyperintensity with variable involvement of the brain. The first two children were treated with pulsed dose methylprednisolone, and the last child received intravenous immunoglobulin followed by methylprednisolone. All were followed with oral prednisolone. LETM has a varied presentation with different etiologies. Antineuromyelitis optica immunoglobulin G (IgG) antibody (Aquaporin-4 IgG) and antimyelin oligodendrocyte glycoprotein antibody are strongly recommended though they may not be locally available or not affordable. Early and aggressive immunomodulatory therapy may help faster recovery, as did with two of our three children.

Infection-Related Myelopathies

Recent years have seen growing attention to inflammatory and infectious disorders of the spinal cord, not only due to the discovery of autoantibody-mediated disorders of the spinal cord [e.g., aquaporin-4 immunoglobulin G (IgG) antibodies and myelin oligodendrocyte glycoprotein IgG antibodies], but also due to the emergence of clusters of infection-related myelopathy, now known as acute flaccid myelitis. We review the spectrum of infection-related myelopathies and outline a nosological classification system based on association with infection. We describe the epidemiology and definitions of myelopathies, with a discussion of clinical presentation and neuroimaging features, and then turn to specific discussion of myelopathies due to direct pathogen invasion and those considered to be post- or parainfectious. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Therapeutic plasma exchange in critically ill children: experience of the pediatric intensive care unit of two centers in Chile

INTRODUCTION

Therapeutic plasma exchange (TPE) is an extracorporeal blood purification technique used in a wide spectrum of diseases. We aim to review the indications, complications, and outcomes of critically ill children who received TPE and to compare a membrane versus centrifugal method in this cohort.

METHODS

A retrospective observational study in two pediatric intensive care units in Chile during eight years (2011-2019) Results: A total of 36 patients underwent 167 TPE sessions (20 centrifugation and 16 membrane-based). The more frequent indications for TPE were autoimmune neurological diseases in 14 cases, renal diseases (9), and rheumatological disorders (5). 58 % of children received other immunomodulatory therapy. According to ASFA, 45 % of cases were I-II category, 50 % to III, and 5% not classified. Response to treatment was complete in 64 % (23/36) and partial in 33 % (12/36). Complications occurred in 17.4 % of sessions, and the most frequent was transient hypotension during the procedure. Overall survival at discharge from the PICU was 92 %. Patients who received TPE as a single therapy (n = 26) survived 96 %. The clinical outcomes between the two apheresis methods were similar. Survivors had a significantly lower PELOD score on admission (14.5 vs. 6.5, p = 0.004).

CONCLUSIONS

TPE is mainly indicated as a rescue treatment in neurological autoimmune diseases refractory to conventional immunomodulatory treatment. Complications in critically ill children are mild and low. The outcome in children requiring TPE as a single therapy is good, and no differences were observed with centrifugation or membrane method.

Paediatric multiple sclerosis and antibody-associated demyelination: clinical, imaging, and biological considerations for diagnosis and care

The field of acquired CNS neuroimmune demyelination in children is transforming. Progress in assay development, refinement of diagnostic criteria, increased biological insights provided by advanced neuroimaging techniques, and high-level evidence for the therapeutic efficacy of biological agents are redefining diagnosis and care. Three distinct neuroimmune conditions-multiple sclerosis, myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and aquaporin-4 antibody-associated neuromyelitis optica spectrum disorder (AQP4-NMOSD)-can now be distinguished, with evidence from humans and animal models supporting distinct pathobiological disease mechanisms. The development of highly effective therapies for adult-onset multiple sclerosis and AQP4-NMOSD that suppress relapse rate by more than 90% has motivated advocacy for trials in children. However, doing clinical trials is challenging because of the rarity of these conditions in the paediatric age group, necessitating new approaches to trial design, including age-based trajectory modelling based on phase 3 studies in adults. Despite these limitations, the future for children and adolescents living with multiple sclerosis, MOGAD, or AQP4-NMOSD is far brighter than in years past, and will be brighter still if successful therapies to promote remyelination, enhance neuroprotection, and remediate cognitive deficits can be further accelerated.

Plasma Exchange for Treatment of Refractory Demyelination

Researchers from the National Pediatric Hospital in Buenos Aires, Argentina, describe their experience with therapeutic plasma exchange (TPE) for refractory inflammatory central nervous system (CNS) attacks in children over the course of the last 15 years.

Acute Disseminated Encephalomyelitis: Current Perspectives

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated central nervous system (CNS) disorder, characterized by polyfocal symptoms, encephalopathy and typical magnetic resonance imaging (MRI) findings, that especially affects young children. Advances in understanding CNS neuroimmune disorders as well as the association of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) with both monophasic and recurrent forms of ADEM have led to new insights into its definition, management and outcome. In this review, we aim to provide an update based on current epidemiologic, clinical, radiological and immunopathological aspects and clinical outcome of ADEM.

E.U. paediatric MOG consortium consensus: Part 5 - Treatment of paediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

In recent years, the understanding about the different clinical phenotypes, diagnostic and prognostic factors of myelin oligodendrocyte glycoprotein-antibody-associated disorders (MOGAD) has significantly increased. However, there is still lack of evidence-based treatment protocols for acute attacks and children with a relapsing course of the disease. Currently used acute and maintenance treatment regimens are derived from other demyelinating central nervous system diseases and are mostly centre-specific. Therefore, this part of the Paediatric European Collaborative Consensus attempts to provide recommendations for acute and maintenance therapy based on clinical experience and evidence available from mainly retrospective studies. In the acute attack, intravenous methylprednisolone (IVMP) leads to a favourable outcome in the majority of patients and can be followed by tapering of oral steroids up to a maximum of three months to maintain the benefit of acute treatment by suppressing disease activity. Intravenous immunoglobulins (IVIG) and plasmapheresis constitute second-line therapies in case of insufficient response to IVMP. After a first relapse, maintenance treatment should be started in order to prevent further relapses and the possibility of permanent sequelae. Four first-line therapies consisting of rituximab (RTX), azathioprine, mycophenolate mofetil or monthly IVIG have been identified by the consensus group. In case of further relapses despite maintenance treatment, the consensus group recommends treatment escalation with RTX or IVIG, followed by combining those two, and ultimately adding maintenance oral steroids. Many open questions remain which need to be addressed in further international prospective evaluation of MOGAD treatment. This international collaboration is essential to expand the state of current knowledge.

Feasibility & safety of plasma exchange in paediatric neuro-immunology: A single center experience

BACKGROUND

There is limited data available on the safety of therapeutic plasma exchange (TPE) for paediatric neuro-immunological disorders (PNID). In this study, we report our data on safety and feasibility of TPE for these disorders.

METHODS

Retrospective chart review was performed to include all patient who received TPE for four major PNID conditions: autoimmune encephalitis (AIE), acute disseminated encephalomyelitis (ADEM), Neuromyelitis optic spectrum disorder (NMOSD) and transverse myelitis (TM). We recorded minor and major adverse effects (AEs) associated with each TPE procedure. Secondary analysis also looked at the efficacy data of TPE on these patients.

RESULTS

Thirty-two patients with PNID received a total of 186 TPE cycles. Out of these, only 1 cycle (0.89%) in AIE subgroup, 1 (4.3%) in NMOSD and 1 (4.5%) in TM had adverse effects. No patients had major side effects.

CONCLUSION

TPE was safe and well tolerated in our PNID patients.

Plasma Exchange or Immunoadsorption in Demyelinating Diseases: A Meta-Analysis

Multiple sclerosis (MS) is an inflammatory disease mainly affecting the central nervous system. In MS, abnormal immune mechanisms induce acute inflammation, demyelination, axonal loss, and the formation of central nervous system plaques. The long-term treatment involves options to modify the disease progression, whereas the treatment for the acute relapse has its focus in the administration of high-dose intravenous methylprednisolone (up to 1000 mg daily) over a period of three to five days as a first step. If symptoms of the acute relapse persist, it is defined as glucocorticosteroid-unresponsive, and immunomodulation by apheresis is recommended. However, several national and international guidelines have no uniform recommendations on using plasma exchange (PE) nor immunoadsorption (IA) in this case. A systematic review and meta-analysis was conducted, including observational studies or randomized controlled trials that investigated the effect of PE or IA on different courses of MS and neuromyelitis optica (NMO). One thousand, three hundred and eighty-three patients were included in the evaluation. Therapy response in relapsing-remitting MS and clinically isolated syndrome was 76.6% (95%CI 63.7–89.8%) in PE- and 80.6% (95%CI 69.3–91.8%) in IA-treated patients. Based on the recent literature, PE and IA may be considered as equal treatment possibilities in patients suffering from acute, glucocorticosteroid-unresponsive MS relapses.