Utility and safety of plasma exchange in paediatric neuroimmune disorders

International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE) incl. Febrile Infection-Related Epilepsy Syndrome (FIRES): Statements and Supporting Evidence

OBJECTIVE

To develop consensus-based recommendations for the management of adult and paediatric patients with NORSE/FIRES based on best evidence and experience.

METHODS

The Delphi methodology was followed. A facilitator group of 9 experts was established, who defined the scope, users and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment and research directions were generated which were then voted on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was greater or equal to 7, and inappropriate if the median score was less than or equal to 3. The analysis of evidence was mapped to the results of each statement included in the Delphi survey.

RESULTS

Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: 1) disease characteristics, 2) diagnostic testing and sampling, 3) acute treatment, 4) treatment in the post-acute phase, and 5) research, registries and future directions in NORSE/FIRES. The detailed results and discussion of all 85 statements are outlined herein. A corresponding summary of findings and practical flowsheets are presented in a companion article.

SIGNIFICANCE

This detailed analysis offers insight into the supporting evidence and the current gaps in the literature that are associated with expert consensus statements related to NORSE/FIRES. The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research.

Clinical Presentation and Outcomes of Acute Disseminated Encephalomyelitis in Adults Worldwide: Systematic Review and Meta-Analysis

Background

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating disorder that is often misdiagnosed. To improve early diagnosis, we performed a systematic review and meta-analysis of clinical features, outcomes for ADEM in adults.

Methods

The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies reporting the clinical features of adults with ADEM between January 1990 and May 2021. A random-effects meta-analysis model was used to pool data on clinical features and functional outcomes.

Results

Twelve studies examining 437 adults with ADEM met the inclusion criteria. Overall, the clinical features and diagnostic findings observed in more than two-thirds of the patients were white matter lesions [87.1%, 95% confidence interval (CI)=75-95.6], polyfocal onset (80.5%, 95% CI=50.5-98.9) and pyramidal signs (68.7%, 95% CI =40.0-91.9). The mortality rate was 7.8% (95% CI = 3.3–13.5), and the risk of residual deficits was 47.5% (95% CI = 31.8–63.4).

Conclusions

Adults with ADEM had worse outcomes than children. Clinicians should maintain high clinical suspicion for patients presenting with certain clinical features and diagnostic findings.

Connections Between Febrile Infection-Related Epilepsy Syndrome and Autoimmune Encephalitis. A Case Report of a Child With New Anti-neuronal Antibodies

Acute encephalitis and febrile infection-related epilepsy syndrome (FIRES) are debilitating neurological disorders. It is increasingly accepted that FIRES should be considered an autoinflammation-mediated epileptic encephalopathy, but the debate about its etiopathogenesis is still very much open. Despite showing a considerable overlap with encephalitis, it continues to be regarded as a distinct entity. We describe the case of a previously healthy 5-year-old child who, following a fever, developed acute encephalopathy, status epilepticus, neurological, neuropsychological, and psychiatric manifestations, and claustrum involvement on MRI. At symptom onset, his clinical and instrumental data met the diagnostic criteria for both FIRES and acute encephalitis. He received benzodiazepines, levetiracetam, phenytoin, phenobarbital, thiopental, and first-line immunotherapy for acute inflammatory encephalopathy (intravenous methylprednisolone and immunoglobulins), without substantial improvement. Following the detection of anti-neuronal antibodies through immunohistochemistry performed on rat brain slices, he received therapeutic plasma exchange (TPE). His neurological and behavioral conditions improved drastically and his antibody titer fell sharply from the first to the last course of PE. Claustrum abnormalities on MRI disappeared. The patient's long-term outcome is favorable. At 13 months after discharge, he experienced a focal seizure and carbamazepine was started, achieving seizure control. At 10 years of age, he is still on carbamazepine, with well-controlled seizures, focal EEG abnormalities, and an otherwise normal neurological and cognitive profile and normal MRI. This case strengthens the view that FIRES might constitute the initial clinical presentation of a CNS inflammatory disease that could have, among multiple distinct etiologies, an autoimmune cause. Immunological and specific second- or third-level investigations including immunohistochemistry should be included in the diagnostic work up of patients with FIRES-like phenotypes. PE could be effective in this subset of patients, protecting them from long-term neurological sequelae.

International Consensus Recommendations for the Treatment of Pediatric NMDAR Antibody Encephalitis

Objective

To create an international consensus treatment recommendation for pediatric NMDA receptor antibody encephalitis (NMDARE).

Methods

After selection of a panel of 27 experts with representation from all continents, a 2-step Delphi method was adopted to develop consensus on relevant treatment regimens and statements, along with key definitions in pediatric NMDARE (disease severity, failure to improve, and relapse). Finally, an online face-to-face meeting was held to reach consensus (defined as ≥75% agreement).

Results

Corticosteroids are recommended in all children with NMDARE (pulsed IV preferred), with additional IV immunoglobulin or plasma exchange in severe patients. Prolonged first-line immunotherapy can be offered for up to 3–12 months (oral corticosteroids or monthly IV corticosteroids/immunoglobulin), dependent on disease severity. Second-line treatments are recommended for cases refractory to first-line therapies (rituximab preferred over cyclophosphamide) and should be considered about 2 weeks after first-line initiation. Further immunotherapies for refractory disease 1-3 months after second-line initiation include another second-line treatment (such as cyclophosphamide) and escalation to tocilizumab. Maintenance immune suppression beyond 6 months (such as rituximab redosing or mycophenolate mofetil) is generally not required, except for patients with a more severe course or prolonged impairments and hospitalization. For patients with relapsing disease, second-line and prolonged maintenance therapy should be considered. The treatment of NMDARE following herpes simplex encephalitis should be similar to idiopathic NMDARE. Broad guidance is provided for the total treatment duration (first line, second line, and maintenance), which is dictated by the severity and clinical course (i.e., median 3, 9 and 18 months in the best, average, and worst responders, respectively). Recommendations on the timing of oncologic searches are provided.

Conclusion

These international consensus recommendations for the management of pediatric NMDARE aim to standardize the treatment and provide practical guidance for clinicians, rather than absolute rules. A similar recommendation could be applicable to adult patients.

Therapeutic plasma exchange in clinical pediatric neurology practice: Experience from a tertiary referral hospital

OBJECTIVE

This study aims to retrospectively evaluate the long-term efficacy, tolerability, and safety of therapeutic plasma exchange (TPE) in children with various neuroimmunological disorders.

METHODS

This analysis was a single-center, retrospective cohort study of pediatric patients with neuroimmunological events undergoing TPE procedures in a tertiary referral center.

RESULTS

There were 23 patients, 14 boys (60.9%), aged at diagnosis onset 8 months to 16.8 years. The main indications of TPE were Guillain-Barré syndrome (GBS, n = 8), autoimmune encephalitis (n = 5), febrile infection-related epilepsy syndrome (FIRES, n = 4), and acute disseminated encephalomyelitis (ADEM, n = 3). There was no life-threatening complication due to the TPE procedures. Eight (34.8%) of 23 patients experienced 13 (7%) complications in 186 TPE procedures, mostly electrolyte disturbances (n = 5). None of patients discontinued TPE due to complications. Two (8.7%) of 23 patients had marked improvement, 6 (26.1%) had moderate and 11 (47.8%) had mild improvement after TPE. The last follow-up visit revealed neurological sequelae in 12 (52.2%) patients. Therapeutic plasma exchange was found to be more effective on GBS, autoimmune encephalitis and myasthenia gravis, less effective on ADEM and FIRES. There was no correlation between improvement with TPE and clinical parameters, including age, sex, diagnosis, disease duration before TPE, presence of intubation, and length of stay in the intensive care unit and hospital.

CONCLUSION

Therapeutic plasma exchange was found to be effective and well-tolerated in children with various types of neuroimmunological disorder, with at least mild improvement in approximately 80% of the patients and no life-threatening complications.

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.

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.