Neuroimmunological Disorders Research Articles

Tryptophan-immunoadsorption plasmapheresis regulates polymorphonuclear-myeloid-derived suppressor cells and pro-inflammatory cytokines.

Immunoadsorption plasmapheresis (IA) has been reported to have immunoregulatory effects, in addition to the removal of autoantibodies. This study aimed to investigate the effects of IA on the proportion of myeloid-derived suppressor cells (MDSCs) that potentially suppress autoimmune responses and regulate immunity. The study included 21 patients with autoimmune neurological diseases and 8 healthy participants. We measured polymorphonuclear (PMN)-MDSCs (CD14-CD11b+CD33+) and inflammation-related mediators before and after a single session of tryptophan-IA. We also investigated whether an increase in PMN-MDSCs after initial IA was a predictor of clinical efficacy in nine patients with myasthenia gravis based on the Quantitative Myasthenia Gravis score. For a total of 36 times of IA procedures, the number of PMN-MDSCs significantly increased after IA. Interleukin-10, monocyte chemoattractant protein-1 and macrophage inflammatory protein-1β levels showed significant increases after IA. Despite similar severity at admission, the Quantitative Myasthenia Gravis scores at discharge were significantly lower in the group in which IA increased PMN-MDSCs to a level of 20% of peripheral blood mononuclear cells or more. Tryptophan-IA regulates PMN-MDSCs and pro-inflammatory cytokines, possibly leading to suppression of autoimmune responses and tissue damage in neuroimmunological disorders.

Nano-based approaches for the treatment of neuro-immunological disorders: a special emphasis on multiple sclerosis

Nano-based approaches for the treatment of neuro-immunological disorders: a special emphasis on multiple sclerosis

Sleep and neuroimmunology: a narrative review.

Numerous neuroimmunological disorders present with sleep-related symptoms. The identification of novel autoantibodies introduces new clinical categories in autoimmune diseases of the central nervous system and generates interest in the dynamic interaction between sleep and the immune system. In this review, the complex relationship among sleep, immune regulation, and neuroimmunological disorders was examined with emphasis on the vital role of sleep in modulating immune function and its influence on these conditions, This relationship emphasizes the importance of assessments and management of sleep quality in the treatment approaches for neuroimmunological disorders.

The PNS Nurse Program: A Health Care Support Concept for Patients With Immune-Mediated Peripheral Nervous System Diseases.

Immune-mediated peripheral nervous system (PNS) disorders pose diagnostic and therapeutic challenges, necessitating collaborative, patient-centered care. Limited access to specialized centers leads to delayed diagnosis and care, as seen during the COVID-19 pandemic. To address these challenges, accessible specialized care is crucial. On-site support plays a vital role in advising and assisting patients and caregivers, enabling multidisciplinary care for PNS diseases. The PNS Nurse Education Program tackles these complexities, using specialized nurses experienced in multiple sclerosis and Parkinson disease. Focusing on peripheral neuroimmunologic disorders, PNS nurses monitor disease severity, optimize communication, and provide therapeutic support in the recently started era of available immunotherapies. Collaboration with other healthcare sectors and support groups further enhances patient care. Ultimately, the PNS Nurse Education Program aims to bridge the gap between complex treatments and limited specialized care, improving patient outcomes and relieving burdens on patients, caregivers, and healthcare systems.

Single-center Experience of Therapeutic Plasma Exchange in Children with Neuroimmunological Disorders: Indications, Efficacy, and Safety

Single-center Experience of Therapeutic Plasma Exchange in Children with Neuroimmunological Disorders: Indications, Efficacy, and Safety

Evaluation of SARS-CoV-2 Vaccine-Induced Antibody Responses in Patients with Neuroimmunological Disorders: A Real-World Experience.

This study evaluates the antibody responses to SARS-CoV-2 vaccines in patients with neuroimmunological disorders (pwNID) who are receiving immunomodulating treatments, compared to healthy individuals. It included 25 pwNID with conditions such as optic neuritis, neuromyelitis optica spectrum disorder, multiple sclerosis, myasthenia gravis, and polymyositis, as well as 56 healthy controls. All participants had completed their full SARS-CoV-2 vaccination schedule, and their blood samples were collected within six months of their last dose. The concentration of anti-SARS-CoV-2 IgG antibodies was measured using an enzyme-linked immunosorbent assay. The results showed that pwNID had significantly lower antibody titers (58.4 ± 49.2 RU/mL) compared to healthy individuals (81.7 ± 47.3 RU/mL). This disparity persisted even after adjusting for age and the interval between the final vaccination and sample collection. A notable correlation was found between the use of immunomodulating treatments and reduced antibody levels, whereas mRNA vaccines were linked to higher antibody concentrations. The conclusion of this study is that immunomodulating treatments may reduce the effectiveness of SARS-CoV-2 vaccines in pwNID. This insight is crucial for healthcare providers in designing vaccination strategies and managing treatment plans for pwNID on immunomodulating therapies, highlighting the need for personalized approaches in this subgroup.

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.

Effects of Denosumab and Bisphosphonates on Glucocorticoid-induced Osteoporosis in Patients with Neuroimmunological Disorders.

Objective Although patients with neuroimmunological disorders often need to be treated with glucocorticoids and are at risk of developing glucocorticoid-induced osteoporosis, no research has focused on the treatment of glucocorticoid-induced osteoporosis in such patients. Methods We compared the efficacy of denosumab and bisphosphonates in glucocorticoid-induced osteoporosis in neuroimmunological diseases. In 57 patients with neuroimmunological disorders treated with corticosteroids (34 with neuromyelitis optica spectrum disorders, 16 with myasthenia gravis, and 7 with others), we retrospectively studied the long-term effects of denosumab (n=23) and bisphosphonates (n=34) on spine and total hip bone mineral density (BMD) measured by dual energy X-ray absorptiometry. Results There were no significant differences in the age, lumbar spine BMD, or mean dose or duration of prednisolone administration at baseline between the denosumab and bisphosphonate groups. During the follow-up period of up to 6 years, the increase in the lumbar spine and total hip BMD was greater in the denosumab group than in the bisphosphonate group (p<0.01). Insufficient bone fractures were observed in 2 (9%) of the 23 patients in the denosumab group and in 2 (6%) of the 34 patients in the bisphosphonate group (not significant). Conclusion Denosumab is more effective than bisphosphonates in increasing the BMD of patients with neuroimmunological disorders receiving glucocorticoids.

Efficacy and Safety of Therapeutic Plasma Exchange in Children with Neuroimmunological Disorders: A Limited Unicentral Study.

Therapeutic plasma exchange (TPE) is a plasmapheresis procedure whose Safety data for pediatric neuro-immunological disorders (PNID) is confined. The present research documents TPE's safety and feasibility data in these conditions. The current study involved six distinct groups of patients with PNID undergoing TPE: neuromyelitis optic spectrum disorder (NMOSD), autoimmune encephalitis (AIE), acute disseminated encephalomyelitis (ADEM), multiple sclerosis (MS), Guillain-Barre syndrome (GBS), and optic neuritis (ON). This study documented complications related to each TPE process. In addition, TPE's efficacy was studied in these patients. The present study recorded adverse effects in 18 patients with PNID that received 121 TPE cycles: five cycles (4.13%) in MS, three (2.48%) in AIE subgroup, one (0.82%) in ADEM, and two (1.65%) in GBS. No severe complications were observed among the patients. Patients with PNID tolerated therapeutic plasma exchange, which was a safe process.

Examining the Features of Neuroleptic Malignant Syndrome in Anti-NMDA Receptor Encephalitis: A Case-Control Study

Anti-N-methyl-D-aspartate receptor encephalitis (ANMDARE) is a neuroimmunological disorder that frequently improves with immunotherapy. Symptomatic treatment with antipsychotics is common in the early stages when psychiatric symptoms predominate, and their use has been associated with serious side effects including neuroleptic malignant syndrome (NMS). The observation of an adverse response to antipsychotics, raising the suspicion of NMS, has been included as a criterion for possible autoimmune psychosis. This case-control study included patients who received antipsychotics before referral to the National Institute of Neurology and Neurosurgery of Mexico, where they were diagnosed as having definite ANMDARE, and patients with ANMDARE who did not receive antipsychotics before referral. The neurologic and systemic features that are used to measure an adverse response to antipsychotics, raising the suspicion of NMS, were measured in both groups, including akinesia, autonomic instability, generalized rigidity, elevated concentrations of creatine phosphokinase, and hyperthermia. A logistic regression analysis was used to determine the relationship between the previous use of antipsychotics and the occurrence of NMS-like reactions. A total sample of 112 patients with definite ANMDARE were included in the study. Fifty patients received antipsychotics before being referred to our institution. In this group, thirty-six patients (72%) were initially classified as having an adverse response, raising the suspicion of NMS, with the following features: akinesia (64%), autonomic instability (58%), generalized rigidity (52%), elevated concentrations of creatine phosphokinase (50%), and hyperthermia (14%). Six patients fulfilled the criteria for NMS (12%). The comparison with patients who did not receive antipsychotics before the clinical assessment did not show a significant difference between groups regarding the frequency of akinesia, autonomic instability, generalized rigidity, elevated concentrations of creatine phosphokinase, or hyperthermia. Among different antipsychotics, only haloperidol was significantly associated with generalized rigidity as compared to patients who did not receive antipsychotics. Our study supports previous observations about the high frequency of autonomic dysfunction, hyperthermia, tachycardia, rigidity, and elevated creatine phosphokinase levels in patients with anti-NMDAR encephalitis following the administration of antipsychotic medications. Nevertheless, our study does not suggest a causal link between atypical antipsychotics and the onset of these neurological symptoms, as they were equally frequent among the group of patients who did not receive antipsychotic treatment.

Antibody induced seizure susceptibility and impaired cognitive performance in a passive transfer rat model of autoimmune encephalitis.

Autoimmune encephalitis (AE) is a distinct neuro-immunological disorder associated with the production of autoantibodies against neuronal proteins responsible for pharmacoresistant seizures, cognitive decline and behavioral problems. To establish the causal link between leucine-rich glioma inactivated 1 (LGI1) antibody and seizures, we developed an in-vivo antibody-mediated AE rat model in which serum antibodies (IgG) obtained from blood samples of leucine-rich glioma inactivated 1 (LGI1) protein antibody (IgG) positive encephalitis patients were passively transferred into non-epileptic Wistar rats. Serum IgG of N-methyl-d-aspartate receptor (NMDAR) antibody positive patients were used as positive control since the pathogenicity of this antibody has been previously shown in animal models. Total IgG obtained from the pooled sera of NMDAR and LGI1-IgG positive patients with epileptic seizures and healthy subjects was applied chronically every other day for 11 days into the cerebral lateral ventricle. Spontaneous seizure development was followed by electroencephalography. Behavioral tests for memory and locomotor activity were applied before and after the antibody infusions. Then, pentylenetetrazol (PTZ) was administered intraperitoneally to evaluate seizure susceptibility. Immunohistochemistry processed for assessment of hippocampal astrocyte proliferation and expression intensity of target NMDAR and LGI1 antigens. No spontaneous activity was observed during the antibody infusions. PTZ-induced seizure stage was significantly higher in the NMDAR-IgG and LGI1-IgG groups compared to control. Besides, memory deficits were observed in the NMDAR and LGI1-IgG groups. We observed enhanced astrocyte proliferation in NMDAR- and LGI1-IgG groups and reduced hippocampal NMDAR expression in NMDAR-IgG group. These findings suggest that neuronal surface auto-antibody administration induces seizure susceptibility and disturbed cognitive performance in the passive transfer rat model of LGI1 AE, which could be a potential in-vivo model for understanding immune-mediated mechanisms underlying epileptogenesis and highlight the potential targets for immune-mediated seizures in AE patients.

Sleep Disturbances in Autoimmune Neurological Diseases.

To summarize the current evidence on the associations between autoimmune neurological diseases (e.g., multiple sclerosis, myasthenia gravis) and sleep disturbances (e.g., insomnia, parasomnias), as well as to review the main characteristics of sleep disorders with an immune-related pathophysiology (e.g., narcolepsy, anti-IgLON5 disease). An immune-mediated damage of the areas in the central nervous system that control sleep and wake functions (e.g., hypothalamus, brainstem) can lead to sleep disorders and sleep symptoms. Sleep disturbances are the reason to seek for medical attention in certain neuroimmunological conditions (e.g., narcolepsy, anti-IgLON5 disease) where sleep-related alterations are the main clinical feature. The assessment of sleep-related symptomatology and disorders should be included in the routine evaluation of patients with autoimmune neurological diseases. Clinicians should be aware of the typical clinical presentation of certain neuroimmunological disorders mainly affecting sleep.

Neuroinflammatory disorders of the brain and inner ear: a systematic review of auditory function in patients with migraine, multiple sclerosis, and neurodegeneration to support the idea of an innovative 'window of discovery'.

Hearing can be impaired in many neurological conditions and can even represent a forme fruste of specific disorders. Auditory function can be measured by either subjective or objective tests. Objective tests are more useful in identifying which auditory pathway (superior or inferior) is most affected by disease. The inner ear's perilymphatic fluid communicates with the cerebrospinal fluid (CSF) via the cochlear aqueduct representing a window from which pathological changes in the contents of the CSF due to brain inflammation could, therefore, spread to and cause inflammation in the inner ear, damaging inner hair cells and leading to hearing impairment identifiable on tests of auditory function. A systematic review of the literature was performed, searching for papers with case-control studies that analyzed the hearing and migraine function in patients with neuro-inflammatory, neurodegenerative disorders. With data extracted from these papers, the risk of patients with neurological distortion product otoacoustic emission (DPOAE) was then calculated. Patients with neurological disorders (headache, Parkinson's disease, and multiple sclerosis) had a higher risk of having peripheral auditory deficits when compared to healthy individuals. Existing data lend credence to the hypothesis that inflammatory mediators transmitted via fluid exchange across this communication window, thereby represents a key pathobiological mechanism capable of culminating in hearing disturbances associated with neuroimmunological and neuroinflammatory disorders of the nervous system.

Rituximab Treatment for Neuroimmunologic Disorders

Rituximab is a monoclonal chimeric antibody that targets CD20, which is expressed on the surface of B cells ranging from pre-B cells to mature B cells; rituximab treatment leads to depletion of B cells. It is widely used to treat various autoimmune neurological diseases including neuromyelitis optica spectrum disorder, multiple sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyradiculoneuropathy, and autoimmune encephalitis. When administering rituximab for treatment, it is essential to consider potential adverse reactions, such as hypersensitivity, infection, and hypogammaglobulinemia, and to monitor B cell levels regularly to maintain the efficacy of treatment and prevent relapse. This review aims to explore the treatment of neuroimmunologic disorders with rituximab.

Identifying Key Components for Diagnosing Stiff Person Syndrome Spectrum Disorders: A Sensitivity and Specificity Study (P4-5.018)

<h3>Objective:</h3> To evaluate the sensitivity and specificity of clinical and paraclinical features of stiff person syndrome spectrum disorders (SPSD) to help aid in their diagnosis. <h3>Background:</h3> SPSD are a group of rare, disabling neuroimmunological disorders. SPSD is often challenging to diagnose since it can be insidious in nature and hallmark symptoms and signs are not readily identified by clinicians. Moreover, there is limited data on which clinical feature(s) and diagnostic test(s) are most helpful in making a diagnosis of SPSD. <h3>Design/Methods:</h3> The Johns Hopkins SPS center’s longitudinal observational database was used, which contains clinical characteristics, and diagnostic studies of people with SPSD. Patients with a diagnosis of either Classic SPS or SPS-plus phenotypes were compared to patients who were evaluated for SPSD but received an alternative diagnosis (control group). Each clinical and paraclinical feature important for a diagnosis of SPSD was evaluated for its sensitivity and specificity, and used to define its diagnostic odds ratio. <h3>Results:</h3> A total of 161 Classic SPS cases, 45 SPS-plus cases, and 66 controls were included. The most sensitive findings for classic SPS included clinical involvement of the lower extremities (98.1%), stress as a trigger for physical symptoms (96.8%), paravertebral stiffness/tightness (95.7%), and abnormal gait (91.4%). The most specific findings for SPS included characteristic EMG findings (98.3%), a high GAD65 antibody titer defined as &gt;1000IU/mL and/or &gt;20nmol/L (98.2%), and the presence of hyperlordosis on examination (87.1%). For SPS-plus, cerebellar and brainstem involvement were also highly specific (98.5% and 100%, respectively) as were the aforementioned paraclinical tests. Analyses are ongoing to assess whether major and minor criterion can be developed for a more accurate diagnosis leveraging the above data. <h3>Conclusions:</h3> This study identified key clinical and paraclinical tests that can help enhance diagnostic accuracy of SPSD. Further studies can help validate these findings and inform development of revised diagnostic criteria. <b>Disclosure:</b> Dr. Roy has nothing to disclose. Miss Hu has nothing to disclose. The institution of Dr. Wang has received research support from Genentech. The institution of Dr. Fitzgerald has received research support from NIH. The institution of Dr. Fitzgerald has received research support from National MS Society. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Autobahn. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Newsome has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Genentech. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for EMD Serono. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Greenwich Biosciences. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Bristol Myers Squibb. Dr. Newsome has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Horizon Therapeutics. The institution of Dr. Newsome has received research support from Biogen. The institution of Dr. Newsome has received research support from Genentech/Roche. The institution of Dr. Newsome has received research support from Department of Defense. The institution of Dr. Newsome has received research support from Patient Centered Outcomes Research Institute. The institution of Dr. Newsome has received research support from National MS Society. The institution of Dr. Newsome has received research support from The Stiff Person Syndrome Research Foundation. Dr. Newsome has received personal compensation in the range of $5,000-$9,999 for serving as a Clinical adjudication committee member for clinical trial with medDay Pharmaceuticals. Dr. Newsome has received personal compensation in the range of $10,000-$49,999 for serving as a Lead PI for Clinical Trial with Roche.

Distinct Etiologies of RANBP2-negative Acute Necrotizing Encephalopathy of Childhood (P10-9.008)

<h3>Objective:</h3> We sought to determine the etiology of <i>RANBP2</i>-negative pediatric patients presenting with acute necrotizing encephalopathy of childhood (ANEC). <h3>Background:</h3> ANEC is a rare childhood syndrome associated with fulminant encephalopathy and characteristic neuroimaging typically precipitated by acute infection and often associated with heterozygous mutation in <i>RANBP2</i>. Additional genes implicated in ANEC include <i>CPT2, MC1DN1</i> and <i>ILAE4</i>, yet many patients who meet clinical criteria for ANEC do not have mutations in any known genes and the cause of these cases has remained cryptic. <h3>Design/Methods:</h3> We performed a multicenter trio-based whole exome analysis of 12 <i>RANBP2</i>-negative pediatric patients diagnosed with ANEC using our established pipeline and filtering criteria. Whole exome sequencing was performed using a TruSeq exome capture kit and run on an Illumina NovaSeq 6000. Fastq files were analyzed using our established GATK-based pipeline and filtered for rare variants using our published approach. We prioritized rare candidate genes to determine plausible candidates based on the existing literature. <h3>Results:</h3> 32 candidate genes survived filtering and were considered in our analysis. We identified three high-confidence candidate genes. The first was <i>SCN1A</i>, segregating a heterozygous <i>de novo</i> (p.F1765Cfs*28). SCN1A encodes a voltage-gated sodium channel subunit. Mutations in SCN1A are well-known causes of Dravet Syndrome and other forms of epilepsy, but have also been associated with a fulminant encephalopathy phenotype independent of seizure burden. The second was <i>TNFAIP3</i> (heterozygous <i>de novo</i> p.R728C), previously shown to lead to an autoinflammatory Behcet-like syndrome. The third was <i>PRF1</i> (homozygous p.R225W), associated with a hemophagocytic lymphocystiocytosis-like phenotype with encephalopathy, ataxia, deep white matter lesions, and increased intracranial pressure. <h3>Conclusions:</h3> Our study indicates that ANEC is genetically heterogeneous and highlights three additional genes that should be considered in individuals presenting with ANEC. Our results also showcase how monogenic conditions can impact immune system regulation and lead to neuroimmunologic disorders. <b>Disclosure:</b> Dr. Vaidyanathan has nothing to disclose. Somayeh Bakhtiari has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant for Xilis Inc. Somayeh Bakhtiari has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant (Bioinformatics) with Phoenix Childrens Hospital. Dr. Appavu has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Natus. The institution of Dr. Appavu has received research support from American Heart Association. The institution of Dr. Appavu has received research support from United States Department of Defense. Derek Neilson has nothing to disclose. The institution of Dr. Kruer has received research support from NIH NINDs. Dr. Kruer has received research support from Cure CP. Dr. Kruer has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant with NHRSA.

Central Nervous System Neuroimmunologic Complications of COVID-19.

Autoimmune disorders of the central nervous system following COVID-19 infection include multiple sclerosis (MS), neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, autoimmune encephalitis, acute disseminated encephalomyelitis, and other less common neuroimmunologic disorders. In general, these disorders are rare and likely represent postinfectious phenomena rather than direct consequences of the SARS-CoV-2 virus itself. The impact of COVID-19 infection on patients with preexisting neuroinflammatory disorders depends on both the disorder and disease-modifying therapy use. Patients with MS do not have an increased risk for severe COVID-19, though patients on anti-CD20 therapies may have worse clinical outcomes and attenuated humoral response to vaccination. Data are limited for other neuroinflammatory disorders, but known risk factors such as older age and medical comorbidities likely play a role. Prophylaxis and treatment for COVID-19 should be considered in patients with preexisting neuroinflammatory disorders at high risk for developing severe COVID-19.

Immunomodulatory Aspects of Therapeutic Plasma Exchange in Neurological Disorders—A Pilot Study

Therapeutic plasma exchange (TPE) is used for drug-resistant neuroimmunological disorders, but its mechanism of action remains poorly understood. We therefore prospectively explored changes in soluble, humoral, and cellular immune components associated with TPE. We included ten patients with neurological autoimmune disorders that underwent TPE and assessed a panel of clinically relevant pathogen-specific antibodies, total serum immunoglobulin (Ig) levels, interleukin-6 (IL-6, pg/mL), C-reactive protein (CRP, mg/dL), procalcitonin (PCT, µg/L) and major lymphocyte subpopulations (cells/µL). Blood was collected prior to TPE (pre-TPE, baseline), immediately after TPE (post-TPE), as well as five weeks (follow-up1) and 130 days (follow-up2) following TPE. Pathogen-specific antibody levels were reduced by -86% (p < 0.05) post-TPE and recovered to 55% (follow-up1) and 101% (follow-up2). Ig subclasses were reduced by -70-89% (p < 0.0001) post-TPE with subsequent complete (IgM/IgA) and incomplete (IgG) recovery throughout the follow-ups. Mean IL-6 and CRP concentrations increased by a factor of 3-4 at post-TPE (p > 0.05) while PCT remained unaffected. We found no alterations in B- and T-cell populations. No adverse events related to TPE occurred. TPE induced a profound but transient reduction in circulating antibodies, while the investigated soluble immune components were not washed out. Future studies should explore the effects of TPE on particular cytokines and assess inflammatory lymphocyte lineages to illuminate the mode of action of TPE beyond autoantibody removal.

Facilities, selection, outcome measurement, and limitations of therapeutic plasma exchange for neuroimmunological disorders: The South East Asian survey study.

Therapeutic plasma exchange (TPE) for neuroimmunological disorders has played an important role in the Southeast Asian region. This study investigates the challenges of performing TPE within the region. A questionnaire-based survey was conducted and launched to 15 South East Asian Therapeutic Plasma Exchange Consortium (SEATPEC) members from seven countries in January 2021. It included demographics, TPE techniques, indications, challenges, timing, outcome measurement, and access to laboratory testing in each local center. A total of 15 neurologists from 12 participating centers were included. They usually perform five sessions of TPE (100.0%), with 1 to 1.5 plasma volume (93.3%), and exchanges via the central catheter (100.0%). Acute relapses of neuromyelitis optica spectrum disorder and myasthenia gravis are the most common indications. They used a combination of normal saline and 5% albumin (60.0%) as replacement fluid. Most (66.7%) used TPE as an add-on treatment in steroid-refractory cases or as first-line treatment for severe attacks. They suggested assessing the TPE efficacy of TPE by the interval to the next attack, post-TPE relapse rates, and TPE-related complications. The major challenges within our region are expense, reimbursibility, and access to TPE. Although countrywise differences exist, all share similarities regarding methods, indications, timing, obstacles, and challenges of TPE for neuroimmunological conditions. Regional collaboration will be essential to identify strategies to reduce these barriers to access to TPE in the future.

Therapeutic plasma exchange in the management of stiff person syndrome spectrum disorders: a case series and review of the literature.

Stiff person syndrome spectrum disorders (SPSD) are a rare group of disabling neuroimmunological disorders. SPSD often requires immune therapies, especially in the setting of inadequate response to symptomatic treatments. The safety and efficacy of therapeutic plasma exchange (TPE) in SPSD remains uncertain. To describe the safety, tolerability, and efficacy of TPE in patients with SPSD. A retrospective observational study. A retrospective review of SPSD patients seen at Johns Hopkins Hospital (JHH) from 1997 to 2021 was performed. Patient demographics/history, examination/diagnostic findings, treatment response, and TPE-related complications were recorded. Assessment for any associations between clinical characteristics, including age, sex, clinical phenotype, and time on immunotherapy, and response to TPE 3 months after treatment was performed. A subgroup of 18 patients treated with TPE at JHH and 6 patients treated with TPE at outside institutions were evaluated for any change in usage of symptomatic medications 3 months after the TPE treatment. Literature review of SPSD and TPE was also conducted. Thirty-nine SPSD patients were treated with TPE (21 at JHH and 18 at outside institutions); median age 48 years, 77% female, median modified Rankin Scale 3; mean initial anti-GAD65 antibody titer was 23,508 U/mL. Twenty-four patients (62%) had classic SPS, 10 (26%) had SPS-plus, 2 (5%) had progressive encephalomyelitis with rigidity and myoclonus, and 3 (8%) had pure cerebellar ataxia. All patients were on symptomatic treatments, 30 (77%) previously received IVIg, and 3 (8%) previously received rituximab. Four patients (10%) had a TPE-related adverse event. One developed asymptomatic hypotension, another had both line thrombosis and infection, and two had non-life-threatening bleeding events. Twenty-three (59%) patients reported improvement in symptoms after TPE. Of the subgroup of 24 patients evaluated for any change in usage of symptomatic medications 3 months after the TPE treatment, 14 (58%) required fewer GABAergic symptomatic medications. Literature review identified 57 additional patients with SPSD; 43 (75%) reported temporary improvement after TPE. The majority of patients treated with TPE had improvement. Moreover, most patients evaluated for any change in usage of symptomatic medications after the TPE treatment no longer required as much symptomatic medications months after TPE. TPE appears safe and well-tolerated in SPSD. Further studies are needed to assess the long-term efficacy of TPE in SPSD and identify which patients may benefit the most from TPE.