Immune mediated diseases and immune modulation in the neurocritical care unit

Real-world application of plasmapheresis for neurological disease: Results from the Japan-Plasmapheresis Outcome and Practice Patterns Study

INTRODUCTION

Plasmapheresis is a well-recognized treatment for autoimmune neurological diseases in Japan. However, the practice varies depending on the facility, and the actual treatment conditions are unclear.

METHODS

To clarify real-world conditions, a prospective observational study was conducted on patients with neurological diseases who were scheduled to receive plasmapheresis. A dataset was analyzed that included 887 treatments from 210 patients with myasthenia gravis (MG), multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and other diseases for 82, 30, 24, and 74 patients, respectively.

RESULTS

The types of plasmapheresis performed included immunoadsorption plasmapheresis, plasma exchange, and double filtration plasmapheresis with 620, 213, and 54 treatments, respectively. Approximately, 60% of the treatments were performed using peripheral blood access alone. Non-serious adverse events were observed in 10 patients.

CONCLUSIONS

A statistically significant improvement was observed after plasmapheresis in patients with MG, MS, and NMOSD. These were evaluated using the modified Rankin Scale.

Autoimmune Neurologic Emergencies

Over the past decade, understanding of autoimmune neurologic disorders has exponentially increased. Many patients present as a neurologic emergency and require timely evaluation with rapid management and intensive care. However, the diagnosis is often either missed or delayed, which may lead to a significant burden of disabling morbidity and even mortality. A high level of suspicion in the at-risk population should be maintained to facilitate more rapid diagnosis and prompt treatment. At present, there is no all-encompassing algorithm specifically applicable to the management of fulminant autoimmune neurologic disorders. This article discusses manifestations and management of various autoimmune neurologic emergencies.

Seronegative Paraneoplastic Limbic Encephalitis Associated with Thymoma

Paraneoplastic limbic encephalitis is an autoimmune syndrome characterized by the acute or subacute onset of encephalopathy, memory loss, confusion, temporal lobe seizures, and behavioral and mood changes. Although most patients with paraneoplastic limbic encephalitis have antineuronal antibodies, advances in the field now permit the diagnosis without autoantibody test results. In this case illustrating the new diagnostic criteria, we report a 70-year-old woman who was brought to the emergency room after the acute onset of cognitive impairment, altered mental status, and choreoathetoid movements. Brain magnetic resonance imaging showed hyperintense signals in both temporal lobes, and a chest computed tomogram revealed a thymoma. Because the patient met current diagnostic criteria for autoimmune limbic encephalitis, we were able to start treatment before her antibody tests were processed. The patient received immunotherapy and her tumor was resected. Her choreoathetoid movements disappeared and her other neurologic symptoms improved. Her cerebrospinal fluid proved to be negative for paraneoplastic limbic encephalitis antibodies. Most but not all patients with paraneoplastic limbic encephalitis associated with thymoma have evidence of paraneoplastic antibodies. Prompt management of the underlying malignancy determines whether patients survive and may minimize future cognitive and functional impairment. Practicing neurologists and psychiatrists should be aware of this diagnosis.

Intravenous immunoglobulins for refractory status epilepticus, part I: A scoping systematic review of the adult literature

PURPOSE

Our goal was to perform a scoping systematic review of the literature on the use of intravenous immunoglobulins (IVIG) for refractory status epilepticus (RSE) in adults.

METHOD

Articles from MEDLINE, BIOSIS, EMBASE, Global Health, Healthstar, Scopus, Cochrane Library, the International Clinical Trials Registry Platform, clinicaltrials.gov (inception to May 2016), reference lists of relevant articles, and gray literature were searched. The strength of evidence was adjudicated using both the Oxford and GRADE methodology by two independent reviewers.

RESULTS

Twenty-four original articles were identified. A total of 33 adult patients were described as receiving IVIG for RSE. Seizure reduction/control with IVIG occurred in 15 of the 33 patients (45.4%), with 1 (3.0%) and 14 (42.4%) displaying partial and complete responses respectively. No adverse events were recorded.

CONCLUSION

Oxford level 4, GRADE D evidence exists to suggest an unclear impact of IVIG therapy in adult RSE. Routine use of IVIG in adult RSE cannot be recommended at this time.

Cost-minimization analysis comparing intravenous immunoglobulin with plasma exchange in the management of patients with myasthenia gravis

INTRODUCTION

Myasthenia gravis (MG) exacerbations may be treated with intravenous immunoglobulin (IVIg) or plasma exchange (PLEX), which have equivalent effectiveness. This cost-minimization analysis compared IVIg with PLEX for treatment of patients with MG exacerbation.

METHODS

We combined the Ontario-based health cost data with clinical data from a randomized clinical trial. Analyses were undertaken from the perspective of a public healthcare insurer and from the perspective of a tertiary university hospital payer.

RESULTS

PLEX was less costly than IVIg among patients with a body mass index (BMI) > 15.7 kg/m(2) , from the perspective of the public healthcare insurer (P < 0.0001). However, PLEX was more costly than IVIg from the perspective of the hospital payer when the costs of blood products were excluded (P < 0.0001).

CONCLUSIONS

PLEX can be considered a short-term cost-minimizing therapy when compared with IVIg for treatment of MG exacerbation among patients with BMI >15.7 kg/m(2) , from the perspective of a public healthcare insurer. Muscle Nerve 53: 872-876, 2016.

Removal kinetics of antibodies against glutamic acid decarboxylase by various plasmapheresis modalities in the treatment of neurological disorders

Plasmapheresis is one of the acute treatment modalities for neurological disorders associated with antibodies against glutamic acid decarboxylase (anti-GAD). However, there is little information about the removal kinetics of anti-GAD by various plasmapheresis modalities. Here, we investigated the removal rate of anti-GAD and fibrinogen (Fib) by immunoadsorption (IA), plasma exchange using a conventional plasma separator (OP-PE), and plasma exchange using a high cut-off selective membrane plasma separator (EC-PE) in two cases of anti-GAD-associated neurological diseases. In case 1, IA and OP-PE were used, and the percent reductions were as follows: anti-GAD: 38.2% and 69.1% and Fib: 67.7% and 68.2%, respectively. In case 2, OP-PE and EC-PE were used, and the percent reductions were as follows: anti-GAD: 65.8% and 48.5% and Fib: 68.5% and 19.8%, respectively. OP-PE could remove anti-GAD more efficiently than IA. Further, EC-PE could maintain coagulation factors such as Fib better than IA and OP-PE. It is important to select the appropriate plasmapheresis modality on the basis of the removal kinetics.

Is dosing of therapeutic immunoglobulins optimal? A review of a three-decade long debate in europe

The consumption of immunoglobulins (Ig) is increasing due to better recognition of antibody deficiencies, an aging population, and new indications. This review aims to examine the various dosing regimens and research developments in the established and in some of the relevant off-label indications in Europe. The background to the current regulatory settings in Europe is provided as a backdrop for the latest developments in primary and secondary immunodeficiencies and in immunomodulatory indications. In these heterogeneous areas, clinical trials encompassing different routes of administration, varying intervals, and infusion rates are paving the way toward more individualized therapy regimens. In primary antibody deficiencies, adjustments in dosing and intervals will depend on the clinical presentation, effective IgG trough levels and IgG metabolism. Ideally, individual pharmacokinetic profiles in conjunction with the clinical phenotype could lead to highly tailored treatment. In practice, incremental dosage increases are necessary to titrate the optimal dose for more severely ill patients. Higher intravenous doses in these patients also have beneficial immunomodulatory effects beyond mere IgG replacement. Better understanding of the pharmacokinetics of Ig therapy is leading to a move away from simplistic "per kg" dosing. Defective antibody production is common in many secondary immunodeficiencies irrespective of whether the causative factor was lymphoid malignancies (established indications), certain autoimmune disorders, immunosuppressive agents, or biologics. This antibody failure, as shown by test immunization, may be amenable to treatment with replacement Ig therapy. In certain immunomodulatory settings [e.g., idiopathic thrombocytopenic purpura (ITP)], selection of patients for Ig therapy may be enhanced by relevant biomarkers in order to exclude non-responders and thus obtain higher response rates. In this review, the developments in dosing of therapeutic immunoglobulins have been limited to high and some medium priority indications such as ITP, Kawasaki' disease, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, myasthenia gravis, multifocal motor neuropathy, fetal alloimmune thrombocytopenia, fetal hemolytic anemia, and dermatological diseases.

Imaging and clinical properties of inflammatory demyelinating pseudotumor in the spinal cord

Inflammatory demyelinating pseudotumor usually occurs in the brain and rarely occurs in the spinal cord. On imaging, inflammatory demyelinating pseudotumor appears very similar to intramedullary tumors such as gliomas. It is often misdiagnosed as intramedullary tumor and surgically resected. In view of this, the clinical and magnetic resonance imaging manifestations and the pathological fea-tures of 36 cases of inflammatory demyelinating pseudotumor in the spinal cord were retrospec-tively analyzed and summarized. Most of these cases suffered from acute or subacute onset and exhibited a sensorimotor disorder. Among them, six cases were misdiagnosed as having intra-dullary gliomas, and inflammatory demyelinating pseudotumor was only identified and pathologi-cally confirmed after surgical resection. Lesions in the cervical and thoracic spinal cord were com-mon. Magnetic resonance imaging revealed edema and space-occupying lesions to varying grees at the cervical-thoracic junction, with a predominant feature of non-closed rosette-like forcement (open-loop sign). Pathological examination showed perivascular cuffing of predominantly dense lymphocytes, and demyelination was observed in six of the misdiagnosed cases. These re-sults suggest that tumor-like inflammatory demyelinating disease in the spinal cord is a kind of special demyelinating disease that can be categorized as inflammatory pseudotumor. These solitary lesions are easily confused with intramedullary neoplasms. Patchy or non-closed reinforcement (open-ring sign) on magnetic resonance imaging is the predominant property of inflammatory myelinating pseudotumor, and inflammatory cell infiltration and demyelination are additional pa-logical properties.