Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis Complicated by Thrombotic Microangiopathy with Posterior Reversible Encephalopathy Syndrome Successfully Treated with Eculizumab: A Case Report

Thrombotic microangiopathy is characterised by endothelial cell injury, intravascular platelet-fibrin thrombi, and vascular damage, leading to acute kidney injury, thrombocytopenia, and microangiopathic haemolytic anaemia. Among the autoimmune diseases related to thrombotic microangiopathy, anti-neutrophil cytoplasmic antibody-associated vasculitis-related thrombotic microangiopathy cases have been rarely reported; therefore, the optimal treatment for associated vasculitis-related thrombotic microangiopathy remains unknown. An 84-year-old woman without significant medical history presented with a 1-month history of general fatigue, fever, and deteriorating bilateral leg numbness and was admitted to our hospital. She had elevated myeloperoxidase anti-neutrophil cytoplasmic antibody levels, polyneuropathy, and rapid progressive glomerulonephritis because of pauci-immune crescentic glomerulonephritis, as revealed by a kidney biopsy. Accordingly, we diagnosed her with microscopic polyangiitis. After administering methylprednisolone pulse therapy, rituximab, and intravenous immunoglobulin, the patient's mental state deteriorated, presenting signs of thrombotic microangiopathy with posterior reversible encephalopathy syndrome. Intermittent haemodialysis and plasma exchange were initiated; however, her condition was not improved, and eculizumab administration was initiated thereafter. The patient's symptoms showed a remarkable response to eculizumab; thrombotic microangiopathy findings, kidney function, and neurological symptoms improved after only two doses of eculizumab, and she achieved sustained remission. The extremely effective course of eculizumab treatment indicated that overt complement activation affected the development of thrombotic microangiopathy. Anti-neutrophil cytoplasmic antibody-associated vasculitis-related thrombotic microangiopathy may be mediated by complement activation, and prompt induction of eculizumab therapy may be a superior strategy to prevent organ damage. Further studies should elucidate the role of complement activation in associated vasculitis-related thrombotic microangiopathy and the efficacy of eculizumab treatment.

Posterior Reversible Encephalopathy Syndrome in Guillain-Barré Syndrome: Just a Problem of Immunoglobulins? Controversy From Two Atypical Case Reports

Background

Posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome (RCVS), or the coexistence of these two entities shares similar risk factors and clinical features. For these conditions, a common origin has been supposed. Even if the majority of patients show a favorable course and a good prognosis, a small percentage of cases develop neurological complications. Up to date, only about 30 cases of PRES associated with Guillain-Barré syndrome (GBS) have been reported in the literature.

Cases

Here, we present two cases of a particularly aggressive PRES/RCVS overlap syndrome, associated with acute motor axonal neuropathy (AMAN) and acute inflammatory demyelinating polyneuropathy (AIDP) variants of GBS, respectively, presenting with similar initial clinical aspects and developing both an atypical and unfavorable outcome. On MRI examination, the first patient showed typical aspects of PRES, while, in the second case, radiological features were atypical and characterized by diffusion restriction on the apparent diffusion coefficient (ADC) map. The first patient demonstrated rapid worsening of clinical conditions until death; the second one manifested and maintained neurological deficits with a permanent disability.

Conclusions

We suggest that PRES may conceal RCVS aspects, especially in most severe cases or when associated with a dysimmune syndrome in which autoimmune system and endothelial dysfunction probably play a prominent role in the pathogenesis. Although the role of IVIg treatment in the pathogenesis of PRES has been proposed, we suggest that GBS itself should be considered an independent risk factor in developing PRES.

Posterior reversible encephalopathy syndrome (PRES): diagnosis and management

Posterior reversible encephalopathy syndrome (PRES) may present with diverse clinical symptoms including visual disturbance, headache, seizures and impaired consciousness. MRI shows oedema, usually involving the posterior subcortical regions. Triggering factors include hypertension, pre-eclampsia/eclampsia, renal failure, cytotoxic agents and autoimmune conditions. The mechanism underlying PRES is not certain, but endothelial dysfunction is implicated. Treatment is supportive and involves correcting the underlying cause and managing associated complications, such as seizures. Although most patients recover, PRES is not always reversible and may be associated with considerable morbidity and even mortality.

Statin-Associated Necrotizing Autoimmune Myositis Complicated by an Uncommon Adverse Effect to Treatment

Statin-associated necrotizing autoimmune myositis (NAM) is an autoimmune condition characterized by severe acute-onset proximal muscle weakness, a very high creatinine kinase (CK) level, and prominent myofiber necrosis and minimal lymphocytic infiltration on muscle biopsy. Unlike self-limited statin myopathy, this condition usually requires aggressive immunomodulation therapy to assist recovery and prevent future disability. In this case report, we present a patient who developed progressive muscle weakness after taking atorvastatin for one year. At initial presentation, her CK level was 28,000 U/L. She was diagnosed with statin-associated NAM and started on high-dose intravenous solumedrol, mycophenolate, and intravenous immunoglobulin (IVIG) therapy. However, she subsequently developed acute bilateral vision loss and right side hemineglect; she was diagnosed with posterior reversible encephalopathy syndrome (PRES), thought to be a possible delayed adverse reaction to IVIG. IVIG was discontinued, and the patient was treated with supportive therapy. At six-month follow-up, she had significant improvement in muscle strength and vision.

Adverse Effects of Immunoglobulin Therapy

Immunoglobulin has been widely used in a variety of diseases, including primary and secondary immunodeficiency diseases, neuromuscular diseases, and Kawasaki disease. Although a large number of clinical trials have demonstrated that immunoglobulin is effective and well tolerated, various adverse effects have been reported. The majority of these events, such as flushing, headache, malaise, fever, chills, fatigue and lethargy, are transient and mild. However, some rare side effects, including renal impairment, thrombosis, arrhythmia, aseptic meningitis, hemolytic anemia, and transfusion-related acute lung injury (TRALI), are serious. These adverse effects are associated with specific immunoglobulin preparations and individual differences. Performing an early assessment of risk factors, infusing at a slow rate, premedicating, and switching from intravenous immunoglobulin (IVIG) to subcutaneous immunoglobulin (SCIG) can minimize these adverse effects. Adverse effects are rarely disabling or fatal, treatment mainly involves supportive measures, and the majority of affected patients have a good prognosis.

Intravenous immunoglobulin: pharmacological properties and use in polyneuropathies

INTRODUCTION

Intravenous immunoglobulin (IVIg) is increasingly used for the treatment of autoimmune and systemic inflammatory diseases with both licensed and off-label indications. The mechanism of action is complex and not fully understood, involving the neutralization of pathological antibodies, Fc receptor blockade, complement inhibition, immunoregulation of dendritic cells, B cells and T cells and the modulation of apoptosis. Areas covered: First, this review describes the pharmacological properties of IVIg, including the composition, mechanism of action, and adverse events. The second part gives an overview of some of the immune-mediated polyneuropathies, with special focus on the pathomechanism and clinical trials assessing the efficacy of IVIg. A literature search on PubMed was performed using the terms IVIg, IVIg preparations, side effects, mechanism of action, clinical trials, GBS, CIDP. Expert opinion: Challenges associated with IVIg therapy and the treatment possibilities for immune-mediated polyneuropathies are discussed. The availability of IVIg is limited, the expenses are high, and, in several diseases, a chronic therapy is necessary to maintain the immunomodulatory effect. The better understanding of the mechanism of action of IVIg could open the possibility of the development of disease-specific, targeted immune therapies.

Seizure outcomes of posterior reversible encephalopathy syndrome and correlations with electroencephalographic changes

RATIONALE

Seizures are among the most common clinical presentations of posterior reversible encephalopathy syndrome (PRES). This syndrome has rarely been reported to cause chronic epilepsy or persistent cortical dysfunction. The prognostic value of EEG findings during PRES is unknown. We retrospectively evaluated EEG characteristics in patients with PRES in a single medical center. We also evaluated the long-term outcome regarding seizure occurrence beyond the acute phase in these patients.

METHODS

We searched a radiology database at the University of Minnesota from 1997 to 2012 to identify patients with clinically and radiologically diagnosed PRES. Among the patients with PRES, we reviewed MRI images, EEG findings, clinical manifestations including seizure occurrences, and clinical outcomes beyond the acute phase.

RESULTS

Seventy-five patients were included in the study. Fifty-eight out of seventy-five (77.3%) patients with PRES had seizures. A total of 48 EEG studies were performed in 38 patients. Generalized slowing was the most common EEG pattern. Among the 38 patients who had EEGs, 37 (97.3%) patients had diffuse or focal slowing of the background, and 11 (28.9%) patients had IEDs. Four out of seventy-five (5.3%) patients had seizures later than one month beyond their hospitalization for PRES. None of these 4 patients had seizures before the episode of PRES. Two patients developed chronic epilepsy, with seizures occurring later than one year after the PRES.

CONCLUSION

Most patients who had seizures or who had epileptiform activities in EEG during PRES did not subsequently develop chronic epilepsy. No patient developed chronic epilepsy in the absence of clinical seizures during PRES. Posterior reversible encephalopathy syndrome may infrequently be associated with subsequent development of symptomatic epilepsy.

PRES in Children Undergoing Hematopoietic Stem Cell or Solid Organ Transplantation

Posterior reversible encephalopathy syndrome (PRES) is a clinical neuroradiologic entity that is becoming increasingly well known and documented in pediatrics. It is characterized by a variable association of seizures, headache, vomiting, altered mental status, visual disturbances, and seizures, as well as imaging suggesting white-gray matter edema involving the posterior regions of the central nervous system in most cases. The pathophysiology of PRES remains unclear. Although PRES has been associated with a widespread range of clinical conditions, namely infections, adverse drug events, autoimmune diseases, and many others, its onset after hematopoietic stem cell and solid organ transplantation remains the most commonly reported. Historically, PRES has proved to be generally reversible and associated with good clinical outcomes; however, severe complications, sometimes life-threatening, can also occur. Most reported cases of childhood PRES after hematopoietic stem cell or solid organ transplantation have been case reports or series across a broad spectrum of different transplant settings, and no clear consensus exists regarding how best to manage the syndrome. Thus, in this article, we provide a comprehensive review of the pathophysiological, clinical, and diagnostic aspects of PRES in children, with a specific focus on the transplant scenario. Differential diagnoses with other neurologic complications after pediatric transplantation are reviewed, and crucial issues in the management of PRES and the development of future research are ultimately addressed.

Toxic leukoencephalopathies

Leukoencephalopathy is a syndrome of neurologic deficits, including alteration of mental status, caused by pathologic changes in the cerebral white matter. The term, toxic leukoencephalopathy, encompasses a wide variety of exposures and clinical presentations. The diagnosis in these Frontiers in Clinical Neurotoxicology syndromes is made by careful attention to the history, clinical features, and radiologic findings. This article details three of the best-defined toxic leukoencephalopathies: delayed posthypoxic leukoencephalopathy, including delayed neurologic sequelae after carbon monoxide poisoning; heroin inhalation leukoencephalopathy; and posterior reversible encephalopathy syndrome.

Cortical blindness in a child with acute glomerulonephritis

The association between hypertensive encephalopathy and cortical blindness in children with acute glomerulonephritis is extremely rare. We report the case of a 9-year old girl who presented with headache, seizures, altered sensorium, hematuria, and transient cortical blindness as a complication of hypertensive encephalopathy which showed complete reversal following normalization of blood pressure and an underlying post-infectious acute glomerulonephritis was revealed.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual disturbances, and seizures. Radiological features typically include edema of the posterior cerebral regions, especially of the parietooccipital lobes. Atypical imaging features, such as involvement of anterior cerebral regions, deep white matter, and the brain stem are also frequently seen. Vasoconstriction is common in vascular imaging. Different conditions have been associated with PRES, but toxemia of pregnancy, solid organ or bone marrow transplantation, immunosuppressive treatment, cancer chemotherapy, autoimmune diseases, and hypertension are most commonly described. The pathophysiology of PRES is unclear and different hypotheses are being discussed. Posterior reversible encephalopathy syndrome is best managed by monitoring and treatment in the setting of a neurointensive care unit. The prognosis is usually benign with complete reversal of clinical symptoms within several days, when adequate treatment is immediately initiated. Treatment of severe hypertension, seizures, and withdrawal of causative agents represent the hallmarks of specific therapy in PRES. Delay in diagnosis and treatment may lead to permanent neurological sequelae. Therefore, awareness of PRES is of crucial importance for the intensivist.

Is passive immunization for Alzheimer's disease 'alive and well' or 'dead and buried'?

BACKGROUND

Passive immunization strategies are under investigation as potential disease-modifying therapies for Alzheimer's disease (AD). Current approaches, based on data demonstrating behavioral improvement and reduced pathology in transgenic animal models, have focused exclusively on immune targeting of beta-amyloid.

OBJECTIVE

To examine immunization strategies for AD.

METHODS

A review of relevant publications.

RESULTS/CONCLUSIONS

Preliminary results from three Phase II trials suggest both the promise and the need to exercise caution with this method of immunotherapy. The strategies used were distinct, using monoclonal N-terminal, central epitope, and polyclonal antibodies to maximize the efficacy and safety of each approach. The tested compounds are moving into Phase III trials for mild to moderate AD. We await the discoveries that from these studies that may yield the first disease-modifying therapy for AD.