Neuroinflammation Associated With Inborn Errors of Immunity

Electroacupuncture Inhibits Neuroinflammation Induced by Astrocytic Necroptosis Through RIP1/MLKL/TLR4 Pathway in a Mouse Model of Spinal Cord Injury

Astrocytic necroptosis plays an essential role in the progression and regression of neurological disorders, which contributes to the neuroinflammation and disrupts neuronal regeneration and remyelination of severed axons. Electroacupuncture (EA), an effective therapeutic efficacy against spinal cord injury (SCI), has been proved to reduce neuronal cell apoptosis, inhibit inflammation, and prompt neural stem cell proliferation and differentiations. However, there have been few reports on whether EA regulate astrocytic necroptosis in SCI model. To investigate the effects of EA on astrocytic necroptosis and the mechanisms involved in the inhibition of astrocytic necroptosis after SCI in mice by EA, 8-week-old female C57BL/6 mice were subjected to SCI surgery and randomly divided into EA and SCI groups. Mice receiving sham surgery were included as sham group. "Jiaji" was selected as points for EA treatment, 10 min/day for 14 days. The in vitro data revealed that EA treatment significantly improved the nervous function and pathological changes after SCI. EA also reduced the number of GFAP/P-MLKL, GFAP/MLKL, GFAP/HMGB1, and Iba1/HMGB1 co-positive cells and inhibited the expressions of IL-6, IL-1β, and IL-33. The results indicate a significant reduction in inflammatory reaction and astrocytic necroptosis in mice with SCI by EA. Additionally, the expressions of RIP1, MLKL, and TLR4, which are associated with necroptosis, were found to be downregulated by EA. In this study, we confirmed that EA can inhibit neuroinflammation by reducing astrocytic necroptosis through downregulation of RIP1/MLKL/TLR4 pathway in mice with SCI.

Virus-Induced Epilepsy vs. Epilepsy Patients Acquiring Viral Infection: Unravelling the Complex Relationship for Precision Treatment

The intricate relationship between viruses and epilepsy involves a bidirectional interaction. Certain viruses can induce epilepsy by infecting the brain, leading to inflammation, damage, or abnormal electrical activity. Conversely, epilepsy patients may be more susceptible to viral infections due to factors, such as compromised immune systems, anticonvulsant drugs, or surgical interventions. Neuroinflammation, a common factor in both scenarios, exhibits onset, duration, intensity, and consequence variations. It can modulate epileptogenesis, increase seizure susceptibility, and impact anticonvulsant drug pharmacokinetics, immune system function, and brain physiology. Viral infections significantly impact the clinical management of epilepsy patients, necessitating a multidisciplinary approach encompassing diagnosis, prevention, and treatment of both conditions. We delved into the dual dynamics of viruses inducing epilepsy and epilepsy patients acquiring viruses, examining the unique features of each case. For virus-induced epilepsy, we specify virus types, elucidate mechanisms of epilepsy induction, emphasize neuroinflammation's impact, and analyze its effects on anticonvulsant drug pharmacokinetics. Conversely, in epilepsy patients acquiring viruses, we detail the acquired virus, its interaction with existing epilepsy, neuroinflammation effects, and changes in anticonvulsant drug pharmacokinetics. Understanding this interplay advances precision therapies for epilepsy during viral infections, providing mechanistic insights, identifying biomarkers and therapeutic targets, and supporting optimized dosing regimens. However, further studies are crucial to validate tools, discover new biomarkers and therapeutic targets, and evaluate targeted therapy safety and efficacy in diverse epilepsy and viral infection scenarios.

Inborn errors of immunity: A field without frontiers

The study of primary immunodeficiencies or inborn errors of immunity continues to drive our knowledge of the function of the human immune system. From the outset, the study of inborn errors has focused on unraveling genetic etiologies and molecular mechanisms. Aided by the continuous growth in genetic diagnostics, the field has moved from the study of an infection dominated phenotype to embrace and unravel diverse manifestations of autoinflammation, autoimmunity, malignancy, and severe allergy in all medical disciplines. It has now moved from the study of ultrarare presentations to producing meaningful impact in conditions as diverse as inflammatory bowel disease, neurological conditions, and hematology. Beyond offering immunogenetic diagnosis, the study of underlying inborn errors of immunity in these conditions points to targeted treatment which can be lifesaving.

The Emerging Role of Toll-Like Receptor-Mediated Neuroinflammatory Signals in Psychiatric Disorders and Acquired Epilepsy

The new and evolving paradigms of psychiatric disorders pathogenesis are deeply inclined toward chronic inflammation that leads to disturbances in the neuronal networks of patients. A strong association has been established between the inflammation and neurobiology of depression which is mediated by different toll-like receptors (TLRs). TLRs and associated signalling pathways are identified as key immune regulators to stress and infections in neurobiology. They are a special class of transmembrane proteins, which are one of the broadly studied members of the Pattern Recognition Patterns family. This review focuses on summarizing the important findings on the role of TLRs associated with psychotic disorders and acquired epilepsy. This review also shows the promising potential of TLRs in immune response mediated through antidepressant therapies and TLRs polymorphism associated with various psychotic disorders. Moreover, this also sheds light on future directions to further target TLRs as a therapeutic approach for psychiatric disorders.

Nucleotide metabolism, leukodystrophies, and CNS pathology

The balance between a protective and a destructive immune response can be precarious, as exemplified by inborn errors in nucleotide metabolism. This class of inherited disorders, which mimics infection, can result in systemic injury and severe neurologic outcomes. The most common of these disorders is Aicardi Goutières syndrome (AGS). AGS results in a phenotype similar to "TORCH" infections (Toxoplasma gondii, Other [Zika virus (ZIKV), human immunodeficiency virus (HIV)], Rubella virus, human Cytomegalovirus [HCMV], and Herpesviruses), but with sustained inflammation and ongoing potential for complications. AGS was first described in the early 1980s as familial clusters of "TORCH" infections, with severe neurology impairment, microcephaly, and basal ganglia calcifications (Aicardi & Goutières, Ann Neurol, 1984;15:49-54) and was associated with chronic cerebrospinal fluid (CSF) lymphocytosis and elevated type I interferon levels (Goutières et al., Ann Neurol, 1998;44:900-907). Since its first description, the clinical spectrum of AGS has dramatically expanded from the initial cohorts of children with severe impairment to including individuals with average intelligence and mild spastic paraparesis. This broad spectrum of potential clinical manifestations can result in a delayed diagnosis, which families cite as a major stressor. Additionally, a timely diagnosis is increasingly critical with emerging therapies targeting the interferon signaling pathway. Despite the many gains in understanding about AGS, there are still many gaps in our understanding of the cell-type drivers of pathology and characterization of modifying variables that influence clinical outcomes and achievement of timely diagnosis.

Anti-Inflammatory and Immunomodulatory Effect of High-Dose Immunoglobulins in Children: From Approved Indications to Off-Label Use

BACKGROUND

The large-scale utilization of immunoglobulins in patients with inborn errors of immunity (IEIs) since 1952 prompted the discovery of their key role at high doses as immunomodulatory and anti-inflammatory therapy, in the treatment of IEI-related immune dysregulation disorders, according to labelled and off-label indications. Recent years have been dominated by a progressive imbalance between the gradual but constant increase in the use of immunoglobulins and their availability, exacerbated by the SARS-CoV-2 pandemic.

OBJECTIVES

To provide pragmatic indications for a need-based application of high-dose immunoglobulins in the pediatric context.

SOURCES

A literature search was performed using PubMed, from inception until 1st August 2023, including the following keywords: anti-inflammatory; children; high dose gammaglobulin; high dose immunoglobulin; immune dysregulation; immunomodulation; immunomodulatory; inflammation; intravenous gammaglobulin; intravenous immunoglobulin; off-label; pediatric; subcutaneous gammaglobulin; subcutaneous immunoglobulin. All article types were considered.

IMPLICATIONS

In the light of the current imbalance between gammaglobulins' demand and availability, this review advocates the urgency of a more conscious utilization of this medical product, giving indications about benefits, risks, cost-effectiveness, and administration routes of high-dose immunoglobulins in children with hematologic, neurologic, and inflammatory immune dysregulation disorders, prompting further research towards a responsible employment of gammaglobulins and improving the therapeutical decisional process.

What General Neurologists Should Know about Autoinflammatory Syndromes?

Autoinflammatory disorders encompass a wide range of conditions with systemic and neurological symptoms, which can be acquired or inherited. These diseases are characterized by an abnormal response of the innate immune system, leading to an excessive inflammatory reaction. On the other hand, autoimmune diseases result from dysregulation of the adaptive immune response. Disease flares are characterized by systemic inflammation affecting the skin, muscles, joints, serosa, and eyes, accompanied by unexplained fever and elevated acute phase reactants. Autoinflammatory syndromes can present with various neurological manifestations, such as aseptic meningitis, meningoencephalitis, sensorineural hearing loss, and others. Early recognition of these manifestations by general neurologists can have a significant impact on the prognosis of patients. Timely and targeted therapy can prevent long-term disability by reducing chronic inflammation. This review provides an overview of recently reported neuroinflammatory phenotypes, with a specific focus on genetic factors, clinical manifestations, and treatment options. General neurologists should have a good understanding of these important diseases.

Central nervous system manifestations of LRBA deficiency: case report of two siblings and literature review

BACKGROUND

LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency disease (PID) characterized by a regulatory T cell defect resulting in immune dysregulation and autoimmunity. We present two siblings born to consanguineous parents of North African descent with LRBA deficiency and central nervous system (CNS) manifestations. As no concise overview of these manifestations is available in literature, we compared our patient's presentation with a reviewed synthesis of the available literature.

CASE PRESENTATIONS

The younger brother presented with enteropathy at age 1.5 years, and subsequently developed Evans syndrome and diabetes mellitus. These autoimmune manifestations led to the genetic diagnosis of LRBA deficiency through whole exome sequencing with PID gene panel. At 11 years old, he had two tonic-clonic seizures. Brain MRI showed multiple FLAIR-hyperintense lesions and a T2-hyperintense lesion of the cervical medulla.  His sister presented with immune cytopenia at age 9 years, and developed diffuse lymphadenopathy and interstitial lung disease. Genetic testing confirmed the same mutation as her brother. At age 13 years, a brain MRI showed multiple T2-FLAIR-hyperintense lesions. She received an allogeneic hematopoietic stem cell transplantation (allo-HSCT) 3 months later. Follow-up MRI showed regression of these lesions.

CONCLUSIONS

Neurological disease is documented in up to 25% of patients with LRBA deficiency. Manifestations range from cerebral granulomas to acute disseminating encephalomyelitis, but detailed descriptions of neurological and imaging phenotypes are lacking. LRBA deficiency amongst other PIDs should be part of the differential diagnosis in patients with inflammatory brain lesions. We strongly advocate for a more detailed description of CNS manifestations in patients with LRBA deficiency, when possible with MR imaging. This will aid clinical decision concerning both anti-infectious and anti-inflammatory therapy and in considering the indication for allo-HSCT.

Familial Mediterranean Fever and Transverse Myelitis: A Causal Relation?

Familial Mediterranean fever (FMF) is a rare autoinflammatory disorder characterized mainly by recurrent self-limited episodes of fever and polyserositis. FMF-related neurologic complication is an old debate, and the correlation between FMF and demyelinating disorders has been a matter of dispute for a long time. Few reports demonstrated a relationship between FMF and multiple sclerosis; however, the existence of a causal relationship between FMF and demyelinating disorders is still a puzzle. This report presents the first case of transverse myelitis following FMF attacks in which neurologic manifestations were resolved using colchicine treatment. Due to relapses of FMF, which were accompanied by transverse myelitis, rituximab was administered, which resulted in stabilizing disease activity. Accordingly, in the case of colchicine-resistant FMF and FMF-related demyelinating conditions, rituximab could be considered as a potential therapeutic option to alleviate both polyserositis and demyelinating manifestations.

Mesoporous Silica-Based Nanoplatforms Are Theranostic Agents for the Treatment of Inflammatory Disorders

Complete recovery from infection, sepsis, injury, or trauma requires a vigorous response called inflammation. Inflammatory responses are essential in balancing tissue homeostasis to protect the tissue or resolve harmful stimuli and initiate the healing process. Identifying pathologically important inflammatory stimuli is important for a better understanding of the immune pathways, mechanisms of inflammatory diseases and organ dysfunctions, and inflammatory biomarkers and for developing therapeutic targets for inflammatory diseases. Nanoparticles are an efficient medical tool for diagnosing, preventing, and treating various diseases due to their interactions with biological molecules. Nanoparticles are unique in diagnosis and therapy in that they do not affect the surroundings or show toxicity. Modern medicine has undergone further development with nanoscale materials providing advanced experimentation, clinical use, and applications. Nanoparticle use in imaging, drug delivery, and treatment is growing rapidly owing to their spectacular accuracy, bioavailability, and cellular permeability. Mesoporous silica nanoparticles (MSNs) play a significant role in nano therapy with several advantages such as easy synthesis, loading, controllability, bioavailability over various surfaces, functionalization, and biocompatibility. MSNs can be used as theranostics in immune-modulatory nano systems to diagnose and treat inflammatory diseases. The application of MSNs in the preparation of drug-delivery systems has been steadily increasing in recent decades. Several preclinical studies suggest that an MSN-mediated drug-delivery system could aid in treating inflammatory diseases. This review explains the role of nanoparticles in medicine, synthesis, and functional properties of mesoporous silica nanoparticles and their therapeutic role against various inflammatory diseases.

The role of type I IFN in autoimmune and autoinflammatory diseases with CNS involvement

Type I interferons (IFNs) are major mediators of innate immunity, with well-known antiviral, antiproliferative, and immunomodulatory properties. A growing body of evidence suggests the involvement of type I IFNs in the pathogenesis of central nervous system (CNS) manifestations in the setting of chronic autoimmune and autoinflammatory disorders, while IFN-β has been for years, a well-established therapeutic modality for multiple sclerosis (MS). In the present review, we summarize the current evidence on the mechanisms of type I IFN production by CNS cellular populations as well as its local effects on the CNS. Additionally, the beneficial effects of IFN-β in the pathophysiology of MS are discussed, along with the contributory role of type I IFNs in the pathogenesis of neuropsychiatric lupus erythematosus and type I interferonopathies.