A case of acute motor and sensory axonal neuropathy following hepatitis a infection

Immune-Mediated Neuropathies: Pathophysiology and Management

Dysfunction of the immune system can result in damage of the peripheral nervous system. The immunological mechanisms, which include macrophage infiltration, inflammation and proliferation of Schwann cells, result in variable degrees of demyelination and axonal degeneration. Aetiology is diverse and, in some cases, may be precipitated by infection. Various animal models have contributed and helped to elucidate the pathophysiological mechanisms in acute and chronic inflammatory polyradiculoneuropathies (Guillain-Barre Syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, respectively). The presence of specific anti-glycoconjugate antibodies indicates an underlying process of molecular mimicry and sometimes assists in the classification of these disorders, which often merely supports the clinical diagnosis. Now, the electrophysiological presence of conduction blocks is another important factor in characterizing another subgroup of treatable motor neuropathies (multifocal motor neuropathy with conduction block), which is distinct from Lewis-Sumner syndrome (multifocal acquired demyelinating sensory and motor neuropathy) in its response to treatment modalities as well as electrophysiological features. Furthermore, paraneoplastic neuropathies are also immune-mediated and are the result of an immune reaction to tumour cells that express onconeural antigens and mimic molecules expressed on the surface of neurons. The detection of specific paraneoplastic antibodies often assists the clinician in the investigation of an underlying, sometimes specific, malignancy. This review aims to discuss the immunological and pathophysiological mechanisms that are thought to be crucial in the aetiology of dysimmune neuropathies as well as their individual electrophysiological characteristics, their laboratory features and existing treatment options. Here, we aim to present a balance of discussion from these diverse angles that may be helpful in categorizing disease and establishing prognosis.

Campylobacter jejuni and Postinfectious Autoimmune Diseases: A Proof of Concept in Glycobiology

Glycans, one of the most diverse groups of macromolecules, are ubiquitous constituents of all cells and have many critical functions, including the interaction between microbes and their hosts. One of the best model organisms to study the host-pathogen interaction, the gastrointestinal pathogen Campylobacter jejuni dedicates extensive resources to glycosylation and exhibits a diverse array of surface sugar-coated displays. The first bacterium where N-linked glycosylation was described, C. jejuni can additionally modify proteins by O-linked glycosylation, has extracellular capsular polysaccharides that are important for virulence and represent the major determinant of the Penner serotyping scheme, and has outer membrane lipooligosaccharides that participate in processes such as colonization, survival, inflammation, and immune evasion. In addition to causing gastrointestinal disease and extraintestinal infections, C. jejuni was also linked to postinfectious autoimmune neuropathies, of which Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) are the most extensively characterized ones. These postinfectious autoimmune neuropathies occur when specific bacterial surface lipooligosaccharides mimic gangliosides in the host nervous system. C. jejuni provided the first proof of concept for the involvement of molecular mimicry in the pathogenesis of an autoimmune disease and, also, for the ability of a bacterial polymorphism to shape the clinical presentation of the postinfectious autoimmune neuropathy. The scientific journey that culminated with elucidating the mechanistic details of the C. jejuni-GBS link was the result of contributions from several fields, including microbiology, structural biology, glycobiology, genetics, and immunology and provides an inspiring and important example to interrogate other instances of molecular mimicry and their involvement in autoimmune disease.

A 30-Year-Old Man with Acute Motor Axonal Neuropathy Subtype of Guillain-Barré Syndrome Having Hepatitis A Virus Infection

Guillain-Barré syndrome (GBS) is an acute monophasic immune-mediated polyradiculoneuropathy. Here, we report a case of a young man with acute motor axonal neuropathy (AMAN) subtype of GBS having hepatitis A virus (HAV) infection.

A 30-year-old man with icterus was referred to emergency center of Razi Hospital. He complained of flu-like symptoms 10 days before the onset of icterus. Also, he suffered from gradual fatigue and weakness with dark urine. He experienced neurological symptoms of muscle paralysis (ascending from the legs to hands). Neurological consultant suspected GBS at the first step based on clinical examinations. He was candidate for five sessions of plasmapheresis. The ultrasonography revealed liver span 166 mm, which was greater than the normal range, with normal parenchymal echo. The gallbladder wall was thicker than normal and gallstone with lesion was not seen in different conditions. He was discharged after total improvement of neurological symptoms and muscular power. In addition, the results of International normalized ratio (INR), partial thromboplastin time (PTT), prothrombin time (PT), alkaline phosphatase (ALK), alanine aminotransferase (ALT) , aspartate aminotransferase (AST), bilirubin total and direct (Bil T, D) tests were normal after 2-month follow-up.

Although, acute viral infections such as hepatitis E virus (HEV) is common in patients with GBS; the possibility of HAV infection in patients with its risk factor should not be neglected.

Pulse-steroid therapy in a 37-year-old man with acute motor and sensory axonal neuropathy: A case report

We report a case of 37-year-old man admitted with acute motor and sensory axonal neuropathy (AMSAN) which was treated with pulse-steroid therapy after the plasmapheresis and intravascular immunoglobulin. The improvement of the symptoms of AMSAN after pulse-steroid therapy may represent a therapeutic alternative for this variant of Guillain-Barré syndrome.

Antimicrobial Nanostructures for Neurodegenerative Infections

Nanostructures have been widely involved in changes in the drug delivery system. Nanoparticles have unique physicochemical properties, e.g., ultrasmall size, large surface area, and the ability to target specific actions. Various nanomaterials, like Ag, ZnO, Cu/CuO, and Al₂O₃, have antimicrobial activity. Basically, six mechanisms are involved in the production of antimicrobial activity, i.e., (1) destruction of the peptidoglycan layer, (2) release of toxic metal ions, (3) alteration of cellular pH via proton efflux pumps, (4) generation of reactive oxygen species, (5) damage of nuclear materials, and (6) loss of ATP production. Nanomedicine contributes to various pharmaceutical applications, like diagnosis and treatment of various ailments including microbial diseases. Furthermore, nanostructured antimicrobial agents are also involved in the treatment of the neuroinfections associated with neurodegenerative disorders. This chapter focuses on the nanostructure and nanomedicine of antimicrobial agents and their prospects for the possible management of infections associated with neurodegenerative disorders.