Recurrent demyelinating myelitis associated with hepatitis C viral infection

Hepatitis C Virus-Related Central and Peripheral Nervous System Disorders

Hepatitis C Virus (HCV), despite being a hepatotropic virus, is the causative agent of many systemic disorders, such as vasculitis, autoimmune diseases, lymphoproliferative disorders, and a broad spectrum of neurological and psychiatric manifestations. Although symptoms have been misdiagnosed or underdiagnosed, only recently, evidence of direct (inflammatory) or indirect (immune-mediated) HCV-dependent cerebral effects has been established. HCV infection can promote acute inflammatory response, pro-coagulative status and ischemic disorders, and neurodegeneration. These effects rely on cerebral HCV replication, possibly mediated by blood-brain barrier alterations. Further study is needed to better understand the HCV-related mechanisms of brain damage.

Gastrointestinal Disorders and the Nervous System

PURPOSE OF REVIEW

This article describes the neurologic sequelae of various nutritional micronutrient deficiencies, celiac disease, inflammatory bowel disease, and liver disease. Where relevant, appropriate treatments for these conditions are also discussed. The developing field of the microbiome and nervous system interaction is also outlined.

RECENT FINDINGS

Pathology in the gastrointestinal system can affect the nervous system when it causes micronutrient deficiency, when immune responses created by the gastrointestinal system affect the nervous system, when toxins caused by gastrointestinal organ failure harm the nervous system, and when treatments aimed at a gastrointestinal medical condition cause damage to the nervous system as a side effect.

SUMMARY

This article addresses familiar concepts and new developments in the treatment and understanding of diseases that affect the gut and nervous system simultaneously.

Hepatitis C virus and neurological damage

Chronic hepatitis C virus (HCV) infection exhibits a wide range of extrahepatic complications, affecting various organs in the human body. Numerous HCV patients suffer neurological manifestations, ranging from cognitive impairment to peripheral neuropathy. Overexpression of the host immune response leads to the production of immune complexes, cryoglobulins, as well as autoantibodies, which is a major pathogenic mechanism responsible for nervous system dysfunction. Alternatively circulating inflammatory cytokines and chemokines and HCV replication in neurons is another factor that severely affects the nervous system. Furthermore, HCV infection causes both sensory and motor peripheral neuropathy in the mixed cryoglobulinemia as well as known as an important risk aspect for stroke. These extrahepatic manifestations are the reason behind underlying hepatic encephalopathy and chronic liver disease. The brain is an apt location for HCV replication, where the HCV virus may directly wield neurotoxicity. Other mechanisms that takes place by chronic HCV infection due the pathogenesis of neuropsychiatric disorders includes derangement of metabolic pathways of infected cells, autoimmune disorders, systemic or cerebral inflammation and alterations in neurotransmitter circuits. HCV and its pathogenic role is suggested by enhancement of psychiatric and neurological symptoms in patients attaining a sustained virologic response followed by treatment with interferon; however, further studies are required to fully assess the impact of HCV infection and its specific antiviral targets associated with neuropsychiatric disorders.

HCV-related central and peripheral nervous system demyelinating disorders

Chronic infection with hepatitis C virus (HCV) is associated with a large spectrum of extrahepatic manifestations (EHMs), mostly immunologic/rheumatologic in nature owing to B-cell proliferation and clonal expansion. Neurological complications are thought to be immune-mediated or secondary to invasion of neural tissues by HCV, as postulated in transverse myelitis and encephalopathic forms. Primarily axonal neuropathies, including sensorimotor polyneuropathy, large or small fiber sensory neuropathy, motor polyneuropathy, mononeuritis, mononeuritis multiplex, or overlapping syndrome, represent the most common neurological complications of chronic HCV infection. In addition, a number of peripheral demyelinating disorders are encountered, such as chronic inflammatory demyelinating polyneuropathy, the Lewis-Sumner syndrome, and cryoglobulin-associated polyneuropathy with demyelinating features. The spectrum of demyelinating forms also includes rare cases of iatrogenic central and peripheral nervous system disorders, occurring during treatment with pegylated interferon. Herein, we review HCV-related demyelinating conditions, and disclose the novel observation on the significantly increased frequency of chronic demyelinating neuropathy with anti-myelin-associated glycoprotein antibodies in a cohort of 59 consecutive patients recruited at our institution. We also report a second case of neuromyelitis optica with serum IgG autoantibody against the water channel aquaporin-4. The prompt recognition of these atypical and underestimated complications of HCV infection is of crucial importance in deciding which treatment option a patient should be offered.

Acute myelitis associated with HCV infection

We report a case of acute myelitis associated with hepatitis C virus (HCV) infection. A Japanese woman developed left calf pain and weakness, but this quickly generalised to paraplegia. We diagnosed acute myelitis based on the results of clinical manifestations, an MRI examination and a cerebrospinal fluid (CSF) examination. The clinical condition and spinal cord lesions improved following intravenous administration of methylprednisolone. The patient had been diagnosed with HCV infection 11 years before the onset. We detected HCV RNA in the CSF, supporting the strong association of our patient's myelitis. However, it is difficult to conclude whether the neurological condition was caused directly by the viral load or indirectly by the immune response. We suggest that testing for HCV infection is important in patients with myelitis. In particular, anti-HCV antibody and HCV RNA should be measured in the patients' serum as well as CSF.

HCV-related nervous system disorders

Chronic infection with hepatitis C virus (HCV) is associated with a wide spectrum of extrahepatic manifestations, affecting different organ systems. Neurological complications occur in a large number of patients and range from peripheral neuropathy to cognitive impairment. Pathogenetic mechanisms responsible for nervous system dysfunction are mainly related to the upregulation of the host immune response with production of autoantibodies, immune complexes, and cryoglobulins. Alternative mechanisms include possible extrahepatic replication of HCV in neural tissues and the effects of circulating inflammatory cytokines and chemokines.

Immune-mediated myelitis associated with hepatitis virus infections

Virus-induced spinal cord damage results from a cytolytic effect on anterior horn cells or from predominantly cellular immune-mediated damage of long white matter tracts. Infection with the hepatitis virus group, most notably hepatitis C virus, has infrequently been associated with the occurrence of myelitis. The pathogenesis of hepatitis virus-associated myelitis has not been clarified: virus-induced autoimmunity (humoral or cell-mediated, possibly vasculitic) seems the most likely disease mechanism. Limited available information offers no evidence of direct hepatitis virus infection of the spinal cord. Virus neuropenetration may occur after virus-infected mononuclear cells penetrate the blood-brain barrier, but a true neurolytic effect has not been demonstrated. Attacks of acute myelitis usually respond favorably to immunomodulatory therapy. Antiviral therapy plays no confirmed role in the treatment of acute bouts of myelitis, but may limit the relapsing course of HCV-associated myelitis.

Spinal cord biopsy findings of anti-aquaporin-4 antibody-negative recurrent longitudinal myelitis in a patient with sicca symptoms and hepatitis C viral infection

We describe the pathological features of a spinal cord biopsy from a 69-year-old woman with anti-aquaporin-4 antibody-negative recurrent longitudinal myelitis. Spinal cord MRI showed T2 high-intensity lesions with strong gadolinium enhancement, when episodes of sensory-motor impairment were repeated. The radiological abnormality was corrected by corticosteroid administration, but improvement of the symptoms was minimal. Although the patient had sicca symptoms and fulfilled four of the diagnostic criteria for Sjögren syndrome, the diagnosis was excluded, because of infection with hepatitis C virus, an exclusion criterion of Sjögren syndrome. In the spinal cord lesions, necrotic changes affected both myelin and axons. Infiltrating lymphocytes were predominantly T-cells. The proliferation of small vessels with hyalinization and concomitant occlusive change was remarkable. These pathological findings resembled those previously reported in Sjögren syndrome. Ultrastructurally, the endothelial cells of the small vessels showed features of activated cells and contained vesiculo-tubular structures in the cytoplasm, indicating that increased blood-brain barrier (BBB) permeability might contribute to pathogenesis. We speculated that increased BBB permeability and T-cell entry in the spinal parenchyma triggered pathological reactions resulting in necrotic changes in the spinal cord. Obstruction of small vessels might add ischemic damage to the lesions. The clinical course and pathological findings indicated that damage progressed rapidly in the spinal cord and was irreversible. The lesions apparently differed from typical demyelination plaques. Faced with such spinal cord lesions, a preventive therapeutic approach is necessary to avoid attack-associated disability.

Fulminant central nervous system demyelination associated with interferon-α therapy and hepatitis C virus infection

Hepatitis C virus (HCV) infection is common in the general population and may coincide with disease in the central and peripheral nervous system. Interferon-α (IFN-α) is used as treatment for HCV infection. The therapeutic benefit is assumed to result from activation of natural killer cells and CD8+ T cells. Despite its beneficial effects, it has been associated with a number of autoimmune disorders, such as chronic inflammatory demyelinating polyneuropathy and multiple sclerosis. Several clinical reports including magnetic resonance imaging exist, but neuropathological confirmation of MS associated with IFN-α therapy and HCV infection is lacking. We report a case of a female patient with chronic HCV infection who developed `acute MS'-like demyelinating disease after IFN-α administration, with extensive lesions throughout brain and thoracic spinal cord. The patient died after a disease duration of 6 months. Brain autopsy revealed Baló-like demyelinating plaques with positive HCV sequences within florid lesions. The development of fulminant demyelinating disease after administration of IFN-α suggests that autoimmune mechanisms such as T cell mediated tissue damage might be initiated or aggravated by IFN-α therapy. Additionally, the presence of HCV RNA within the demyelinated lesion indicates a possible role in triggering or propagating disease. Multiple Sclerosis 2007; 13: 1100—1106. http://msj.sagepub.com

[A new case of acute transverse myelitis following hepatitis A virus infection]

Transverse myelitis is a rare manifestation of hepatitis A virus infection. We report the case of an eleven-year-old girl who presented a progressive flabby paraplegia with sphincter incontinence, superficial hypoesthesia, without deep involvement. Medullar MRI was suggestive of myelitis. Despite the absence of jaundice and hepatic cytolysis, the serology yielded a high rate of anti-hepatitis A immunoglobulin M. Neurological disorders disappeared within 15 days, after treating with a high dose of corticosteroids and physical rehabilitation. 24 months later she was asymptomatic. Screening for hepatitis A virus infection in patients with acute transverse myelitis should be indicated specially in endemic countries were vaccinal prophylaxis is not common practice.

Idiopathic inflammatory demyelinating disorders after acute transverse myelitis

Acute transverse myelitis (ATM) is commonly para-infectious. Recurrent ATM occurs in connective tissue diseases (CTD), infective myelitis and idiopathic inflammatory demyelinating disorders (IIDD) including multiple sclerosis (MS) and neuromyelitis optica (NMO). Previous studies might include NMO and idiopathic recurrent transverse myelitis (IRTM) as MS. The aim was to study the outcome of patients after a first attack of idiopathic ATM. Idiopathic ATM patients over a 6-year period were retrospectively studied. Known causes of myelopathy were excluded. Among 32 patients studied, 20 (63%) had single ATM attack upon follow up for 39-93 months, three developed recurrent ATM related to CTD (two systemic lupus erythematosus and one anti-Ro antibody positive) and nine (28.1%) developed recurrent neuroinflammation compatible with IIDD. Among IIDD patients, three had NMO, two restricted variant of NMO, three IRTM and one classical MS. NMO, its variant and IRTM had mean spinal MRI abnormality of 3.7, 2.1 and 3.9 vertebral segments respectively while non-recurrent ATM had 1.6 vertebral segments. Four (80%) of the five patients with NMO or its variant had poor neurological prognosis versus only one (5%) of non-recurrent ATM patients. IRTM patients had advanced mean onset age, 62 years vs. 43 years for non-recurrent ATM patients. In IIDD patients presenting with ATM as first attack of neuroinflammation, NMO and its variant (56%) were most frequent, then IRTM (33%), with classical MS (11%) the rarest. As long-term treatments for NMO are different from MS, early recognition of NMO and its variant is important for prevention of serious neurological deficits.