Altered monoaminergic transporter binding in hepatitis C related cerebral dysfunction: a neuroimmunologial condition?

HCV Extrahepatic Manifestations

Hepatitis C virus (HCV) has been shown to affect many tissues other than liver. However, of the many extrahepatic manifestations (EMs) that have been associated with HCV, including cryoglobulinemia, lymphoma, insulin resistance, type 2 diabetes and neurological disorders, only a few have been shown to be directly related to HCV infection of extrahepatic tissues. HCV-triggered immune-mediated mechanisms account for most of the EMs. It is estimated that up to 74% of patients with chronic hepatitis C can develop at least one EM. All HCV patients with EMs should be considered for antiviral therapy, although not all will resolve with sustained virological response.

Hepatitis C Virus Infection in the Older Patient

Hepatitis C virus (HCV) is the most common blood-borne infection in the United States and is of concern in older adults. HCV infection is associated with not only hepatic but also extrahepatic comorbidities common to the aging patient including diabetes, kidney and cardiovascular diseases, and neurocognitive impairment. The effect of direct-acting antiviral agents to treat HCV on these outcomes is limited. This article summarizes the literature regarding the epidemiology and natural history of HCV infection; the impact of age on clinical outcomes in HCV-infected persons; and current knowledge regarding safety and efficacy of HCV treatment regimens in the older patient.

Extrahepatic manifestations of chronic hepatitis C virus infection

During hepatitis C virus (HCV) chronic infection, extrahepatic manifestations are frequent and polymorphous. This article reports on a large cohort of patients with HCV-related autoimmune or lymphoproliferative disorders, from mixed cryoglobulinemia vasculitis to frank lymphomas. The relationship between HCV infection and such immune-related diseases has been formally demonstrated by epidemiological, clinical, immunological and pathological data, and results of therapeutic trials. More recently, other nonliver-related HCV disorders have been reported, including cardiovascular (i.e. stroke, ischemic heart disease), renal, metabolic and central nervous system diseases. For these manifestations, most evidence comes from large epidemiological studies; there is a need for mechanistic studies and therapeutic trials for confirmation. Beyond the risk of developing liver complications, that is, cirrhosis and liver cancer, patients with HCV infection have an increased risk of morbidity and mortality related to nonliver diseases. HCV chronic infection should be analyzed as a systemic disease in which extrahepatic consequences increase the weight of its pathological burden. The need for effective viral eradication measures is underlined.

Extrahepatic manifestations in chronic hepatitis C virus carriers

Patients with chronic hepatitis C virus (HCV) infection frequently present with extrahepatic manifestations covering a large spectrum, involving different organ systems leading to the concept of systemic HCV infection. These manifestations include autoimmune phenomena and frank autoimmune and/or rheumatic diseases and may dominate the course of chronic HCV infection. Chronic HCV infection causes liver inflammation affecting the development of hepatic diseases. HCV is also a lymphotropic virus that triggers B cells and promotes favorable conditions for B lymphocyte proliferation, including mixed cryoglobulinemia (MC) and MC vasculitis, which is the most prominent extrahepatic manifestation of chronic HCV infection. HCV may also promote a low-grade chronic systemic inflammation that may affect the development of some extrahepatic manifestations, particularly cardiovascular and cerebral vascular diseases. Recognition of extrahepatic symptoms of HCV infection could facilitate early diagnosis and treatment. The development of direct-acting antiviral agents (DDAs) has revolutionized HCV treatment. DDAs, as well as new B-cell-depleting or B-cell-modulating monoclonal antibodies, will expand the panorama of treatment options for HCV-related extrahepatic manifestations including cryoglobulinemic vasculitis. In this context, a proactive, integrated approach to HCV therapy should maximize the benefits of HCV therapy, even when liver disease is mild.

Extrahepatic manifestations of chronic hepatitis C virus infection

Hepatitis C virus (HCV) infected patients are known to be at risk of developing liver complications i.e. cirrhosis and liver cancer. However, the risks of morbidity and mortality are underestimated because they do not take into account non-liver consequences of chronic hepatitis C virus infection. Numerous extrahepatic manifestations have been reported in up to 74% of patients, from perceived to disabling conditions. The majority of data concern hepatitis C virus-related autoimmune and/or lymphoproliferative disorders, from mixed cryoglobulinaemia vasculitis to frank lymphomas. More recently, other hepatitis C virus-associated disorders have been reported including cardiovascular, renal, metabolic, and central nervous system diseases. This review aims to outline most of the extrahepatic manifestations that are currently being investigated, including some of autoimmune and/or lymphoproliferative nature, and others in which the role of immune mechanisms appears less clear. Beyond the liver, hepatitis C virus chronic infection should be analyzed as a multifaceted systemic disease leading to heavy direct and indirect costs. The accurate consideration of extrahepatic consequences of such a systemic infection significantly increases the weight of its pathological burden. The need for effective viral eradication measures is underlined.

Depressive symptoms in chronic hepatitis C are associated with plasma apolipoprotein E deficiency

Neuro-psychiatric and cognitive disorders are frequent in patients with chronic hepatitis C (CHC) virus (HCV) infection which adversely impact quality of life, antiviral treatment adherence and outcome. HCV has neurotrophic properties and affects lipid metabolism, essential for cognitive function. We evaluated the relationship of lipid profiles with depression and anxiety symptoms and the effects of 12-weeks of therapy with fluvastatin and omega-3 ethyl esters (n-3 PUFA) in a randomised pilot study of CHC prior non-responders. Participants (n = 60) had fasting lipid profiles and assessment of depression and anxiety symptoms using the Hospital Anxiety and Depression Scale (HADS) questionnaire at each study visit. At screening 26/60 (43 %) had HADS-A score ≥8 and 13/60 (22 %) had HADS-D scores ≥8. Depressed patients had significantly lower apolipoprotein-E concentrations (30 mg/l vs 39 mg/l, P = 0.029) than those without depression and a tendency toward lower total cholesterol (3.8 vs 4.4 mmol/l, P = 0.053). 3 patients discontinued lipid-modifying treatment because of worsening depression. However, there was a small but significant improvement in anxiety symptoms after 12-weeks of high-dose (2-4 g daily) n-3 PUFA. In conclusion, depression in CHC is associated with plasma apoE deficiency. We postulate that apoE deficiency disrupts blood brain barrier integrity to promote HCV infection of the CNS. High-dose n-PUFAs may alleviate anxiety in some CHC patients but the use of lipid lowering therapy must be balanced against risks of worsening depression.

Manifestations of chronic hepatitis C virus infection beyond the liver

In addition to its effects in the liver, chronic hepatitis C virus (HCV) infection can have serious consequences for other organ systems. Extrahepatic manifestations include mixed cryoglobulinemia (MC) vasculitis, lymphoproliferative disorders, renal disease, insulin resistance, type 2 diabetes, sicca syndrome, rheumatoid arthritis-like polyarthritis, and autoantibody production; reductions in quality of life involve fatigue, depression, and cognitive impairment. MC vasculitis, certain types of lymphoma, insulin resistance, and cognitive function appear to respond to anti-HCV therapy. However, treatments for HCV and other biopsychosocial factors can reduce quality of life and complicate management. HCV treatment has a high overall cost that increases when extrahepatic manifestations are considered. HCV appears to have a role in the pathogenesis of MC vasculitis, certain types of lymphoma, and insulin resistance. Clinicians who treat patients with HCV infections should be aware of potential extrahepatic manifestations and how these can impact and alter management of their patients.

Hepatitis C virus infection and the brain

There is growing evidence that hepatitis C virus (HCV)-infection may affect the brain. About half of the HCV-infected patients complain of chronic fatigue irrespective of their stage of liver disease or virus replication rate. Even after successful antiviral therapy fatigue persists in about one third of the patients. Many patients, in addition, report of deficits in attention, concentration and memory, some also of depression. Psychometric testing revealed deficits in attention and verbal learning ability as characteristic for HCV-afflicted patients with normal liver function. Magnetic resonance spectroscopic studies showed alterations of the cerebral choline, N-acetyl-aspartate, and creatine content in the basal ganglia, white matter and frontal cortex, respectively. Recently, pathologic cerebral serotonin and dopamine transporter binding and regional alterations of the cerebral glucose utilisation compatible with alterations of the dopaminergic attentional system were observed. Several studies detected HCV in brain samples or cerebro-spinal fluid. Interestingly, viral sequences in the brain often differed from those in the liver, but were closely related to those found in lymphoid tissue. Therefore, the Trojan horse hypothesis emerged: HCV-infected mononuclear blood cells enter the brain, enabling the virus to reside within the brain (probably in microglia) and to infect brain cells, especially astrocytes.