Neuromuscular diseases associated with chronic hepatitis C virus infection

Comorbidity, concomitant medication, use of resources and healthcare costs associated with chronic hepatitis C virus carriers in Spain

OBJECTIVES

To assess the comorbidity, concomitant medications, healthcare resource use and healthcare costs of chronic hepatitis C virus patients in the Spanish population.

PATIENTS AND METHODS

Retrospective, observational, non-interventional study. Patients included were≥18 years of age who accessed medical care between 2010-2013. Patients were divided into 2 groups based on the presence or absence of liver cirrhosis. The follow-up period was 12 months. Main assessment criteria included general comorbidity level (determined by the resource utilisation band score) and prevalence of specific comorbidities, concomitant medications, healthcare resource use and healthcare costs. Statistical analysis was performed using regression models and ANCOVA, P<.05.

RESULTS

One thousand fifty-five patients were enrolled, the mean age was 57.9 years and 55.5% were male. A percentage of 43.5 of patients had a moderate level of comorbidity according to the resource utilisation band score. The mean time from diagnosis was 18.1 years and 7.5% of the patients died during the follow-up period. The most common comorbidities were dyslipidaemia (40.3%), hypertension (40.1%) and generalised pain (38.1%). Cirrhosis was associated with cardiovascular events (OR 3.8), organ failures (OR 2.2), alcoholism (OR 2.1), diabetes (OR 1.2) and age (OR 1.2); P<.05. The most commonly used medications were anti-infectives (67.8%) and nervous system medications (66.8%). The mean total cost per patient was 3,198€ (71.5% healthcare costs, 28.5% indirect/non-healthcare costs). In the corrected model, the total costs per patient-year were 2,211€ for those without cirrhosis and 7,641€ for patients with cirrhosis; P<.001.

CONCLUSIONS

Chronic hepatitis C virus patients are associated with a high level of comorbidity and the use of concomitant medications, especially in patients with liver cirrhosis. Chronic hepatitis C virus infection represents a substantial economic burden on the Spanish National Health System.

Inflammatory myopathies and lymphoma

The inflammatory myopathies comprise a group of immune-mediated muscle diseases. Lymphoma is a term for a variety of lymphatic system malignancies. Autoimmune diseases and lymphoproliferative malignancies share a complex bidirectional relationship. A causal relationship between inflammatory mypathies and lymphoma has not been established. The diagnosis/treatment of inflammatory myopathy usually precedes the detection/diagnosis of lymphoma. Immune system dysregulation presumably underlies the evolution of lymphoma in patients with inflammatory myopathies. Inflammatory activity with chronic B-cell activation and/or antigen stimulation is deemed the major risk factor for lymphoma in patients with autoimmunity. A "paraneoplastic" phenomenon or the effects of immunosuppressive therapy may be alternative immune-based mechanisms. In chronic lymphocytic leukemia immune system disturbance rarely results in non-hematological autoimmune disease, including inflammatory myopathies.

Neurologic Manifestations of Chronic Liver Disease and Liver Cirrhosis

The normal functioning of brain is intimately as well as intricately interrelated with normal functioning of the liver. Liver plays a critical role of not only providing vital nutrients to the brain but also of detoxifying the splanchnic blood. Compromised liver function leads to insufficient detoxification thus allowing neurotoxins (such as ammonia, manganese, and other chemicals) to enter the cerebral circulation. In addition, portosystemic shunts, which are common accompaniments of advanced liver disease, facilitate free passage of neurotoxins into the cerebral circulation. The problem is compounded further by additional variables such as gastrointestinal tract bleeding, malnutrition, and concurrent renal failure, which are often associated with liver cirrhosis. Neurologic damage in chronic liver disease and liver cirrhosis seems to be multifactorial primarily attributable to the following: brain accumulation of ammonia, manganese, and lactate; altered permeability of the blood-brain barrier; recruitment of monocytes after microglial activation; and neuroinflammation, that is, direct effects of circulating systemic proinflammatory cytokines such as tumor necrosis factor, IL-1β, and IL-6. Radiologist should be aware of the conundrum of neurologic complications that can be encountered in liver disease, which include hepatic encephalopathy, hepatocerebral degeneration, hepatic myelopathy, cirrhosis-related parkinsonism, cerebral infections, hemorrhage, and osmotic demyelination. In addition, neurologic complications can be exclusive to certain disorders, for example, Wilson disease, alcoholism (Wernicke encephalopathy, alcoholic cerebellar degeneration, Marchiafava-Bignami disease, etc). Radiologist should be aware of their varied clinical presentation and radiological appearances as the diagnosis is not always straightforward.

Hepatitis C virus infection and autoimmune diseases

Hepatitis C virus (HCV) infection is associated with a number of extrahepatic disorders. The most studied conditions associated with HCV are type II mixed cryoglobulinemia and B cell lymphoma. However, many reports suggest that HCV might also be associated with a number of autoimmune disorders, both organ-specific and not organ-specific. Although concomitant treatment of HCV infection is a confounding factor when ascertaining the actual role of HCV in inducing autoimmune disease, a considerable amount of experimental data indicates that HCV is able to subvert the immune system and consequently induce autoimmunity. In the present review, we report a series of observations which associate chronic HCV infection with the onset of autoimmune disorders.