Hepatitis C virus infection and mixed cryoglobulinaemia vasculitis: a review of neurological complications

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.

Natural History of Hepatic and Extrahepatic Hepatitis C Virus Diseases and Impact of Interferon-Free HCV Therapy

The hepatitis C virus (HCV) infects 71.1 million persons and causes 400,000 deaths annually worldwide. HCV mostly infects the liver, causing acute and chronic necroinflammatory damage, which may progress toward cirrhosis and hepatocellular carcinoma. In addition, HCV has been associated with several extrahepatic manifestations. The advent of safe and effective direct-acting antivirals (DAAs) has made the dream of eliminating this public health scourge feasible in the medium term. Prospective studies using DAA-based regimens have shown the benefit of HCV clearance in terms of both liver- and non-liver-related mortality.

Antiviral therapy reduces risk of haemorrhagic stroke in patients with HCV infection: a nationwide cohort study

BACKGROUND

The tendency for haemorrhagic stroke in patients with chronic HCV infection has emerged recently but the finding may be confounded by comorbidities. Proving the causality between HCV infection and haemorrhagic stroke is mandatory. Our study was designed to investigate the incidence of intracranial haemorrhage in HCV-infected patients with and without treatment.

METHODS

In the 11-year and population-based retrospective study, we acquired data from the Taiwan National Health Insurance Research Database. The patients with major comorbidities were excluded and 97,198 HCV-infected patients were included for analysis. Treated and untreated cohorts were matched with propensity score to make the confounding factors in two groups comparable. Cox proportional hazard regression analysis was performed to evaluate the hazard ratio of haemorrhagic stroke in the cohorts. We applied survival analysis to compare the cumulative incidence of outcome events between the two cohorts.

RESULTS

After matching, the incidence density (ID) of haemorrhagic stroke in the untreated cohort is significantly higher than in the treated cohort (ID: 1.0 versus 0.6 events per 1,000 person-years; P=0.0014). The adjusted hazard ratio (aHR) of haemorrhagic stroke is significantly reduced in the treated group (P<0.05). Cumulative incidence of haemorrhagic stroke is significantly lower in the treated group than in the untreated group (P=0.013).

CONCLUSIONS

The study demonstrates that antiviral therapy significantly reduces the events of intracranial haemorrhage in HCV-infected patients and consolidates the novel concept that chronic HCV infection is a risk factor for haemorrhagic stroke.

Cryoglobulinemia: An update in 2019

Cryoglobulinemia is defined as the persistent presence in serum of abnormal immunoglobulins (Igs) that precipitate at low temperatures and dissolve again upon warming. Cryoglobulins may be composed only of a monoclonal Ig (simple type I cryoglobulinemia), of a monoclonal Ig bound to the constant domain of polyclonal Ig heavy chains (mixed type II cryoglobulinemia), or only of polyclonal Igs (mixed type III cryoglobulinemia). The manifestations of type I cryoglobulinemia are often related to intravascular obstruction, whereas those seen in the mixed cryoglobulinemias often originate in true immune complex-mediated vasculitis. The main clinical manifestations affect the skin (purpura, necrotic ulcers), joints, peripheral nervous system, and kidneys (membranoproliferative glomerulonephritis). Patients with type I cryoglobulinemia should be investigated for hematological malignancies (myeloma and B-cell lymphoma). Hepatitis C is the main diagnosis to consider in patients with mixed cryoglobulinemia, followed by connective tissue disease and B-cell non-Hodgkin's lymphoma. The treatment depends mainly on the cause of the cryoglobulinemia. For instance, hepatitis C virus (HCV) eradication is in order in patients with HCV-associated cryoglobulinemia vasculitis, and the underlying hematological malignancy must be treated in patients with type I cryoglobulinemia.

Psychiatric and functional neuroimaging abnormalities in chronic hepatitis C virus patients: Is vasculitis a contributing factor?

BACKGROUND AND STUDY AIMS

Central nervous system (CNS) involvement in hepatitis C virus (HCV) infection has different facets such as anxiety, depression, cognitive impairment and vasculitis. We were interested in detecting subclinical CNS involvement in chronic HCV infected subjects with and without systemic vasculitis.

PATIENTS AND METHODS

Nineteen patients (15 females and 4 males) with chronic HCV infection (mean age 46.5 ± 7 and mean duration since diagnosis of HCV infection 4.7 ± 4 years, including 6 (32%) Child-Pugh class A cirrhotic patients) and 30 age, sex and education matched healthy control subjects were studied. Thirteen patients had associated vasculitis. Patients and control subjects were assessed using the block design and comprehension subtests of Wechsler Bellevue Adult Intelligence Scale, Wechsler Memory scale (WMS), Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI). Brain HMPAO Single Photon Emission Computed Tomography (SPECT) was performed for HCV patients.

RESULTS

Patients with HCV had lower scores on the block design test compared to control subjects (8.37 ± 1.89 versus 10.37 ± 1.47, p < 0.001), lower total WMS scores (43.15 ± 10.49 versus 60.27 ± 8.08, p < 0.001) and higher anxiety and depression scores (16.94 ± 10.46 and 37.17 ± 10.38 versus 10.3 ± 4.67 and 28.9 ± 5.99, p = 0.004 and 0.001, respectively). Total WMS were lower in HCV patients with vasculitis compared to those without vasculitis (39.14 ± 9.3 versus 51.17 ± 8.3, p = 0.019) while the block design and comprehension tests, BAI and BDI were not significantly different between both groups. The block design and comprehension tests, WMS, BAI and BDI were not significantly different between cirrhotic and non-cirrhotic patients. Seven patients had different patterns of cerebral hypoperfusion on SPECT, and all of them had associated vasculitis. Abnormal SPECT was associated with lower total WMS scores (35.87 ± 10.8 versus 46.79 ± 8.6 in those with normal SPECT, p = 0.049).

CONCLUSIONS

Vasculitis may contribute to the development of neuropsychiatric involvement in HCV patients.

HCV RNA Genomic sequences and HCV-E2 glycoprotein in sural nerve biopsies from HCV-infected patients with peripheral neuropathy

AIMS

Peripheral neuropathy (PN), the major neurological complication of chronic HCV infection, is frequently associated with mixed cryoglobulinaemia (MC) and small-vessel systemic vasculitis. While humoral and cell-mediated immune mechanisms are suspected to act together in an aberrant immune response that results in peripheral nerve damage, the role of HCV remains largely speculative. The possible demonstration of HCV in peripheral nerve tissue would obviously assume important pathogenic implications.

METHODS

We studied sural nerve biopsies from 11 HCV-positive patients with neuropathic symptoms: five with and six without MC. In situ hybridization (ISH) and immunofluorescence studies were carried out to detect genomic and antigenomic HCV RNA sequences and HCV-encoded E2-glycoprotein, respectively.

RESULTS

Epineurial vascular deposits of E2-glycoprotein were found in four (80%) MC and in two (33.3%) non-MC patients, respectively. These findings were enhanced by the perivascular deposition of positive-, though not negative-strand replicative RNA, as also found in the nerve extracts of all patients. Mild inflammatory cell infiltrates with no deposits of immunoglobulins and/or complement proteins were revealed around small vessels, without distinct vasculitis changes between MC and non-MC patients.

CONCLUSIONS

These results indicate that nerve vascular HCV RNA/E2 deposits associated to perivascular inflammatory infiltrates were similar in chronically HCV-infected patients, regardless of cryoglobulin occurrence. Given the failure to demonstrate HCV productive infection in the examined sural nerve biopsies, nerve damage is likely to result from virus-triggered immune-mediated mechanisms.

Vasculitic syndromes in hepatitis C virus: A review

Vasculitis is a remarkable presentation of the extrahepatic manifestations of HCV. According to the presence or absence of cryoglobulins it is subdivided into two main types: cryoglobulinemic vasculitis and non cryoglobulinemic vasculitis based on the attribution of vasculitis to serum cryoglobulins as a pathogenic factor. The attribution of cryoglobulinemia to HCV represents a success story in the history of immunology, microbiology, and clinical medicine. HCV can bind to and invade lymphocytes, consequently triggering an immune response through different mechanisms. The epidemiology of the disease is well described and the clinical picture describes cutaneous, pulmonary, musculoskeletal, neurological, renal, endocrine, gastrointestinal, hepatic and cardiovascular manifestations. It may also be associated with sicca symptoms, an increased risk of lymphoma and serious catastrophic events. The pathology is well characterized. A classification criteria of the syndrome that was validated in 2014 is discussed. Management of CV is decided according to the presence and severity of its clinical presentation. It is divided into asymptomatic, mild, moderate, severe and life threatening disease. Recently introduced direct antiviral agents are proving safe and effective in the management of cryoglobulinemic vasculitis, and it is advocated that the two types of vasculitis be given prioritization in the Egyptian mass campaign to eradicate HCV.

International diagnostic guidelines for patients with HCV-related extrahepatic manifestations. A multidisciplinary expert statement

Hepatitis C virus (HCV) infection is responsible for both hepatic and extra-hepatic disorders (HCV-EHDs); these latter are correlated on one hand clearly with HCV lymphotropism causing immune-system dysregulation as well as with viral oncogenic potential, and on the other hand probably with chronic inflammatory status causing cardio-metabolic complications as well as neurocognitive disturbances. The spectrum of HCV-EHDs ranges from mild or moderate manifestations, such as arthralgia, sicca syndrome, peripheral neuropathy, to severe, life-threatening complications, mainly vasculitis and neoplastic conditions. Given the clinical heterogeneity of HCV-EHDs, HCV-infected individuals are inevitably referred to different specialists according to the presenting/prevalent symptom(s); therefore, the availability of comprehensive diagnostic guidelines is necessary for a patient's whole assessment that is decisive for early diagnosis and correct therapeutic approach of various hepatic and HCV-EHDs, regardless of the specific competencies of different physicians or referral centers. In this respect, a multidisciplinary network of experts, the International Study Group of Extrahepatic Manifestations Related to Hepatitis C Virus Infection (ISG-EHCV), was organized with the intention to formulate diagnostic guidelines for the work-up of possible HCV-EHDs. There was a broad consensus among ISG-EHCV members on the proposed guidelines, which essentially are based on two main levels of patient's assessment. At the referral stage, it is proposed that all patients with HCV infection should be invariably examined by means of first-line diagnostic procedures including virological and hepatic parameter evaluation, as well as the detection of clinical findings that may suggest one or more HCV-EHDs. This preliminary assessment should reveal specific HCV-EHDs, which will be deeper analyzed by means of second-line, targeted investigations. The proposed multidisciplinary expert statement represents the first attempt to draw comprehensive diagnostic guidelines for HCV-infected individuals encompassing the entire spectrum of HCV-related disorders, namely typical hepatic manifestations along with less common, often unpredictable HCV-EHDs. The HCV-EHDs may compromise to a substantial degree the overall disease outcome in a significant number of HCV-infected individuals that renders their timely identification and treatment an imperative. In conclusion, the application of standardized but thorough diagnostic guidelines of HCV-EHDs is advisable at the referral stage as well as during the follow-up period of HCV infected patients. It is envisioned that the proposed strategy will result in improvement of clinical outcomes in such patients.

Screening for Electrophysiological Abnormalities in Chronic Hepatitis C Infection: Peripheral Neuropathy and Optic Neuropathy

INTRODUCTION

To investigate the existence of peripheral and optic neuropathies in asymptomatic individuals with hepatitis C infection.

METHODS

Thirty consecutive patients who were followed in a hepatitis C outpatient clinic were recruited for electrophysiological evaluation together with 30 age- and gender-compatible healthy controls. All patients had a detailed neurological examination. The information regarding the disease duration and management with interferons were collected. Nerve conduction studies and visual evoked potentials (VEP) were recorded in all subjects. The results of the patient and control groups were statistically compared.

RESULTS

Of the patients with hepatitis C infection, 16 were females and 14 males. The mean age was 57.5 years, and the average disease duration was 6.43 years. The P100 latencies in the patient group were within normal limits, while the amplitudes were meaningfully small by comparison with the controls. There were some abnormalities in the nerve conduction studies of 15 patients. Sensorial neuropathy was detected in two patients, sensorimotor polyneuropathy in four, carpal tunnel syndrome in seven, and carpal tunnel syndrome and sensorimotor polyneuropathy as comorbid states in another two patients. The nerve conduction studies and VEP parameters were entirely normal in the control group.

CONCLUSION

Hepatitis C-related neurological abnormalities may occur both in the central and peripheral nervous system. Mononeuritis multiplex, sensorial axonal neuropathy, and multiple mononeuropathies are some of the presentations of the peripheral nervous system involvement. The mode of infection is considered to be via vasculitic mechanisms. In addition, optic neuropathy is a known complication of interferon treatment. Autoantibodies, cytokines, chemokines, and cryoglobulins are accused to play roles in the pathogenesis. In this study, we investigated the involvement of the peripheral nervous system and optic nerves in a group of patients with hepatitis C. The results were in favor of peripheral nerve injury of various types and optic neuropathy of the axonal type.

Hepatitis E virus and neurological injury

Hepatitis E is hyperendemic in many developing countries in Asia and Africa, and is caused by hepatitis E virus (HEV) genotypes 1 and 2, which are spread via the faecal-oral route by contaminated water. Recent data show that HEV infection is also endemic in developed countries. In such geographical settings, hepatitis E is caused by HEV genotypes 3 and 4, and is mainly a porcine zoonosis. In a minority of cases, HEV causes acute and chronic hepatitis, but infection is commonly asymptomatic or unrecognized. HEV infection is associated with a number of extrahepatic manifestations, including a range of neurological injuries. To date, 91 cases of HEV-associated neurological injury--most commonly, Guillain-Barré syndrome, neuralgic amyotrophy, and encephalitis/myelitis--have been reported. Here, we review the reported cases, discuss possible pathogenic mechanisms, and present our perspectives on future directions and research questions.

Hepatitis C virus infection and pain sensitivity in patients on methadone or buprenorphine maintenance therapy for opioid use disorders

BACKGROUND

Patients with opioid use disorders on opioid agonist therapy (OAT) have lower pain tolerance compared to controls. While chronic viral infections such as HCV and HIV have been associated with chronic pain in this population, no studies have examined their impact on pain sensitivity.

METHODS

We recruited 106 adults (41 uninfected controls; 40 HCV mono-infected; and 25 HCV/HIV co-infected) on buprenorphine or methadone to assess whether HCV infection (with or without HIV) was associated with increased experimental pain sensitivity and self-reported pain. The primary outcome was cold pain tolerance assessed by cold-pressor test. Secondary outcomes were cold pain thresholds, wind-up ratios to repetitive mechanical stimulation (i.e., temporal summation) and acute and chronic pain. Multivariable regression models evaluated associations between viral infection status and outcomes, adjusting for other factors.

RESULTS

No significant differences were detected across groups for primary or secondary outcomes. Adjusted mean cold pain tolerance was 25.7 (uninfected controls) vs. 26.8 (HCV mono-infection) vs. 25.3 (HCV/HIV co-infection) seconds (global p-value=0.93). Current pain appeared more prevalent among HCV mono-infected (93%) compared to HCV/HIV co-infected participants (76%) and uninfected controls (80%), as did chronic pain (77% vs. 64% vs. 61%, respectively). However, differences were not statistically significant in multivariable models.

CONCLUSION

This study did not detect an association between HCV infection and increased sensitivity to pain among adults with and without HIV who were treated with buprenorphine or methadone for opioid use disorders. Results reinforce that pain and hyperalgesia are common problems in this population.

Tumefactive multiple sclerosis and hepatitis C virus 2a/2C infection: Dual benefit of long-term interferon beta-1a therapy?

Hepatitis C virus (HCV) infection has been implicated in triggering acute disseminated encephalomyelitis but not tumefactive multiple sclerosis. We report the case of a 17-year-old female who presented with a 5-day history of left hemiparesis and hemisensory loss followed by a right third nerve palsy. Tumefactive multiple sclerosis was diagnosed based on the absence of encephalopathic signs, the presence of tumefactive brain lesions, the exclusion of neoplastic and infectious causes of the lesions by biopsy, and the occurrence of relapse after a period of remission. The patient was at risk for HCV infection due to parenteral drug abuse and multiple sexual partners. Serial HCV antibody tests and RNA polymerase chain reaction assays revealed acute HCV infection and genotyping showed HCV genotype 2a/2c. She was treated with high-dose methylprednisolone and discharged with only mild left hand weakness. Interferon beta-1a 30mcg was administered intramuscularly once a week. Remission from HCV infection was achieved in three years without standard anti-HCV therapy. This case suggests that CNS myelin is a potential target of the immune response to HCV 2a/2c infection, the HCV 2a/2c virus may be involved in triggering autoimmune tumefactive brain lesions, and interferon beta-1a is effective against HCV 2a/2c infection. We recommend serial HCV antibody testing and HCV RNA PCR assay, preferably with HCV genotyping, in all patients with acute inflammatory demyelinating diseases of the CNS.

Treatment for cryoglobulinemic and non-cryoglobulinemic peripheral neuropathy associated with hepatitis C virus infection

BACKGROUND

Peripheral neuropathy is the most common neurologic complication of hepatitis C virus (HCV) infection. The pathophysiology of the neuropathy associated with HCV is not definitively known; however, proposed mechanisms include cryoglobulin deposition in the vasa nervorum and HCV-mediated vasculitis. The optimal treatment for HCV-related peripheral neuropathy has not been established.

OBJECTIVES

To assess the effects of interventions (including interferon alfa, interferon alfa plus ribavirin, corticosteroids, cyclophosphamide, plasma exchange, and rituximab) for cryoglobulinemic or non-cryoglobulinemic peripheral neuropathy associated with HCV infection.

SEARCH METHODS

On 26 August 2014, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, and EMBASE. We also searched two trials registers, the Networked Digital Library of Theses and Dissertations (NDLTD) (October 2014), and three other databases. We checked references in identified trials and requested information from trial authors to identify any additional published or unpublished data.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) and quasi-RCTs involving participants with cryoglobulinemic or non-cryoglobulinemic peripheral neuropathy associated with HCV infection. We considered any intervention (including interferon alfa, interferon alfa plus ribavirin, corticosteroids, cyclophosphamide, plasma exchange, and rituximab) alone or in combination versus placebo or another intervention ('head-to-head' comparison study design) evaluated after a minimum interval to follow-up of at least six months.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. The planned primary outcome was change in sensory impairment (using any validated sensory neuropathy scale or quantitative sensory testing) at the end of the follow-up period.  Other planned outcomes were: change in impairment (any validated combined sensory and motor neuropathy scale), change in disability (any validated disability scale), electrodiagnostic measures, number of participants with improved symptoms of neuropathy (global impression of change), and severe adverse events.

MAIN RESULTS

Four trials of HCV-related cryoglobulinemia fulfiled selection criteria and the review authors included three in quantitative synthesis. All studies were at high risk of bias. No trial addressed the primary outcome of change in sensory impairment. No trial addressed secondary outcomes of change in combined sensory and motor impairment, disability, or electrodiagnostic measures. A single trial of HCV-related mixed cryoglobulinemia treated with pegylated interferon alfa (peginterferon alfa), ribavirin, and rituximab versus peginterferon alfa and ribavirin did not show a significant difference in the number of participants with improvement in neuropathy at 36 months post treatment (risk ratio (RR) 4.00, 95% confidence interval (CI) 0.27 to 59.31, n = 9). One study of interferon alfa (n = 22) and two studies of rituximab (n = 61) provided adverse event data. Severe adverse events were no more common with interferon alfa (RR 7.00, 95% CI 0.38 to 128.02) or rituximab (RR 3.00, 95% CI 0.13 to 67.06) compared to the control group.

AUTHORS' CONCLUSIONS

There is a lack of RCTs and quasi-RCTs addressing the effects of interventions for peripheral neuropathy associated with HCV infection. At present, there is insufficient evidence from RCTs and quasi-RCTs to make evidence-based decisions about treatment.

Peripheral nervous system manifestations of infectious diseases

Infectious causes of peripheral nervous system (PNS) disease are underrecognized but potentially treatable. Heightened awareness educed by advanced understanding of the presentations and management of these infections can aid diagnosis and facilitate treatment. In this review, we discuss the clinical manifestations, diagnosis, and treatment of common bacterial, viral, and parasitic infections that affect the PNS. We additionally detail PNS side effects of some frequently used antimicrobial agents.

Clinical, neurophysiological, and skin biopsy findings in peripheral neuropathy associated with hepatitis C virus-related cryoglobulinemia

Hepatitis C virus (HCV)-related cryoglobulinemia commonly causes disabling complications including peripheral neuropathy and neuropathic pain. In this prospective clinical, neurophysiological, and skin biopsy study we aimed at assessing clinical characteristics and risk factors of peripheral neuropathy and neuropathic pain in patients with HCV-related cryoglobulinemia. We enrolled 69 consecutive patients with HCV-related cryoglobulinemia. We diagnosed neuropathic pain with the DN4 (Neuropathic Pain Diagnostic) questionnaire, and rated the various neuropathic pains with the Neuropathic Pain Symptom Inventory (NPSI). All patients underwent a standard nerve conduction study to assess Aβ-fiber function, laser-evoked potentials to assess Aδ-fiber function, and skin biopsy to assess C-fiber terminals. Of the 69 patients studied, 47 had a peripheral neuropathy, and 29 had neuropathic pain. Patients with peripheral neuropathy were older than those without (P < 0.0001). While peripheral neuropathy was significantly associated with the duration of HCV infection (P < 0.01), it was unrelated to the duration of cryoglobulinemia and cryocrit (P > 0.5). The severity of peripheral neuropathy significantly correlated with the duration of HCV infection (P < 0.05). Laser-evoked potential amplitudes were significantly lower in patients with than in those without neuropathic pain (P < 0.05). Conversely, no difference was found in nerve conduction study and skin biopsy findings (P > 0.05). Our findings show that peripheral neuropathy is related to age and HCV infection, rather than to cryoglobulinemia, and neuropathic pain is associated with damage to nociceptive pathways as assessed with laser-evoked potentials; this might be useful for designing more effective clinical interventions for these common HCV related-cryoglobulinemia complications.

Central nervous system vasculitis associated with hepatitis C virus infection: a brain MRI-supported diagnosis

BACKGROUND

The Hepatitis C virus (HCV) infection is associated with various extrahepatic manifestations, being the Central Nervous System (CNS) rarely involved.

CASE REPORT

We report a case of a 54 year-old black man with arterial hypertension who presented with progressively worsening headaches, apathy, somnolence and left hemiparesis. Brain MRI showed an acute ischemic lesion in the left anterior cerebral artery (ACA) and an old ischemic infarct in the right ACA territory. Brain MRI with gadolinium revealed mural thickening and contrast enhancement of the A1 and A2 segments of the ACAs, of the middle and distal basilar artery and of the P1 segment of the left posterior cerebral artery, suggesting active vasculitis. Digital angiography confirmed those irregularities and stenosis. Laboratory evaluation revealed ESR (73 mm/h), transaminase elevation, elevated HCV viral load genotype 2, positive IGRA, negative cryoglobulins, CSF protein elevation with oligoclonal bands (mirror pattern) and no pleocytosis; investigation excluded other infectious causes. Pegylated interferon alpha-2a and ribavirin, corticotherapy and tuberculosis prophylaxis were started with clinical and imagiological improvement.

CONCLUSION

The typical inflammation signs of the vascular wall demonstrated by the gadolinium-enhanced MRI strengthened the hypothesis of CNS vasculitis. The association with HCV infection is rare but should be investigated once specific therapeutic is required.

The two-edged sword: vasculitis associated with HIV and hepatitis C coinfection

Vasculitis has long been associated with chronic viral infections, thus the twin perils of the infection and the immune response against it that bedevils the specialties of infection and immunity. After HIV was identified, it too became associated with vasculitic syndromes. Later, hepatitis C virus was also isolated, identified and described with its own spectrum of vasculitic diseases, including hepatitis C virus-associated cryoglobulinaemia. With the increasing prevalence of HIV and hepatitis C virus coinfection, there has come an increasing recognition of the range of vasculitides that can occur in this population leading to significant morbidity, diagnostic and treatment challenges. In this review, we examine the epidemiology, pathogenesis and general principles of treatment of these systemic diseases in HIV/hepatitis C virus coinfected individuals.

HIV peripheral neuropathy

Peripheral neuropathies are the most common neurological manifestations occurring in HIV-infected individuals. Distal symmetrical sensory neuropathy is the most common form encountered today and is one of the few that are specific to HIV infection or its treatment. The wide variety of other neuropathies is akin to the neuropathies seen in the general population and should be managed accordingly. In the pre-ART era, neuropathies were categorized according to the CD4 count and HIV viral load. In the early stages of HIV infection when CD4 count is high, the inflammatory demyelinating neuropathies predominate and in the late stages with the decline of CD4 count opportunistic infection-related neuropathies prevail. That scenario has changed with the present almost universal use of ART (antiretroviral therapy). Hence, HIV-associated peripheral neuropathies are better classified according to their clinical presentations: distal symmetrical polyneuropathy, acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), mononeuropathies, mononeuropathies multiplex and cranial neuropathies, autonomic neuropathy, lumbosacral polyradiculomyelopathy, and amyotrophic lateral sclerosis (ALS)-like motor neuropathy. Treated with ART, HIV-infected individuals are living longer and are at a higher risk of metabolic and age-related complications; moreover they are also prone to the potentially neurotoxic effects of ART. There are no epidemiological data regarding the incidence and prevalence of the peripheral neuropathies. In the pre-ART era, most data were from case reports, series of patients, and pooled autopsy data. At that time the histopathological evidence of neuropathies in autopsy series was almost 100%. In large prospective cohorts presently being evaluated, it has been found that 57% of HIV-infected individuals have distal symmetrical sensory neuropathy and 38% have neuropathic pain. It is now clear that distal symmetrical sensory neuropathy is caused predominantly by the ART's neurotoxic effect but may also be caused by the HIV itself. With a sizeable morbidity, the neuropathic pain caused by distal symmetrical sensory neuropathy is very difficult to manage; it is often necessary to change the ART regimen before deciding upon the putative role of HIV infection itself. If the change does not improve the pain, there are few options available; the most common drugs used for neuropathic pain are usually not effective. One is left with cannabis, which cannot be recommended as routine therapy, recombinant human nerve growth factor, which is unavailable, and topical capsaicin with its side-effects. Much has been done to and learned from HIV infection in humans; HIV-infected individuals, treated with ART, are now dying mostly from cardiovascular disease and non-AIDS-related cancers. It hence behooves us to find new approaches to mitigate the residual neurological morbidity that still impacts the quality of life of that population.

Neurological complications of hepatitis C infection

Though well-known as a cause of liver disease, Hepatitis C virus infection is emerging as a cause of a variety of peripheral and central nervous system disorders. The virus causes chronic persistent infection with complex immune responses in the majority of individuals. Viral infection may have the potential to generate neurological illness through direct infection of neural cells or through immune-mediated mechanisms, including enhancement of autoimmune responses. Moreover, the mainstay of antiviral treatment of hepatitis C infection, interferon-alpha, is itself associated with neurological morbidity. Thus neurologists are increasingly faced with diagnosing or even predicting a wide spectrum of neurological complications of hepatitis C infection and/or its treatment.

Adult primary central nervous system vasculitis

Primary CNS vasculitis is an uncommon disorder of unknown cause that is restricted to brain and spinal cord. The median age of onset is 50 years. The neurological manifestations are diverse, but generally consist of headache, altered cognition, focal weakness, or stroke. Serological markers of inflammation are usually normal. Cerebrospinal fluid is abnormal in about 80-90% of patients. Diagnosis is unlikely in the presence of a normal MRI of the brain. Biopsy of CNS tissue showing vasculitis is the only definitive test; however, angiography has often been used for diagnosis even though it has only moderate sensitivity and specificity. The size of the affected vessels varies and determines outcome and response to treatment. Early recognition is important because treatment with corticosteroids with or without cytotoxic drugs can often prevent serious outcomes. The differential diagnosis includes reversible cerebral vasoconstriction syndromes and secondary cerebral vasculitis.

Central nervous system vasculitis and polyneuropathy as first manifestations of hepatitis C

Sensory or motor peripheral neuropathy may be observed in a significant proportion of hepatitis C virus (HCV)-infected patients. However, central nervous system (CNS) involvement is uncommon, especially in cryoglobulin-negative subjects. We describe a case of peripheral neuropathy combined with an ischemic CNS event as primary manifestations of chronic HCV infection without cryoglobulinemia. Significant improvement was observed after antiviral therapy. We discuss the spectrum of neurological manifestations of HCV infection and review the literature.

Hepatitis C virus and autoimmunity

Hepatitis C virus infection is associated with several extrahepatic manifestations. About 60% of patients infected with HCV develop at least one extrahepatic manifestation. The majority of these diseases seem to be triggered through autoimmune mechanisms, such as autoantibody production, autoreactive T cells and complex autoimmune mechanisms leading to systemic autoimmune disorders. In this review we categorize these diseases into three groups according to the main pathogenetic process involved, in particular B-cell-mediated, T-cell-mediated and complex autoimmune systemic diseases.

Chronic hepatitis C virus infection associated with autonomic dysfunction

BACKGROUND

Impaired autonomic function has been described in patients with chronic liver diseases from different aetiologies, and has proven to be a poor prognostic indicator. To date, it is not known how chronic hepatitis C virus (HCV) infection affects the autonomic nervous system.

AIMS

In the present study, we compared cardiovagal autonomic function in patients with chronic HCV infection and healthy controls and examined the relation between autonomic function and serum levels of aminotransferases, HCV RNA, cryoglobulins, albumin and glucose.

METHODS

Autonomic function was assessed in 45 treatment-naïve patients with chronic HCV infection and in 40 healthy controls by determining spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV) indices. The R-R interval was determined by electrocardiogram recording; continuous radial artery pressure was monitored simultaneously by applanation tonometry. Laboratory analyses and quantitative polymerase chain reaction for serum HCV RNA level were performed by standard procedures.

RESULTS

BRS and HRV time and frequency domain indices were lower in patients with HCV infection compared with healthy controls [7.1+/-3.4 vs. 11.5+/-6.5 ms/mmHg for BRS, 168.5+/-160.9 vs. 370.7+/-349.4 ms(2) for low-frequency HRV (mean+/-SD); P<0.01]. Multivariate analysis showed that autonomic dysfunction in HCV-infected patients correlated with elevated alanine aminotransferase levels, but was not associated with serum HCV RNA levels and cryoglobulins.

CONCLUSION

Our results suggest that impaired autonomic function is caused by chronic HCV infection. Further studies are needed, however, to identify the underlying mechanisms.

The role of infectious agents in the pathogenesis of vasculitis

Numerous human studies and animal models have implicated various infectious agents in the pathogenesis of vasculitis in susceptible hosts. However, the link between infection and vasculitis is very complex and only incompletely understood. In fact, different agents can induce the same type of vasculitis, as the case of leukocytoclastic vasculitis exemplifies. Conversely, the same agent can give rise to a panoply of host responses ranging from a clinically silent infection or localized organ involvement to devastating, widespread vasculitis.

Acute encephalomyelitis associated with acute viral hepatitis type B

We describe the case of a 36-year-old woman who developed acute encephalo-myelitis after acute viral hepatitis type B. She was admitted to the hospital with a history of general malaise and nausea of 5 days duration. Her serum showed high transaminase levels and positive HBs-Ag and increased IgM HBc-Ab titers. She had urinary dysfunction, myoclonus and postural tremor of her extremities. Several days later, she developed bilateral limb ataxia and alteration of consciousness. The cerebrospinal fluid examinations showed pleocytosis and increased protein. Treatment with high-dose methylprednisolone resulted in a marked improvement of the clinical and CSF examination. Magnetic resonance imaging of the brain and the spinal cord did not disclose abnormal lesions. The symptoms and clinical course were quite similar to those of acute disseminated encephalomyelitis.

Hepatitis C virus infection induced vasculitis

Cryoglobulinemia are immune complexes that may induce systemic cryoglobulinemic vasculitis, a small-vessel vasculitis involving the skin, the joints, the peripheral nerve system, and the kidneys. During the last 15 years, progresses have been done after the discovery of the hepatitis C virus, the main cause of cryoglobulins. Main factors associated with cryoglobulin production are female gender, alcohol intake above 50 g/day, extensive liver fibrosis, and steatosis. Symptomatic cryoglobulins (i.e., vasculitis) are associated with older age, longer duration of infection, and main characteristics of cryoglobulin (type II, IgM kappa, high serum levels). The physiopathology is complex, and it involves humoral immunity, B- and T-cellular immunity but not the virus itself. Peg-Interféron alpha Ribavirine combination leads to a virological and clinical response of the vasculitis in about 70% of patients. In nonresponders, recent open series suggested the efficacy of Rituximab with a good response in up to 80% of patients but a relapse in 42% after 7 months after the last infusion. For future prospects and projects, new therapeutic strategies include a combination of best antiviral treatment with Peg-Interferon plus Ribavirin and Rituximab. Multicenter controlled trials are mandatory.

Chronic hepatitis C virus infection: Prevalence of extrahepatic manifestations and association with cryoglobulinemia in Bulgarian patients

AIM: To assess the prevalence of extrahepatic manifestations in Bulgarian patients with chronic hepatitis C virus (HCV) infection and identify the clinical and biological manifestations associated with cryoglobulinemia.

METHODS: The medical records of 136 chronically infected HCV patients were reviewed to assess the prevalence of extrahepatic manifestations. Association between cryoglobulin-positivity and other manifestations were identified using χ² and Fisher’s exact test. Risk factors for the presence of extrahepatic manifestations were assessed by logistic regression analysis.

RESULTS: Seventy six percent (104/136) of the patients had at least one extrahepatic manifestation. Clinical manifestations included fatigue (59.6%), kidney impairment (25.0%), type 2 diabetes (22.8%), paresthesia (19.9%), arthralgia (18.4%), palpable purpura (17.6%), lymphadenopathy (16.2%), pulmonary fibrosis (15.4%), thyroid dysfunction (14.7%), Raynaud’s phenomenon (11.8%), B-cell lymphoma (8.8%), sicca syndrome (6.6%), and lichen planus (5.9%). The biological manifestations included cryoglobulin production (37.5%), thrombocytopenia (31.6%), and autoantibodies: anti-nuclear (18.4%), anti-smooth muscle (16.9%), anti-neutrophil cytoplasm (13.2%) and anti-cardiolipin (8.8%). All extrahepatic manifestations showed an association with cryoglobulin-positivity, with the exception of thyroid dysfunction, sicca syndrome, and lichen planus. Risks factors for the presence of extrahepatic manifestations (univariate analysis) were: age ≥ 60 years, female gender, virus transmission by blood transfusions, longstanding infection (≥ 20 years), and extensive liver fibrosis. The most significant risks factors (multivariate analysis) were longstanding infection and extensive liver fibrosis.

CONCLUSION: We observed a high prevalence of extrahepatic manifestations in patients with chronic HCV infection. Most of these manifestations were associated with impaired lymphoproliferation and cryoglobulin production. Longstanding infection and extensive liver fibrosis were significant risk factors for the presence of extrahepatic manifestations in HCV patients.

Approach to vasculitic neuropathies

Since vasculitic neuropathy is treatable and potentially debilitating, clinicians should develop an approach to neuropathy that increases the likelihood of uncovering existing systemic or nonsystemic vasculitis. The presence of a connective tissue disease, systemic vasculitis, asymmetric or non--length-dependent axonal polyneuropathy, or multiple axonal mononeuropathies should heighten suspicion, but vasculitic neuropathy can also present as a distal symmetric polyneuropathy with or without other organ involvement. Electrodiagnostic testing utilizing extensive nerve conductions may be helpful in identifying features suggestive of vasculitic neuropathy and in selecting an abnormal nerve and muscle for biopsy confirmation. An array of laboratory tests may lead to identification of a systemic disorder that is either characterized by or predisposes to vasculitic neuropathy. The mainstays of treatment are corticosteroids and cyclophosphamide, but other drugs are used in specific conditions. With early diagnosis and careful monitoring of treatment regimens, the prognosis is usually good.

Emergency in cryoglobulinemic syndrome: what to do?

The clinical course of cryoglobulinemic syndrome (CS) is usually slow; however, fast aggravations have been frequently reported in recent years. In these cases vasculitic ischemic tissue damage accounts for glomerular involvement, neuropathy, cutaneous ulcers, ischemic heart disease, lung or jejunal impairment and stroke. Other critical events in CS may be represented by sepsis, liver insufficiency, hepatocellular carcinoma and non-Hodgkin's lymphomas. Sometimes emergency can not be controlled and the evolution is fatal. Long-term follow up, emergency outcome and cause of death have not been considered in controlled studies, in large series. Here we report a 53-year old woman affected by IgG-IgMk type II HCV-related mixed cryoglobulinemia, who presented several critical events over the course of the disease, which required therapeutical emergency interventions. The latter consisted of plasma exchange, cytotoxic agents, corticosteroids, intravenous immunoglobulin, antihypertensive drugs, antibiotics, and rituximab. Eventually no therapy was effective and the patient died from a catastrophic-like syndrome. This case is relevant because it enables us to consider some important steps in the treatment of emergency in CS.

Pharmacokinetics of the antiviral agent beta-D-2'-deoxy-2'-fluoro-2'-C-methylcytidine in rhesus monkeys

beta-D-2'-Deoxy-2'-fluoro-2'-C-methylcytidine (PSI-6130) is an effective inhibitor of hepatitis C virus (HCV) replication in vitro. The purpose of this study was to evaluate the single-dose pharmacokinetics of PSIota-6130 in rhesus monkeys following intravenous (i.v.) and oral administration. Noncompartmental analysis of the serum data obtained following oral and i.v. administration was performed. Pharmacokinetic studies with rhesus monkeys indicated slow and incomplete absorption with a mean absorption time (MAT) of 4.6 h and an oral bioavailability of 24.0% +/- 14.3% (mean +/- standard deviation), with comparable mean apparent half-lives following i.v. (4.54 +/- 3.98 h) and oral (5.64 +/- 1.13 h) administrations. The average percentages of the total dose recovered unchanged and in deaminated form in the urine were 32.9% +/- 12.6% and 18.9% +/- 6.6% (i.v.) and 6.0% +/- 3.9% and 3.9% +/- 1.0% (oral), respectively. The total bioavailability, taking into account the parent drug and its deaminated metabolite 2'-deoxy-2'-fluoro-2'-C-methyluridine (PSI-6206), was 64% +/- 26%. PSI-6130 was present in the cerebrospinal fluid after oral and i.v. dosing. However, no deamination of radiolabeled PSI-6130 was detected after 8 h of incubation in monkey and human whole blood. An N(4)-modified prodrug of PSI-6130 (PSI-6419) was orally administered to monkeys, but it failed to improve the oral bioavailability of PSI-6130. Further studies are warranted to improve the oral bioavailability and reduce the deamination of PSI-6130 in order to explore the potential of this drug for the treatment of HCV-infected individuals.

Role of matrix metalloproteinases, proinflammatory cytokines, and oxidative stress-derived molecules in hepatitis C virus-associated mixed cryoglobulinemia vasculitis neuropathy

OBJECTIVE

Mixed cryoglobulinemia (MC) is a systemic vasculitis, usually associated with hepatitis C virus (HCV) infection. The molecular mechanisms responsible for HCV-associated MC (HCV-MC) vasculitis are largely unknown. This study was undertaken to assess the expression profile of selected genes involved in inflammatory vascular damage in patients with HCV-MC vasculitis, patients with polyarteritis nodosa (PAN), and patients with noninflammatory idiopathic neuropathy.

METHODS

The quantitative expression levels of 42 selected genes involved in inflammatory vascular damage were assessed in nerve lesions of patients with HCV-MC vasculitis, PAN (rheumatic disease controls), and noninflammatory idiopathic neuropathy (noninflammatory neuropathy controls), using real-time reverse transcriptase-polymerase chain reaction. Genes were considered to be differentially expressed when there was a >2-fold difference in mean expression levels between groups and the P value was less than 0.05.

RESULTS

Expression levels of 8 genes were significantly increased in HCV-MC patients versus control patients with noninflammatory idiopathic neuropathy, with the highest increase for metallothionein 1 H (MT1H), a hypoxic and oxidative stress protein. Compared with PAN patients, HCV-MC patients had higher expression levels of genes encoding oxidative stress-derived molecules (MT1H, endothelial cell nitric oxide synthase 3, Hsp70, and Hsp90) and tissue plasminogen activator and lower expression levels of matrix metalloproteinase 7 (MMP-7). HCV-MC neuropathies were classified according to their morphologic pattern and the presence or absence of necrotizing arteritis. MMP-1, MMP-7, MMP-9, and interleukin-1beta were up-regulated in patients with necrotizing arteritis.

CONCLUSION

This comprehensive molecular study of HCV-MC vasculitis provides strong evidence that MMPs, proinflammatory cytokines, and oxidative stress-derived molecules have a role in the pathogenesis of HCV-MC vasculitis neuropathy.

Severe hepatitis C virus-related cryoglobulinaemic sensory-motor polyneuropathy treated with pegylated interferon-a2b and ribavirin: clinical, laboratory and neurophysiological study

BACKGROUND/AIMS

Severe involvement of central and/or peripheral nervous system is a rare complication of hepatitis C virus (HCV)-related cryoglobulinaemia.

METHOD

Four patients with HCV-related type II/III cryoglobulinaemia (three males with genotype 1, one female with genotype 3) who presented with severe sensory-motor polyneuropathy, one with central nervous system involvement as well, were treated with pegylated IFNa-2b 1.5 microg/kg/week and ribavirin 10.6 mg/kg/daily for 48 weeks. Neurological evaluation involved detailed clinical motor and sensory scores/scales and neurophysiological studies before and after treatment.

RESULTS/CONCLUSION

Three out of four patients had undetectable serum HCV-RNA, normal levels of aminotransferases and substantially lower or undetectable levels of cryoglobulins at the end of treatment and at 24 weeks follow-up period. Treatment was well tolerated and all patients exhibited significant improvement of neuropathy based on solid clinical and laboratory criteria that was associated with the virological response.

Extrahepatic replication of HCV: insights into clinical manifestations and biological consequences

An estimated 170 million persons are infected with the hepatitis C virus (HCV) worldwide. While hepatocytes are the major site of infection, a broad clinical spectrum of extrahepatic complications and diseases are associated with chronic HCV infection, highlighting the involvement of HCV in a variety of non-hepatic pathogenic processes. There is a growing body of evidence to suggest that HCV can replicate efficiently in extrahepatic tissues and cell types, including peripheral blood mononuclear cells. Nonetheless, laboratory confirmation of HCV replication in extrahepatic sites is fraught with technical challenges, and in vitro systems to investigate extrahepatic replication of HCV are severely limited. Thus, future studies of extrahepatic replication should combine innovative in vitro assays with a prospective cohort design to maximize our understanding of this important phenomenon to the pathogenesis and treatment response rates of HCV.

Paraproteinemic neuropathies

Paraproteinemic neuropathies comprise a diverse group of disorders that includes monoclonal gammopathy of undetermined significance, primary amyloidosis, multiple myeloma, cryoglobulinemia, POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes) syndrome, and Waldenstrom macroglobulinemia. Various factors including hepatitis C virus, vascular endothelial growth factor, and an array of cytokines are implicated in the pathogenesis of these conditions. More recently, a variety of novel antibody specificities, and vasculitis, have also been described as contributory factors in the development of these neuropathies. Therapeutic approaches for paraproteinemic neuropathies have included administration of cytotoxic agents, steroids, interferon-alpha, intravenous immunoglobulin, radiation, bone marrow transplantation, and more recently, drugs such as rituximab and bevacizumab. In this article, we review some of the well-known features of these diseases, and highlight some of the more recent findings from the vast literature for these diseases.