Peripheral neuropathy associated with essential mixed cryoglobulinaemia: a role for hepatitis C virus infection?

Infection, Infectious Agents and Vascular Disease

BACKGROUND

Infectious agents may be involved in the pathogenesis of vascular disease and related complications. The aim of this review is to analyze the most relevant information on the common infections related to vascular disease, discussing the main pathophysiological mechanisms.

METHODS

In the current review, the most important evidence on the issue of infections and vascular disease is searched on Medline, Scopus, and ScienceDirect database.

RESULTS

Among infectious agents, herpesviruses, parvovirus B19, hepatitis viruses, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, treponema pallidum, mycobacterium tuberculosis, pseudomonas aeruginosa, staphylococcus aureus, and candida albicans seem to particularly related to vascular disease.

CONCLUSION

Infectious agents may affect vessel's homeostasis and functionality, both on the arterial and venous side, by means of several pathophysiological mechanisms such as dysregulation in vasomotor function, thromboembolic complications, initiation and progression of atherosclerosis, alteration of perivascular adipose tissue, recruiting inflammatory cells and molecules.

Clinical electrophysiology of axonal polyneuropathies

Axonal neuropathies encompass a wide range of acquired and inherited disorders with electrophysiologic characteristics that arise from the unique neurophysiology of the axon. Accurate interpretation of nerve conduction studies and electromyography requires an in-depth understanding of the pathophysiology of the axon. Here we review the unique neurophysiologic properties of the axon and how they relate to clinical electrodiagnostic features. We review the length-dependent Wallerian or "dying-back" processes as well as the emerging body of literature from acquired axonal neuropathies that highlights the importance of axonal disease at the nodes of Ranvier. Neurophysiologic features of individual inherited and acquired axonal diseases, including primary nerve disease as well as systemic immune mediated, metabolic, and toxic diseases involving the peripheral nerve, are reviewed. This comprehensive review of electrodiagnostic findings coupled with the current understanding of pathophysiology will aid the clinician in the evaluation of axonal polyneuropathies.

Sofosbuvir-daclatasvir improves hepatitis C virus-induced mixed cryoglobulinemia: Upper Egypt experience

BACKGROUND AND AIMS

Hepatitis C virus (HCV) infection is associated with extrahepatic manifestations such as cryoglobulinemia and accounts for up to 90% of all cases of mixed cryoglobulinemia (MC). The present study aimed to evaluate the effect of sofosbuvir-daclatasvir therapy on symptomatic HCV-related MC and sustained virologic response (SVR) achievement.

PATIENTS AND METHODS

This prospective cohort study was carried out on 120 patients with chronic HCV infection, clinically suspected to have MC, but only 63 of whom were positive for cryoglobulins. HCV-MC patients were treated with sofosbuvir 400 mg and daclatasvir 60 mg once daily for 3 months. The serum cryoglobulins levels, complement 3 (C3), complement 4 (C4) (using ELISA assay kits) and rheumatoid factor (RF) (using immunoturbidimetric assay kit), were measured in the included HCV infected patients (to confirm HCV-MC diagnosis), in addition to quantitave HCV-RNA assays, using real time PCR. All these measurements have been done before stating therapy and 12, 24 weeks post-therapy for assessments of immunological recovery, viral load and SVR.

RESULTS

Significant increase in the serum cryoglobulin levels and RF with significant decrease in C3 and C4 serum levels were detected in only 63 out of 120 included HCV infected patients, upon whom the study has been completed. They showed significant decrease in their mean cryoglobulin levels from 41.47 µg/mL ±12.32 SD to 5.12 µg/mL ±3.59 SD then to 5.09 µg/mL ±3.02 SD, 12 to 24 weeks post-therapy respectively (p<0.001), with significant decline in RF concentrations and rise in C3 and C4 serum levels approaching the normal values. There were improvements in the presenting HCV-MC clinical manifestations in variable degrees, ranging from 5 (71.42%) in patients with glomerulonephritis to 62 (98.4%) in patients with purpura. Eighty-seven percent of the included patients showed complete response (clinical, virological and immunological recovery) and 13% showed partial response (virological and immunological recovery without clinical improvement of cryoglobulinemia associated manifestations).

CONCLUSION

A combined therapy of sofosbuvir 400 mg and daclatasvir 60 mg once daily for 3 months was associated with a significant decrease in serum cryoglobulin levels and appears as a reasonable treatment option for HCV-associated MC.

Hepatitis C-related cryoglobulinemic neuropathy: potential role of oxcarbazepine for pain control

BACKGROUND

Peripheral neuropathy is one most common, limiting and invalidating neurological symptom in subjects with hepatitis C virus and mixed cryoglobulinemia. Notably, the medical therapy proposed to eradicate HCV, can frequently exacerbate the painful neuropathy. Therefore, neuropathy therapies are insufficient and inadequate, and comprise immunosuppressive drugs, such as steroid or cyclosporine, intravenous immunoglobulin or plasma exchange. These have shown variable success in case reports, with a presumably temporary effect, but with major side effects.

METHODS

We assessed the effects of oxcarbazepine treatment in 67 cases of cryoglobulinemia related neuropathy, who did not respond to either steroid or Gabapentin, or Pregabalin. Oxcarbazepine was chosen based on the promising preliminary results.

RESULTS

Patients treated with Oxcarbazepine showed a rapid, discrete and persistent relief of polyneuropathic signs, without consistent side effects, and with a limited interaction with concomitant drugs.

CONCLUSIONS

These data favor the use of oxcarbazepine as a useful tool in the management of neuropathic pain associated with Hepatitis-C cryoglobulin neuropathy.

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.

Neuromuscular diseases associated with chronic hepatitis C virus infection

Hepatitis C virus (HCV) infection is a growing international health problem, and more than 170 million people are chronic carriers. Up to 50% of HCV-positive patients develop at least one extrahepatic manifestation during the course of disease. To varying degrees of certainty, there is evidence of an association between chronic HCV infection and a variety of neuromuscular diseases. The pathogenesis of most extrahepatic diseases remains unclear but possibly includes HCV lymphotropism and/or HCV-induced autoantibodies. The therapeutic approach to HCV-associated autoimmune disorders entails eradication of HCV with one of the recombinant interferon-alpha preparations with or without additional immunosuppressive drugs.

Sensory neuropathy in patients with cryoglobulin negative hepatitis-C infection

There is growing evidence that hepatitis-C virus (HCV) infection might cause peripheral neuropathy. We aimed to investigate the prevalence, clinical and electrophysiological features of sensory neuropathy in patients with cryoglobulin negative HCV infection. We studied 46 consecutive cryoglobulin negative HCV positive patients (24 of them with and 22 without neuropathic symptoms, NS) and compared to 28 age and gender matched controls. In all patients and controls, clinical neuropathy symptom (NSS) and neuropathy deficit scores (NDS) were assessed and standard nerve conduction velocity (SNCV) and pain related-evoked potentials (PREP) were recorded. Both, SNCV and PREP were abnormal in 13 NS positive patients (13/46, 28%). Abnormal PREP but normal SNCV were found in 5 (5/46, 11%) NS positive and in 2 NS negative patients (2/46, 4%). PREP abnormalities correlated positive with both clinical neuropathy scores (NSS r=0.62; p<0.001; NDS r=0.57; p<0.001), but not with the duration of the disease, current viral load, or the virus subtype. PREP abnormalities were more frequent (16/33, 48.5%) in HCV patients treated with interferon than in therapy naïve patients (4/13, 30.8%); the difference was, however, not significant. In our present study (1) all virus subtypes are capable of inducing neuropathy, (2) no differences were found between interferon therapy and treatment naive patients, (3) the prevalence of peripheral sensory neuropathy including small sensory fibers (20/46, 43.5%) is higher than previously reported and (4) we found that detection of HCV associated neuropathy depends on the evaluation method.

High prevalence of neuropathies in patients with end-stage liver disease

OBJECTIVES

Peripheral neuropathy has been reported in association with end-stage liver disease, but there is only a limited number of reports on the incidence and features of these neuropathies.

MATERIALS AND METHODS

In this study, 83 patients awaiting liver transplantation were evaluated for the presence of peripheral and autonomic neuropathy.

RESULTS

Sixty-five percent of the patients had evidence of neuropathy, in agreement with peripheral NCS or cardiovascular autonomic function test. The neuropathy was more frequent in patients with advanced hepatic failure, evaluated with the MELD score. The most frequent abnormalities in nerve conduction studies were sensory-motor neuropathies and sensory neuropathies, with a length-dependent pattern.

CONCLUSION

Peripheral neuropathy and autonomic neuropathy are common in patients with end-stage liver disease with different etiology and correlate with the severity of the liver disease.

Management of hepatitis C virus-related mixed cryoglobulinemia

Mixed cryoglobulinemia is a chronic immune complex-mediated disease strongly associated with hepatitis C virus (HCV) infection. Mixed cryoglobulinemia is a vasculitis of small and medium-sized arteries and veins, due to the deposition of complexes of antigen, cryoglobulin and complement in the vessel walls. The main clinical features of mixed cryoglobulinemia vasculitis include the triad of palpable purpura, arthralgias, and weakness, and other pathological conditions such as glomerulonephritis, peripheral neuropathy, skin ulcers, and widespread vasculitis. The treatment of HCV-related mixed cryoglobulinemia is difficult due to the multifactorial origin and clinical polymorphism of the syndrome. It can be directed to eradicate the HCV infection, suppress the B-cell clonal expansion and cryoglobulin production, or ameliorate symptoms. The choice of the most appropriate treatment is strictly related to the assessment of disease activity, and to the extent and severity of organ involvement.

An update on nerve biopsy

Indications for nerve biopsy have decreased during the last 20 years. For the most part, this is a result of progress in the application of molecular biologic diagnostic testing for genetic peripheral neuropathies (PNs) and the increasing use of skin biopsy. The latter is primarily used to evaluate small-fiber PN, although it rarely discloses the specific etiology of a PN. Nerve biopsies are usually performed on either the sural or the superficial peroneal nerve, the latter in combination with removal of portions of the peroneus brevis muscle. The definite diagnosis of vasculitic lesions can be readily established on small paraffin-embedded nerve biopsy samples, although in some cases, the characteristic lesions are only apparent in muscle specimens. Other nerve specimens are routinely fixed in buffered glutaraldehyde and prepared for semithin sections and electron microscopy; frozen specimens are used for immunofluorescence studies. Electron microscopy is of great value in some cases of chronic inflammatory demyelinating polyneuropathies, monoclonal gammopathy, and storage diseases. Because more than 30 genes may be involved in genetic PNs, analysis of nerve lesions can direct the search for mutations in specific genes. Electron microscopy immunocytochemistry is mandatory in some cases of monoclonal dysglobulinemia. Thus, nerve biopsy is still of value in specific circumstances when it is performed by trained physicians and examined in a laboratory with expertise in nerve pathology.

Observations on cryoglobulin testing: I. The association of cryoglobulins containing rheumatoid factors with manifestation of cryoglobulinemic vasculitis

OBJECTIVE

To investigate the results of mixed cryoglobulin tests performed on patients with and without hepatitis C virus (HCV) infection, to determine whether type II cryoglobulins containing rheumatoid factor (Type II-RF) were associated with cryoglobulinemic vasculitis.

METHODS

The cryoglobulin test protocol differed from the routine protocol. In addition to determination of both cryoglobulin concentration and immunoglobulin composition, the presence or absence of RF concentrated in the cryoglobulins was determined.

RESULTS

A qualitative and quantitative association of Type II-RF cryoglobulins with cryoglobulinemic vasculitis was present among HCV-infected patients.

CONCLUSION

Detection and quantification of Type II-RF may enhance clinical monitoring of cryoglobulinemic vasculitis in HCV-infected patients.

Observations on cryoglobulin testing: II. The association of oligoclonal mixed cryoglobulinemia with cirrhosis in patients infected with hepatitis C virus

OBJECTIVE

To determine whether a mixed cryoglobulin type correlated with cirrhosis in patients infected with hepatitis C virus (HCV).

METHODS

We investigated the results of mixed cryoglobulin tests performed in the clinical laboratory on patients with and without HCV infection.

RESULTS

A higher prevalence of oligoclonal cryoglobulins designated Type IIa was present in HCV-infected patients with cirrhosis than in those without cirrhosis.

CONCLUSION

An association of Type IIa cryoglobulins with cirrhosis in HCV-infected patients has not previously been reported.

The clinical spectrum of the neurological involvement in vasculitides

Both the central nervous system (CNS) and the peripheral nervous system (PNS) are major target organs in primary vasculitides. They may either be affected in the setting of systemic vasculitis, potentially involving any other organ, or they may be the sole site of the inflammatory process. In both cases, the clinical pattern of PNS involvement is essentially uniform, presenting as sensory axonal polyneuropathy or mononeuritis multiplex. The damage is related to the ischemic occlusion of the vasanervorum due to small-vessel vasculitis. On the contrary, the range of manifestations of CNS vasculitis is much wider and several pathogenetic mechanisms are implicated, including angiitis of the hemispheres and spinal cord, thrombosis of dural sinuses, stenosis and aneurysms of medium and large arteries, granulomatous meningeal involvement and direct cytokine damage presenting with encephalopathy. Besides, even extracranial noninflammatory vascular disease may induce CNS symptoms, as is the case of carotid stenosis, vena cava syndrome and renovascular hypertension. In this paper we will review the broad spectrum of clinical manifestations of CNS and PNS neuropathy as they occur in primary systemic and non systemic vasculitides.

Surgical treatment of superimposed nerve compressions in hepatitis C neuropathy

The plastic surgeon's usual involvement in patients with hepatitis C is most frequently limited to an inner city population with hand and forearm abscesses from intravenous drug use or to incidences of needle-stick injury in the operating room when the patient is hepatitis C positive. Hand surgeons and peripheral nerve surgeons often treat patients with underlying neuropathies who have superimposed overlying nerve compressions such as carpal tunnel syndrome. We have applied this experience to a patient with underlying peripheral neuropathy associated with Hepatitis C and clinical evidence of overlying lower extremity nerve compressions. We believe that she is the first successful surgical treatment of peripheral nerve compressions in a patient with hepatitis C-associated neuropathy, documented by noninvasive neurosensory testing.

Peripheral neuropathy in patients with hepatitis virus C infection in the Amazon region

INTRODUCTION

Hepatitis virus C (HCV) infection is considered a health problem in the State of Acre localized in the Brazilian Amazon which has a prevalence rate of 5.9%. Peripheral neuropathy is a common extra-hepatic manifestation in patients with HCV.

OBJECTIVE

To determine the prevalence of peripheral neuropathies using clinical and neurophysiological parameters.

METHOD

A cross sectional study was performed in patients assisted by a specialized center of infectious diseases in the State of Acre. All patients completed a clinicoepidemiological questionnaire, physical examination and nerve conduction studies (NCS).

RESULTS

We studied 78 patients with mean age 45.5 years (range from 10 to 76 years), two thirds were male, 51% had at least 8 years of formal education and 96% lived in the capital city of Acre State. Roughly 34% of patients complained about paresthesias mainly in upper limbs. The NCS diagnosed multiple mononeuropathy in 11 (14.1%; IC95% 7.6-23.2) patients and carpal tunnel syndrome in 4 (5.1%) patients.

CONCLUSION

Subclinical involvement of peripheral nerves seems common in patients with HCV, with multiple mononeuropathy the main manifestation of nerve injury in this region as suggested by electrophysiological studies.

Immunohistochemical detection of HCV in nerves and muscles of patients with HCV associated peripheral neuropathy and myositis

BACKGROUND

Chronic hepatitis C Virus (HCV) infection may be associated with numerous extrahepatic manifestations, such as mixed cryoglobulinaemia, membranoproliferative glomerulonephritis, sicca syndrome. Cryoglobulinaemia (CG) is a condition characterized by the presence of serum proteins that reversibly precipitate in the cold. The objective of the present work was to study the histopathological changes in neuromuscular biopsies in patients with HCV associated peripheral neuropathy, or myopathy; with and without cryoglobulinemia, and to assess the presence of HCV in nerve and muscle tissues of those patients which might clarify some pathogenetic mechanisms for neuropathy, and myopathy associated with HCV.

METHODS

The study was conducted on 17 cases of HCV infected patients with peripheral neuropathy and myositis. All patients were subjected to thorough laboratory investigations, neurological examination, electrophysiologic studies including nerve conduction, and needle EMG studies.

RESULTS

Histopathological examination of nerve biopsies showed features of vascultis in 2/10 cases, interstitial inflammatory infiltrates in 5/10. Muscle biopsies showed intense inflammatory reaction, degenerative changes in the muscles of 3/10 cases diagnosed as myositis. Immunohistochemical results, showed in nerve biopsies, 7/10 cases with positive reaction for HCV with nuclear and perinuclear staining.. Two patients showed positive reaction in the epineural, and endoneural blood vessels and a negative reaction in nerve bundles, while in five patients, reaction was only positive in the nerve bundles. In muscle biopsies, 7/10 cases showed positive reaction for HCV in the nuclei of the muscle fibers, including the cases presented with myositis.

CONCLUSION

The presence of HCV particles in nerve and muscle biopsies of patients with peripheral neuropathy suggests a virus triggered immune mediated mechanism.

Persistent multifocal conduction block in vasculitic neuropathy with IgM anti-gangliosides

A 30-year-old man with essential cryoglobulinemia presented with an axonal neuropathy and was found to have vasculitis at nerve biopsy. After 44 months, in accord with clinical deterioration, motor conduction studies showed excessive temporal dispersion multifocally, with partial conduction block persisting for 3 years. Antibody testing showed the presence of IgM anti-GM1, anti-GD1a, and anti-GM2 antibodies. Transitory conduction block has been reported occasionally in patients with vasculitis. The persistent multifocal conduction abnormalities found in this patient were more likely due to a superimposed immunomediated demyelination rather than to chronic nerve ischemia secondary to vasculitis.

[Neuromuscular biopsy and diagnosis of vasculitis]

One characteristic histological lesion on biopsy specimens is mandatory to establish the diagnosis of vasculitis. Combined nerve and muscle biopsies, by the same cutaneous incision, improve significantly the percentage of positive results. Nerve fragments should be taken in every patient presenting sensory manifestations. Such vasculitic lesions are present in medium-sized arterioles and/or small vessels, and correspond mainly to 4 necrotizing vasculitis: panarteritis nodosa (PAN), microscopic polyangiitis (MPA), Churg and Strauss syndrome and Wegener granulomatosis. Microvasculitis should be added to these classical entities, because it corresponds to small vessel wall infiltration by inflammatory cells, as observed in PAN and MPA, but without any necrosis. Microvasculitis has to be differentiated from the inflammatory cell infiltrates surrounding small vessels. However, such perivascular inflammatory cell infiltrates enable the diagnosis of probable vasculitis when associated with clusters of neo-vessels, hemosiderin deposits, or a focal damage of nerve fibers. Grossly, one third of vasculitis diagnosis is confirmed on muscle fragments, a second third on nerve fragments, and the last third on both nerve and muscle fragments. Moreover, in the search for vasculitis, an unpredicted diagnosis of lymphoma or amyloidosis is occasionally established on the neuro-muscular biopsy.

Lewis-Sumner syndrome in hepatitis C virus infection: a possible pathogenetic association with therapeutic problems

A patient with chronic hepatitis from hepatitis C virus (HCV) infection developed Lewis-Sumner syndrome (LSS). The neuropathy worsened after intravenous immunoglobulins, remitted after intravenous methylprednisolone, relapsed during interferon-alpha, but responded again to steroids continued for 68 weeks with clinical remission and without worsening of hepatitis. We are not aware of other reports of HCV infection and LSS. This association may be coincidental or related to a virus-triggered immune-mediated process. Although the coexistence of a dysimmune neuropathy with hepatitis makes problematic the choice of treatment, we emphasize that the patient's condition during treatment with steroids and the 46 following weeks without therapy has been excellent.

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.

Prevalence and characteristics of peripheral neuropathy in hepatitis C virus population

OBJECTIVE

To assess the prevalence of peripheral neuropathy (PN) and its correlation with cryoglobulinemia (CG) in an unselected, untreated referral hepatitis C virus (HCV) population.

PATIENTS AND METHODS

Two hundred and thirty four patients (120 women and 114 men) with untreated HCV infection were consecutively enrolled by seven Italian centres. Clinical neuropathy was diagnosed when symptoms and signs of peripheral sensory or motor involvement were present. Median, ulnar, peroneal, and sural nerves were explored in all patients and distal symmetric polyneuropathy was diagnosed when all explored nerves or both lower limb nerves were affected. Mononeuropathy and mononeuropathy multiplex were diagnosed when one nerve or two non-contiguous nerves with asymmetrical distribution were affected. Screening for CG was done in 191 unselected patients.

RESULTS

Clinical signs of PN were observed in 25 of the 234 patients (10.6%). Electrophysiological PN was found in 36 (15.3%). CG was present in 56/191 patients (29.3%). The prevalence of CG increased significantly with age (p<0.001) and disease duration (p<0.05). PN was present in 12/56 (21%) patients with CG and 18/135 (13%) without CG (p=NS). PN increased significantly with age (p<0.001) and logistic regression analysis confirmed age as the only independent predictor of PN (OR 1.10 for each year; 95% CI 1.04 to 1.15; p<0.001).

CONCLUSIONS

Electrophysiological examination detected subclinical neuropathy in 11 patients (4.7%). Statistical analysis showed that CG was not a risk factor for PN whereas PN prevalence increased significantly with age.

Neuropathies périphériques sans cryoglobulinémie révélatrices de l’hépatite virale C

INTRODUCTION

Peripheral neuropathies are the most common neurological complication of viral hepatitis C infection with mixed cryoglobulinemia.

CASES REPORT

We report five cases (three men, two women) of peripheral neuropathies revealing viral hepatitis C infection without cryoglobulinemia; the patients' mean age was 56 years. Paresthesias were the most frequent symptom. Electroneuromyographic examination found one case of polyneuropathy and four cases of multiplex mononeuropathies; the complement level was normal in all patients and the rheumatoid factor positive in two cases. Etiological investigations for peripheral neuropathy remained negative. Treatment and outcome were variable.

DISCUSSION

Negative cryoglobulinemia in cases of VHC infection with neurological features has been described in the last few years, suggesting the possibility of other mechanisms such as direct action of the virus on the nervous system. There is no consensus on the treatment and outcome is variable.

CONCLUSION

Peripheral neuropathy may reveal VHC infection, underscoring the need for VHC serology testing in etiological investigations for peripheral neuropathies.

Diagnosis and Treatment of Chronic Immune-mediated Neuropathies

The chronic autoimmune neuropathies are a diverse group of disorders, whose diagnosis and classification is based on the clinical presentations and results of ancillary tests. In chronic inflammatory demyelinating polyneuropathy, controlled therapeutic trials demonstrated efficacy for intravenous gamma-globulins, corticosteroids, and plasmaphereis. In multifocal motor neuropathy, intravenous gamma-globulins have been shown to be effective. In the other immune-mediated neuropathies, there are no reported controlled therapeutic trials, but efficacy has been reported for some treatments in non-controlled trials on case studies. Choice of therapy in individual cases is based on reported efficacy, as well as severity, progression, coexisting illness, predisposition to developing complications, and potential drug interactions.

Clinical spectrum of cryoglobulinaemic neuropathy

BACKGROUND AND OBJECTIVE

Cryoglobulinaemic neuropathy (CN) is probably common, as it is usually related to HCV infection. The aim of this study was to delineate the clinical spectrum of CN in a large series and to investigate the factors influencing its expression.

METHODS

Seventy one consecutive patients (12 men, 59 women), diagnosed as having CN on the basis of clinical features of neuropathy, clinical and serological findings of mixed cryoglobulinaemia, and exclusion criteria, were identified during a six year period. All patients underwent clinical examination, and electrophysiological and laboratory investigations.

RESULTS

Results of the patients with "pure" CN (n = 54) and those with comorbidities (n = 17) were evaluated separately. Of the former 76% had sensory neuropathy (including selective small fibre sensory neuropathy (SFSN) in 14 patients), 15% had sensorimotor polyneuropathy, and 9% had mononeuritis multiplex. The pattern of distribution was similar in the patients with comorbidities. In 30/54 patients, CN was the first manifestation of cryoglobulinaemia. Patients with mild cryoglobulinaemic syndrome had sensory neuropathy more frequently than patients with active syndrome (p < 0.001), in particular SFSN (p < 0.001). The latter group had more severe features, with significantly more cases of reduced or absent motor (p = 0.028) and sensory action potentials (p < 0.001), and a tendency towards higher Rankin scores (p = 0.06).

CONCLUSIONS

Sensory neuropathy, often in the form of SFSN, is by far the commonest form of CN. Cryoglobulinaemia should be vigorously investigated in the diagnosis of sensory neuropathy, especially in older women. Activity of the cryoglobulinaemic syndrome is a major factor influencing the clinical expression and severity of CN.

[Vasculitis associated with viral infections]

VIRUSES, THE CAUSE OF VASCULITIS: Although the majority of systemic vasculitis are of unknown causes, the responsibility of a viral infection has been formally demonstrated in some of them and specific treatment can permanently cure them. Each virus incriminated accounts for a particular type of vasculitis. HEPATITIS B VIRAL INFECTION (HBV): Is the cause of polyarteritis nodosa in 36 to 50% of cases. The onset of the symptomatology is acute, usually within a few months following the infection; it is comparable to that observed in the absence of HBV infection. CRYOGLOBULINEMIA RELATED TO THE HEPATITIS C VIRUS (HCV): The clinical manifestations are those of systemic vasculitis with particular tropism for the skin (involvement generally inaugural and almost constant), peripheral nerves and the glomerula. They occur fairly late during the infection. VASCULITIS ASSOCIATED WITH HIV INFECTION: There is strong tropism for the peripheral (multi-neuritis) and central nervous system. During acute parvovirus B19 infection Vasculitis lesions have occasionally been reported following the viremic phase, generally limited to one or several flares of vascular purpura predominating on the lower limbs. FOLLOWING VARICELLA-HERPES ZOSTER INFECTION: Vasculitis occasionally develops in the form of a central neurological deficiency (locomotor deficiency with or without aphasia around one month after an ophthalmologic herpes zoster) or involving the retina or, more rarely, the skin or the kidneys. VASCULITIS ASSOCIATED WITH CYTOMEGALOVIRAL INFECTION: Predominantly observed in immunodepressed patients, vasculitis after CMV infection is diffuse and basically involving the digestive tube, notably the colon, the central nervous system and the skin. A RARE COMPLICATION OF AN HTLV1 INFECTION: Vasculitis of the retina often in the form of necrotic retinitis is often associated with spasmodic paraparessia.

THERAPEUTIC STRATEGY

For many vasculitis of viral origin, corticosteroid and immunosuppressive treatments are only indicated in second intention following failure with antiviral agents and the combination of antivirals and plasma exchanges.

Hepatitis C virus-associated extrahepatic manifestations: a review

The hepatitis C virus (HCV) infection is a worldwide disease that is characterized by a preferential chronic evolution with mild to severe liver disease, including cirrhosis and, in lesser proportion, hepatocarcinoma. Out of these complications, HCV is frequently reported to complicate extrahepatic manifestations. Among those associated to HCV infection with a high degree of certainty, mixed cryoglobulinemia and its complications (skin, neurological, renal, rheumatological involvement) are the most prevalent (50%) in HCV-infected patients. The other diseases include noncryoglobulinemic systemic vasculitis, splenic lymphoma with villous lymphocytes, fatigue, porphyria cutanea tarda, sicca syndrome, and autoantibodies production. The extrahepatic manifestations that share mild-degree certainty of association with HCV infection include B-cell non-Hodgkin lymphoma, autoimmune thrombocytopenia, pruritus, and type II diabetes mellitus. The other diseases such as autoimmune thyroiditis, lichen planus are more questionable for their eventual association with HCV and others (pulmonary fibrosis with or without polymyositis, progressive encephalomyelitis, Mooren's corneal ulcers, erythema nodosum, chronic polyradiculonevritis) are mostly case reports. Howerver, even in cases of tight association, the mechanisms through which HCV may promote or induce extrahepatic manifestations remain unclear and merit further investigations.

Autoimmune neuropathies

Autoimmune neuropathies are common and treatable disorders of the peripheral nerves, which should be properly recognized. This article discusses their diagnosis, differential diagnosis and proper treatment.

Peripheral neuropathy in hepatitis C virus infection with and without cryoglobulinaemia

OBJECTIVES

Hepatitis C virus (HCV) infection is often associated with cryoglobulinaemia (CG). Peripheral neuropathy (PN) is a comparatively common complication of CG associated with HCV infection and it is thought to be attributable to nerve ischaemia. Only few HCV CG patients with PN have been reported. The recent finding of HCV RNA in nerve biopsy specimens has suggested a possible direct role of HCV in the pathogenesis of PN. The authors studied 51 HCV patients to determine the prevalence of CG and to clarify the possible mechanism by which HCV determines the PN.

METHODS

All the patients were studied clinically, by laboratory tests and electrophysiologically. Twenty eight patients underwent sural nerve biopsy where both morphological and morphometric evaluation of the biopsy specimen was performed, as well as statistical analysis.

RESULTS

CG was found in 40 of 51 cases (78%). Polyneuropathy was significantly prevalent in CG+ patients compared with CG- (18 of 40 compared with 1 of 11 patients; p=0.01). HCV CG- patients more frequently developed well defined mononeuropathy or multiple neuropathy when compared with HCV CG+ (10 of 11 compared with 22 of 40; p<0.03). HCV CG+ patients showed significantly higher proportion of rheumatoid factor positivity (p<0.001) and low C4 levels (p=0.001). Nerve biopsy was performed in 25 of 40 HCV CG+ patients and in 3 of 11 HCV CG- patients: epineurial vasculitis was present in 8 of 25 HCV CG+ (32%) and in 2 of 3 HCV CG-. Differential fascicular loss of axons was found in 10 of 25 CG+ (40%) and 1 of 3 CG-, signs of both demyelination and axonal degeneration were present in 7 of 25 CG+ (28%). No significant difference was found in neuropathological features, while histometrical analysis disclosed more severe involvement in CG+ patients.

CONCLUSIONS

These findings suggest that the presence of CG is a negative predictive factor for the associated PN. Morphological findings in the sural nerve from HCV CG- and CG+ are consistent with an ischaemic mechanism of nerve damage and are against a direct role of the virus in causing the associated PN.

Motor-axonal polyneuropathy associated with hepatitis C virus

The association between hepatitis C virus (HCV) infection, the presence of mixed cryoglobulinemia and peripheral neuropathy is well-documented (Apartis et al., 1996). HCV is the chief cause of essential mixed cryoglobulinemia (type II cryoglobulinemia) with cryoglobulins present in up to half of patients with HCV infection (Akriviadis et al., 1997). More recently it has been stated that peripheral polyneuropathy may be associated with HCV chronic infection without mixed cryoglobulinemia (Lidove et al., 2001). Patients usually present with a clinical and electrophysiology--predominantly sensory axonopathies (Apartis et al., 1996; Heckmann et al., 1999) or less frequently with fulminating vasculitis and mononeuropathy multiplex syndrome (David et al., 1996)--especially when associated with cryoglobulinemia. We report, for the first time, the association between pure motor-axonal polyneuropathy and HCV infection without cryoglobulinemia.

Interferon-alpha and ribavirin treatment in patients with hepatitis C virus-related systemic vasculitis

OBJECTIVE

Hepatitis C virus (HCV)-related vasculitis may involve multiple organs, including the skin, kidneys, and nervous system, and may be life-threatening. Although HCV is increasingly recognized as a cause of systemic vasculitis, limited data are available regarding the optimal treatment of this potentially serious condition. Therefore, we retrospectively analyzed the response to treatment in patients with chronic hepatitis C complicated by systemic vasculitis who had received antiviral therapy with interferon-alpha (IFNalpha) and ribavirin.

METHODS

This retrospective study included 27 patients with systemic vasculitis and chronic HCV infection. Each patient had received treatment with IFNalpha and ribavirin for at least 6 months. The response to antiviral treatment was analyzed by comparing clinical, immunologic, and virologic data at the time of entry and during followup. Clinical response was defined according to the evolution of weight, arthralgia, nervous system, renal system, and cutaneous involvement. The virologic and immunologic responses were defined by the absence of HCV RNA and the absence of cryoglobulinemia, respectively, both 6 months after stopping antiviral therapy and at the end of followup.

RESULTS

Patients received IFNalpha for a mean +/- SD of 20 +/- 14 months and ribavirin (at a mean +/- SD dosage of 895 +/- 250 mg/day) for 14 +/- 12 months. Other treatments included low-dose corticosteroids and plasma exchange. After a mean +/- SD followup of 57 +/- 29 months, 25 of 27 patients are alive and are being followed up as outpatients. Because of the heterogeneity of anti-HCV treatments received, the main results were stratified according to patients with 6 months of followup after stopping antiviral treatment (group 1, n = 14) and those who were still undergoing antiviral therapy at the time of analysis (group 2, n = 13). Nine patients in group 1 had a sustained virologic response and were clinical and immunologic complete responders. Four patients in group 1 were virologic nonresponders, and 3 of these patients had partial clinical and immunologic responses. Overall, 10 patients in group 1 had a complete clinical and immunologic response of their vasculitis (all 9 of the sustained virologic responders and 1 of the 5 patients who remained viremic). At the end of followup, 7 patients in group 2 were negative for HCV RNA; 6 were complete clinical responders. Among the other 6 patients in group 2, who had persistent viremia, 4 had a partial clinical response. Among the patients in group 1, HCV RNA was more often undetectable and genotype 1 was less frequent in complete clinical responders compared with partial/nonresponders. Age, sex, clinical vasculitic involvement, mean duration or total cumulative dose of IFNalpha or ribavirin, and use of steroids or plasmapheresis did not differ significantly according to clinical response.

CONCLUSION

Treatment with IFNalpha and ribavirin can achieve a complete clinical response in most patients with HCV-related systemic vasculitis. Complete clinical response correlates with the eradication of HCV.

Neuromuscular diseases and disorders of the alimentary system

This review outlines the relationship and interaction between neuromuscular diseases and disorders of the alimentary system. Neuromuscular manifestations of gastrointestinal and hepatobiliary diseases are first considered. Such diseases may cause neuromuscular disorders by leading to nutritional deficiency or by more direct mechanisms. The pathogenesis, clinical features, and treatment of these various neuromuscular manifestations are discussed. The impact of disorders of nerve, neuromuscular transmission, and muscle on the alimentary system is then reviewed. The main sequelae are impaired deglutition and gastrointestinal dysmotility. The management of these complications is considered.

Impact of treatment on extra hepatic manifestations in patients with chronic hepatitis C

BACKGROUND/AIMS

Fatigue and other extra hepatic manifestations of hepatitis C have never been studied prospectively in a large cohort. The aim was to assess the prevalence of these symptoms prior to any treatment, and on prolonged follow-up in treated and untreated patients.

METHODS

A single-center cohort of consecutive patients with chronic hepatitis C was investigated prior to any treatment. A questionnaire was completed every 6 months for 18 months of follow-up.

RESULTS

Of 1614 patients, 431 met the inclusion criteria (56% male; age 49 years; 60% with significant fibrosis or cirrhosis; 46% with cryoglobulinemia). Seventy-six were untreated; of the treated patients, 83 were sustained responders, 47 relapsers and 225 non-responders. At baseline, fatigue and other extrahepatic manifestations were present in 254 (59%) and 225 (52%) patients. Fatigue was improved in 29 of 83 (35%) responders versus 75 of 348 (22%) patients with detectable hepatitis C virus (HCV)-RNA (P=0.01). The impact of virologic response on fatigue persisted after adjusting for age, gender, fibrosis stage, and depression (odds ratio: 0.34, P<0.001). A cryoglobulin was detectable in two of 34 (6%) responders versus 38 of 115 (33%) patients with detectable HCV-RNA (P<0.001).

CONCLUSIONS

In hepatitis C, a sustained virologic response is associated with a reduction in fatigue and cryoglobulin, but fatigue frequently persists despite a virologic response.

Cryoglobulinemia is a frequent cause of peripheral neuropathy in undiagnosed referral patients

Cryoglobulinemia represents an emerging cause of peripheral neuropathy, especially in Southern Europe, in view of its relationship with hepatitis C virus infection. In a series of 100 consecutive referral patients with uncharacterized peripheral neuropathies, we systematically investigated cryoglobulinemia to assess its diagnostic yield. The most frequent diagnosis was hereditary neuropathy (33%), 29% were acquired neuropathies of different types, and no cause could be identified in 27%. Cryoglobulinemic neuropathy was diagnosed in 11 patients (7 women and 4 men), aged 54-77 (mean = 63.5 years), most presenting with sensory polyneuropathy, often asymmetrical. Cryoglobulin was also detected in 2 additional patients in whom a final diagnosis of non-Hodgkin lymphoma was made. Purpura was absent in 4 patients (and in 2 with lymphoma), or restricted to discrete manifestations in the remaining patients, which did not provide a clue to the diagnosis. Thus, search for cryoglobulin proves useful in a substantial number of undiagnosed peripheral neuropathies (11% to 13% in our series), even in the absence of typical skin lesions, and it is recommended as a first-line investigation in patients with unexplained neuropathy presenting in middle to older age.

Cryoglobulinemia vasculitis

Cryoglobulins are immunogloblulins that persist in the serum, precipitate with cold temperature, and resolubilize when rewarmed. Mixed cryoglobulins, composed of different immunoglobulins, with a monoclonal component in type II and only polyclonal immunoglobulins in type III, are associated with connective tissue, malignant hematologic, or obvious infectious diseases. The syndrome of mixed cryoglobulinemia represents the consequence of an immune complex-type vasculitis. It is characterized by the clinical triad of purpura, arthralgia, and asthenia, and may involve numerous organs, particularly the peripheral nervous system and the kidneys. Mixed cryoglobulinemia frequently is associated with clinical and biologic evidence of liver disease. It seems fairly clear that mixed cryoglobulinemia is often a manifestation of underlying chronic active or persistent hepatitis. In the last 10 years, many studies have demonstrated that infection with hepatitis C virus is involved in the pathogenesis of most mixed cryoglobulinemia vasculitis. This review analyzes the main published data of hepatitis C virus-mixed cryoglobulinemia, the role of liver alterations, the predictive factors associated with mixed cryoglobulin production in hepatitis C virus patients and whether its character is symptomatic, and the different types of vasculitis associated with hepatitis C virus chronic infection and their treatments.

[Peripheral neuropathy and hepatitis C virus infection: more than cryoglobulinemia]

PURPOSE

To study characteristics of peripheral neuropathies associated with hepatitis C virus infection.

METHODS

A study of two groups of four patients with peripheral neuropathy and infected with hepatitis C virus, and a literature review.

RESULTS

We observed four cases of peripheral neuropathy in patients with hepatitis C virus infection with persistent negativity of mixed cryoglobulinemia, and with no purpura, rheumatoid factor, or low C4 level. Neuropathy improved with treatment in three patients between 8 and 28 months after treatment was begun. We report four other observations of peripheral neuropathy with mixed cryoglobulinemia. Worsening of peripheral neuropathy was observed 2 to 13 weeks after initiation of interferon alpha despite improvement of hepatic parameters. After stopping interferon, peripheral neuropathy worsened (one case), stabilized (one case), or improved (two cases).

DISCUSSION

In patients infected with hepatitis C virus, peripheral neuropathy can be due to mixed cryoglobulinemia, periarteritis nodosa, and perhaps hepatitis C virus itself as suggested by our first observations. Low doses of interferon alpha may worsen peripheral neuropathy in patients with mixed cryoglobulinemia, as suggested in our later observations.

Paraproteinemic Neuropathy

Few prospective, randomized, placebo-controlled trials have been performed to guide clinicians in the management of neuropathies seen in the setting of monoclonal gammopathies (paraproteins). Recommendations must be made on the basis of clinical experience and information gleaned from various uncontrolled and open-label trials. In every instance, decisions concerning therapy must be based on the clinical setting in which the paraprotein occurs. Treatment of paraproteinemic neuropathies associated with multiple myeloma, amyloidosis, and Waldenström's macroglobulinemia should be directed at the treatment of the underlying disease. These neuropathies often remain recalcitrant to therapy. If the paraprotein results from cryoglobulinemia due to hepatitis C virus infection, interferon-alpha (with or without ribavirin) provides optimal subjective and objective relief from symptoms. For neuropathy associated with osteosclerotic myeloma (POEMS syndrome) and solitary bone lesions, radiation therapy is the most effective and least toxic initial therapy. In those patients with monoclonal gammopathies of undetermined significance (MGUS), consideration of the clinical syndrome may be very helpful in selecting appropriate treatment. Patients who fulfill diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are best treated in a manner similar to that used for idiopathic CIDP (ie, with intravenous immunoglobulin, plasma exchange, and corticosteroids). Class I evidence documents plasma exchange to be effective in peripheral neuropathies associated with MGUS of the IgG and IgA, but not IgM, types. The most difficult cases to treat are those with peripheral neuropathies associated with IgM monoclonal gammopathies, with or without reactivity to myelin-associated glycoprotein (MAG). A number of published case series propose therapeutic regimens for these conditions, yet optimal treatment remains to be established. In many cases, mildly symptomatic patients should not be subjected to the morbidity associated with current treatment regimens. In those patients requiring treatment, this author initially tries plasma exchange, followed by a course of chlorambucil if the symptoms and signs are predominantly sensory. For cases with rapid progression or significant disability, a regimen of monthly pulses with prednisone and cyclophosphamide is recommended. If improvement does not ensue, a trial of a newer agent, such as rituximab, is recommended. Supportive treatment with physical therapy, orthotics, and ambulatory aids enhances patient independence at a relatively low cost.

Neuromuscular complications of connective tissue diseases

The connective tissue diseases, such as rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus, systemic sclerosis, and vasculitis, may cause various disorders of the peripheral nervous system. In this review, the clinical effects of the connective tissues diseases on nerve and muscle are examined with particular attention to mononeuritis multiplex, distal symmetric neuropathy, fulminant motor neuropathy, compression neuropathy, sensory neuronopathy, and trigeminal sensory neuropathy.