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

Peripheral Neuropathy in Patients with Hepatitis C Infection-Reversibility after HCV Eradication: A Single Center Study

Chronic hepatitis C virus (HCV) infection is characterized by a variety of extra-hepatic manifestations; peripheral neuropathy (PN) is one of the most common, especially when mixed cryoglobulinemia (MCG) is present. The prevalence and risk factors of HCV-related PN in the absence of MCG are largely unknown. We conducted a prospective, single-center study, examining the prevalence and reversibility of HCV-associated neuropathy in the absence of MCG. Nerve fiber density in the epidermis was evaluated through skin biopsy and electroneurography (ENG) before HCV-treatment initiation and 1 year post sustained virological remission (SVR). Forty HCV-infected individuals (nine HIV co-infected) with no other neuron-harming factors were included; four other HCV mono- and three HIV co-infected individuals were excluded due to presence of diabetes, B12 insufficiency, or neurotoxic drugs. Twelve consecutive controls with no neuron-harming conditions were also recruited; eight more were excluded due to meeting exclusion criteria. Four patients had ENG signs of polyneuropathy (two with HCV mono- and two with HIV co-infection), while seven more (five with HCV mono- and two with HIV co-infection) had signs of mono-neuropathy, leading to PN prevalences of 22.5% and 44% for mono- and co-infection, respectively (p value 0.179). The two patients with HCV mono-infection and polyneuropathy and the one with ulnar nerve damage showed ENG improvement 1 year post SVR. Regarding intraepidermal nerve density, HCV infection, irrespective of HIV co-infection, was correlated with a lower intraepidermal neuron density that improved 1 year post SVR (p value 0.0002 for HCV and 0.0326 for HCV/HIV co-infected patients). PN is common in HCV infection; successful eradication of HCV leads to PN improvement.

Considering hepatitis C virus infection as a systemic disease

Hepatitis C virus (HCV) infection has been demonstrated to result in several adverse hepatic outcomes and has been associated with a number of important extrahepatic manifestations. The scope of extrahepatic clinical possibilities includes systemic diseases such as vasculitis and lymphoproliferative disorders, cardiovascular disease, myalgia, arthritis, and sicca syndrome. These end-organ effects of HCV may dominate the clinical course beyond the hepatic complications and significantly worsen the long-term prognosis of infected patients. Until several years ago, the standard of care for the treatment of HCV infection had been interferon-alpha-based regimens, which not only had limited effectiveness in achieving a cure but were often poorly tolerated, especially in patients with kidney disease. In those HCV-infected patients with significant systemic manifestations, the interferon-based regimens were problematic given their association with a wide variety of toxicities. The development of highly effective direct-acting antiviral agents to treat HCV infection presented an opportunity to improve the HCV care cascade with the eradication of HCV in most infected patients and by reducing the burden of both hepatic and extrahepatic complications.

Immune-Mediated Systemic Vasculitis as the Proposed Cause of Sudden-Onset Sensorineural Hearing Loss following Lassa Virus Exposure in Cynomolgus Macaques

Lassa virus (LASV) causes a severe, often fatal hemorrhagic disease in regions in Africa where the disease is endemic, and approximately 30% of patients develop sudden-onset sensorineural hearing loss after recovering from acute disease. The causal mechanism of hearing loss in LASV-infected patients remains elusive. Here, we report findings after closely examining the chronic disease experienced by surviving macaques assigned to LASV exposure control groups in two different studies. All nonhuman primates (NHPs) developed typical signs and symptoms of Lassa fever, and seven succumbed during the acute phase of disease. Three NHPs survived beyond the acute phase and became chronically ill but survived to the study endpoint, 45 days postexposure. All three of these survivors displayed continuous disease symptoms, and apparent hearing loss was observed using daily subjective measurements, including response to auditory stimulation and tuning fork tests. Objective measurements of profound unilateral or bilateral sensorineural hearing loss were confirmed for two of the survivors by brainstem auditory evoked response (BAER) analysis. Histologic examination of inner ear structures and other tissues revealed the presence of severe vascular lesions consistent with systemic vasculitides. These systemic immune-mediated vascular disorders have been associated with sudden hearing loss. Other vascular-specific damage was also observed to be present in many of the sampled tissues, and we were able to identify persistent virus in the perivascular tissues in the brain tissue of survivors. Serological analyses of two of the three survivors revealed the presence of autoimmune disease markers. Our findings point toward an immune-mediated etiology for Lassa fever-associated sudden-onset hearing loss and lay the foundation for developing potential therapies to prevent and/or cure Lassa fever-associated sudden-onset hearing loss.IMPORTANCE Lassa virus is one of the most common causes of viral hemorrhagic fever. A frequent, but as yet unexplained, consequence of infection with Lassa virus is acute, sudden-onset sensorineural hearing loss in one or both ears. Deafness is observed in approximately 30% of surviving Lassa fever patients, an attack rate that is approximately 300% higher than mumps virus infection, which was previously thought to be the most common cause of virus-induced deafness. Here, we provide evidence from Lassa virus-infected cynomolgus macaques implicating an immune-mediated vasculitis syndrome underlying the pathology of Lassa fever-associated deafness. These findings could change the way human Lassa fever patients are medically managed in order to prevent deafness by including diagnostic monitoring of human survivors for onset of vasculitides via available imaging methods and/or other diagnostic markers of immune-mediated vascular disease.

Increased Oxidative Stress as a Risk Factor in Chronic Idiopathic Axonal Polyneuropathy

Chronic idiopathic axonal polyneuropathy (CIAP) is a disorder with insidious onset and slow progression, where no etiology is identified despite appropriate investigations. We aimed to investigate the role of oxidative stress as a risk factor for the pathogenesis of CIAP. Sera of patients with CIAP were tested for protein carbonyl (PC) and 8-hydroxydeoxyguanosine (8H). As a control group, we recruited patients with gluten neuropathy. Twenty-one patients with CIAP and 21 controls were recruited. The two groups did not differ significantly regarding demographics or clinical characteristics (i.e., neuropathy type or disease severity). After adjusting for gender, having CIAP was positively correlated with both the 8H titer (standardized beta coefficient 0.349, p = 0.013) and the PC titer (standardized beta coefficient 0.469, p = 0.001). Oxidative stress appears to be increased in CIAP and might have a role in the pathogenesis of the disease.

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.

New insights into HCV-related rheumatologic disorders: A review

Hepatitis C virus (HCV) infected patients are known to be exposed to major liver complications i.e. cirrhosis and hepatocellular carcinoma. In addition, many extrahepatic manifestations including rheumatologic disorders have been reported in up to two-third of HCV infected patients. These manifestations include frank auto-immune and rheumatic diseases (such as arthralgia, myalgia, arthritis, sicca syndrome and vasculitis) which may dominate the course of infection. Until recently, the standard of care of HCV has been the use of interferon-alpha based regimens, which not only had limited effectiveness in HCV cure but were poorly tolerated. In patients with rheumatic diseases interferon-based regimens may be problematic given their association with a wide variety of autoimmune toxicities. Recent therapeutic advances with new direct anti-HCV therapies (interferon-free) which are more effective and better tolerated, make screening for this comorbidity in patients with rheumatic disorders more important than ever. This review aimed to outline main HCV extrahepatic with a special focus on rheumatologic manifestations.

Extrahepatic manifestations of chronic hepatitis C virus infection

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

Extrahepatic manifestations of chronic hepatitis C virus infection

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

Combined treatment of glibenclamide and CoCl2 decreases MMP9 expression and inhibits growth in highly metastatic breast cancer

Background

To observe the influence of combination treatment with glibenclamide and CoCl₂ on the growth and invasiveness of TA2 breast cancer, and to detect the protein and mRNA expression of MMP9.

Methods

50 adult female TA2 mice were randomly divided into 5 groups including DMSO control, CoCl_2, glibenclamide, CoCl₂ + glibenclamide and paclitaxel. All of these mice were inoculated with TA2 spontaneous breast cancer cells in the left groin. Nine days after inoculation the tumor could be palpated. Different treatments for each group were then subcutaneously administered near the tumors on the 9th and 14th days after injection. Tumor size was measured to determine the growth curve. All mice were sacrificed on the 18th day after initial inoculation and tumor tissues were collected. Some fresh tissues without necrosis were stored at −80°C for mRNA detection and the other tumor tissue was fixed with 10% formalin for H&E and immunohistochemical staining.

Results

The growth rate of tumor cells in the CoCl₂ + glibenclamide group was lower than that seen in the other groups. On the 14th day, the average volume of tumor in the CoCl₂ + glibenclamide group was the lowest and the difference has statistical significance (P < 0.05), while the differences among the CoCl₂, glibenclamide and paclitaxel had no statistical significance. The mean percentage of cells expressing MMP9 and PCNA was the lowest in the CoCl₂ + glibenclamide group (P < 0.05). MMP9 mRNA expression paralleled MMP9 protein expression in these groups (P < 0.05).

Conclusions

Combined treatment with glibenclamide and CoCl₂ inhibits TA2 spontaneous breast cancer growth and invasiveness with effects similar to paclitaxel.

Vasculitic neuropathy

Vasculitis is a primary phenomenon in autoimmune diseases such as polyarteritis nodosa, Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, and essential mixed cryoglobulinemia. As a secondary feature vasculitis may complicate, for example, connective tissue diseases, infections, malignancies, and diabetes. Vasculitic neuropathy is a consequence of destruction of the vessel wall and occlusion of the vessel lumen of small epineurial arteries. Sometimes patients present with nonsystemic vasculitic neuropathy, i.e., vasculitis limited to peripheral nerves and muscles with no evidence of further systemic involvement. Treatment with corticosteroids, sometimes in combination with other immunosuppressants, is required to control the inflammatory process and prevent further ischemic nerve damage.

Coexistence of vasculitides with familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most common autoinflammatory disease characterized by recurrent self-limited attacks of fever accompanied with peritonitis, pleuritis, or arthritis. FMF may coexist with various systemic inflammatory diseases including vasculitides, spondyloarthritis, multiple sclerosis, and inflammatory bowel disease. Among these coexistences, this review concentrates on vasculitic disorders, with the aim of increasing the awareness of FMF-vasculitis association. This association does not merely show a coincidentally increased frequency of vasculitic disorders in FMF; rather, it seems that FMF patients might be at increased risk of developing vasculitis. Indeed, as also suggested by some authors, vasculitis might be an essential feature of FMF. Among the vasculitic disorders reported to be associated with FMF, Henoch-Schönlein purpura, and classical polyarteritis nodosa come the first, possibly followed up by protracted febrile myalgia. There is also an ongoing debate whether Behçet's disease (BD) more frequently seen in FMF than expected by chance alone. In this review, the associations of various vasculitic disorders with FMF and the possible pathogenic mechanisms underlying these associations, as well as the frequencies and clinical significances of FMF-related MEFV mutations in various vasculitides including BD, are discussed in the context of the available data.

Interleukin-1β, C-x-C motif ligand 10, and interferon-gamma serum levels in mixed cryoglobulinemia with or without autoimmune thyroiditis

The aim of this study was to evaluate serum levels of interleukin-1β (IL-1β), chemokine (C-X-C motif) ligand 10 (CXCL10), and interferon-gamma (IFN-γ) in a series of patients with "mixed cryoglobulinemia and hepatitis C virus chronic infection" (MC + HCV) in the presence or absence of autoimmune thyroiditis (AT) and to relate them to the clinical phenotype of these patients. Serum IL-1β, IFN-γ, and CXCL10 were assayed in 30 patients with MC + HCV without AT, in 30 patients with MC + HCV and AT, and in 30 sex- and age-matched controls. Cryoglobulinemic patients showed significantly higher mean IL-1β and CXCL10 levels than controls (P < 0.01). Moreover, CXCL10 was significantly increased in patients with AT patients with respect to those without AT (P < 0.01). Serum IFN-γ levels were not significantly higher in MC + HCV patients than in controls. In conclusion, our study demonstrates significantly high serum levels of IL-1β in patients with MC + HCV with and without AT compared with healthy controls. Further, significantly high serum levels of CXCL10 in patients with MC + HCV compared with healthy controls were confirmed, overall in the presence of AT. Moreover, a pathophysiological association between high circulating levels of IL-1β and CXCL10 has been suggested. A possible therapeutic role of the anti-IL-1 receptor antagonist (Anakirna) in MC remains to be evaluated.

Immunohistochemical approach to the pathogenesis of clinical cases of bovine Herpesvirus type 5 infections

Meningoencephalitis by Herpesvirus type 5 (BoHV-5) in cattle has some features that are similar to those of herpetic encephalitis in humans and other animal species. Human Herpesvirus 3 (commonly known as Varicella-zoster virus 1), herpes simplex viruses (HSV), and equid Herpesvirus 1 (EHV-1) induce an intense inflammatory, vascular and cellular response. In spite of the many reports describing the histological lesions associated with natural and experimental infections, the immunopathological mechanisms for the development of neurological disorder have not been established. A total of twenty calf brains were selected from the Veterinary School, University of São Paulo State, Araçatuba, Brazil, after confirmation of BoHV-5 infection by virus isolation as well as by a molecular approach. The first part of the study characterized the microscopic lesions associated with the brain areas in the central nervous system (CNS) that tested positive in a viral US9 gene hybridization assay. The frontal cortex (Fc), parietal cortex (Pc), thalamus (T) and mesencephalon (M) were studied. Secondly, distinct pathogenesis mechanisms that take place in acute cases were investigated by an immunohistochemistry assay. This study found the frontal cortex to be the main region where intense oxidative stress phenomena (AOP-1) and synaptic protein expression (SNAP-25) were closely related to inflammatory cuffs, satellitosis and gliosis, which represent the most frequently observed neurological lesions. Moreover, MMP-9 expression was shown to be localized in the leptomeninges, in the parenchyma and around mononuclear infiltrates (p < 0.0001). These data open a new perspective in understanding the role of the AOP-1, MMP-9 and SNAP-25 proteins in mediating BoHV-5 pathogenesis and the strategies of host-virus interaction in order to invade the CNS.

Interleukin-25: a cytokine linking eosinophils and adaptive immunity in Churg-Strauss syndrome

Churg-Strauss syndrome (CSS) is characterized by systemic vasculitis and blood and tissue eosinophilia. Blood eosinophilia correlates with disease activity, and activated T cells from CSS patients are predominantly T helper 2 (Th2). Interleukin (IL)-25 has been shown to link innate and adaptive immunity by enhancing Th2 cytokine production. We sought to determine the involvement of IL-25 and its receptor IL-17RB in the pathogenesis of CSS. We found increased levels of IL-25 in the serum of active CSS patients (952 ± 697 vs 75 ± 49 pg/mL in inactive patients and 47 ± 6 pg/mL in healthy donors). IL-25 was correlated with disease activity and eosinophil level. Eosinophils were the main source of IL-25, whereas activated CD4(+) memory T cells were the IL-17RB-expressing cells in CSS. IL-25 enhanced the production of IL-4, IL-5, and IL-13 by activated peripheral blood mononuclear cells. IL-25 and IL-17RB were observed within the vasculitic lesions of patients with CSS, and IL-17RB colocalized with T cells. Increased expression of IL-17RB, tumor necrosis factor receptor-associated factor 6, and JunB in vasculitic lesions of CSS underscored the IL-25-mediated activation, whereas up-regulation of GATA3 and IL-10 supported Th2 differentiation. Our findings suggest that eosinophils, through the production of IL-25, exert a critical role in promoting Th2 responses in target tissues of CSS.

Serum levels of proinflammatory cytokines interleukin-1beta, interleukin-6, and tumor necrosis factor alpha in mixed cryoglobulinemia

OBJECTIVE

No single previous study has evaluated serum levels of the proinflammatory cytokines interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor alpha (TNFalpha) in patients with hepatitis C virus-associated mixed cryoglobulinemia (HCV-MC). This study was undertaken to evaluate serum levels of these cytokines in patients with HCV-MC.

METHODS

Serum IL-1beta, IL-6, and TNFalpha were assayed in 43 patients with HCV-MC, in 43 sex- and age-matched patients with chronic HCV without cryoglobulinemia, and in 43 sex- and age-matched controls.

RESULTS

HCV-MC patients showed significantly higher mean IL-1beta, IL-6, and TNFalpha levels than did the controls (P<0.01) or the HCV patients (P<or=0.04). Serum levels of IL-6 and TNFalpha were significantly higher in HCV patients than in controls (P<0.05).

CONCLUSION

Our findings demonstrate elevated serum levels of IL-1beta, IL-6, and TNFalpha in patients with HCV-MC. If the importance of IL-1beta and IL-6 in the pathogenesis of MC is confirmed, these results will open the way for the evaluation of new therapies for MC.

Serum concentrations of interleukin 1beta, CXCL10, and interferon-gamma in mixed cryoglobulinemia associated with hepatitis C infection

OBJECTIVE

Mixed cryoglobulinemia (MC) is a systemic vasculitis of small and medium-size vessels, often associated with the hepatitis C virus. Research has shown an emerging role for chemokines and type 1 cytokines in the pathophysiology of this vasculitis. Interleukin 1 (IL-1) plays a role in initiating the cascade of immunoinflammatory responses, and levels of the interferon-gamma (IFN-gamma) inducible chemokine CXCL10 have been shown to be significantly associated with the presence of active vasculitis in patients with MC. We evaluated serum levels of IL-1beta, IFN-gamma, and CXCL10 in a series of patients with hepatitis C-related MC (MC+HCV), and correlated these measurements with clinical disease features.

METHODS

Serum IL-1beta, IFN-gamma, and CXCL10 were assayed in 54 patients with MC+HCV, in 54 sex- and age-matched patients with type C chronic hepatitis without cryoglobulinemia (HCV+), and in 54 controls.

RESULTS

MC+HCV patients showed significantly higher mean IL-1beta and CXCL10 serum levels than controls (p < 0.01) or HCV+ patients (p < 0.01). CXCL10 was significantly increased in 14 cryoglobulinemic patients with active vasculitis (necrotizing vasculitis or vasculitic skin ulcers) compared to those without (p < 0.001); IL-1beta was increased in cryoglobulinemic patients with active vasculitis (p = 0.06). No differences were observed for serum IFN-gamma levels.

CONCLUSION

Serum levels of IL-1beta and CXCL10 were high in patients with MC+HCV. Increased CXCL10 and IL-1beta levels were associated with the presence of active vasculitis in MC+HCV patients.