High values of CXCL10 serum levels in mixed cryoglobulinemia associated with hepatitis C infection

Evaluating the role of chemokines and chemokine receptors involved in coronavirus infection

INTRODUCTION

Coronaviruses are a large family of positive-stranded nonsegmented RNA viruses with genomes of 26-32 kilobases in length. Human coronaviruses are commonly associated with mild respiratory illness; however, the past three decades have seen the emergence of severe acute respiratory coronavirus (SARS-CoV), middle eastern respiratory coronavirus (MERS-CoV), and SARS-CoV-2 which is the etiologic agent for COVID-19. Severe forms of COVID-19 include acute respiratory distress syndrome (ARDS) associated with cytokine release syndrome that can culminate in multiorgan failure and death. Among the proinflammatory factors associated with severe COVID-19 are the chemokines CCL2, CCL3, CXCL8, and CXCL10. Infection of susceptible mice with murine coronaviruses, such as mouse hepatitis virus (MHV), elicits a similar chemokine response profile as observed in COVID-19 patients and these in vivo models have been informative and show that targeting chemokines reduces the severity of inflammation in target organs.

AREAS COVERED

PubMed was used using keywords: Chemokines and coronaviruses; Chemokines and mouse hepatitis virus; Chemokines and COVID-19. Clinicaltrials.gov was used using keywords: COVID-19 and chemokines; COVID-19 and cytokines; COVID-19 and neutrophil.

EXPERT OPINION

Chemokines and chemokine receptors are clinically relevant therapeutic targets for reducing coronavirus-induced inflammation.

Role of Chemokine (C-X-C Motif) Ligand 10 (CXCL10) in Renal Diseases

Chemokine C-X-C ligand 10 (CXCL10), also known as interferon-γ-inducible protein 10 (IP-10), exerts biological function mainly through binding to its specific receptor, CXCR3. Studies have shown that renal resident mesangial cells, renal tubular epithelial cells, podocytes, endothelial cells, and infiltrating inflammatory cells express CXCL10 and CXCR3 under inflammatory conditions. In the last few years, strong experimental and clinical evidence has indicated that CXCL10 is involved in the development of renal diseases through the chemoattraction of inflammatory cells and facilitation of cell growth and angiostatic effects. In addition, CXCL10 has been shown to be a significant biomarker of disease severity, and it can be used as a prognostic indicator for a variety of renal diseases, such as renal allograft dysfunction and lupus nephritis. In this review, we summarize the structures and biological functions of CXCL10 and CXCR3, focusing on the important role of CXCL10 in the pathogenesis of kidney disease, and provide a theoretical basis for CXCL10 as a potential biomarker and therapeutic target in human kidney disease.

The aggregation between AITD with rheumatologic, or dermatologic, autoimmune diseases

Autoimmune thyroid diseases (AITD) are organ-specific autoimmune disorders mediated by Th1 lymphocytes, whose main clinical presentations are Hashimoto's thyroiditis (HT), or Graves' disease (GD). HT, GD, thyroid autoantibodies and thyroid dysfunctions have been shown in systemic rheumatologic diseases (as Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, or cryoglobulinemia). New associations of AITD with other autoimmune diseases are being discovered, for example with psoriatic arthritis and dermatological diseases. Several investigations suggest the importance of a shared genetic susceptibility and of environmental factors in patients with AITD and associated systemic autoimmunity. A major Th1 autoimmune response occurs in the initial, and/or active phases of organ-specific autoimmune disorders and/or systemic rheumatologic diseases with increased serum, or tissue, expressions of the Th1 chemokine CXCL10. Thyroid dysfunctions might have an important clinical impact, so a periodic thyroid screening in women with systemic or dermatological autoimmunity, overall in presence of thyroid autoantibodies is suggested.

Inflammatory and cardiovascular diseases biomarkers in chronic hepatitis C virus infection: A review

Hepatitis C virus (HCV) infects 180 million people worldwide and over 4 million people in the United States. HCV infection is a major cause of chronic liver disease and is recognized as a risk factor for clinical cardiovascular disease (CVD). Many studies have shown increased prevalence of cardiac and inflammatory biomarkers in patients with chronic HCV infection (CHC), and though these markers may be used to risk stratify people for cardiac disease in the general population their role in the HCV population is unknown. Patients with CHC have elevated cardiac and inflammatory biomarkers compared to noninfected controls which may play a role in CVD risk stratification. We undertook a systematic review of inflammatory and cardiac biomarkers in people with HCV infection with a focus on the effect of CHC on serum levels of these markers and their utility as predictors of CVD in this population. Medline, EMBASE, and Cochrane databases were searched for relevant articles until June 2019. A total of 2430 results were reviewed with 115 studies included. Our review revealed that HCV infection significantly alters serum levels of markers of inflammation, endothelial function, and cardiac dysfunction prior to HCV treatment, and some of which may change in response to HCV therapy. Current risk stratification tools for development of CVD in the general population may not account for the increased inflammatory markers that appear to be elevated among HCV‐infected patients contributing to increased CVD risk.

Fisiopatología de la hepatitis C y diabetes mellitus. Hacia la cura de dos epidemias en el siglo XXI

La infección crónica por virus de la hepatitis C (VHC) y la diabetes mellitus (DM) son dos problemas de salud pública que impactan los sistemas de salud, con una alta carga económica global. La infección por VHC produce manifestaciones hepáticas tales como hepatitis, cirrosis y carcinoma hepatocelular; asimismo, se ha involucrado en la patogénesis de manifestaciones extrahepáticas, entre las cuales se ha asociado con alteraciones metabólicas como la DM. Estudios longitudinales y transversales han reportado mayor incidencia y prevalencia de DM en pacientes con infección crónica por VHC. La DM acelera la progresión histológica y clínica en pacientes con infección crónica por VHC y las complicaciones cardiovasculares. Recientemente se ha avanzado en el tratamiento y la introducción de nuevos medicamentos como los antivirales de acción directa, que mejoran el control glucémico en estos pacientes.

Biomarkers in Vasculitides of the Nervous System

Besides being affected by the rare and severe primary angiitis of the central nervous system (PACNS) the nervous system is also affected by primary systemic vasculitides (PSV). In contrast to PACNS, PSV affect not only the central but also the peripheral nervous system, resulting in a large array of potential symptoms. Given the high burden of disease, difficulties in distinguishing between differential diagnoses, and incomplete pathophysiological insights, there is an urgent need for additional precise diagnostic tools to enable an earlier diagnosis and initiation of effective treatments. Methods available to date, such as inflammatory markers, antibodies, cerebrospinal fluid (CSF) analysis, imaging, and biopsy, turn out to be insufficient to meet all current challenges. We highlight the use of biomarkers as an approach to extend current knowledge and, ultimately, improve patient management. Biomarkers are considered to be useful for disease diagnosis and monitoring, for predicting response to treatment, and for prognosis in clinical practice, as well as for establishing outcome parameters in clinical trials. In this article, we review the recent literature on biomarkers which have been applied in the context of different types of nervous system vasculitides including PACNS, giant-cell arteritis, Takayasu's arteritis, polyarteritis nodosa, ANCA (anti-neutrophil cytoplasm antibody)-associated vasculitides, cryoglobulinemic vasculitis, IgA vasculitis, and Behçet's disease. Overall, the majority of biomarkers is not specific for vasculitides of the nervous system.

Chemokines in hyperthyroidism

The term “hyperthyroidism” indicates a condition due to an exaggerate production of thyroid hormone; the most frequent cause is Graves’ disease (GD).

We review cytokines and chemokines in hyperthyroidism, with a special focus in GD.

In GD, recruited Th1 lymphocytes are responsible for enhanced IFN-γ and TNF-α production, which in turn stimulates Th1 chemokines release from thyrocytes, initiating and perpetuating the autoimmune process.

Circulating levels of these chemokines are associated with the active phase of GD.

Additional studies are necessary to investigate whether Th1 chemokines could be a novel therapeutic target in this disease.

Hepatitis C virus infection is a risk factor for non-Hodgkin lymphoma: A MOOSE-compliant meta-analysis

Previous studies have reached conflicting results regarding the possibility that hepatitis C virus (HCV) infection may increase the risk of non-Hodgkin lymphoma (NHL). We performed a meta-analysis to clarify the relationship between HCV infection and development of NHL. The PubMed, Web of Science, and Embase databases were searched for relevant studies estimating the association between HCV infection and NHL risk through October 31, 2017. Fixed effects or random effects models were used to calculate the pooled odds ratio (OR) and its 95% confidence interval (CI). A total of 18 studies met the inclusion criteria. We found a positive association between HCV infection and NHL (pooled OR 1.69, 95% CI 1.40-2.03, P < .05). In conclusion, our meta-analysis suggested that HCV infection was associated with increased risk of developing NHL.

Pro-inflammatory effects of the Th1 chemokine CXCL10 in acquired aplastic anaemia

CXCL10/IFN-γ-induced protein 10 (IP-10) and its corresponding receptor CXCR3 have long been considered to be involved in the pathophysiology of type 1 T (Th1) cell-orientated autoimmune diseases. However, the exact role of CXCL10 in the pathogenesis of aplastic anaemia (AA) has not been thoroughly studied. The aim of our study was to evaluate the plasma level of CXCL10 and its effects on CD4⁺ T cell differentiation in AA. In our study, we found that an elevated plasma level of CXCL10 was negatively correlated with platelet, absolute neutrophil and reticulocyte counts, while it was positively correlated with the proportion of lymphocytes in white blood cells in AA patients. To confirm the pro-inflammatory effects of CXCL10 in AA, we isolated CD4⁺ T cells and evaluated the function of CXCL10 in CD4⁺ T cell differentiation. In vitro stimulation experiments further revealed the pro-inflammatory role of CXCL10 in AA, partially by promoting the secretion of interferon (IFN)-γ and IL-17. In addition, CXCL10 significantly skewed CD4⁺ T cell differentiation to Th1 cells and T helper 17 (Th17) cells in AA patients, while it inhibited the differentiation of type 2 T (Th2) cells only in controls. The mRNA expression of transcription factors representative of T cell differentiation was detected by RT-PCR. Consistently, our results showed that after CXCL10 treatment, the expression of T-bet and RORγt was significantly enhanced, while the expression of GATA3 was inhibited. In conclusion, our results indicated that CXCL10, a pro-inflammatory chemokine, might be involved in the abnormal immune response in AA.

CXCL10 in psoriasis

Chemokine (C-X-C motif) ligand (CXCL)10 is involved in the pathogenesis of psoriasis. It has been demonstrated that chemokine (C-X-C motif) receptors (CXCR)3 and CXCL10 were detected in keratinocytes and the dermal infiltrate obtained from active psoriatic plaques and that successful treatment of active plaques decreased the expression of CXCL10. Elevated CXCL10 serum levels have been shown in patients with psoriasis, with a type 1 T helper cells immune predominance at the beginning of the disease, while a decline of this chemokine has been evidenced later, in long lasting psoriasis. Circulating CXCL10 is significantly higher in patients with psoriasis in the presence of autoimmune thyroiditis. It has been hypothesized that CXCL10 could be a good marker to monitor the activity or progression of psoriasis. Efforts have been made to modulate or inhibit the CXCR3/CXCL10 axis in psoriasis to modify the course of the disease.

Virus-driven autoimmunity and lymphoproliferation: the example of HCV infection

HCV chronic infection is characterized by possible development of both hepatic and extrahepatic manifestations. The infection by this both hepatotropic and lymphotropic virus is responsible for polyoligoclonal B-lymphocyte expansion, leading to several immune-mediated disorders. Mixed cryoglobulinemia syndrome that in some cases may evolve to frank B-cell non-Hodgkin's lymphoma is the prototype of HCV-driven autoimmune and lymphoproliferative disorders. The HCV oncogenic potential has been suggested by several clinicoepidemiological and laboratory studies; it includes hepatocellular carcinoma, B-cell non-Hodgkin's lymphoma and papillary thyroid cancer. The definition HCV syndrome refers to the complex of HCV-driven diseases; these latter are characterized by heterogeneous geographical distribution, suggesting a role of other important genetic and/or environmental cofactors. The natural history of HCV syndrome is the result of a multifactorial and multistep pathogenetic process, which may evolve from mild manifestations to systemic autoimmune disorders, and less frequently to malignant neoplasias. The present updated review analyzes the clinical and pathogenetic aspects of the main HCV-associated diseases.

Cytokines and HCV-related autoimmune disorders

Cytokines are intercellular mediators involved in viral control and liver damage being induced by infection with hepatitis C virus (HCV). The complex cytokine network operating during initial infection allows a coordinated, effective development of both innate and adaptive immune responses. However, HCV interferes with cytokines at various levels and escapes immune response by inducing a T-helper (Th)2/T cytotoxic 2 cytokine profile. Inability to control infection leads to the recruitment of inflammatory infiltrates into the liver parenchyma by interferon (IFN)-γ-inducible CXC chemokine ligand (CXCL)9, -10, and -11 chemokines, which results in sustained liver damage and eventually in liver cirrhosis. The most important systemic HCV-related extrahepatic diseases-mixed cryoglobulinemia, lymphoproliferative disorders, thyroid autoimmune disorders, and type 2 diabetes-are associated with a complex dysregulation of the cytokine/chemokine network, involving proinflammatory and Th1 chemokines. The therapeutical administration of cytokines such as IFN-α may result in viral clearance during persistent infection and revert this process. Theoretically agents that selectively neutralize CXCL10 could increase patient responsiveness to traditional IFN-based HCV therapy. Several studies have reported IL-28B polymorphisms and circulating CXCL10 may be a prognostic markers for HCV treatment efficacy in HCV genotype 1 infection.

Abnormal CD4 + T helper (Th) 1 cells and activated memory B cells are associated with type III asymptomatic mixed cryoglobulinemia in HCV infection

Background

Mixed cryoglobulinemia (MC) in hepatitis C virus (HCV) infection is associated with abnormal immune responses mediated by T cells and B cells, while the relationships of different subsets of CD4 + T helper (Th) cells, B cells and associated cytokines with type III asymptomatic MC in HCV infection are poorly understood.

Methods

Fifty-four chronic hepatitis C (CHC) patients and 23 healthy controls (HCs) were enrolled in the study. Serum cryoglobulins were detected by cryoprecipitation. The types of cryoglobulin were determined by western blot. The phenotypes and frequencies of Th cell and B cell subsets were detected by flow cytometric analysis. The cytokines IFN-γ, IL-4, IL-17, IL-21, IL-22, and TGF-β were measured by enzyme-linked immunosorbent assay.

Results

Twenty-six CHC patients were detected with type III asymptomatic MC. The frequencies of Th2, Th17, follicular helper T (Tfh cells), Th22, and tissue-like B cells were significantly higher in CHC patients compared to HCs, while these cell subsets were not significantly different between CHC patients and HCV-related MC patients. The frequencies of Th1 and activated memory B cells increased in HCV-related MC patients compared to HCs, although the difference between the two cell subsets in CHC patients and HCs was not significant. The frequency of regulatory T cells (Treg cells) was higher in CHC patients than in HCV-related MC patients and HCs. Higher expressions of serum IFN-γ, IL-17, IL-21, and IL-22 were observed in CHC patients than in HCs, but the differences were not significantly different in CHC patients and HCV-related MC patients. The frequency of Th1 cells was associated with activated memory B cells in HCV-related MC patients, and the frequency of Th1 cells and activated memory B cells was closely related to HCV RNA in HCV-related MC patients.

Conclusions

The increased frequencies of Th17 cells, Tfh cells, Th22 cells, Treg cells, cytokines IL-17, IL-21, IL-22, and tissue-like B cells, were related to HCV infection but not type III asymptomatic MC. Higher frequencies of Th1 cells and activated memory B cells were associated with type III asymptomatic MC in HCV infection.

Hepatitis C virus syndrome: A constellation of organ- and non-organ specific autoimmune disorders, B-cell non-Hodgkin's lymphoma, and cancer

The clinical course of chronic hepatitis C virus (HCV) infection is characterized by possible development of both liver and extrahepatic disorders. The tropism of HCV for the lymphoid tissue is responsible for several immune-mediated disorders; a poly-oligoclonal B-lymphocyte expansion, commonly observed in a high proportion of patients with HCV infection, are responsible for the production of different autoantibodies and immune-complexes, such as mixed cryoglobulins. These serological alterations may characterize a variety of autoimmune or neoplastic diseases. Cryoglobulinemic vasculitis due to small-vessel deposition of circulating mixed cryoglobulins is the prototype of HCV-driven immune-mediated and lymphoproliferative disorders; interestingly, in some cases the disease may evolve to frank malignant lymphoma. In addition, HCV shows an oncogenic potential as suggested by several clinico-epidemiological and laboratory studies; in addition to hepatocellular carcinoma that represents the most frequent HCV-related malignancy, a causative role of HCV has been largely demonstrated in a significant percentage of patients with isolated B-cells non-Hodgkin's lymphomas. The same virus may be also involved in the pathogenesis of papillary thyroid cancer, a rare neoplastic condition that may complicate HCV-related thyroid involvement. Patients with HCV infection are frequently asymptomatic or may develop only hepatic alteration, while a limited but clinically relevant number can develop one or more autoimmune and/or neoplastic disorders. Given the large variability of their prevalence among patients' populations from different countries, it is possible to hypothesize a potential role of other co-factors, i.e., genetic and/or environmental, in the pathogenesis of HCV-related extra-hepatic diseases.

Peroxisome Proliferator-Activated Receptor- γ in Thyroid Autoimmunity

Peroxisome proliferator-activated receptor- (PPAR-) γ expression has been shown in thyroid tissue from patients with thyroiditis or Graves' disease and furthermore in the orbital tissue of patients with Graves' ophthalmopathy (GO), such as in extraocular muscle cells. An increasing body of evidence shows the importance of the (C-X-C motif) receptor 3 (CXCR3) and cognate chemokines (C-X-C motif) ligand (CXCL)9, CXCL10, and CXCL11, in the T helper 1 immune response and in inflammatory diseases such as thyroid autoimmune disorders. PPAR-γ agonists show a strong inhibitory effect on the expression and release of CXCR3 chemokines, in vitro, in various kinds of cells, such as thyrocytes, and in orbital fibroblasts, preadipocytes, and myoblasts from patients with GO. Recently, it has been demonstrated that rosiglitazone is involved in a higher risk of heart failure, stroke, and all-cause mortality in old patients. On the contrary, pioglitazone has not shown these effects until now; this favors pioglitazone for a possible use in patients with thyroid autoimmunity. However, further studies are ongoing to explore the use of new PPAR-γ agonists in the treatment of thyroid autoimmune disorders.

Hepatitis C virus induced endothelial inflammatory response depends on the functional expression of TNFα receptor subtype 2

In hepatitis C virus (HCV) infection, morbidity and mortality often result from extrahepatic disease manifestations. We provide evidence for a role of receptors of the innate immune system in virally induced inflammation of the endothelium in vitro and in vivo. Corresponding to the in vitro finding of an HCV-dependent induction of proinflammatory mediators in endothelial cells, mice treated with poly (I:C) exhibit a significant reduction in leukocyte rolling velocity, an increase in leukocyte adhesion to the vessel wall and an increased extravasation of leukocytes. HCV directly promotes activation, adhesion and infiltration of inflammatory cells into the vessel wall by activation of endothelial viral receptors. Poly (I:C) induces the expression of TLR3 in vivo and hereby allows for amplification of all of the aforementioned responses upon viral infection. Proinflammatory effects of viral RNA are specifically mediated by TLR3 and significantly enhanced by tumor necrosis factor alpha (TNFα). HCV-RNA induces the endothelial expression of TNFα and TNFα receptor subtype 2 and we provide evidence that leucocyte adhesion and transmigration in response to activation of viral RNA receptors seem to depend on expression of functional TNFR2. Our results demonstrate that endothelial cells actively participate in immune mediated vascular inflammation caused by viral infections.

Autoimmune thyroid disorders

Autoimmune thyroid diseases (AITD) result from a dysregulation of the immune system leading to an immune attack on the thyroid. AITD are T cell-mediated organ-specific autoimmune disorders. The prevalence of AITD is estimated to be 5%; however, the prevalence of antithyroid antibodies may be even higher. The AITD comprise two main clinical presentations: Graves' disease (GD) and Hashimoto's thyroiditis (HT), both characterized by lymphocytic infiltration of the thyroid parenchyma. The clinical hallmarks of GD and HT are thyrotoxicosis and hypothyroidism, respectively. The mechanisms that trigger the autoimmune attack to the thyroid are still under investigation. Epidemiological data suggest an interaction among genetic susceptibility and environmental triggers as the key factor leading to the breakdown of tolerance and the development of disease. Recent studies have shown the importance of cytokines and chemokines in the pathogenesis of AT and GD. In thyroid tissue, recruited T helper 1 (Th1) lymphocytes may be responsible for enhanced IFN-γ and TNF-α production, which in turn stimulates CXCL10 (the prototype of the IFN-γ-inducible Th1 chemokines) secretion from the thyroid cells, therefore creating an amplification feedback loop, initiating and perpetuating the autoimmune process. Associations exist between AITD and other organ specific (polyglandular autoimmune syndromes), or systemic autoimmune disorders (Sjögren's syndrome, rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, cryoglobulinemia, sarcoidosis, psoriatic arthritis). Moreover, several studies have shown an association of AITD and papillary thyroid cancer. These data suggest that AITD patients should be accurately monitored for thyroid dysfunctions, the appearance of thyroid nodules, and other autoimmune disorders.

Hepatitis C virus infection and type 1 and type 2 diabetes mellitus

Hepatitis C virus (HCV) infection and diabetes mellitus are two major public health problems that cause devastating health and financial burdens worldwide. Diabetes can be classified into two major types: type 1 diabetes mellitus (T1DM) and T2DM. T2DM is a common endocrine disorder that encompasses multifactorial mechanisms, and T1DM is an immunologically mediated disease. Many epidemiological studies have shown an association between T2DM and chronic hepatitis C (CHC) infection. The processes through which CHC is associated with T2DM seem to involve direct viral effects, insulin resistance, proinflammatory cytokines, chemokines, and other immune-mediated mechanisms. Few data have been reported on the association of CHC and T1DM and reports on the potential association between T1DM and acute HCV infection are even rarer. A small number of studies indicate that interferon-α therapy can stimulate pancreatic autoimmunity and in certain cases lead to the development of T1DM. Diabetes and CHC have important interactions. Diabetic CHC patients have an increased risk of developing cirrhosis and hepatocellular carcinoma compared with non-diabetic CHC subjects. However, clinical trials on HCV-positive patients have reported improvements in glucose metabolism after antiviral treatment. Further studies are needed to improve prevention policies and to foster adequate and cost-effective programmes for the surveillance and treatment of diabetic CHC patients.

Extra-ocular muscle cells from patients with Graves' ophthalmopathy secrete α (CXCL10) and β (CCL2) chemokines under the influence of cytokines that are modulated by PPARγ

To our knowledge, no study has evaluated the involvement of T helper (Th)1- and Th2-chemokines in extra-ocular muscle (EOM) myopathy in "patients with thyroid-associated ophthalmopathy" (TAO-p). We tested the effects of interferon (IFN)γ and tumor necrosis factor (TNF)α stimulation, and of increasing concentrations of peroxisome proliferator-activated receptor (PPAR)γ agonists (pioglitazone or rosiglitazone; 0.1 μM-20 μM), on Th1-chemokine [C-X-C motif ligand (CXCL)10] and Th2-chemokine [C-C motif ligand (CCL)2] secretion in primary EOM cultures from TAO-p vs. control myoblasts. Moreover, we evaluated serum CXCL10 and CCL2 in active TAO-p with prevalent EOM involvement (EOM-p) vs. those with prevalent orbital fat expansion (OF-p). Serum CXCL10 was higher in OF-p and EOM-p vs. controls, while serum CCL2 was not significantly different in controls, or in OF-p and EOM-p. We showed the expression of PPARγ in EOM cells. In primary EOM cultures from TAO-p: a) CXCL10 was undetectable in the supernatant, IFNγ dose-dependently induced it, whereas TNFα did not; b) EOM produced basally low amounts of CCL2, TNFα dose-dependently induced it, whereas IFNγ did not; c) the combination of TNFα and IFNγ had a significant synergistic effect on CXCL10 and CCL2 secretion; and d) PPARγ agonists have an inhibitory role on the modulation of CXCL10, while they stimulate CCL2 secretion. EOM participates in the self-perpetuation of inflammation by releasing both Th1 (CXCL10) and Th2 (CCL2) chemokines under the influence of cytokines, in TAO. PPARγ agonist activation plays an inhibitory role on CXCL10, but stimulates the release of CCL2.

Useful biomarkers for assessment of hepatitis C virus infection-associated autoimmune disorders

During the course of chronic hepatitis C virus (HCV) infection, various extrahepatic manifestations of autoimmune disorders may occur, including arthralgia/arthritis, sicca complex, purpura, cutaneous ulcer, and thyroid dysfunction. In addition, the prevalence of circulating autoantibodies is high among patients with HCV infection. Commonly detected autoantibodies in HCV-infected patients include rheumatoid factor, antinuclear antibody, anti-SSA/anti-SSB antibody, cryoglobulin, antineutrophil cytoplasmic antibody, anti-smooth muscle antibody, anti-liver and anti-thyroid autoantibodies. These autoantibodies may be associated with underlying autoimmune disorders or liver inflammation in HCV infection. A possible reason for antibody production is overactivation and proliferation of B lymphocytes, via the interaction with the surface protein of HCV. Because immunotherapy can cause HCV flare-up or liver damage, overdiagnosis of HCV-related autoimmune symptoms as primary autoimmune disorders should be avoided. This review describes biomarkers that are useful in clinically evaluating autoimmune manifestations and disorders associated with HCV infection.

CXCR3, CXCL10 and type 1 diabetes

Type 1 diabetes (T1D) is due to antigen-specific assaults on the insulin producing pancreatic β-cells by diabetogenic T-helper (Th)1 cells. (C-X-C motif) ligand (CXCL)10, an interferon-γ inducible Th1 chemokine, and its receptor, (C-X-C motif) receptor (CXCR)3, have an important role in different autoimmune diseases. High circulating CXCL10 levels were detected in new onset T1D patients, in association with a Th1 autoimmune response. Furthermore β-cells produce CXCL10, under the influence of Th1 cytokines, that suppresses their proliferation. Viral β-cells infections induce cytokines and CXCL10 expression, inducing insulin-producing cell failure in T1D. CXCL10/CXCR3 system plays a critical role in the autoimmune process and in β-cells destruction in T1D. Blocking CXCL10 in new onset diabetes seems a possible approach for T1D treatment.

Assessment of liver stiffness in patients with HCV and mixed cryoglobulinemia undergoing rituximab treatment

INTRODUCTION

Mixed cryoglobulinemia (MC) is a HCV-related lymphoproliferative disorder generally associated with advanced liver disease. Liver stiffness has been significantly correlated with histopathological stage of fibrosis. Moreover, it was influenced by necroinflammatory activity. Rituximab (RTX) is a chimeric anti-CD20 monoclonal antibody inducing transient B lymphocytes depletion that was shown to be useful and safe in the majority of HCV MC patients, leading also to improvement of cirrhotic syndrome. Aim of this study was to evaluate the modifications of liver stiffness following RTX treatment in HCV-related MC patients.

MATERIALS AND METHODS

Fourteen consecutive patients (10 F, 4 M; mean age 60.43 ± 43) with HCV-related chronic hepatitis (n = 10) or cirrhosis (n = 4) and MC, eligible for RTX treatment, were prospectively enrolled. Intravenous injection of 1 g of RTX was performed at day 0 and at day 15. Assessment of stiffness was carried out by Fibroscan (Echosens, Paris-France) at baseline, 15 days after the first infusion, and at month 1, 3 and 6 after therapy.

RESULTS

MC symptoms significantly improved during the study, especially during the first 3 months. Liver stiffness observed 3 months after treatment was significantly reduced when compared with pre-treatment values (p = 0.01). This difference disappeared after 6 months of follow-up. Cytofluorimetric analysis showed a decrease of CD19+ peripheral blood cells, with the nadir at month 3 after therapy and B cell compartment reconstitution after 6 months.

CONCLUSION

This study, for the first time showed that RTX-treatment in HCV-related MC induces a reduction of liver stiffness that is strictly associated with the B-cell depletion.

Autoimmune and neoplastic thyroid diseases associated with hepatitis C chronic infection

Frequently, patients with hepatitis C virus (HCV) chronic infection have high levels of serum anti-thyroperoxidase and/or anti-thyroglobulin autoantibodies, ultrasonographic signs of chronic autoimmune thyroiditis, and subclinical hypothyroidism, in female gender versus healthy controls, or hepatitis B virus infected patients. In patients with "HCV-associated mixed cryoglobulinemia" (MC + HCV), a higher prevalence of thyroid autoimmune disorders was shown not only compared to controls, but also versus HCV patients without cryoglobulinemia. Patients with MC + HCV or HCV chronic infection show a higher prevalence of papillary thyroid cancer than controls, in particular in patients with autoimmune thyroiditis. Patients with HCV chronic infection, or with MC + HCV, in presence of autoimmune thyroiditis, show higher serum levels of T-helper (Th)1 (C-X-C motif) ligand 10 (CXCL10) chemokine, but normal levels of Th2 (C-C motif) ligand 2 chemokine, than patients without thyroiditis. HCV thyroid infection could act by upregulating CXCL10 gene expression and secretion in thyrocytes recruiting Th1 lymphocytes that secrete interferon-γ and tumor necrosis factor-α. These cytokines might induce a further CXCL10 secretion by thyrocytes, thus perpetuating the immune cascade, which may lead to the appearance of autoimmune thyroid disorders in genetically predisposed subjects. A careful monitoring of thyroid function, particularly where nodules occur, is recommended in HCV patients.

Chemokine (C-X-C motif) ligand (CXCL)10 in autoimmune diseases

(C-X-C motif) ligand (CXCL)10 (CXCL10) belongs to the ELR(-) CXC subfamily chemokine. CXCL10 exerts its function through binding to chemokine (C-X-C motif) receptor 3 (CXCR3), a seven trans-membrane receptor coupled to G proteins. CXCL10 and its receptor, CXCR3, appear to contribute to the pathogenesis of many autoimmune diseases, organ specific (such as type 1 diabetes, autoimmune thyroiditis, Graves' disease and ophthalmopathy), or systemic (such as rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, mixed cryoglobulinemia, Sjögren syndrome, or systemic sclerosis). The secretion of CXCL10 by cluster of differentiation (CD)4+, CD8+, natural killer (NK) and NK-T cells is dependent on interferon (IFN)-γ, which is itself mediated by the interleukin-12 cytokine family. Under the influence of IFN-γ, CXCL10 is secreted by several cell types including endothelial cells, fibroblasts, keratinocytes, thyrocytes, preadipocytes, etc. Determination of high level of CXCL10 in peripheral fluids is therefore a marker of host immune response, especially T helper (Th)1 orientated T-cells. In tissues, recruited Th1 lymphocytes may be responsible for enhanced IFN-γ and tumor necrosis factor-α production, which in turn stimulates CXCL10 secretion from a variety of cells, therefore creating an amplification feedback loop, and perpetuating the autoimmune process. Further studies are needed to investigate interactions between chemokines and cytokines in the pathogenesis of autoimmune diseases and to evaluate whether CXCL10 is a novel therapeutic target in various autoimmune diseases.

The role of chemokines in acute and chronic hepatitis C infection

Hepatitis C imposes a significant burden on global healthcare. Chronic infection is associated with progressive inflammation of the liver which typically manifests in cirrhosis, organ failure and cancer. By virtue of elaborate evasion strategies, hepatitis C virus (HCV) succeeds as a persistent human virus. It has an extraordinary capacity to subvert the immune response enabling it to establish chronic infections and associated liver disease. Chemokines are low molecular weight chemotactic peptides that mediate the recruitment of inflammatory cells into tissues and back into the lymphatics and peripheral blood. Thus, they are central to the temporal and spatial distribution of effector and regulatory immune cells. The interactions between chemokines and their cognate receptors help shape the immune response and therefore, have a major influence on the outcome of infection. However, chemokines represent a target for modulation by viruses including the HCV. HCV is known to modulate chemokine expression in vitro and may therefore enable its survival by subverting the immune response in vivo through altered leukocyte chemotaxis resulting in impaired viral clearance and the establishment of chronic low-grade inflammation. In this review, the roles of chemokines in acute and chronic HCV infection are described with a particular emphasis placed on chemokine modulation as a means of immune subversion. We provide an in depth discussion of the part played by chemokines in mediating hepatic fibrosis while addressing the potential applications for these chemoattractants in prognostic medicine.

Increased CXCL9 serum levels in hepatitis C-related mixed cryoglobulinemia, with autoimmune thyroiditis, associated with high levels of CXCL10

Until now, no study has evaluated CXCL9 in hepatitis C virus (HCV) infection-related mixed cryoglobulinemia (MC) patients in presence/absence of autoimmune thyroiditis (AT). Serum CXCL9 and CXCL10 have been measured in 60 patients with MC (MCo), in 35 patients with MC and AT (MC-AT), in sex and age-matched controls: 60 healthy (Control 1); 35 patients with AT without cryoglobulinemia (Control 2). CXCL9 and CXCL10 were higher in MC-AT patients than Control 2 (P<0.0001) and MCo (P=0.01), in MCo than Control 1 (P<0.0001), and in Control 2 than Control 1 (P<0.001). By defining a high CXCL9 level as a value>2 SD above the mean value of the Control 1 (>122 pg/mL), 5% of Control 1, 34% of Control 2, 91% of MCo, and 97% of MC+AT had high CXCL9 (P<0.0001, chi-square). By simple regression analysis CXCL9 and CXCL10 were related to each other in MCo (r=0.426, P=0.001) and in MC-AT (r=0.375, P=0.001). We first demonstrate high serum levels of CXCL9 in cryoglobulinemic patients, especially with AT. Further, a strong association between serum CXCL9 and CXCL10 has been observed in patients with MC in presence/absence of AT.

High Circulating Chemokines (C-X-C Motif) Ligand 9, and (C-X-C Motif) Ligand 11, in Hepatitis C-Associated Cryoglobulinemia

(C-X-C motif) ligand 9 and (C-X-C motif) ligand 11 (CXCL9 and CXCL11), are potent chemoattractants for activated T cells, and play an important role in T helper 1 (Th) 1 cell recruitment in chronic hepatitis C. No study has evaluated CXCL9, together with CXCL11, circulating levels in patients with mixed cryoglobulinemia and hepatitis C (MC+HCV-p). The aim of the present study therefore was to measure serum CXCL9, and CXCL11 levels, in MC+HCV-p, and to relate the findings to the clinical phenotype. Serum CXCL9 and CXCL11 were measured in 71 MC+HCV-p and in matched controls. MC+HCV-p showed significantly higher mean CXCL9 and CXCL11 levels than controls (P < 0.001, for both), in particular, in 32 patients with active vasculitis (P < 0.001). By defining high CXCL9 or CXCL11 level as a value of at least 2 SD above the mean value of the control group (> 100 pg/mL): 89% MC+HCV-p and 5% controls had high CXCL9 (P < 0.0001, chi-square); 90% MC+HCV-p and 6% controls had high CXCL11 (P < 0.0001, chi-square). In a multiple linear regression model of CXCL9 vs age, ALT, CXCL11, only CXCL11 was significantly (r = 0.452, P < 0.0001) and independently related to CXCL9. Our study demonstrates in MC+HCV-p vs controls: (i) high serum CXCL9, and CXCL11, significantly associated with the presence of active vasculitis; (ii) a strong relationship between circulating CXCL9 and CXCL11. Future studies on a larger cohort of patients are needed to evaluate the relevance of serum CXCL9 and CXCL11 determination as clinico-prognostic marker of MC+HCV.

Patients with Mixed Cryoglobulinemia and HCV Infection, in Presence or Absence of Autoimmune Thyroiditis, Have High Serum Levels of (CXC MOTIF) Ligand (CXCL)9 and CXCL11 Chemokines

No data are present in the literature regarding chemokine (CXC motif) ligand (CXCL)9 and CXCL11 circulating levels in cryoglobulinemia associated with hepatitis C (MC+HCV), in presence/absence of autoimmune thyroiditis (AT). Serum CXCL9 and CXCL11 have been measured in 38 MC+HCV patients without AT (MCo), 38 MC+HCV patients with AT (MC+AT), and in matched controls without (control 1) or with thyroiditis (control 2). Serum CXCL9 and CXCL11 were significantly higher: in control 2 than control 1 ( p<0.05); in MCo than control 1 and control 2 ( p<0.001, for both); in MC+AT than control 1 and control 2 ( p<0.0001, for both), and than MCo ( p=0.01, for both). Our study demonstrates markedly high serum levels of CXCL9 and CXCL11 in patients with MC+HCV compared to healthy controls; in MC+HCV patients increased CXCL9 and CXCL11 levels were significantly associated with the presence of AT. Moreover, a strong relation between circulating CXCL9 and CXCL11 in MC+HCV has been shown.

HCV and lymphoproliferation

Hepatitis C virus (HCV) infection is a serious public health problem because of its worldwide diffusion and sequelae. It is not only a hepatotropic but also a lymphotropic agent and is responsible not only for liver injury--potentially evolving to cirrhosis and hepatocellular carcinoma--but also for a series of sometimes severely disabling extrahepatic diseases and, in particular, B-cell lymphoproliferative disorders. These latter range from benign, but prelymphomatous conditions, like mixed cryoglobulinemia, to frank lymphomas. Analogously with Helicobacter pylori related lymphomagenesis, the study of the effects of viral eradication confirmed the etiopathogenetic role of HCV and showed it is an ideal model for better understanding of the molecular mechanisms involved. Concerning these latter, several hypotheses have been proposed over the past two decades which are not mutually exclusive. These hypotheses have variously emphasized the important role played by sustained stimulation of the immune system by HCV, infection of the lymphatic cells, viral proteins, chromosomal aberrations, cytokines, or microRNA molecules. In this paper we describe the main hypotheses that have been proposed with the corresponding principal supporting data.

Cytokines and HCV-related disorders

Cytokines are intercellular mediators involved in viral control and liver damage being induced by infection with hepatitis C virus (HCV). The complex cytokine network operating during initial infection allows a coordinated, effective development of both innate and adaptive immune responses. However, HCV interferes with cytokines at various levels and escapes immune response by inducing a T-helper (Th)2/T cytotoxic 2 cytokine profile. Inability to control infection leads to the recruitment of inflammatory infiltrates into the liver parenchyma by interferon (IFN)-gamma-inducible CXC chemokine ligand (CXCL)-9, -10, and -11 chemokines, which results in sustained liver damage and eventually in liver cirrhosis. The most important systemic HCV-related extrahepatic diseases--mixed cryoglobulinemia, lymphoproliferative disorders, thyroid autoimmune disorders, and type 2 diabetes--are associated with a complex dysregulation of the cytokine/chemokine network, involving proinflammatory and Th1 chemokines. The therapeutical administration of cytokines such as IFN-alpha may result in viral clearance during persistent infection and reverts this process.

Circulating CXCL11 and CXCL10 are increased in hepatitis C-associated cryoglobulinemia in the presence of autoimmune thyroiditis

OBJECTIVE

No data are available about circulating levels of the CXCL11 chemokine in hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) patients with or without autoimmune thyroiditis (AT). The aim of the present study, therefore, was to evaluate serum CXCL11 levels in these patients.

DESIGN

Serum CXCL11 (and for comparison, CXCL10) was measured in 45 patients with MC, 45 patients with MC and AT (MC + AT), 45 sex- and age-matched controls without AT (control 1), 45 sex- and age-matched patients with AT without cryoglobulinemia (control 2), and in 45 sex- and age-matched patients with hepatitis C chronic infection without MC (HCV+).

RESULTS

Serum CXCL11 and CXCL10 levels were significantly higher in control 2 than in control 1 (p < 0.01). MC patients had CXCL11 and CXCL10 significantly higher than control 1 (p < 0.01). MC + AT patients had CXCL11 and CXCL10 higher than control 2 (p < 0.01) and MC patients (p = 0.02). Serum CXCL11 levels were not associated with any of the clinical features of cryoglobulinemia in patients with MC and MC + AT, which was the same for CXCL10. CXCL10 and CXCL11 in HCV+ patients were significantly higher than in controls 1 and 2, but lower than in MC or MC+AT patients.

CONCLUSION

Our study first demonstrates higher serum levels of CXCL11 chemokine in patients with MC than in HCV+ patients, and in particular in the presence of AT.

Can interferon-gamma or interferon-gamma-induced-protein-10 differentiate tuberculosis infection and disease in children of high endemic areas?

Background

Diagnosis of childhood tuberculosis (TB) is difficult in high TB burden settings. Interferon-gamma-induced protein 10 (IP10) has been suggested as a marker of TB infection and disease, but its ability to differentiate the two conditions remains uncertain.

Objectives

To describe Interferon-gamma (INFγ) and IP10 expression in children with TB infection and disease and controls to assess their potential to differentiate latent and active TB.

Methods

This was a cross sectional study of 322 1–15 years old children with symptoms of TB (28 confirmed, 136 probable and 131 unlikely TB), 335 children in contact with adults with pulmonary TB and 156 community controls in Southern Ethiopia. The Tuberculin Skin Test (TST) and Quantiferon-In-Tube (QFT-IT) were performed. INFγ and IP10 were measured in plasma supernatants.

Results and Interpretation

Children with confirmed and probable TB and contacts were more likely to have TST+ (78.6%, 59.3% and 54.1%, respectively) than children with unlikely TB (28.7%) and controls (12.8%) (p<0.001). Children with confirmed TB (59.3%) and contacts (44.7%) were more likely to have INFγ+ than children with probable (37.6%) or unlikely TB (28.1%) and controls (13.1%) (p<0.001). IP10 concentrations were higher in INFγ+ children independently of TST (p<0.001). There was no difference between IP10 concentrations of children with confirmed TB and contacts (p = 0.8) and children with and without HIV (p>0.1).

INFγ and IP10 can identify children with TB infection and disease, but cannot differentiate between the two conditions. HIV status did not affect the expression of IP10.

Pathological observations of lung inflammation after administration of IP-10 in influenza virus- and respiratory syncytial virus-infected mice

Pneumonia is a common complication of influenza virus infection and a common cause of death of patients. The aim of this study was to test the hypothesis that interferon-γ-inducible protein-10 (IP-10) is an important chemokine in the development of airway inflammation caused by certain viruses. Mice were infected with influenza virus after administration of murine IP-10 and the severity of pneumonia was compared with the group which was infected with influenza virus alone. Another mice group was infected with respiratory syncytial virus (RSV) after injection of IP-10 and also the severity of pneumonia was compared to the group which was infected with RSV alone. The mice infected with influenza virus or RSV after administration of IP-10 presented with more fulminant and necrotizing diffuse alveolar and bronchiole damage with lymphocyte infiltration. Our results indicate that IP-10 is an important chemokine and is associated with the severity of pneumonia caused by certain viruses.

High Serum Levels of CXCL11 in Mixed Cryoglobulinemia Are Associated with Increased Circulating Levels of Interferon-γ

Objective.

No study has evaluated circulating chemokine C-X-C motif ligand (CXCL)11 in patients with “mixed cryoglobulinemia and chronic hepatitis C infection” (MC+HCV). We measured CXCL11, and correlated this measurement to the clinical phenotype.

Methods.

Serum CXCL11, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) were assayed in 97 MC+HCV patients and in 97 sex- and age-matched controls.

Results.

MC+HCV patients showed significantly higher mean CXCL11 serum levels than controls (254 ± 295, 68 ± 16 pg/ml, respectively; p = 0.0002; ANOVA). CXCL11 was significantly increased in 36 cryoglobulinemic patients with compared to those without active vasculitis (303 ± 208 vs 179 ± 62 pg/ml, respectively; p < 0.001; ANOVA). IFN-γ levels were significantly higher in MC+HCV than in controls [6.1 (range 0.8–114.5), 1.4 (range 0.7–2.4) pg/ml, respectively; p < 0.05; Mann-Whitney U test]. Serum TNF-α mean levels were significantly higher in MC+HCV than in controls [13.4 (range 1.8–369), 1.1 (range 0.7–3.2) pg/ml, respectively; p < 0.0001; Mann-Whitney U test]. A multiple regression analysis considering CXCL11 as a dependent variable, and age, alanine aminotransferase, IFN-γ, and TNF-α as independent variables, showed in MC+HCV patients a significant association only with IFN-γ (p < 0.0001).

Conclusion.

Our study demonstrates markedly high serum levels of CXCL11 in patients with MC+HCV compared to healthy controls overall in the presence of active vasculitis. A strong relationship between circulating IFN-γ and CXCL11 was shown, strongly supporting the role of a T helper 1 immune response in the pathogenesis of MC+HCV.

TLR3-dependent regulation of cytokines in human mesangial cells: a novel role for IP-10 and TNF-alpha in hepatitis C-associated glomerulonephritis

In viral infections, disease manifestations and tissue damage often result primarily from immune cells infiltrating target organs on the basis of an ineffectual viral clearance with persistent antigenemia or an inappropriate immune response. Cell types and mediators defining these inflammatory processes are still inadequately understood. In hepatitis C virus-associated glomerulonephritis, analysis of interferon-γ-inducible protein (IP-10) as a chemokine centrally involved in early antiviral response and TNF-α known to balance proinflammatory and immunosuppressive effects in inflammation shows a significant upregulation of both IP-10 and TNF-α mediated specifically by the viral receptor Toll-like receptor 3 expressed on mesangial cells. IP-10 induction is further potentiated by TNF-α signaling, preferentially via the TNF-α receptor subtype 2 selectively increased upon stimulation of viral receptors in the proinflammatory milieu.

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.

N-terminal pro-brain natriuretic peptide and tumor necrosis factor-alpha both are increased in patients with Hepatitis C

Many patients with hepatitis C chronic infection (HCV+ patients) experience symptoms (fatigue, dyspnea) not proportional to the liver involvement and resemble symptoms of heart failure (HF). To our knowledge, no study evaluated at the same time serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and tumor necrosis factor alpha (TNF-alpha) in HCV+ patients. Circulating NT-proBNP and TNF-alpha were assayed in 60 HCV+ patients, and in 60 sex- and age-matched controls. HCV+ patients showed significantly higher mean NT-proBNP and TNF-alpha levels than controls (P < 0.003). By defining high NT-proBNP level as a value higher than 125 pg/mL (the single cutoff point for outpatients under 75 years of age), 28% of HCV+ and 7% controls had high NT-proBNP (chi-square; P < 0.002). With a cutoff point of 900 pg/mL (that should be used for ruling in HF in patients age 50-75; such as the patients in our study), 3% HCV+ and 0 controls had high NT-proBNP. In conclusion, the study demonstrates high levels of circulating NT-proBNP and TNF-alpha in HCV+ patients. The increase of NT-proBNP may indicate the presence of a subclinical cardiac dysfunction. Further prospective studies quantifying symptoms and correlating these with echocardiographic parameters are needed to confirm this association.

High circulating levels of N-terminal pro-brain natriuretic peptide and interleukin 6 in patients with mixed cryoglobulinemia

Many patients with mixed cryoglobulinemia and chronic HCV infection experience symptoms, such as dyspnea, which sometimes do not seem to indicate the involvement of the liver but rather the symptoms of heart failure. To our knowledge, there has been no other study evaluating the serum levels of N-terminal pro-brain natriuretic peptide (NTproBNP) and Interleukin 6 (IL-6) in such patients. Serum NTproBNP and IL-6 were assayed in 54 patients with mixed cryoglobulinemia and chronic HCV infection, and in 54 sex- and age-matched controls. Cryoglobulinemic-patients showed significantly higher mean NTproBNP and IL-6 levels than the controls (P = 0.005). By defining a high NTproBNP level as a value higher than 125 pg/ml (the single cut-off point for patients under 75 years of age), 30% of patients with mixed cryoglobulinemia and chronic HCV infection and 7% of controls had high NTproBNP (chi-square; P < 0.003). With a cut-off point of 300 pg/ml (used to rule out heart failure in patients under 75 years of age), 5/49 patients with mixed cryoglobulinemia and chronic HCV infection and 0/54 controls had high NTproBNP (chi-square; P < 0.04). With a cut-off point of 900 pg/ml (used for including heart failure in patients aged between 50 and 75, such as the patients in this study) 3/51 of patients with mixed cryoglobulinemia and chronic HCV infection and 0/54 controls had high NTproBNP (chi-square; P = 0.07). The study revealed high levels of circulating NTproBNP and IL-6 in patients with mixed cryoglobulinemia and chronic HCV infection. The increase in NTproBNP could indicate the presence of a subclinical cardiac dysfunction.

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.

High circulating N-terminal pro-brain natriuretic peptide and tumor necrosis factor-α in mixed cryoglobulinemia

AIM: To evaluate serum levels of N-terminal pro-brain natriuretic peptide (NTproBNP) and tumor necrosis factor α (TNF-α) in a large series of patients with hepatitis C associated with mixed cryoglobulinemia (MC+HCV).

METHODS: Serum NTproBNP and TNF-α levels were assayed in 50 patients with MC+HCV, and in 50 sex- and age-matched controls.

RESULTS: Cryoglobulinemic patients showed significantly higher mean NTproBNP and TNF-α levels than controls (P < 0.001; Mann-Whitney U test). By defining high NTproBNP level as a value higher than 125 pg/mL (the single cut-off point for outpatients under 75 years of age), 30% of MC+HCV and 6% of controls had high NTproBNP (χ², P < 0.01). With a cut-off point of 300 pg/mL (used to rule out heart failure (HF) in patients under 75 years of age), 8% of MC+HCV and 0 controls had high NTproBNP (χ², P < 0.04). With a cut-off point of 900 pg/mL (used for ruling in HF in patients aged 50-75 years; such as the patients of our study), 6% of MC+HCV and 0 controls had high NTproBNP (χ², P = 0.08).

CONCLUSION: The study demonstrates high levels of circulating NTproBNP and TNF-α in MC+HCV patients. The increase of NTproBNP may indicate the presence of a subclinical cardiac dysfunction.

Hepatitis C-associated rheumatic disorders

Hepatitis C virus (HCV) is an important causative agent of liver diseases. However, HCV infection is also associated with numerous hematologic, renal, dermatologic, rheumatic, and autoimmune disorders. These include arthralgia, arthritis, vasculitis, sicca syndrome, myalgia, and fibromyalgia. The purpose of this article is to review the prevalence and spectrum of rheumatic disorders and autoimmune phenomena in HCV-infected patients. It evaluates and current treatment options including nonsteroidal anti-inflammatory drugs, low-dose corticosteroids, hydroxychloroquine, methotrexate, penicillamine, combined antiviral therapy, cyclosporin A, anti-TNF-a agents, and rituximab. It concludes that larger, controlled studies are needed to establish further the treatment indications, efficacy, and safety of these agents.

High interleukin-6 and tumor necrosis factor-alpha serum levels in hepatitis C infection associated or not with mixed cryoglobulinemia

The objective of this study is to evaluate serum levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-a) in a series of patients with hepatitis C virus (HCV)-related mixed cryoglobulinemia (HCV-MC) and to correlate these parameters with the clinical features of the disease. Serum IL-6 and TNF-a were assayed in 61 patients with HCV-MC, in 61 sex- and age-matched patients with HCV chronic hepatitis without cryoglobulinemia (HCV+), and in 61 sex- and age-matched healthy controls. HCV-MC patients showed significantly higher mean IL-6 levels than controls (p=0.005) or HCV+ patients (p = 0.02). Moreover, IL-6 was increased in cryoglobulinemic patients with active vasculitis, even if the statistical significance was not reached (p=0.056). Serum TNF-a levels were significantly higher in HCV-MC than in HCV+ or in controls (p<0.01). The study demonstrates high IL-6 and TNF-a serum levels in HCV-MC patients; moreover, IL-6 levels tended to be higher in HCV-MC patients in presence of active vasculitis.