Th1/Th2 cytokine imbalance in patients with Sjögren syndrome secondary to hepatitis C virus infection

Knowledge mapping of programmed cell death in osteonecrosis of femoral head: a bibliometric analysis (2000-2022)

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a common, refractory and disabling disease of orthopedic department, which is one of the common causes of hip pain and dysfunction. Recent studies have shown that much progress has been made in the research of programmed cell death (PCD) in ONFH. However, there is no bibliometric analysis in this research field. This study aims to provide a comprehensive overview of the knowledge structure and research hot spots of PCD in ONFH through bibliometrics.

METHOD

The literature search related to ONFH and PCD was conducted on the Web of Science Core Collection (WoSCC) database from 2002 to 2021. The VOSviewers, "bibliometrix" R package and CiteSpace were used to conduct this bibliometric analysis.

RESULTS

In total, 346 articles from 27 countries led by China and USA and Japan were included. The number of publications related to PCD in ONFH is increasing year by year. Shanghai Jiao Tong University, Xi An Jiao Tong University, Wuhan University and Huazhong University of Science and Technology are the main research institutions. Molecular Medicine Reports is the most popular journal in the field of PCD in ONFH, and Clinical Orthopaedics and Related Research is the most cocited journal. These publications come from 1882 authors among which Peng Hao, Sun Wei, Zhang Chang-Qing, Zhang Jian and Wang Kun-zheng had published the most papers and Ronald S Weinstein was cocited most often. Apoptosis, osteonecrosis, osteonecrosis of the femoral head, glucocorticoid and femoral head appeared are the main topics the field of PCD in ONFH. Autophagy was most likely to be the current research hot spot for PCD in ONFH.

CONCLUSION

This is the first bibliometric study that comprehensively summarizes the research trends and developments of PCD in ONFH. This information identified recent research frontiers and hot directions, which will provide a reference for scholars studying PCD in ONFH.

Altered subgroups of regulatory T cells in patients with primary Sjögren's syndrome

Primary Sjögren syndrome (pSS) is a systemic autoimmune inflammatory disease. Up to now, the role of regulatory T cells (Tregs) and their subgroups in pSS is still in controversial. In this study we tried to elucidate the roles of Tregs and its subgroups in pSS. Total 43 pSS patients and 23 health persons as control were enrolled in this study. We grouped the pSS patients according to the anti-SSa/SSb and the EULAR Sjögren's syndrome disease activity index (ESSDAI). Among the 43 pSS patients, 14 patients were followed after treatment. The percentage of rTregs (resting Treg cells) among Tregs was increased in the pSS group, and decreased after treatment. In the high disease activity subpopulation (ESSDAI ≥ 5), the percentage of rTregs among Tregs decreased after treatment. On the contrary, the percentage of aTregs (activated Treg cells) increased after treatment. It was in an inverse correlation between the percentage of aTreg and rTreg in pSS patients. The Tregs are co-cultured with responder T cells. Tregs from pSS patients showed poorer proliferation inhibitory function. Our results show that the percentages of Tregs and their subgroups altered in pSS patients. The percentage of aTreg and the percentage of rTreg have an inverse correlation in pSS patients. Compared to the control group, the percentage of rTregs among Tregs was increased in the pSS patients and decreased after the treatment. Our study also showed that The Tregs from pSS patients may have poorer inhibitory functions.

Cytotoxic CD8(+) T cells may be drivers of tissue destruction in Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune disorder whose pathogenesis is poorly understood and that lacks effective therapies. Detailed quantitative and spatial analyses of tissues affected by Sjögren's syndrome were undertaken, including the quantitation of the frequency of selected cell-cell interactions in the disease milieu. Quantitative analyses of CD4⁺ T cell subsets and of CD8⁺ T cells in the labial salivary glands from untreated patients with primary Sjögren's syndrome revealed that activated CD8⁺ cytotoxic T cells (CD8⁺CTLs) were the most prominent T cells in these infiltrates. An accumulation of apoptotic glandular epithelial cells, mainly ductal and acinar cells, was observed, consistent with the impaired salivary secretion often observed in patients with this disease. FasL expressing activated CD8⁺ T cells were seen to accumulate around Fas expressing apoptotic epithelial cells. Quantitative analyses of apoptotic cell types and of conjugates between cytotoxic T cells and epithelial cells undergoing apoptosis suggest that Sjögren's syndrome is primarily driven by CD8⁺CTL mediated execution of epithelial cells mainly represented by ductal and acinar cells.

Hepatitis C-induced Sjögren's Syndrome With Positive Serology: A Case Report

Sjögren's syndrome (SjS) is a chronic autoimmune disease with a tendency to inflame the exocrine glands, and hepatitis C virus (HCV) infection is considered an exclusion criterion for the diagnosis of this condition; however, it is a highly debated topic, mainly because HCV is viewed as a possible etiopathogenic factor in the disease onset. We report a case of a female patient diagnosed with HCV chronic infection with positive serological markers of SjS (anti-Ro and anti-La autoantibodies). She presented with neuropsychiatric manifestations and casual sicca symptoms and was eventually diagnosed with HCV-induced SjS. Initially, the patient developed symptoms that fulfilled the histopathological criteria of primary SjS and co-existence of mixed cryoglobulinemia, which is viewed as an HCV-related marker.

Sjögren's Syndrome and Viral Infections

Sjögren's syndrome (SS) is a systemic autoimmune disease, characterized by lymphocytic infiltration of the secretory glands. This leads to dryness of the main mucosal surfaces such as the mouth, eyes, nose, larynx, pharynx, and vagina. Although there is little morbidity data at the initial diagnosis, SS may be a serious disease, with extra mortality caused by hematological cancer. The cause of SS is unknown, but factors postulated to play a role include genetic and environmental factors, hormonal abnormality, and viral infection. Under the influence of these factors, the immune system becomes abnormal and the tissue is damaged. In this study, we summarize recent developments in our understanding of the relationship between SS and viral infections, including Epstein-Barr virus (EBV), hepatitis C virus (HCV), human T cell lymphotropic virus type 1 (HTLV-1), cytomegalovirus (CMV), and human immunodeficiency virus (HIV).

Surgical Procedures for Hip Joint Preservation for Osteonecrosis of the Femoral Head: A Bibliometric Analysis

Background and Objective. Studies have concentrated on the surgical procedures for hip joint preservation for osteonecrosis of the femoral head (ONFH). This study is aimed at presenting a bibliometric analysis of the relevant articles published from 1999 to 2019. Method. Articles which concentrated on surgical procedures for hip joint preservation for ONFH were searched using Web of Science database. The data were analyzed by using bibliometric analysis. Additionally, VOS viewer software was used for bibliographic coupling, coauthorship, cocitation, and cooccurrence analyses and to investigate the publication trends of the mentioned field. Results. A total of 3467 articles were included. China had the highest number of relevant published articles. However, the USA made the highest contributions to the global research with the highest citations and $h$ -index. The journal of Clinical Orthopaedics and Related Research published the highest number of relevant articles. Studies could be classified into four clusters: “process and clinical treatment,” “risk factors and diagnosis,” “pathophysiology,” and “basic research.” “Pathophysiology” and “basic research” clusters were predicted as the next hot topics of surgical procedures for hip joint preservation for ONFH. Conclusion. Based on the current global trends, the number of published articles related to surgical procedures for hip joint preservation for ONFH has increased. The USA was noted as the leading country in global research in the target field. “Pathophysiology” and “basic research” clusters may be the next hot spots, and scholars need to further concentrate on the target topic.

Infections as Risk Factor of Sjögren's Syndrome

Purpose

Sjögren's syndrome (SS) is an autoimmune disease targeting exocrine glands, leading to low body fluids production, especially on the salivary and lacrimal glands. Due to the low saliva and tear production, the common symptoms of Sjögren's syndrome are dry eyes and dry mouth, later on leading to uncomfortable sensations on the eye surface, cornea destruction, dental caries, and oral cavity infections. Several infections are known to cause similar side-effects to Sjögren's syndrome symptoms, including low saliva flow; therefore, infection is hypothesized as one of the risk factors of Sjögren's syndrome.

Results

Based on our literature research, there are several infectious agents which cause similar disease manifestations to Sjögren's syndrome, including infections of hepatitis C virus, Epstein-Barr virus, cytomegalovirus, and human T-lymphotropic virus-1 (HTLV-1), and these four agents are found to cause persistent infection on the salivary gland after the first infection and later lead to organ destruction, thus causing sicca syndrome in the oral cavity. Other findings show possible Heliobacter pylori infection might lead on the increasing level of anti-Ro/SSA and anti-La/SSB of infected individuals.

Conclusion

Some research has shown persistent infection could trigger autoimmune disorders due to continuous T-cells and B-cells activation in an attempt of infected cells eradication, leading to autoimmune reaction and high autoreactive cells concentration around the healthy cells causing the immune cells to eradicate the healthy cells nearby. However, the results in this literature study found persistent infection is not the only risk factor of Sjögren's syndrome but there are various unknown factors that trigger infection to develop into Sjögren's syndrome.

The effect of black barberry hydroalcoholic extract on immune mediators in patients with active rheumatoid arthritis: A randomized, double-blind, controlled clinical trial

Rheumatoid arthritis (RA) is an autoimmune disease associated with inflammation. In this trial, we aimed to investigate the Immunomodulatory effect of hydroalcoholic extract of black barberry on immune mediators in patients with active rheumatoid arthritis. In this randomized, double-blind, placebo-controlled clinical trial, 80 women with active RA were randomly assigned into two groups of two capsules, each containing 1,000 mg black barberry extract (n = 40) or maltodextrin placebo (n = 40) daily for 12 weeks. Demographic indices, physical activity, dietary intake, and disease activity were investigated using suitable questionnaires. Concentration of cytokines IL-2, IL-4, IL-10, and IL-17 in blood sample were measured using PBMC method. Statistical analysis was performed using SPSS (version 22). At baseline, there were no differences between the two groups in terms of demographic indices, physical activity, and dietary intake (p > .05). Black barberry supplementation reduced the severity of RA. It showed no significant effect on IL-2 and IL-4 cytokines (p > .05). IL-17 levels decreased significantly after the intervention within the black barberry group, while IL-10 had a significant increase in this group (p < .05). Barberry extract may reduce inflammatory and increase anti-inflammatory cytokines in RA, and stimulates the immune response by increasing Th2 production.

B7-H3: A promising therapeutic target for autoimmune diseases

B7-H3 as a newly identified costimulatory molecule that belongs to B7 ligand family, is broadly expressed in both lymphoid and non-lymphoid tissues. The overexpression of B7-H3 has been verified to be correlated with the poor prognosis and poor clinical outcome of several human cancers. In recent years, researchers reveal that B7-H3 is involved in the pathogenesis of various autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), Sjögren's syndrome (SS), ankylosing spondylitis (AS), etc. In this review, we will discuss the biological function of B7-H3 and summarize the progress made over past years regarding its role in the occurrence and development of autoimmune diseases. The insights gained from these findings could serve as the foundation for future therapies of these diseases.

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.

A Study of Association Between Oral Lichen Planus and Immune Balance of Th1/Th2 Cells

The aims of this study are to investigate the key role of Th1 and Th2 in the pathogenesis of oral lichen planus (OLP) and to explore the possible association between OLP and immune balance of Th1/Th2 cells. We selected 35 patients diagnosed with OLP and 35 age- and sex-matched controls as subjects. The expressed level of interferon-gamma (IFN-γ) and interleukin-4 (IL-4) and the characteristic cytokines of Th1 and Th2 were assayed in the serum of peripheral blood of the patients. The lesional tissue of the two groups was investigated with the methods of double immunofluorescence. The ratio of Th1/Th2 was evaluated, and the difference of the results between serum and lesional tissue was compared. Both IFN-γ and IL-4 levels increased in the serum and lesional tissue compared with those of the controls (P < 0.001, P = 0.030, P < 0.001, and P < 0.001) and IFN-γ/IL-4 ratio of OLP patients, which increased significantly (P = 0.001 and P = 0.003). The difference between serum and lesional tissue was obviously insignificant (P = 0.982). Th1 cytokine predominance was proven in this research on Chinese subjects. Th1 cells may play leading roles on Th1/Th2 immune balance to pathogenesis of OLP.

Total glucosides of peony ameliorates Sjögren's syndrome by affecting Th1/Th2 cytokine balance

The present study aimed to investigate the molecular mechanisms underlying the effects of total glucosides of peony (TGP) in the treatment of Sjögren's syndrome (SS). A total of 40 mice with SS were evenly assigned into four groups, including: Control group; TGP group, receiving 1 mg TGP daily; hydroxychloroquine (HCQ) group, receiving 0.25 mg HCQ daily; and a combined group, receiving 1 mg TGP and 0.25 mg HCQ daily. After 8 weeks, quantitative polymerase chain reaction and an enzyme-linked immunosorbent assay were used to detect the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), Fas and FasL in each group of mice. In addition, immunohistochemical analysis was used to determine the expression levels of IFN-γ and IL-4. IFN-γ, IL-4, Fas and FasL levels were significantly increased in the control group compared with the other three groups (P<0.05). Furthermore, the expression levels of these factors were reduced in the combined group in comparison with the HCQ group (P<0.05). The ratios of IFN-γ to IL-4 were decreased in the TGP and combined groups compared with the control group (P<0.05). The present results indicate that TGP ameliorates SS by affecting the Th1/Th2 cytokine balance and decreasing the expression levels of IFN-γ, IL-4, Fas and FasL. Therefore, TGP may represent a potential novel therapeutic agent for the treatment of SS.

The potential of interleukin 12 receptor beta 2 (IL12RB2) and tumor necrosis factor receptor superfamily member 8 (TNFRSF8) gene as diagnostic biomarkers of oral lichen planus (OLP)

OBJECTIVE

This study evaluated the potential of interleukin 12 receptor beta 2 and tumor necrosis factor receptor superfamily member 8 as diagnostic biomarkers of oral lichen planus (OLP).

MATERIALS AND METHODS

The mRNA expression of IL12RB2 and TNFRSF8 in FFPE OLP samples (OLP group, n = 38) were investigated with quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis and compared to those of chronic non-specific mucositis (Non-OLP group, n = 25) and normal mucosa (Normal group, n = 18). Predictive modeling of the expression of IL12RB2 and TNFRSF8 was constructed using support vector machine (SVM), random forest (RF), linear discriminant analysis (LDA), neural network (NN) and naive Bayes (NB) methods.

RESULTS

Normalized expression of IL12RB2 in the OLP group (3.78 ± 1.67) was significantly higher than the Normal group (1.97 ± 1.12), but lower than the Non-OLP group (6.86 ± 1.67). TNFRSF8 gene expression in the OLP group (7.46 ± 1.51) was significantly higher than the Normal group (2.90 ± 1.61), but no significant difference was found between the OLP and Non-OLP groups. The ratio of IL12RB2/TNFRSF8 in the OLP group (0.52 ± 0.23) was significantly lower than the Normal group (0.74 ± 0.39) and the Non-OLP group (1.07 ± 0.38). In the predictive modeling, the area under receiver operating characteristic (ROC) curves (AUC) ranged from 0.83-0.92 and their accuracy was higher than 0.75 in all methods.

CONCLUSIONS

The IL12RB2/TNFRSF8 ratio can be a useful diagnostic tool for OLP.

Interferon-ribavirin therapy induces serum antibodies determining 'rods and rings' pattern in hepatitis C patients

A cytoplasmic antigen associated to inosine-5'-monophosphatedehydrogenase 2 eliciting specific antibodies (antirods and rings, RR) has been identified in patients with chronic hepatitis C who were exposed to pegylated interferon (PI) and ribavirin (RBV). The significance of anti-RR in these patients merits to be investigated. Sera from 88 chronic hepatitis C virus (HCV)-infected patients undergoing PI-RBV therapy were analysed for the presence of RR pattern by indirect immunofluorescence on HEp-2 substrate (Inova Diagnostics, San Diego, CA, USA). Anti-RR antibodies developed de novo in 32 patients independently of any demographic and virological feature, but with a significant association with cumulative exposure to PI-RBV (P = 0.0089; chi-square test). RR pattern was significantly more frequent in relapsers than in patients achieving sustained virological response (56% vs 30%; P = 0.0282, chi-square test). Anti-RR titre ranged from 1:80 to 1:1280, but significantly declined following treatment cessation. Anti-RR develop de novo in a substantial proportion of patients exposed to PI-RBV in relation to the duration of treatment exposure. Further investigations are necessary to unravel the mechanisms leading to the formation of these autoantibodies.

Extrahepatic immune related manifestations in chronic hepatitis C virus infection

The association of chronic hepatitis C with immune related syndromes has been frequently reported. There is a great range of clinical manifestations affecting various systems and organs such as the skin, the kidneys, the central and peripheral nervous system, the musculoskeletal system and the endocrine glands. Despite the high prevalence of immune related syndromes in patients with chronic hepatitis C, the exact pathogenesis is not always clear. They have been often associated with mixed cryoglobulinemia, a common finding in chronic hepatitis C, cross reaction with viral antigens, or the direct effect of virus on the affected tissues. The aim of this review is to analyze the reported hepatitis C virus immune mediated syndromes, their prevalence and clinical manifestations and to discuss the most supported theories regarding their pathogenesis.

Autoimmunity and infection in Sjögren's syndrome

PURPOSE OF REVIEW

To summarize the recent developments concerning the potential viral pathomechanisms and involvement of viruses in Sjögren's syndrome, and to highlight the areas for future research and therapies.

RECENT FINDINGS

Activated IFN-1 pathway plays an important part in the autoimmune disease process of Sjögren's syndrome; therefore, several therapies aiming to reduce or inhibit the IFN-1 production and its effects may be a target for future treatment plans. Activated aryl hydrocarbon receptor may interact with latent Epstein-Barr virus (EBV) infection, which in turn may predispose to the development of Sjögren's syndrome. It is estimated that the population is 95% positive for EBV serology. Microbial factors may incite autoimmune disease. Although this hypothesis is proven in a few illnesses such as rheumatic fever, there is no definitive evidence of an infectious environmental trigger in Sjögren's syndrome. However, there are circumstantial data with regard to viruses and several potential mechanisms of disease. These include antigen mimicry, polyclonal lymphocyte activation, and infection-mediated innate end-organ inflammation. In addition, hepatitis C virus infection clearly causes a Sjögren's-syndrome-like illness.

SUMMARY

Data continue to implicate viral infection in the cause of Sjögren's syndrome, but there are no definitive studies incriminating a particular virus.

B cell activating factor (BAFF) in the natural history of chronic hepatitis C virus liver disease and mixed cryoglobulinaemia

B cell activating factor (BAFF) plays a crucial role in the process of development, maturation and activation of B lymphocytes. Chronic hepatitis C virus (HCV) infection is characterized by multiple B cell disorders. It is a major cause of type II mixed cryoglobulinaemia (MC). We measured serum BAFF levels in several clinical situations to elucidate the potential role of BAFF in chronic HCV infection. We used a commercially available solid phase enzyme-linked immunosorbent assay. We estimated serum BAFF in stored sera from uninfected controls (n = 8), patients with chronic hepatitis B virus infection HBV (n = 5) and chronic HCV infection with (n = 16) and without mixed cryoglobulinaemia (n = 14). In two patients with HCV and MC we correlated BAFF with HCV RNA after pegylated interferon (peg-I). We correlated serum BAFF levels at baseline and at 12 weeks with treatment response: sustained virological response SVR (n = 5), non-responders (n = 6) and relapsers (n = 2). Finally, we estimated BAFF levels after complete depletion of B cells with rituximab in patients with chronic HCV with MC (n = 3). Serum levels of BAFF were increased in chronic HCV with MC, but not in chronic HBV infection, suggesting an association between BAFF and cryoglobulinaemia. Peg-I increased BAFF levels in serum and this paralleled HCV RNA very closely. Serum BAFF levels at week 12 of therapy with peg-I and R were significantly higher in responders than non-responders. Finally, B cell depletion was associated with markedly increased levels of BAFF.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Extrahepatic manifestations and autoantibodies in patients with hepatitis C virus infection. Clin Dev Immunol. 2012;2012:871401. [PMID: 22988469 DOI: 10.1155/2012/871401].]

Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Interaction of Hepatitis C virus proteins with pattern recognition receptors

Hepatitis C virus (HCV) is an important human pathogen that causes acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma worldwide. This positive stranded RNA virus is extremely efficient in establishing persistent infection by escaping immune detection or hindering the host immune responses. Recent studies have discovered two important signaling pathways that activate the host innate immunity against viral infection. One of these pathways utilizes members of Toll-like receptor (TLR) family and the other uses the RNA helicase retinoic acid inducible gene I (RIG-I) as the receptors for intracellular viral double stranded RNA (dsRNA), and activation of transcription factors. In this review article, we summarize the interaction of HCV proteins with various host receptors/sensors through one of these two pathways or both, and how they exploit these interactions to escape from host defense mechanisms. For this purpose, we searched data from Pubmed and Google Scholar. We found that three HCV proteins; Core (C), non structural 3/4 A (NS3/4A) and non structural 5A (NS5A) have direct interactions with these two pathways. Core protein only in the monomeric form stimulates TLR2 pathway assisting the virus to evade from the innate immune system. NS3/4A disrupts TLR3 and RIG-1 signaling pathways by cleaving Toll/IL-1 receptor domain-containing adapter inducing IFN-beta (TRIF) and Cardif, the two important adapter proteins of these signaling cascades respectively, thus halting the defense against HCV. NS5A downmodulates the expressions of NKG2D on natural killer cells (NK cells) via TLR4 pathway and impairs the functional ability of these cells. TLRs and RIG-1 pathways have a central role in innate immunity and despite their opposing natures to HCV proteins, when exploited together, HCV as an ever developing virus against host immunity is able to accumulate these mechanisms for near unbeatable survival.

Hepatitis C virus infection, mixed cryoglobulinemia and BLyS upregulation: targeting the infectious trigger, the autoimmune response, or both?

Mixed cryoglobulinemia syndrome (MCsn) is a systemic vasculitis prevalently mediated by immune complexes, i.e., mixed cryoglobulins, and characterized by non-neoplastic B-cell lymphoproliferation favouring the progression into frank B-cell non-Hodgkin lymphoma (NHL) in 5-10% of patients. The hepatitis C virus (HCV) infection is the etiologic agent in the large majority of MCsn cases and chronic antigenic stimulation by HCV is considered a key mechanism sustaining the proliferation of the RF-secreting B-cell clones. Besides chronic antigenic stimulation, cytokines and growth factors may also play a key role in sustaining B-cell overactivation. B-lymphocyte stimulator (BlyS) was recently described as a critical survival factor for B cells, promoting their activation and maturation. Abnormal production of BLyS alters immune tolerance by allowing the survival of autoreactive B cells, thus triggering autoimmune disorders. BLyS inhibits B-cell apoptosis, and B-cell apoptosis is implicated in the pathogenesis of MCsn, as well as of other autoimmune diseases. Both antiviral therapy and B- cell depletive therapy in MCsn may influence BlyS expression. Antiviral therapy, monotherapy against biologic targets downstream viral infection, or the combination of the two, should be optimized in the single patient and stage of the disease, based on disease pathobiology, efficacy and safety issues.

Oral diseases associated with hepatitis C virus infection. Part 1. sialadenitis and salivary glands lymphoma

Morbidity associated with hepatitis C virus (HCV) infection is due not only to the sequelae of chronic liver disease, but also to a variety of extraheaptic manifestations (EHM). Some of the most frequently reported EHM of HCV infection involves the oral region predominantly or exclusively and they are the topics of this 2-part review. The current part 1 discusses the evidences on the association of salivary glands disorders with HCV. HCV- infected patients may frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, the pathogenetic role of HCV in Sjogren Syndrome (SS) development and the characteristics distinguishing classic SS from HCV-related sialadenitis are still an issue. It is unclear if the virus may cause a disease mimicking primary SS or if HCV is directly responsible for the development of SS in a specific subset of patients. Notably, some patients may present a triple association between HCV, SS-like sialadenitis and salivary gland lymphoma and the virus may be involved in the lymphomagenesis. The risk of having a salivary gland lymphoma is particularly high in patients with mixed cryoglobulinemia. Little attention has been paid to the effects of anti-HCV treatment on sialadenitis or lymphoma development.

Viral and host factors induce macrophage activation and loss of toll-like receptor tolerance in chronic HCV infection

BACKGROUND & AIMS

Persistent inflammation contributes to progression of liver damage in chronic HCV (cHCV) infection. Repeated exposure to toll-like receptor (TLR) ligands results in tolerance, a protective mechanism aimed at limiting inflammation.

METHODS

Monocytes/macrophages were repeatedly stimulated via proinflammatory cytokine-inducing TLRs and evaluated for activation markers.

RESULTS

Unlike monocytes of controls or patients with nonalcoholic steatohepatitis, the monocytes of cHCV patients were hyperresponsive and failed to show homo- or heterotolerance to TLR ligands, manifested by elevated tumor necrosis factor (TNF)-alpha production. Serum levels of interferon (IFN)-gamma, endotoxin (TLR4 ligand), and HCV core protein (TLR2 ligand) were elevated in cHCV patients suggesting potential mechanisms for in vivo monocyte preactivation. Treatment of normal monocytes with IFN-gamma resulted in loss of tolerance to lipopolysaccharide (LPS) or HCV core protein. Furthermore, we found increased levels of MyD88-IRAK1 complexes and nuclear factor (NF)-kappaB activity both in monocytes of cHCV patients and in normal monocytes that lost TLR tolerance after IFN-gamma + LPS pretreatment. In vitro differentiation of TLR non-tolerant cHCV monocytes into macrophages restored their capacity to exhibit TLR tolerance to LPS and HCV core protein, and this could be reversed by administration of IFN-gamma. cHCV patients exhibited increased TNF-alpha in the circulation and in the liver. In cHCV livers, we found Kupffer cell/macrophage activation indicated by increased CD163 and CD33 expression.

CONCLUSIONS

We identified that host-derived factors (IFN-gamma and endotoxin) and viral factors (HCV core protein) act in tandem to induce and maintain monocyte/macrophage activation, thus favoring persistent inflammation in patients with cHCV infection.

Advances in Lupus and Sjogren's Syndrome: A Tribute to Josep Font

Dr. Josep Font (Barcelona, 1953-2006) devoted his professional career to the care of patients with systemic autoimmune diseases (SAD). In 1995, he created the Department of Autoimmune Diseases at the Hospital Clinic in Barcelona, a pioneering unit in Europe specifically dedicated to the clinical management of these patients. The research output of Dr. Font has been prodigious, with a total of over 500 scientific articles published in 25 years, and was especially focused on the clinical and immunological characterization of systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS). This review briefly analyzes some of the main contributions of Josep Font to our current knowledge about these diseases. In SLE, the research was centered on the epidemiological and clinical characterization, the study of cardiovascular and vasculitic involvements, and the investigation of the etiopathogenic role of the innate immunity. In primary SS, basic research conducted by Dr. Font contributed to a better understanding of the autoimmune etiopathogenesis of the disease, while the clinical research expanded our knowledge about the systemic and immunological expression of the disease and its frequent association with lymphoma, other SAD, and chronic viral infections.

Th1/Th2 cytokine ratio in tissue transudates from patients with oral lichen planus

OBJECTIVE

The characteristics of oral lichen planus (OLP) provoke investigators to explore possible biomarkers by which to monitor disease activity and therapeutic efficacy. Oral fluids may provide an accessible medium for analysis of such biomarkers. Previous studies have shown that activation of nuclear factor-kappa B (NF-kappa B) plays an important role in the pathogenesis of oral lichen planus (OLP), which is a chronic inflammatory disorder mediated by T cells. Prior to the present investigation, reports of the levels of NF-kappa B and its dependent cytokines in oral fluids have not been forthcoming. The purpose of this study was to detect the level of NF-kappa B dependent cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in tissue transudates directly from lesions of OLP, and explore the feasibility of the data for clinical application.

STUDY DESIGN

Thirteen definitively diagnosed OLP subjects were enrolled in the study as were 13 age-sex matched controls. In each subject, lesion tissue transudates (TTs) were collected by a novel collection technique with a filter paper. The level of cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in three types of oral fluids were determined by ELISA.

RESULTS

In the tissue transudate(TT), there were significantly higher level of cytokines TNF-alpha, IL-1-alpha, IL-6, and IL-8 detected in OLP patients than in controls: (TT: 40.0 +/- 9.8 versus 4.5 +/- 0.7, 710 +/- 114 versus 305 +/- 78, 150 +/- 25 versus 1.7 +/- 0.5, 2800 +/- 260 versus 1450 +/- 130, P < .0001; unit: pg/mL).

CONCLUSIONS

These results indicate that NF-kappa B dependent inflammatory cytokines may be detected at increased levels in oral lesion tissue transudates which may have diagnostic and prognostic potentials for monitoring disease activity and making therapeutic decisions in patients with OLP.

[Update in Hepatitis C virus associated extrahepatic manifestations]

INTRODUCTION

Since the discovery of the hepatitis C virus, many manifestations, so called extra-hepatic manifestations (EHM), are largely reported with more or less relationship proofs.

ACTUALITIES AND MAIN POINTS

This article proposes a review of the main extra-hepatic manifestations associated with the Hepatis C Virus infection and which remain a topical subject, more than fifteen years after the discovery of this virus. Mixed cryoglobulin and its vasculitic manifestations are still one of the more frequent Hepatis C Virus associated-extra-hepatic manifestations. Its management may be critically changed due to the increasing use of anti-CD20 therapy. Among other HCV-EHM, the following extra-hepatic manifestations are still of interest: the chronic fatigue syndrome, the sicca syndrome, the non-insulin-dependent diabetes mellitus, malignant B cell proliferations, mainly the Hepatis C Virus-related splenic lymphoma with villous lymphocytes and the production of auto-antibodies.

PERSPECTIVES AND PROJECTS

The mechanisms underlying these HCV-associated EHM are ill-elucidated and still remain of great interest as proved by current studies. The use of anti-CD20 antibodies in the treatment of cryoglobulinemic vasculitis is also under investigation.

Hepatitis C virus induces toll-like receptor 4 expression, leading to enhanced production of beta interferon and interleukin-6

Hepatitis C virus (HCV) induces inflammatory signals, leading to hepatitis, hepatocellular carcinomas, and lymphomas. The mechanism of HCV involvement in the host's innate immune responses has not been well characterized. In this study, we analyzed expression and regulation of the entire panel of toll-like receptors (TLRs) in human B cells following HCV infection in vitro. Among all of the TLRs (TLRs 1 to 10) examined, only TLR4 showed an altered expression (a three- to sevenfold up-regulation) after HCV infection. Peripheral blood mononuclear cells from HCV-infected individuals also showed a higher expression level of TLR4 compared with those of healthy individuals. HCV infection significantly increased beta interferon (IFN-beta) and interleukin-6 (IL-6) secretion from B cells, particularly after lipopolysaccharide stimulation. The increased IFN-beta and IL-6 production was mediated by TLR4 induction, since the introduction of the small interfering RNA against TLR4 specifically inhibited the HCV-induced cytokine production. Among all of the viral proteins, only NS5A caused TLR4 induction in hepatocytes and B cells. NS5A specifically activated the promoter of the TLR4 gene in both hepatocytes and B cells. In conclusion, HCV infection directly induces TLR4 expression and thereby activates B cells, which may contribute to the host's innate immune responses.

Effect of hepatitis C serology on C-reactive protein in a cohort of Brazilian hemodialysis patients

Hepatitis C (HCV) is not an uncommon feature in hemodialysis (HD) patients and may be a cause of systemic inflammation. Plasma cytokine interleukin-6 (IL-6) is mainly produced by circulating and peripheral cells and induces the hepatic synthesis of C-reactive protein (CRP), which is the main acute phase reactant. The aim of this study was to investigate the influence of HCV on two markers of systemic inflammation, serum CRP and IL-6, in HD patients. The study included 118 HD patients (47% males, age 47 +/- 13 years, 9% diabetics) who had been treated by standard HD for at least 6 months. The patients were divided into two groups depending on the presence (HCV+) or absence (HCV-) of serum antibodies against HCV. Serum albumin (S-Alb), plasma high sensitivity CRP (hsCRP), IL-6, and alanine aminotransferase (ALT) were measured and the values were compared with those for 22 healthy controls. Median hsCRP and IL-6 values and hsCRP/IL-6 ratio were: 3.5 vs 2.1 mg/l, P < 0.05; 4.3 vs 0.9 pg/ml, P < 0.0001, and 0.8 vs 2.7, P < 0.0001, for patients and controls, respectively. Age, gender, S-Alb, IL-6 and hsCRP did not differ between the HCV+ and HCV- patients. However, HCV+ patients had higher ALT (29 +/- 21 vs 21 +/- 25 IU/l) and had been on HD for a longer time (6.1 +/- 3.0 vs 4.0 +/- 2.0 years, P < 0.0001). Moreover, HCV+ patients had a significantly lower median hsCRP/IL-6 ratio (0.7 vs 0.9, P < 0.05) compared to the HCV- group. The lower hsCRP/IL-6 ratio in HCV+ patients than in HCV- patients suggests that hsCRP may be a less useful marker of inflammation in HCV+ patients and that a different cut-off value for hsCRP for this population of patients on HD may be required to define inflammation.

Mortality and causes of death in primary Sjögren's syndrome: A prospective cohort study

OBJECTIVE

This study was undertaken to analyze standardized mortality ratios (SMRs) and causes and predictors of death in primary Sjögren's syndrome (SS) diagnosed according to 3 different classification criteria sets (the Copenhagen criteria, the European criteria, and the American-European consensus criteria (AECC).

METHODS

A linked registry study using information from the Malmö Primary SS Registry combined with the Swedish Cause-of-Death Registry was performed, and SMRs were calculated. Kaplan-Meier survival curves and log rank tests were used to compare survival probability between subgroups of patients with primary SS. Cox regression analysis was used to study the predictive value of various laboratory findings at the time of diagnosis.

RESULTS

Four hundred eighty-four patients with a median followup of 7 years (range 1 month to 17 years 11 months) were included. The SMR for those fulfilling the AECC (n = 265) was 1.17 (95% confidence interval [95% CI] 0.81-1.63). Thirty-four deaths occurred in this group of patients. Excess mortality was found only for lymphoproliferative malignancy (cause-specific SMR 7.89 [95% CI 2.89-17.18]), corresponding to 2.53 excess deaths per 1,000 person-years at risk. In those not fulfilling the AECC (n = 219), 14 deaths occurred, the SMR was 0.71 (95% CI 0.39-1.20), and no excess mortality due to any specific cause was found. Hypocomplementemia, defined as C3 and/or C4 values in the lowest quartile of the SS patients' values at the time of diagnosis, was a significant predictor of death, mainly due to lymphoproliferative malignancy.

CONCLUSION

No increased all-cause mortality could be detected for patients with primary SS compared with the general population. When subgroups of primary SS were compared, excess mortality due to lymphoproliferative malignancy was found in patients fulfilling the AECC, the strongest predictor for unfavorable outcome being low C3 and/or C4 levels at the time of diagnosis.