Hepatitis C virus, Sjögren's syndrome and B-cell lymphoma: linking infection, autoimmunity and cancer

Recent updates in the diagnosis and management of cryoglobulinemic vasculitis

INTRODUCTION

Cryoglobulinemic vasculitis (CV), also known as mixed cryoglobulinemic syndrome (MCS), is a systemic vasculitis that affects small blood vessels. It exhibits a wide range of clinical manifestations, making its treatment a continuing challenge for physicians.

AREAS COVERED

We conducted a comprehensive review to evaluate the current status of diagnosis, management, and treatment of mixed cryoglobulinemia (MC). The accurate clinical and serological evaluation plays a vital role in diagnosing MC, identifying potential comorbidities, and monitoring its main manifestations and complications. Treatment strategies should be individualized based on the underlying etiopathogenesis, the severity of organ involvement, and the associated underlying disease. At present, the two mainstays of CV treatment are direct antiviral agents (for HCV-related CV) and B-cell-targeted therapy.

EXPERT OPINION

MC remains one of the few autoimmune diseases where the etiology is known, at least for the majority of patients. Its pathogenetic mechanism offers a unique opportunity to investigate the interplay between infections and the immune system. Moving forward, the primary challenge will continue to lie in the treatment of resistant or refractory cases of CV, particularly those associated with autoimmune diseases, or cases classified as 'essential' CV.

Tertiary lymphoid structures in breast ductal carcinoma in situ correlate with adverse pathological parameters

AIMS

To investigate tertiary lymphoid structures (TLSs) in ductal carcinoma in situ (DCIS) of the breast and their correlation with pathological features, immune cell markers and clinical outcomes.

METHODS AND RESULTS

Morphological identification of TLSs in 198 DCIS cases incorporated B and T cell zones with high endothelial venules. TLS positivity was defined as ≥ 1 TLSs in lesional areas, while TLS area percentage was divided into two categories: low (TLSs < 5%) and high (TLSs ≥ 5%). Previously reported biomarkers included ER, PR, HER2, CD68, CD163, CD4, CD8 and PD-L1. TLSs were observed in 24.7% (49 of 198) of cases, with a mean diameter of 0.44 mm (median = 0.4 mm, range = 0.12-1.43 mm). TLSs were significantly associated with higher nuclear grade, presence of necrosis, hormone receptor negativity/HER2 positivity, triple negativity, tumour infiltrating lymphocytes (TILs) and immune related biomarkers such as FOXP3, CD163, CD4 and CD4/CD8 ratio (all P < 0.05). There were no significant associations between TLSs and recurrence, but a combination of TLSs^high with FOXP3⁺ , CD4^high , CD4/CD8 ratio^high and CD68^high individually, compared with all other combinations, disclosed significantly poorer disease-free survival (DFS) for ipsilateral invasive recurrence (IIR) on both Kaplan-Meier and multivariable Cox regression analyses (all P < 0.05).

CONCLUSIONS

TLSs in DCIS were associated with unfavourable prognostic features, TILs and immune cell markers in our study. TLSs^high /FoxP3⁺ , TLSs^high /CD4^high , TLSs^high /(CD4/CD8) ratio^high and TLSs^high /CD68^high were independent factors for poorer DFS for IIR. Further exploration of the pathological significance of TLSs may provide a clinical basis for their recognition as an important structure and functional unit in the tumour immune microenvironment.

Burden, Outcome, and Comorbidities of Extrahepatic Manifestations in Hepatitis C Virus Infection

Hepatitis C virus (HCV) is a significant cause of chronic liver diseases worldwide and is associated with negative consequences, including cirrhosis, hepatic decompensation, hepatocellular carcinoma, and increased risk of mortality. In addition to liver-related morbidities, HCV is also associated with several extrahepatic manifestations, including mixed cryoglobulinemia, diabetes mellitus, cardiocerebrovascular disease, lymphoma, and autoimmune diseases. These non-liver-related complications of HCV increase the complexity of this disease and can contribute to the economic burden, morbidity, quality of life, and mortality throughout the world. Therefore, understanding how this virus can contribute to each extrahepatic manifestation is worth investigating. Currently, the advancement of HCV treatment with the advent of direct-acting anti-viral agents (DAAs) has led to a high cure rate as a result of sustained virologic response and tremendously reduced the burden of extrahepatic complications. However, HCV-associated extrahepatic manifestations remain a relevant concern, and this review aims to give an updated highlight of the prevalence, risk factors, associated burdens, and treatment options for these conditions.

Prevalence and Outcome of Serum Autoantibodies in Chronic Hepatitis C Patients Undergoing Direct-Acting Antiviral Treatment

Background

Chronic immune stimulation by hepatitis C virus (HCV) may cause occurrence of several autoantibodies in infected patients, with or without features of clinically overt autoimmune diseases. The recent introduction of direct-acting antivirals (DAAs) has dramatically changed the natural history of chronic HCV infection. The aim of this study was to assess the effects of DAA therapy on serum autoantibodies in chronic hepatitis C (CHC) patients.

Methods

The medical records of 113 CHC patients were reviewed to assess autoantibody behavior following DAA-directed HCV eradication. Statistical analysis was performed to assess correlations between DAA treatment and autoantibody titers, HCV genotypes, and viral loads.

Results

Anti-nuclear (ANA), anti-smooth muscle cell (ASMA) and anti-mitochondrial (AMA) antibody testing was available in 77 patients; 31 out of 77 patients (40%) had one or more serum autoantibodies prior to treatment. Measurement of autoantibody titers before and after HCV eradication was performed in 20 of 31 patients. DAA treatment significantly affected ANA and ASMA titers, leading to disappearance or reduction of autoantibody titers; conversely, AMA were not influenced by DAA treatment. No correlations were observed between autoantibody specificity and both HCV genotypes and viral loads at baseline. Likewise, serum autoantibody titers were independent of HCV genotypes.

Conclusions

DAA-directed HCV clearance may interrupt chronic immune stimulation by removing the drive for autoantibody induction. The isolated persistence of autoantibodies in the small fraction of patients who did not show clearance following DAA treatment may require long-term vigilance.

Sjogren's Syndrome and Pulmonary Disease

Sjogren's syndrome is an autoimmune connective tissue disease targeting the exocrine glands and frequently affecting the respiratory system. The pulmonary disease is the most important extra-glandular manifestation as it carries most of the morbidity and mortality. Typically, it affects the small airways ranging from mild to severe respiratory symptoms. The upper airways are also commonly involved, predisposing sinusitis to occur more frequently than in the normal population. Lymphocytic interstitial pneumonia was initially thought to be the prevailing parenchymal disease; however, multiple cohorts report non-interstitial pneumonia to be the most frequent subtype of interstitial lung disease. In the review of high-resolution computed tomography scans, cystic lesions are commonly found and associate with both the small airways and parenchymal disease. Under their presence, amyloidosis or lymphomas should be considered in the differential. Overall, Sjogren's syndrome has a higher risk for lymphoma, and in lungs this condition should be thought of, especially when the images reveal pulmonary nodularity, lymphocytic interstitial pneumonia and lymphadenopathy. Although, pulmonary artery hypertension was traditionally and exceptionally linked with Sjogren's syndrome, together with systemic lupus erythematosus, they are now acknowledged to be the most common pulmonary vascular disease in east Asian populations, even over patients with systemic sclerosis. Although there are no controlled prospective trials to treat pulmonary disease in Sjogren's syndrome, the mainstay treatment modality still falls on glucocorticoid therapy (systemic and inhaled), combined with immune modulators or alone. Most of the evidence sustains successful outcomes based on reported cases or case series.

Rheumatologic manifestations of Hepatitis C Virus

INTRODUCTION

Hepatitis C Virus (HCV) is a well-known worldwide infection, responsible for hepatic and extrahepatic complications. Among extrahepatic manifestation, the rheumatologic are the most common ones. With the arrival of Direct Antiviral Agents (DAA), the treatment and the clinical perspective have rapidly changed, permitting to achieve a sustained virological response (SVR) and preventing complications of chronic infection.

EVIDENCE ACQUISITION

We performed on PubMed a literature search for the articles published by using the search terms "HCV infection," "HCV syndrome," "HCV-related rheumatologic disorders," "cryoglobulinemia," "cryoglobulinemic vasculitis" and "mixed cryoglobulinemia."

EVIDENCE SYNTHESIS

Mixed cryoglobulinemia (MC) is the prototype of HCV-associated rheumatologic disorder. HCV-related MC is typically considered by physicians as a human model disease to linking infection with autoimmune diseases. Chronic HCV infection can lead to a multistep process from a simple serological alteration (presence of circulating serum cryoglobulins) to frank systemic vasculitis (cryoglobulinemic vasculitis [CV]) and ultimately to overt malignant B lymphoproliferation (such as non-Hodgkin lymphoma [NHL]). Antiviral therapy is indicated to eradicate the HCV infection and to prevent the complications of chronic infection. Immunosuppressive therapy is reserved in case of organ threatening manifestations of CV. In this review, we discuss the main clinical presentation, diagnostic approach and treatment of rheumatologic manifestations of HCV infection.

CONCLUSIONS

Chronic HCV infection is responsible for complex clinical condition, ranging from hepatic to extra-hepatic disorders. Cryoglobulins are the result of this prolonged immune system stimulation, caused by tropism of HCV for B-lymphocyte.

An update to the pathogenesis for monoclonal gammopathy of renal significance

Monoclonal gammopathy of renal significance (MGRS) is characterized by the nephrotoxic monoclonal immunoglobulin (MIg) secreted by an otherwise asymptomatic or indolent B-cell or plasma cell clone, without hematologic criteria for treatment. The spectrum of MGRS-associated disorders is wide, including non-organized deposits or inclusions such as C3 glomerulopathy with monoclonal glomerulopathy (MIg-C3G), monoclonal immunoglobulin deposition disease, proliferative glomerulonephritis with monoclonal immunoglobulin deposits and organized deposits like immunoglobulin related amyloidosis, type I and type II cryoglobulinaemic glomerulonephritis, light chain proximal tubulopathy, and so on. Kidney biopsy should be conducted to identify the exact disease associated with MGRS. These MGRS-associated diseases can involve one or more renal compartments, including glomeruli, tubules and vessels. Hydrophobic residues replacement, N-glycosylated, increase in isoelectric point in MIg causes it to transform from soluble form to tissue deposition, causing glomerular damage. Complement deposition is found in MIg-C3G, which is caused by an abnormality of the alternative pathway and may involve multiple factors including complement component 3 nephritic factor, anti-complement factor auto-antibodies or MIg which directly cleaves C3. The effect of transforming growth factor beta and platelet-derived growth factor-β on mesangial extracellular matrix is associated with glomerular and tubular basement membrane thickening, nodular glomerulosclerosis, and interstitial fibrosis. Furthermore, inflammatory factors, growth factors and virus infection may play an important role in the development of the diseases. In this review, for the first time, we discussed current highlights in the mechanism of MGRS-related lesions.

An update to the pathogenesis for monoclonal gammopathy of renal significance

Monoclonal gammopathy of renal significance (MGRS) is characterized by the nephrotoxic monoclonal immunoglobulin secreted by an otherwise asymptomatic or indolent B cell or plasma cell clone, without hematologic criteria for treatment. These MGRS-associated diseases can involve one or more renal compartments, including glomeruli, tubules, and vessels. Hydrophobic residue replacement, N-glycosylated, increase in isoelectric point in monoclonal immunoglobulin (MIg) causes it to transform from soluble form to tissue deposition, and consequently resulting in glomerular damage. In addition to MIg deposition, complement deposition is also found in C3 glomerulopathy with monoclonal glomerulopathy, which is caused by an abnormality of the alternative pathway and may involve multiple factors including complement component 3 nephritic factor, anti-complement factor auto-antibodies, or MIg which directly cleaves C3. Furthermore, inflammatory factors, growth factors, and virus infection may also participate in the development of the diseases. In this review, for the first time, we discussed current highlights in the mechanism of MGRS-related lesions.

Hematological malignancies in connective tissue diseases

Chronic inflammation has profound tumor-promoting effects. Inflammatory cells are the key players in immunosurveillance against tumors, and immunosuppression is known to increase the risk of tumors. Autoimmune diseases, which manifest as loss of self-tolerance and chronic immune dysregulation, provide a perfect environment for tumor development. Aside from managing the direct inflammatory consequences of autoimmune pathogenesis, cancer risk profiles should be considered as a part of a patient's treatment. In this review, we describe the various associations of malignancies with autoimmune diseases, specifically systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and Sjögren's syndrome, as well as discuss the mechanisms contributing to the pathogenesis of both disorders.

Tertiary lymphoid structures in the era of cancer immunotherapy

Tertiary lymphoid structures (TLSs) are ectopic lymphoid organs that develop in non-lymphoid tissues at sites of chronic inflammation including tumours. Key common characteristics between secondary lymphoid organogenesis and TLS neogenesis have been identified. TLSs exist under different maturation states in tumours, culminating in germinal centre formation. The mechanisms that underlie the role of TLSs in the adaptive antitumour immune response are being deciphered. The description of the correlation between TLS presence and clinical benefit in patients with cancer, suggesting that TLSs could be a prognostic and predictive factor, has drawn strong interest into investigating the role of TLSs in tumours. A current major challenge is to exploit TLSs to promote lymphocyte infiltration, activation by tumour antigens and differentiation to increase the antitumour immune response. Several approaches are being developed using chemokines, cytokines, antibodies, antigen-presenting cells or synthetic scaffolds to induce TLS formation. Strategies aiming to induce TLS neogenesis in immune-low tumours and in immune-high tumours, in this case, in combination with therapeutic agents dampening the inflammatory environment and/or with immune checkpoint inhibitors, represent promising avenues for cancer treatment.

The Influence of GPX1 Pro198Leu, CAT C262T and MnSOD Ala16Val Gene Polymorphisms on Susceptibility for Non-Hodgkin Lymphoma and Overall Survival Rate at Five Years from Diagnosis

Objective: The aim of the current study was to investigate possible associations between catalase C262T (CAT C262T), glutathione peroxidase 1 Pro198Leu (GPX1 Pro198Leu), manganese superoxide dismutase Ala16Val (MnSOD Ala16Val) gene polymorphisms and non-Hodgkin Lymphoma risk (NHL) in a Romanian population and the five-year overall survival rate of the NHL patients.

Methods: We included in this case-control study 406 individuals, divided into two groups: the control group (n=315) and the patients group (n=91). The DNA was extracted from peripheral blood and amplified using specific techniques.

Results: The variant homozygous genotype of GPX1 Pro198Leu represents a risk factor for NHL development and no associations regarding the risk for NHL were found for MnSOD Ala16Val and CAT C262T gene polymorphisms. Two of the studied polymorphisms were associated with the overall survival rate thus: negative association regarding MnSOD Ala16Val, associated with higher overall survival rate and a positive one regarding CAT C262T, associated with lower overall survival rate.

Conclusions: According to our results, the mentioned polymorphisms may be considered as susceptible markers of the five-year overall survival rate for NHL patients. Future studies with a larger number of patients are needed to confirm our results.

Uncommon immune-mediated extrahepatic manifestations of HCV infection

INTRODUCTION

Chronic hepatitis C virus (HCV) infection has been associated with myriad extrahepatic manifestations, often resulting from aberrant immune responses. Among the most common immune-mediated manifestations of HCV infection, mixed cryoglobulinemia is the best known extra-hepatic complication. Areas covered: Here we review less common extrahepatic manifestations of HCV infection, with ascertained or presumed immune pathogenesis and the role of the new all oral direct-acting antiviral agents. Rheumatologic, dermatologic, ophthalmologic, renal, pulmonary, hematologic, cardiovascular, and neuropsychiatric manifestations of HCV infection have been considered. Expert commentary: Pathogenesis of HCV-induced aberrant immune responses resulting in peculiar clinical manifestations is not restricted to a single mechanism. A sound approach would therefore consider implementation of an etiologic treatment, through use of antiviral medications, to stop upstream in the pathogenic process all the immune mechanisms leading to hepatic and extrahepatic abnormalities. With the recent introduction of interferon-free, direct antiviral agents, capable of warranting cure for nearly all HCV-infected patients subjected to therapy, both common and uncommon extrahepatic manifestations of chronic hepatitis C are expected to no longer constitute a matter of comorbidity in the course of HCV infection.

Lymphoma and Lymphomagenesis in Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease mainly affecting exocrine glands and leading to impaired secretory function. The clinical picture is dominated by signs and symptoms of mucosal dryness and the course of the disease is mild and indolent in the majority of cases. However, a subgroup of patients can also experience extraglandular manifestations that worsen the disease prognosis. pSS patients are consistently found to have a higher risk of developing non-Hodgkin lymphoma (NHL) compared with patients with other autimmune disorders and to the general population. NHL is the most severe comorbidity that can occur in pSS, therefore recent research has aimed to identify reliable clinical, serological, and histological biomarkers able to predict NHL development in these subjects. This review article encompasses the body of evidence published so far in this field highlighting the challenges and pitfalls of different biomarkers within clinical practice. We also provide an overview of epidemiological data, diagnostic procedures, and evidence-based treatment strategies for NHL in pSS.

Advances in HCV and Cryoglobulinemic Vasculitis in the Era of DAAs: Are We at the End of the Road?

Hepatitis C Virus (HCV)-related Mixed Cryoglobulinemia (MC) is a unique condition with complex pathogenesis that involves HCV antigen-driven B-lymphocyte clonal proliferation and mutagenesis. Clinical spectrum of MC ranges from asymptomatic state to clinically-apparent vasculitis involving multiple organs. In the era of Direct-Acting Antiviral (DAA) therapy, patients with HCV-related MC achieve high rates of viral clearance that is commonly accompanied by an improvement in clinical symptoms as well as immunological profiles. Rituximab, either alone or in combination with DAA, has also been shown to be effective. Nevertheless, there have been limited and somewhat conflicting data, particularly over the long-term, regarding the rate and degree of clinical response of MC following DAA therapy. It appears that we have come quite a long way in the last decade with this condition. As with non-MC related HCV, undoubtedly long term outcome data will be forthcoming over the next few years. As we move forward successful therapy of HCV is not likely to be a challenge in contrast to access to therapy.

Chronic Hepatitis C Virus Infection and Depression

Hepatitis C virus (HCV) infection is a systemic disease with hepatic and extrahepatic manifestations, including neuropsychiatric conditions. Depression is a frequent disorder, which has been reported in one-third of patients with HCV infection and has an estimated prevalence of 1.5 to 4.0 times higher than that observed in patients with chronic hepatitis B virus infection or the general population. HCV seems to play a direct and indirect role in the development of depression. Impaired quality of life and increasing health care costs have been reported for patients with HCV infection with depression. Treatment-induced HCV clearance has been associated with improvement of depression and quality of life.

Characterization and risk estimate of cancer in patients with primary Sjögren syndrome

BACKGROUND

The purpose of this study is to characterize the risk of cancer in a large cohort of patients with primary Sjögren syndrome (SjS).

METHODS

We had analyzed the development of cancer in 1300 consecutive patients fulfilling the 2002 SjS classification criteria. The baseline clinical and immunological characteristics and systemic activity (ESSDAI scores) were assessed at diagnosis as predictors of cancer using Cox proportional hazards regression analysis adjusted for age at diagnosis and gender. The sex-and age-specific standardized incidence ratios (SIR) of cancer were estimated from 2012 Spanish mortality data.

RESULTS

After a mean follow-up of 91 months, 127 (9.8%) patients developed 133 cancers. The most frequent type of cancer was B-cell lymphoma (including 27 MALT and 19 non-MALT B-cell lymphomas). Systemic activity at diagnosis of primary SjS correlated with the risk of hematological neoplasia and cryoglobulins with a high risk of either B-cell or non-B-cell lymphoma subtypes. Patients with cytopenias had a high risk of non-MALT B-cell and non-B-cell cancer, while those with low C3 levels had a high risk of MALT lymphomas and those with monoclonal gammopathy and low C4 levels had a high risk of non-MALT lymphomas. The estimated SIR for solid cancer was 1.13 and 11.02 for hematological cancer. SIRs for specific cancers were 36.17 for multiple myeloma and immunoproliferative diseases, 19.41 for Hodgkin lymphoma, 6.04 for other non-Hodgkin lymphomas, 5.17 for thyroid cancer, 4.81 for cancers of the lip and oral cavity, and 2.53 for stomach cancer.

CONCLUSIONS

One third of cancers developed by patients with primary SjS are B-cell lymphomas. The prognostic factors identified at SjS diagnosis differed according to the subtype of B-cell lymphoma developed. Primary SjS is also associated with the development of some non-hematological cancers (thyroid, oral cavity, and stomach).

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

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

[Renal involvement during type 1 cryoglobulinemia]

Cryoglobulins are circulating immunoglobulins that precipitate with cold temperature and dissolve with rewarming. Type 1 cryoglobulinemia is composed of a single monoclonal immunoglobulin and is associated with renal involvement in up to 40% of cases. Type 1 cryoglobulinemia is related to an underlying B-cell haematological malignancy in 60% of patients. In the remaining cases, in the absence of criteria for malignancy, the diagnosis of monoclonal gammopathy of renal significance should be established. The clinical and biological setting and histological features of type 1 cryoglobulinemia are globally similar to those of mixed cryoglobulinemia. In case of haematological malignancy, the treatment is guided by the nature of the underlying disease, and aims at inducing haematological remission, which is necessary for the renal response. The management of monoclonal gammopathy of renal significance has been clarified by an international consensus group and is based on the nature of the underlying clone. In case of monoclonal cryoglobulinemia associated with a plasma-cell clone (IgG or IgA), the treatment is based on the combination of bortezomib, cyclophosphamide and dexamethasone. In case of IgM monoclonal cryoglobulinemia, the treatment is similar to that of Waldenström macroglobulinemia, and is based on rituximab. The clinical course of renal monoclonal cryoglobulinemia is intimately associated with the haematological response, and is usually favourable.

Hepatitis C virus infection and the risk of Sjögren or sicca syndrome: a meta-analysis

Previous studies have suggested an association between hepatitis C virus (HCV) infection and the development of Sjögren's syndrome (SS), also known as sicca syndrome. The main objective of this study was to summarize the existing evidence and quantitatively evaluate the association between hepatitis C virus infection and SS/sicca syndrome by performing a meta-analysis of observational studies. MEDLINE and PubMed (January 1980-August 2013) were searched to identify relevant studies in English. Outcomes were calculated and are reported as odds risk (OR) and 95% CIs based on a random-effects model. Heterogeneity was assessed with I(2) statistics. Quality assessment was performed with the Newcastle-Ottawa scale. Based on meta-analysis of five cross-sectional and five cohort studies, a significant positive relationship between HCV infection and development of SS/sicca syndrome was found, the pooled random effects OR being 3.31 (95% CI, 1.46-7.48; P < 0.001). In subset analyses, the studies that used European diagnostic criteria showed a higher summary OR than did studies that adopted other diagnostic criteria. When the data were stratified by source of controls, significant associations were also observed when healthy people (OR = 9.44; 95% CI = 2.67-33.40; P = 0.204) or subjects with hepatitis B virus infection (OR = 6.57; 95% CI = 1.21-35.57; P = 0.5) were used as controls, but not when the controls were hospital-based (OR = 0.99; 95% CI = 0.61-1.61; P = 0.169). In summary, the findings suggest that HCV infection is associated with SS/sicca syndrome. The observed increased risk in studies in which European diagnostic criteria and healthy controls were used and the decreased risk in studies with hospital-based controls may be attributable to selection bias or other unknown factors.

How hepatitis C virus modifies the immunological profile of Sjögren syndrome: analysis of 783 patients

INTRODUCTION

We conducted a study to analyze how infection by hepatitis C virus (HCV) may influence the immunological serum pattern of patients with Sjögren syndrome (SS).

METHODS

Since 1994, we have tested serum HCV-IgG antibodies in 783 patients with SS diagnosed according to the 1993 European classification criteria. The immunological profile at diagnosis was compared according to the presence or absence of HCV.

RESULTS

Of the 783 patients with SS, 105 (13.4 %) tested positive for HCV-IgG antibodies (88 females, 17 males, mean age at SS diagnosis: 62.9 years). Multivariate analysis showed that patients with SS-HCV had a higher mean age and a higher frequency of low C3/C4 levels, cryoglobulins, and hematological neoplasia compared with patients without HCV. The frequency of anti-La antibodies compared with anti-Ro antibodies was higher in patients with SS-HCV (17 % vs. 15 %) and lower in patients without HCV infection (30 % vs. 43 %). The frequency of concomitant detection of the three main cryoglobulin-related markers (cryoglobulins, rheumatoid factor activity, and C4 consumption) was threefold higher in patients with SS-HCV compared with patients without HCV. SS-HCV patients with genotype 1b showed the highest frequencies of immunological abnormalities related to cryoglobulins and the lowest frequencies of anti-Ro/La antibodies.

CONCLUSIONS

We found HCV infection in 13 % of a large series of Spanish patients with SS. The HCV-driven autoimmune response was characterized by a lower frequency of anti-Ro/La antibodies, an abnormal predominance of anti-La among anti-Ro antibodies, and a higher frequency of cryoglobulinemic-related immunological markers in comparison with patients without HCV infection. This immunological pattern may contribute to the poor outcomes found in patients with SS-HCV.

Silicone implants and lymphoma: The role of inflammation

The risk of hematological malignancies is mainly determined by genetic background, age, sex, race and ethnicity, geographic location, exposure to certain chemicals and radiation; along with the more recently proposed immune factors such as chronic inflammation, immunodeficiencies, autoimmunity, and infections. Paradigmatic examples include the development of lymphoma in Sjögren's syndrome and Hashimoto thyroiditis, gastric MALT lymphoma in Helicobacter pylori infection, or lymphomas associated with infections by Epstein-Barr virus, human herpes virus 8 (HHV 8) and leukemia/lymphoma virus 1 (HTLV-1). A growing number of reports indicates an increased risk of lymphoma, particularly of the anaplastic large cell (ALCL) type. The implants, specifically those used in the past, elicit chronic stimulation of the immune system against the prosthetic material. This is particularly the case in genetically susceptible hosts. We suggest that polyclonal activation may result in monoclonality in those at risk hosts, ultimately leading to lymphoma. We suggest that patients with an inflammatory response against silicone implants be monitored carefully.

[Treatment of cryoglobulinemic vasculitis associated with hepatitis C virus infection]

Cryoglobulinemia is a heterogeneous systemic autoimmune disease with a wide variety of causes, symptoms and outcomes, and different etiopathogenic pathways involved in the vasculitic organ damage. The discovery of the hepatitis C virus (HCV) in 1989 changed radically the focus of research of the so-called "essential" cryoglobulinemia. Cryoglobulins can be detected in 25-30% of patients with HCV, overwhelmingly representing mixed cryoglobulins. However, only 10-15% of patients present with cryoglobulinemic vasculitis, with a broad spectrum of symptoms including mild or life-threatening manifestations. Consequently, not all patients can be uniformly treated. The key therapeutic points in HCV+ patients with cryoglobulinemic vasculitis cover different aspects. The first is to treat the underlying cause of cryoglobulinemia whenever possible, hence the use of antiviral therapies must always be considered in these patients. An individualized diagnostic approach to assess the number of organs involved and the severity of organ involvement is also essential in the therapeutic planning. This complex clinical scenario leads to an equally complex therapeutic scenario. There are three main treatment strategies for HCV-associated cryoglobulinemic vasculitis: conventional immunosuppression, antiviral treatment and biological therapies. The most recent studies are suggesting a change from the classical therapeutic approach (monotherapeutic regimens) to combination/sequential regimens, including treatments targeting the virus and those directed against the induced autoimmune disease, with the aim of blocking the various etiopathogenic pathways involved.

Oral manifestations of hepatitis C virus infection

Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV.

Ectopic lymphoid-like structures in infection, cancer and autoimmunity

Ectopic lymphoid-like structures often develop at sites of inflammation where they influence the course of infection, autoimmune disease, cancer and transplant rejection. These lymphoid aggregates range from tight clusters of B cells and T cells to highly organized structures that comprise functional germinal centres. Although the mechanisms governing ectopic lymphoid neogenesis in human pathology remain poorly defined, the presence of ectopic lymphoid-like structures within inflamed tissues has been linked to both protective and deleterious outcomes in patients. In this Review, we discuss investigations in both experimental model systems and patient cohorts to provide a perspective on the formation and functions of ectopic lymphoid-like structures in human pathology, with particular reference to the clinical implications and the potential for therapeutic targeting.

Isolation, characterization, and molecular modeling of a rheumatoid factor from a Hepatitis C virus infected patient with Sjögren's syndrome

We have previously isolated several IgG rheumatoid factors (RFs) from patients with both rheumatoid arthritis and idiopathic thrombocytopenia purpura using phage display system. To study IgG RFs in patients with other autoimmune diseases, phage display antibody libraries from a hepatitis C virus infected patient with Sjögren's syndrome were constructed. After panning, a specific clone RFL11 was isolated for characterization in advance. The binding activity and specificity of RFL11 to IgG Fc fragment were comparable to those of RFs previously isolated. The analysis with existed RF-Fc complex structures indicated the homology model of RFL11 is similar to IgM RF61 complex with high binding affinity of about 6 × 10⁻⁸ M. This effect resulted from longer complementarity-determining region (CDR) combining key somatic mutations. In the RFL11-Fc interfaces, the CDR-H3 loop forms a finger-like structure extending into the bottom of Fc pocket and resulting in strong ion and cation-pi interactions. Moreover, a process of antigen-driven maturation was proven by somatically mutated VH residues on H2 and H3 CDR loops in the interfaces. Taken together, these results suggested that high affinity IgG RFs can be generated in patients with Sjögren's syndrome and may play an important role in the pathogenesis of this autoimmune disease.

Measuring the response of extrahepatic symptoms and quality of life to antiviral treatment in patients with hepatitis C

Background. HCV infection is associated with musculoskeletal manifestations such as chronic widespread pain, sicca syndrome, polyarthritis, and a reduced HRQOL. Little data is available on the effect of treatment on these manifestations. This study measured changes in extrahepatic symptoms and HRQOL before and after antiviral treatment in a large UK patient cohort. Methods. 118 patients completed HQLQ and rheumatological questionnaires before and after treatment with pegylated interferon-α and ribavirin, with specific regard to chronic widespread pain, sicca syndrome, and sustained virological response. Results. There was significant improvement in HQLQ domains of physical functioning, physical disability, social functioning, limitations and health distress due to hepatitis, and general health. There was significant deterioration in domains of positive well-being, health distress, and mental health. There was a significant decline prevalence of CWP (26.3% versus 15.3%, P = 0.015). Sicca syndrome prevalence fell insignificantly (12.7% versus 11%). SVR was associated positively with all HRQOL changes and significantly with CWP remission. Conclusions. HCV antivirals significantly improve poor HRQOL scores and CWP. Before treatment, both were common, coassociated, and unaccounted for through mixed cryoglobulinemia alone. Although a role of the hepatitis C virus in CWP cannot be deduced by these results, symptomatic improvement via antiviral treatment exists for this subset of patients.

Hepatitis C virus infection and autoimmune diseases

Hepatitis C virus (HCV) infection is associated with a number of extrahepatic disorders. The most studied conditions associated with HCV are type II mixed cryoglobulinemia and B cell lymphoma. However, many reports suggest that HCV might also be associated with a number of autoimmune disorders, both organ-specific and not organ-specific. Although concomitant treatment of HCV infection is a confounding factor when ascertaining the actual role of HCV in inducing autoimmune disease, a considerable amount of experimental data indicates that HCV is able to subvert the immune system and consequently induce autoimmunity. In the present review, we report a series of observations which associate chronic HCV infection with the onset of autoimmune disorders.

Advances in the Aetiophatogenesis of Sjögren's Syndrome: a Literature Review

OBJECTIVES

The purpose of present paper is to review and critically address the recent advances on the aetiopathogenesis of the Sjögren's syndrome, taking into account the attained clinical features, with particular relevance given to the oral involvement.

MATERIAL AND METHODS

A comprehensive review of the available literature between 1970 and 2012, regarding to the aetiopathogenesis and clinical findings related to Sjögren's syndrome was conducted. Eligible studies were identified by searching the electronic literature PubMed, Medline, Embase, and ScienceDirect databases for relevant reports (last search update January 2012), combining the MESH heading term "Sjögren's syndrome", with the words "salivary glands, xerostomia, xerophtalmia, aetiology". The authors checked the references of the selected articles to identify additional eligible publications and contacted the authors, if necessary.

RESULTS

This article addresses a large number of the recent advances in the aetiopathogenesis of the disease, taking into account the attained clinical features of both local and systemic nature. Detailed mechanisms of the hypothesized influence of viral infections, genetic and hormonal factors, and the relevance of the altered glandular homeostasis are critically discussed with particular relevance given to the local and systemic involvement of Sjögren's syndrome.

CONCLUSIONS

The increasing number of data published recently on the aetiophatogenesis of Sjögren's syndrome strengthens the hypothesis that this condition, as all autoimmune diseases, is a multifactor disorder. Genetic predisposition, hormonal and environmental factors are thought to be implicated.

Lymphoma cells with increased anti-oxidant defenses acquire chemoresistance

Chronic inflammation increases lymphoma risk. Chronic inflammation exposes cells to increased reactive oxygen species (ROS). Constant exposure to ROS selects for oxidative stress-resistant cells with upregulated anti-oxidant defense enzymes. The impact of oxidative stress resistance on the redox biology and chemotherapy response in lymphoma has not been rigorously tested. To measure the effect of antioxidant defense enzyme upregulation in lymphoid cells, we created oxidative stress-resistant WEHI7.2 thymic lymphoma cell variants. We selected a population of WEHI7.2 cells for resistance to hydrogen peroxide and constructed catalase-overexpressing WEHI7.2 transfectants. The WEHI7.2 variants had: i) increased catalase and total superoxide dismutase activities; ii) an altered GSSG/2GSH redox potential; iii) a more oxidized NADP(+)/NADPH pool; and iv) increased phase 2 enzymes, NAD(P)H:quinone oxidoreductase and glutathione S-transferases μ and π. Regression analysis showed a correlation between the GSSG/2GSH redox potential and the increased phase 2 enzyme activities. As predicted from the anti-oxidant defense enzyme profile, the variants were more resistant to the oxidants hydrogen peroxide and paraquat. The variants exhibited resistance to the common lymphoma chemotherapeutics, cyclophosphamide, doxorubicin, vincristine and glucocorticoids. These data indicate that chronic ROS exposure results in lymphoid cells with multiple changes in their redox biology and a chemoresistance phenotype. These data further suggest that lymphomas that arise at the site of chronic inflammation develop chemoresistance due to a combination of drug detoxification and removal of ROS.

The cryoglobulinaemias

Cryoglobulins are immunoglobulins that precipitate in vitro at temperatures less than 37°C and produce organ damage through two main pathways: vascular sludging (hyperviscosity syndrome, mainly in type I cryoglobulinaemia) and immune-mediated mechanisms (principally vasculitis, in mixed cryoglobulinaemia). Cryoglobulinaemia is associated with many illnesses, which can be broadly grouped into infections, autoimmune disorders, and malignancies; the most common cause is infection with hepatitis C virus. Mixed cryoglobulinaemic syndrome is diagnosed when a patient has typical organ involvement (mainly skin, kidney, or peripheral nerve) and circulating cryoglobulins. Cutaneous purpura is the most common manifestation of cryoglobulinaemic vasculitis. The most frequently affected internal organs are the peripheral nerves, kidneys, and joints. The course varies widely and prognosis is influenced by both cryoglobulinaemic damage to vital organs and by comorbidities associated with underlying diseases. More than 90% of cases of cryoglobulinaemia have a known underlying cause; therefore treatment is focused on the cause of the disorder rather than merely symptomatic relief. Studies suggest that both combined or sequential antiviral therapies and targeted biological treatments might be more effective than monotherapy.

Cryoglobulinaemia related to Sjogren's syndrome or HCV infection: differences based on the pattern of bone marrow involvement, lymphoma evolution and laboratory tests after parotidectomy

OBJECTIVE

The relationship of cryoglobulinaemia with lymphoproliferation of mucosa-associated lymphoid tissue (MALT) as risk factors for lymphoma evolution in SS remains to be clarified. The different biologic background of SS-related cryoglobulinaemia as compared with cryoglobulinaemia linked to HCV infection was clarified by different clinical and biologic approaches.

METHODS

B-cell clonal expansion was analysed in the bone marrow of 27 consecutive cases with primary SS and mixed cryoglobulinaemia, HCV unrelated, in comparison with 55 HCV-related patients with cryoglobulinaemic vasculitis (CV) without SS. The results were related to the possible occurrence and localization of B-cell lymphoma in the single case. Secondly, the prevalence of mixed cryoglobulinaemia was investigated in 41 unselected patients with primary SS showing either parotid myoepithelial sialadenitis (MESA) or a frank B-cell non-Hodgkin's lymphoma. Thirdly, the levels of serum cryoglobulins and RF were followed in one patient with primary SS, CV and parotid B-cell lymphoma of MALT after bilateral subtotal parotidectomy.

RESULTS

A polyclonal pattern of B expansion in the bone marrow was significantly more frequent in SS-related (19/27 cases) than in HCV-related cryoglobulinaemia (19/55) (P = 0.003). Cryoglobulins were positive in a fraction of patients with SS and malignant lymphoma or with parotid MESA (13/18 and 7/23, respectively), whereas MALT involvement by the lymphoproliferative disorder was the rule. Finally, the levels of serum cryoglobulins and RF markedly decreased in the SS patient undergoing bilateral subtotal parotidectomy.

CONCLUSION

Lymphoproliferation of MALT appears as the biologic background of cryoglobulinaemia in SS, differently from HCV-related cryoglobulinaemia.

Immunopathologic differences of Sjögren's syndrome versus sicca syndrome in HCV and HIV infection

A clinical picture of dry eye and dry mouth with the histological counterpart of focal lymphocytic sialoadenitis, usually detected in minor salivary glands, is considered the hallmark of Sjögren's syndrome. The association of sicca complaints and focal sialoadenitis can be also found in a number of other diseases, including some systemic viral infections. Among these conditions, chronic hepatitis C virus infection, associated with mixed cryoglobulinaemia and extra-hepatic manifestations, and HIV infection, particularly in the phase of diffuse interstitial lymphocytic infiltration, may mimic the clinical and histological aspects of Sjögren's syndrome. However, each disorder is characterised by specific, disease-related immunopathological aspects. Besides sicca complaints, the various disorders may also share a number of systemic extra-glandular features and the possible development of mucosa-associated lymphoid tissue lymphomas. This latter event represents in all of these diseases the final result of an antigen-driven chronic stimulation of B lymphocytes.

Cryoglobulin evaluation: best practice?

Cryoglobulins are serum immunoglobulins that precipitate at temperatures below 37 degrees C and re-dissolve on warming. Cryoglobulinaemia leads to variable symptoms including characteristic purpura, ischaemia of extremities, renal failure, peripheral neuropathy, abdominal pain secondary to intestinal ischaemia and arthralgias. Cryoglobulin testing is underutilized in clinical practice. It has been neglected in clinical laboratories and by clinicians due to several factors, such as the length of time it takes for serum cryoglobulin analysis to be performed in the laboratory, the perceived difficulty in getting optimal sampling conditions and a failure to appreciate that even apparently low levels of cryoglobulin can be associated with severe symptoms in some patients. The most important variable confounding standardization of cryoglobulin testing is improper sample handling. A recent report critically appraising the current practice of cryoglobulin evaluation in 137 laboratories in Europe by United Kingdom National External Quality Assurance Scheme (UKNEQAS) illustrated the wide variability in practice. Although many clinical laboratories perform cryoglobulin evaluation, there are widespread differences in the methodology used and the care with which this is carried out and this leads to considerable intralaboratory and interlaboratory variability. The most common sources of error are false-negative results due to loss of cryoprecipitate during transport and storage. Better standardization is needed to avoid missed diagnoses and improve the comparability of results. Laboratories should ensure that sample temperature is maintained at 37 degrees C until the serum is separated. In this article, we briefly review the classification and clinical features of cryoglobulins and suggest best practice guidelines for laboratory detection and identification of cryoglobulins.

Characterization of antibodies directed against the immunoglobulin light kappa chain variable chain region (VK) of hepatitis C virus-related type-II mixed cryoglobulinemia and B-cell proliferations

Autoimmune type-II cryoglobulinemia (II-MC) is sustained by hepatitis C virus (HCV) infection and B-cell (oligo)clones. This is the reason why the disease may be considered an "indolent B-cell lymphoma (NHL)." B clones show a restricted use of immunoglobulin variable genes (BCR), in particular in the use of the variable kappa (VK)3-20/15 light chain, and show a homology between their BCR functional regions and those of autoimmune rheumatoid factors. We underlined the BCR unique repertoire with frequent rheumatoid factor activity also observed in other autoimmune disorders associated with NHL. The immunoglobulin idiotype is a clonal B-cell marker and an ideal target for immunotherapy. Five monoclonal antibodies were produced in our laboratory toward the VK3-20 of a subject with HCV infection and a II-MC-associated NHL. Epitope determination was performed using the epitope excision approach. Monoclonal antibody reactivity was tested in vitro in ELISA, Western blot, and cytofluorimetry. Data confirmed that a panel of antibodies, reactive against shared idiotypes, can be produced from patients with HCV-associated B-cell lymphoproliferative diseases, thus obviating the need to produce an anti-idiotype antibody for each patient.

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.

Prevalence of hepatitis C serum antibody in autoimmune diseases

OBJECTIVE

To evaluate the prevalence of serum antibodies against hepatitis C virus and other infectious agents in a large cohort of well-characterized patients with autoimmune diseases (AID).

METHODS

We utilized 1322 sera from patients with 18 different AID and 236 sera from healthy controls from the same countries and with similar age and sex distribution. All sera were tested for the presence of serum anti-hepatitis C virus (HCV) antibodies as well as antibodies directed at other infectious agents and autoantibodies.

RESULTS

Anti-HCV antibody was detected in 115/1322 (8.7%) of patients with AID and 0.4% of matched healthy controls (P < 0.0001). The prevalence of anti-HCV antibody was significantly higher in 7/18 different AID (i.e. cryoglobulinemia, mixed cryoglobulinemia pemphigus vulgaris, vasculitis, secondary anti-phospholipid syndrome, Hashimoto's thyroiditis, and inflammatory bowel disease) compared to controls. Patients with AID and serum anti-HCV positivity had an increased prevalence of antibodies against hepatitis B virus, Toxoplasma gondii and Cytomegalovirus as opposed to a lower frequency of serum autoantibodies.

CONCLUSIONS

The enhanced prevalence of anti-HCV serum antibodies in AID may suggest a role for HCV in tolerance to breakdown, similarly to its established role in mixed cryoglobulinemia. This immune mediated effect does not rule out the role of other infectious agents.

Mixed cryoglobulinemia

Mixed cryoglobulinemia (MC), type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1), but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers), chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV) infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV) infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome, polyarthritis, and B-cell lymphomas. The first-line treatment of MC should focus on eradication of HCV by combined interferon-ribavirin treatment. Pathogenetic treatments (immunosuppressors, corticosteroids, and/or plasmapheresis) should be tailored to each patient according to the progression and severity of the clinical manifestations. Long-term monitoring is recommended in all MC patients to assure timely diagnosis and treatment of the life-threatening complications. The overall prognosis is poorer in patients with renal disease, liver failure, lymphoproliferative disease and malignancies.

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.

Hepatitis C infection and risk of malignant lymphoma

The association between hepatitis C virus (HCV) infection and risk of malignant lymphoma remains controversial, perhaps due to small-sized studies and low prevalence of HCV in the general population. On the basis of a large Danish-Swedish population-based case-control study, 2,819 lymphoma patients and 1,856 controls of second-generation Danish-Swedish origin were screened for HCV infection using an enzyme-linked immunosorbent assay and a confirming recombinant immunoblot assay (RIBA) test. Positive samples were tested with real-time PCR for the presence of HCV RNA. The association between HCV infection and risk of malignant lymphoma was assessed by logistic regression. When intermediate RIBA test results were interpreted as positive, anti-HCV antibody positivity was associated with a nonsignificant increased risk of non-Hodgkin lymphoma (NHL) overall (odds ratio (OR) = 2.2; 95% confidence interval (CI) 0.9-5.3; n = 20 cases), of B-cell lymphomas combined (OR = 2.4 [1.0-5.8]; n = 20) and of lymphoplasmacytic lymphoma (OR = 5.2 [1.0-26.4]; n = 2). No patients with T-cell or Hodgkin lymphoma were HCV-positive. A more conservative definition of HCV positivity (disregarding intermediate RIBA results) resulted in an OR = 1.6 (0.3-8.5; n = 5) for NHL overall. When the definition was further restricted to require HCV RNA positivity, OR was 1.7 (0.2-16.2; n = 3) for NHL overall. Our findings from a population with a low prevalence of HCV suggest a positive association between HCV and risk of NHL, in particular of B-cell origin.

Lessons from diseases mimicking Sjögren's syndrome

Sjögren's syndrome (SS) is a systemic autoimmune disease that mainly affects the exocrine glands and usually presents as persistent dryness of the mouth and eyes because of functional impairment of the salivary and lacrimal glands. The histological hallmark is a focal lymphocytic infiltration of the exocrine glands, and the spectrum of the disease extends from an organ-specific autoimmune disease (autoimmune exocrinopathy) to a systemic process with diverse extraglandular manifestations. In the absence of an associated systemic autoimmune disease, patients with this condition are classified as having primary SS. The differential diagnosis includes processes that specifically involve the exocrine glands. On the one hand, some chronic viral infections may induce lymphocytic infiltration of the exocrine glands, in some cases indistinguishable from that observed in primary SS. On the other hand, some processes may mimic the clinical picture of SS through nonlymphocytic infiltration of the exocrine glands. This review focuses on these two groups of diseases that mimic SS (infections and infiltrating processes).

Autoimmunity in coxsackievirus B3 induced myocarditis

Virus infections are implicated in several autoimmune diseases. Multiple mechanisms of autoimmunity induction have been proposed including antigenic mimicry, production of cryptic epitopes and infection acting as both adjuvant for self-antigens and the mechanism of releasing these cell antigens. Evidence for these mechanisms in coxsackievirus B3 induced myocarditis is discussed.