Occult hepatitis C virus infection in type II mixed cryoglobulinaemia

Occult Infection with Hepatitis C Virus: Looking for Clear-Cut Boundaries and Methodological Consensus

The sustained virologic response and elimination of HCV is widely viewed as a true cure of chronic hepatitis C as it associates with amelioration of histological liver damage and improved clinical outcomes. Therefore, the existence and clinical burden of occult HCV infection (OCI) has been a controversial issue for many years. In this review, we summarize recently published data that adds new information on the molecular and clinical background of OCI and its epidemiological significance. We also identify and discuss the most important methodological pitfalls, which can be a source of inconsistency between studies. Data that have accumulated so far, strongly support the existence of extrahepatic HCV replication in individuals negative for serum HCV-RNA by conventional clinical tests. OCI emerges as a condition where the immune system is unable to fully resolve infection but it is continuously stimulated by low levels of HCV antigens, leading to progression of liver pathology and extrahepatic HCV-related complications. Moreover, the development of monitoring strategies or management guidelines for OCI is still hampered by the lack of clear definition and the confusion regarding its clinical significance. Careful study design and the introduction of uniform protocols for the detection of low-level HCV-RNA are crucial for obtaining reliable data on OCI.

Residual hepatitis C virus in peripheral blood mononuclear cell as a risk factor for hepatocellular carcinoma after achieving a sustained virological response: a dogma or fiction

BACKGROUND

Clinical worsening after achieving a sustained virological response (SVR) needs to be clarified and explained. Persistence of hepatitis C virus (HCV) core antigen interacts with the host proteins to interfere with signaling pathways and increases the susceptibility to hepatic carcinogenesis.

OBJECTIVE

This study aimed to investigate the risk factors that increase the progression of liver disease and hepatocellular carcinoma in a subgroup of HCV patients who achieved a SVR.

PATIENTS AND METHODS

Eighty-nine HCV patients with hepatic decompensation were selected 8.2 ± 1.8 months after achieving SVR24. HCV core antigen and HCV RNA were detected in peripheral blood mononuclear cells. Matched control (n = 100) and training (n = 200) groups were recruited.

RESULTS

Eighty-five patients showed a progression of Child-Turcotte-Pugh and model for end-stage liver disease scores, with positive RNA in peripheral blood mononuclear cell (357.4 ± 42.1 IU/million cell) and positive hepatitis C virus core antigen (n = 73); four patients were excluded. Susceptibility to decompensation and hepatocellular carcinoma after direct-acting antiviral drugs increased with age [odds ratio (OD) = 1.87], and was associated with male sex (OD = 1.65), diabetes (OD = 3.68), thrombocytopenia (OD = 2.44), pretreatment Alfa-fetoprotein (OD = 3.41), and occult HCV (OD = 4.1).

CONCLUSION

Clinical deterioration after SVR could be explained by occult HCV mainly in older male patients with diabetes and thrombocytopenia.

Detection of Hepatis C Virus-Related Immunologic Markers and Their Impact on Outcomes of Living-Donor Kidney Transplant Recipients

OBJECTIVES

Liver disease is an important cause of morbidity and mortality among recipients of transplanted organs. In addition to the liver, hepatitis C virus infection has a significant prevalence among recipients of kidney transplant and is related to worse graft and recipient survival as the kidney is an important component of the hepatitis C virus clinical syndrome.

MATERIALS AND METHODS

This retrospective single center study included 336 patients with end-stage renal disease who received a kidney transplant at the Mansoura Urology and Nephrology Center from January 1992 to December 1995. Of 336 patients, 63 were excluded, and the remaining 273 patients were divided into 3 groups: viremic active (72 patients), viremic inactive (108 patients), and nonviremic (93 patients). Division of patients was based on hepatitis C virus RNA complement level (C3 and/or C4 consumption), circulating cryoglobulins, and rheumatoid factor detection.

RESULTS

Our study showed insignificant differences regarding patient characteristics and demographic data among the study groups but significantly higher incidence of transaminitis in viremic (active and inactive) patients. Nonsignificant differences were found regarding proteinuria among the 3 groups, including among those who had levels in either nephrotic or nonnephrotic ranges. Biopsy-proven acute rejection episodes among the 3 groups of recipients were statistically comparable, with significantly higher frequency of chronic rejection episodes among viremic active patients. Nonviremic recipients had significantly lower serum creatinine levels than viremic (active and inactive) recipients. Patient and graft survival results were comparable among the groups.

CONCLUSIONS

Presence of hepatitis C virus immunologic markers does not have a significant effect on patient and graft survival; however, it may be a clue for long-term incidence of chronic rejection.

Hepatitis C and kidney disease: A narrative review

Hepatitis-C (HCV) infection can induce kidney injury, mostly due to formation of immune-complexes and cryoglobulins, and possibly to a direct cytopathic effect. It may cause acute kidney injury (AKI) as a part of systemic vasculitis, and augments the risk of AKI due to other etiologies. It is responsible for mesangiocapillary or membranous glomerulonephritis, and accelerates the progression of chronic kidney disease due to other causes. HCV infection increases cardiovascular and liver-related mortality in patients on regular dialysis. HCV-infected patients are at increased risk of acute post-transplant complications. Long-term graft survival is compromised by recurrent or de novo glomerulonephritis, or chronic transplant glomerulopathy. Patient survival is challenged by increased incidence of diabetes, sepsis, post-transplant lymphoproliferative disease, and liver failure. Effective and safe directly acting antiviral agents (DAAs) are currently available for treatment at different stages of kidney disease. However, the relative shortage of DAAs in countries where HCV is highly endemic imposes a need for treatment-prioritization, for which a scoring system is proposed in this review. It is concluded that the thoughtful use of DAAs, will result in a significant change in the epidemiology and clinical profiles of kidney disease, as well as improvement of dialysis and transplant outcomes, in endemic areas.

Occult HCV Infection: The Current State of Knowledge

Context

Occult HCV infection (OCI) is defined as the presence of HCV-RNA in hepatocytes and the absence of HCV in the serum according to usual tests. We aimed to define OCI and provide information about the currently available diagnostic methods. Then we focus on specific groups that are at high risk of OCI and finally investigate immune responses to OCI and the available treatment approaches.

Evidence Acquisition

PubMed, Scopus and Google Scholar were comprehensively searched with combination of following keywords: “occult”, “hepatitis C virus” and “occult HCV infection”. The definition of OCI, diagnostic methods, specific groups that are at high risk and available treatment approaches were extract from literature. An analysis of available articles on OCI also was done based on Scopus search results.

Results

OCI has been reported in several high-risk groups, especially in hemodialysis patients and subjects with cryptogenic liver disease. Furthermore, some studies have proposed a specific immune response for OCI in comparison with chronic hepatitis C (CHC).

Conclusions

With a clinical history of approximately 11 years, occult HCV infection can be considered an occult type of CHC. Evidences suggest that considering OCI in these high-risk groups seems to be necessary. We suggest that alternative diagnostic tests should be applied and that there is a need for the participation of all countries to determine the epidemiology of this type of HCV infection. Additionally, evaluating OCI in blood transfusion centers and in patients who receive large amounts of blood and clotting factors, such as patients with hemophilia, should be performed in future projects.

A New Twist to a Chronic HCV Infection: Occult Hepatitis C

Background. The prevalence of occult hepatitis C infection (OCI) in the population of HCV-RNA negative but anti-HCV positive individuals is presently unknown. OCI may be responsible for clinically overt recurrent disease following an apparent sustained viral response (SVR) weeks to years later. Purpose. To review the available current literature regarding OCI, prevalence, pathogenic mechanisms, clinical characteristics, and future directions. Data Sources. Searching MEDLINE, article references, and national and international meeting abstracts for the diagnosis of OCI (1990-2014). Data Synthesis. The long-term followup of individuals with an OCI suggests that the infection can be transient with the loss of detectable HCV-RNA in PPBMCs after 12-18 months or alternatively exist intermittently and potentially long term. The ultimate outcome of HCV infection is decided by interplay between host immune responses, antiviral therapies, and the various well-identified viral evasion mechanisms as well as the presence of HCV infection within extrahepatic tissues. Conclusion. The currently widely held assumption of a HCV-cure in individuals having had "SVR" after 8-12 weeks of a course of DAA therapy as recently defined may not be entirely valid. Careful longitudinal followup utilizing highly sensitive assays and unique approaches to viral isolation are needed.

High prevalence of occult hepatitis C virus infection in patients with primary and secondary glomerular nephropathies

The association of hepatitis C virus (HCV) infection and glomerulonephritis is well known. However, the relationship between immune-mediated glomerulonephritis and occult HCV, characterized by the presence of HCV-RNA in liver or in peripheral blood mononuclear cells in the absence of serological markers, is unknown. We tested this in 113 anti-HCV-negative patients; 87 with immune-mediated glomerulonephritis and 26 controls with hereditary glomerular nephropathies. All patients were serum HCV-RNA negative by conventional real-time PCR. Significantly, occult HCV-RNA (detectable viral RNA in peripheral blood mononuclear cells or in serum after ultracentrifugation) was found in 34 of 87 patients with immune-mediated glomerulonephritis versus 1 of 26 control patients. The serum creatinine levels were significantly higher in patients with immune-mediated glomerulonephritis with than in those without occult HCV (1.5 versus 1.1 mg/dl, respectively). A multivariate analysis adjusted for gender showed a significantly increased risk of occult HCV in patients with immune-mediated glomerulonephritis versus the controls (odds ratio of 13.29). Progression to end-stage renal disease tended to be faster in patients with immune-mediated glomerulonephritis and occult HCV than in the negative cases. Thus, occult HCV is strongly associated with immune-mediated glomerulonephritis and may have a role in the progression of the disease.

Prevalence of mixed cryoglobulinaemia syndrome and circulating cryoglobulins in a population-based survey: the Origgio study

Mixed cryoglobulinaemia syndrome (MCS) is associated with a number of infectious, autoimmune and lymphoproliferative disorders, particularly chronic hepatitis C infection. Although circulating mixed cryoglobulins (cMCGs) are a frequent finding in HCV-infected patients, only a minority of them develop a frank MCS. The only available data concerning the prevalence of MCS, which is generally considered a rare disease, come from hospital records. The aim of this investigation was to estimate the prevalence of cMCGs and MCS in a population-based study. All of the adult residents in Origgio, a town of about seven thousand inhabitants in northern Italy, were mailed a validated questionnaire, and a randomly selected sample of respondents was invited to undergo a clinical examination and laboratory tests including the determination of cMCGs. The 1594 respondents to the questionnaire (54.3% women, 64.5% aged >49years) accounted for 26.4% of the total adult population. Forty-nine (3.1%) positively responded to at least two questions, including a disproportionately high number of people aged >70years (p=0.001). Of the 266 randomly selected subjects invited to undergo a clinical examination and laboratory tests, 147 accepted, 30 (20.4%) of whom had asymptomatic type III cMCGs and four MCS. The risk of cMCG positivity was independently associated with C4 levels of <16mg/dL (adjusted odds ratio [AOR] 4.40, 95% confidence interval [CI] 1.07-18.08; p=0.040) and HCV positivity (AOR 6.87, 95% CI 1.16-40.79; p=0.034). No co-morbidities known to be related to cMCG production could be detected in more than 50% of the positive cases. After including the other positive respondents who agreed to undergo a clinical examination, the number of diagnosed MCS increased to seven: five HCV-related, one HBV-related, and one essential MCS. In conclusion, MCS seems to be more frequent than expected for a 'rare' disease, and the unexpectedly high prevalence of cMCGs raises questions about the frequency with which they are triggered, the spectrum of diseases involved in triggering them, and their real role as disease indicators.

Prevalence and follow-up of occult HCV infection in an Italian population free of clinically detectable infectious liver disease

Background

Occult hepatitis C virus infection (OCI) is a recently described phenomenon characterized by undetectable levels of HCV-RNA in serum/plasma by current laboratory assays, with identifiable levels in peripheral blood mononuclear cells (PBMCs) and/or liver tissue by molecular tests with enhanced sensitivity. Previous results from our group showed an OCI prevalence of 3.3% in a population unselected for hepatic disease. The present study aimed to evaluate OCI prevalence in a larger cohort of infectious liver disease-free (ILDF) subjects. Clinical follow-up of OCI subjects was performed to investigate the natural history of the infection.

Methods and Findings

439 subjects referred to a Turin Blood Bank for phlebotomy therapy were recruited. They included 314 ILDF subjects, 40 HCV-positive subjects and 85 HBV-positive subjects, of whom 7 were active HBV carriers. Six subjects (4/314 ILDF subjects [1.27%] and 2/7 active HBV carriers [28%]) were positive for HCV-RNA in PBMCs, but negative for serological and virological markers of HCV, indicating OCI. HCV genotypes were determined in the PBMCs of 3/6 OCI subjects two had type 1b; the other had type 2a/2c. OCI subjects were followed up for at least 2 years. After 12 months only one OCI persisted, showing a low HCV viral load (3.73×10¹ UI/ml). By the end of follow-up all OCI subjects were negative for HCV. No seroconversion, alteration of liver enzyme levels, or reduction of liver synthesis occurred during follow-up.

Conclusions

This study demonstrated the existence of OCI in ILDF subjects, and suggested a high OCI prevalence among active HBV carriers. Follow-up suggested that OCI could be transient, with a trend toward the decrease of HCV viral load to levels undetectable by conventional methods after 12–18 months. Confirmation studies with a longer follow-up period are needed for identification of the OCI clearance or recurrence rates, and to characterize the viruses involved.

The place of immunotherapy in the management of HCV-induced vasculitis: an update

Patients with chronic hepatitis C virus (HCV) can develop systemic cryoglobulinemic vasculitis. Combination of pegylated-interferon α and ribavirin is the first-line treatment of this condition. However, in case of severe or life-threatening manifestations, absence of a virological response, or autonomized vasculitis, immunotherapy (alone or in addition to the antiviral regimen) is necessary. Rituximab is to date the only biologic with a sufficient level of evidence to support its use in this indication. Several studies have demonstrated that rituximab is highly effective when cryoglobulinaemic vasculitis is refractory to antiviral regimen, that association of rituximab with antiviral regimen may induce a better and faster clinical remission, and, recently, that rituximab is more efficient than traditional immunosuppressive treatments. Some issues with regard to the optimal dose of rituximab or its use as maintenance treatment remain unsolved. Interestingly, in balance with this anti-inflammatory strategy, a recent pilot study reported the significant expansion of circulating regulatory T lymphocytes with concomitant clinical improvement in patients with refractory HCV-induced cryoglobulinaemic vasculitis using low dose of subcutaneous interleukin-2. This paper provides an updated overview on the place of immunotherapy, especially biologics, in the management of HCV-induced cryoglobulinaemic vasculitis.

Management of noninfectious mixed cryoglobulinemia vasculitis: data from 242 cases included in the CryoVas survey

Data on the clinical spectrum and therapeutic management of noninfectious mixed cryoglobulinemia vasculitis (CryoVas) in the era of hepatitis C virus screening are lacking. We analyzed data from 242 patients with noninfectious mixed CryoVas included in the French multicenter CryoVas survey. Baseline manifestations were purpura (75%), peripheral neuropathy (52%), arthralgia or arthritis (44%), glomerulonephritis (35%), cutaneous ulcers (16%), and cutaneous necrosis (14%). A connective tissue disease was diagnosed in 30% and B-cell non-Hodgkin lymphoma in 22%, whereas the CryoVas was considered to be essential in 48%. With the use of Cox-marginal structural models, rituximab plus corticosteroids showed the greater therapeutic efficacy compared with corticosteroids alone and alkylating agents plus corticosteroids to achieve complete clinical, renal, and immunologic responses and a prednisone dosage < 10 mg/d at 6 months. However, this regimen was also associated with severe infections, particularly when high doses of corticosteroids were used, whereas death rates did not differ between the therapeutic regimens. The role of each of these strategies remains to be defined in well-designed randomized controlled trials.

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.

Occult hepatitis C virus infection and its relevance in clinical practice

Hepatitis C virus (HCV) can persist in the liver, lymphoid (immune) cells, and serum of individuals long after an apparently complete therapy-induced or a spontaneous resolution of hepatitis C. This essential asymptomatic infection, called secondary occult HCV infection (OCI), usually occurs in anti-HCV antibody reactive individuals with normal liver function tests. This infection has been identified when the nucleic acid amplification assays of enhanced sensitivity were applied for the detection of HCV genome and its replication. In addition to the secondary OCI, a form of low-level HCV-RNA-positive infection of unknown etiology coinciding with moderately elevated serum liver enzymes and progressing in the absence of anti-HCV detectable by standard clinical assays has been reported. Because of its undefined origin, it can be termed cryptogenic OCI. In this review, the general characteristics of OCI, the ways of its detection and associated controversies, and the potential clinical implications of its existence will be concisely outlined.

Occult hepatitis C virus infection: what does it mean?

Occult hepatitis C virus infection (OCI) is a recently identified entity of which the existence became evident when nucleic acid amplification assays of enhanced sensitivity were introduced for the detection of hepatitis C virus (HCV) genome and its replication. This form of HCV infection has been found to persist in the presence of antibodies against HCV and normal levels of liver enzymes for years after spontaneous or antiviral therapy-induced resolution of hepatitis C and, therefore, can be termed as secondary OCI. HCV RNA in OCI circulate at fluctuating levels normally not exceeding 200 genome copies per millilitre of serum or plasma, while low levels of virus genome and its replicative intermediate RNA-negative strand are detectable in the liver and, importantly, immune cells, which provide an opportunity to detect active virus replication without the need for acquiring a liver biopsy. In addition to secondary OCI, a form of OCI accompanied by persistently moderately elevated serum liver enzymes in the absence of antibodies to HCV, which can be termed as cryptogenic OCI, has also been described. The current understanding of the nature and characteristics of OCI, methods and pitfalls of its detection, as well as the documented and expected pathological consequences of OCI will be summarized in this review.

Occult HCV infection: an unexpected finding in a population unselected for hepatic disease

Background

Occult Hepatitis C virus (HCV) infection is a new pathological entity characterized by presence of liver disease and absence or very low levels of detectable HCV-RNA in serum. Abnormal values of liver enzymes and presence of replicative HCV-RNA in peripheral blood mononuclear cells are also observed. Aim of the study was to evaluate occult HCV occurrence in a population unselected for hepatic disease.

Methodology/Principal Findings

We chose from previous epidemiological studies three series of subjects (n = 276, age range 40–65 years) unselected for hepatic disease. These subjects were tested for the presence of HCV antibodies and HCV-RNA in plasma and in the peripheral blood mononuclear cells (PBMCs) by using commercial systems. All subjects tested negative for HCV antibodies and plasma HCV-RNA and showed normal levels of liver enzymes; 9/276 patients (3.3%) were positive for HCV-RNA in PBMCs, identifying a subset of subjects with potential occult HCV infection. We could determine the HCV type for 8 of the 9 patients finding type 1a (3 patients), type 1b (2 patients), and type 2a (3 patients).

Conclusions

The results of this study show evidence that occult HCV infection may occur in a population unselected for hepatic disease. A potential risk of HCV infection spread by subjects harbouring occult HCV infection should be considered. Design of prospective studies focusing on the frequency of infection in the general population and on the clinical evolution of occult HCV infection will be needed to verify this unexpected finding.

Persisting mixed cryoglobulinemia in Chikungunya infection

BACKGROUND

Chikungunya virus (CHIKV), an arbovirus, is responsible for a two-stage disabling disease, consisting of an acute febrile polyarthritis for the first 10 days, frequently followed by chronic rheumatisms, sometimes lasting for years. Up to now, the pathophysiology of the chronic stage has been elusive. Considering the existence of occasional peripheral vascular disorders and some unexpected seronegativity during the chronic stage of the disease, we hypothesized the role of cryoglobulins.

METHODS

From April 2005 to May 2007, all travelers with suspected CHIKV infection were prospectively recorded in our hospital department. Demographic, clinical and laboratory findings (anti-CHIKV IgM and IgG, cryoglobulin) were registered at the first consultation or hospitalization and during follow-up.

RESULTS

Among the 66 travelers with clinical suspicion of CHIKV infection, 51 presented anti-CHIKV IgM. There were 45 positive with the serological assay tested at room temperature, and six more, which first tested negative when sera were kept at 4 degrees C until analysis, became positive after a 2-hour incubation of the sera at 37 degrees C. Forty-eight of the 51 CHIKV-seropositive patients were screened for cryoglobulinemia; 94% were positive at least once during their follow-up. Over 90% of the CHIKV-infected patients had concomitant arthralgias and cryoglobulinemia. Cryoglobulin prevalence and level drop with time as patients recover, spontaneously or after short-term corticotherapy. In some patients cryoglobulins remained positive after 1 year.

CONCLUSION

Prevalence of mixed cryoglobulinemia was high in CHIKV-infected travelers with long-lasting symptoms. No significant association between cryoglobulinemia and clinical manifestations could be evidenced. The exact prognostic value of cryoglobulin levels has yet to be determined. Responsibility of cryoglobulinemia was suspected in unexpected false negativity of serological assays at room temperature, leading us to recommend performing serology on pre-warmed sera.

Non HCV-related mixed cryoglobulinemia

A striking association (>90%) between mixed cryoglobulinemia (MC) and hepatitis C virus (HCV) infection has been established by means of clinico-epidemiological and laboratory studies. However, little information is available as regards the etiopathogenesis and the actual percentage of HCV-negative MC. This latter seems to be more frequent in the same geographical areas where the overall prevalence of MC is low. In 195 Italian patients with serum mixed cryoglobulins consecutively analyzed at the laboratory of our hospital, during one year, the prevalence of HCV-negative MC was 15.9%. Moreover, we evaluated the clinico-serological characteristics of our whole series of 65 HCV-negative MC patients: "essential" MC was present in only 25%, while the majority of cases showed different connective tissue diseases or neoplastic disorders. Interestingly, patients with Sjögren's syndrome or lymphoma had higher levels of cryocrit with cryoglobulinemic syndrome comparable to that found in HCV-positive MC patients. MC is a multifactorial disorder; considering possible etiological factors and clinical associations the disease may present different subsets: the prevalent group of HCV-positive MC; HCV-positive MC associated with different autoimmune lymphoproliferative disorders; two MC subsets without any apparent causative agent: those with well-known autoimmune lymphoproliferative disorders and the rare cases of "essential" MC; and finally MC associated with other infectious agents.

Cryoglobulinemic vasculitis

PURPOSE OF REVIEW

Cryoglobulinemic vasculitis is an immune-complex-mediated systemic vasculitis involving small-medium-sized vessels. A causative role of hepatitis C virus in over 80% patients has been definitively established, with heterogeneous geographical distribution. This review focuses on recent etiopathogenetic, clinico-diagnostic, and therapeutical studies.

RECENT FINDINGS

Hepatitis C virus cannot be integrated into the host genome; it may exert a chronic stimulus to the immune system. The interaction between hepatitis C virus envelope protein E2 with B-cell CD 81 receptor may increase the frequency of VDJ rearrangement in antigen-reactive B lymphocytes. One consequence is the activation of various protooncogenes, including anti-apoptotic Bcl-2. The extended B-cell survival is responsible for autoantibody and immune-complex production, including mixed cryoglobulins; some malignancies, mainly B-cell lymphomas, may complicate cryoglobulinemic vasculitis. Environmental or viral/host genetic cofactors should be relevant in the pathogenesis of hepatitis C virus-related diseases. Cryoglobulinemic vasculitis may overlap with other diseases (systemic vasculitides, Sjögren's syndrome, autoimmune hepatitis, lymphoma), which should be carefully considered for a correct diagnosis and treatment. Cumulative survival of cryoglobulinemic vasculitis is significantly lower compared with the general population. Therapeutic strategies for cryoglobulinemic vasculitis include etiologic (antiviral), pathogenetic (cyclophosfamide, rituximab), or symptomatic (steroids, plasmapheresis) treatments, which should be tailored to the individual patient according to the severity/activity of clinical symptoms.

SUMMARY

Cryoglobulinemic vasculitis represents a crossroads among autoimmune and lymphoproliferative disorders; as hepatitis C virus infection is the major causative factor, cryoglobulinemic vasculitis is an important model for etiopathogenetic studies of virus-related diseases.