The etiology and pathophysiology of mixed cryoglobulinemia secondary to hepatitis C virus infection

Post-Treatment Occurrence of Serum Cryoglobulinemia in Chronic Hepatitis C Patients

BACKGROUND

Persistent cryoglobulinemia after the completion of antiviral treatment is an important consideration of clinical management in chronic hepatitis C patients. We aimed to investigate the occurrence of serum cryoglobulinemia in chronic hepatitis C patients without cryoglobulinemia at the initiation of antiviral treatment.

METHODS

In total, 776 patients without cryoglobulinemia were assessed for serum cryoglobulinemia after the completion of anti-HCV treatment. Serum cryoglobulinemia precipitation was assessed upon both the initiation and the completion of the treatment and analyzed for the clinical laboratory factors associated with chronic hepatitis C.

RESULTS

One hundred eighteen (118) patients were checked for serum cryo-precipitation after the completion of the treatment, and eight patients (4.6%) were positive for serum cryoglobulinemia. The patients who tested positive for cryoglobulinemia included a higher proportion of liver cirrhosis patients (4/50%, p = 0.033) and other organ cancer patients (5/62.5%, p = 0.006) than patients who showed no signs of cryoglobulinemia after treatment. In a multivariate analysis, liver cirrhosis (odds ratio [OR]-17.86, 95% confidence interval [95% CI]-1.79-177.35, p = 0.014) and other organ cancer (OR-25.17 95% CI-2.59-244.23, p = 0.005) were independently and significantly associated with positive cryoglobulinemia 3 months after antiviral treatment.

CONCLUSIONS

Three months after the antiviral DAA therapy had concluded, eight patients tested positive for cryoglobulinemia, representing a 6.7% prevalence. Liver cirrhosis and other organ cancer were independently and significantly associated with positive cryoglobulinemia after antiviral treatment. Further investigation into the causes of positive cryoglobulinemia after DAA antiviral therapy is warranted.

Dual stimulation by autoantigen and CpG fosters the proliferation of exhausted rheumatoid factor-specific CD21low B cells in hepatitis C virus-cured mixed cryoglobulinemia

Introduction

Hepatitis C virus (HCV) causes mixed cryoglobulinemia (MC) by driving clonal expansion of B cells expressing B cell receptors (BCRs), often encoded by the VH1-69 variable gene, endowed with both rheumatoid factor (RF) and anti-HCV specificity. These cells display an atypical CD21low phenotype and functional exhaustion evidenced by unresponsiveness to BCR and Toll-like receptor 9 (TLR9) stimuli. Although antiviral therapy is effective on MC vasculitis, pathogenic B cell clones persist long thereafter and can cause virus-independent disease relapses.

Methods

Clonal B cells from patients with HCV-associated type 2 MC or healthy donors were stimulated with CpG or heath-aggregated IgG (as surrogate immune complexes) alone or in combination; proliferation and differentiation were then evaluated by flow cytometry. Phosphorylation of AKT and of the p65 NF-kB subunit were measured by flow cytometry. TLR9 was quantified by qPCR and by intracellular flow cytometry, and MyD88 isoforms were analyzed using RT-PCR.

Discussion

We found that dual triggering with autoantigen and CpG restored the capacity of exhausted VH1-69pos B cells to proliferate. The signaling mechanism for this BCR/TLR9 crosstalk remains elusive, since TLR9 mRNA and protein as well as MyD88 mRNA were normally expressed and CpG-induced phosphorylation of p65 NF-kB was intact in MC clonal B cells, whereas BCR-induced p65 NF-kB phosphorylation was impaired and PI3K/Akt signaling was intact. Our findings indicate that autoantigen and CpG of microbial or cellular origin may unite to foster persistence of pathogenic RF B cells in HCV-cured MC patients. BCR/TLR9 crosstalk might represent a more general mechanism enhancing systemic autoimmunity by the rescue of exhausted autoreactive CD21low B cells.

Infection, Infectious Agents and Vascular Disease

BACKGROUND

Infectious agents may be involved in the pathogenesis of vascular disease and related complications. The aim of this review is to analyze the most relevant information on the common infections related to vascular disease, discussing the main pathophysiological mechanisms.

METHODS

In the current review, the most important evidence on the issue of infections and vascular disease is searched on Medline, Scopus, and ScienceDirect database.

RESULTS

Among infectious agents, herpesviruses, parvovirus B19, hepatitis viruses, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, treponema pallidum, mycobacterium tuberculosis, pseudomonas aeruginosa, staphylococcus aureus, and candida albicans seem to particularly related to vascular disease.

CONCLUSION

Infectious agents may affect vessel's homeostasis and functionality, both on the arterial and venous side, by means of several pathophysiological mechanisms such as dysregulation in vasomotor function, thromboembolic complications, initiation and progression of atherosclerosis, alteration of perivascular adipose tissue, recruiting inflammatory cells and molecules.

Membranoproliferative Glomerulonephritis and Mixed Cryoglobulinemia as a Form of Presentation of Visceral Leishmaniasis

Patient: Male, 69-year-old

Final Diagnosis: Leishmaniasis

Symptoms: Acute renal failure • purpuric skin lesions

Medication: —

Clinical Procedure: Bone marrow biopsy • renal biopsy • ultrasonography

Specialty: Nephrology

Rheumatoid factor and immunoglobulin M mark hepatitis C-associated mixed cryoglobulinaemia: an 8-year prospective study

OBJECTIVES

The prevalence and factors of hepatitis C virus (HCV) -associated mixed cryoglobulinaemia in Asia remain elusive, and we aimed to investigate these topics.

METHODS

An 8-year prospective cohort study was conducted in 678 consecutive Taiwanese individuals with chronic HCV infection (438 completed an anti-HCV therapy course).

RESULTS

Of 678 individuals, 437 (64.5%) had mixed cryoglobulinaemia and 20 (2.9%) had mixed cryoglobulinaemic syndrome. At baseline, IgM (cut-off >122 mg/dL), triglycerides and IgG levels, and HCV genotype 3 were independently associated with mixed cryoglobulinaemia. Rheumatoid factor (RF) levels were associated with mixed cryoglobulinaemic syndrome (cut-off >12.2 IU/mL). At 24 weeks post-therapy, the 362 individuals with a sustained virological response (SVR) had higher cured (106/362 (29.3%) versus 10/76 (13.2%), p = 0.003) and lower persistent (100/362 (27.6%) versus 33/76 (43.4%), p = 0.003) mixed cryoglobulinaemia rates than non-SVR patients. Among SVR patients, compared with baseline levels, RF, IgG and IgM levels decreased, except in individuals with new mixed cryoglobulinaemia. Pre-therapy IgM levels were associated with 24-week post-therapy new (95% CI of OR 1.002-1.023) and persistent (95% CI of OR 1.004-1.015) mixed cryoglobulinaemia in SVR patients. After up to 8 years, 24-week post-therapy IgM levels were associated with mixed cryoglobulinaemia in SVR patients (9/51; 17.64%; 95% CI of HR 1.004-1.011). Among 17 SVR patients with pre-therapy mixed cryoglobulinaemic syndrome, 5 (29.4%) had long-term mixed cryoglobulinaemia and 4 (23.5%) had mixed cryoglobulinaemic syndrome.

CONCLUSIONS

Over 60% of chronic HCV-infected individuals had mixed cryoglobulinaemia, and 17.64% of SVR patients had mixed cryoglobulinaemia 8 years post-therapy. Pre-therapy RF and IgM levels marked HCV-associated mixed cryoglobulinaemic syndrome and mixed cryoglobulinaemia, respectively.

Clinical practice: hepatitis C virus infection, cryoglobulinemia and cryoglobulinemic vasculitis

Cryoglobulins are circulating immunoglobulins that reversibly precipitate at temperatures below 37 °C. Type-II cryoglobulins consist of monoclonal IgM/polyclonal IgG immune complexes (ICs), whereas in type-III cryoglobulins both IgM and IgG are polyclonal. The clinical condition resulting from the presence of cryoglobulins in the blood is called mixed cryoglobulinemia (MC), which can be asymptomatic or manifest as cryoglobulinemic vasculitis (CV). Type-I cryoglobulins, consisting of a single monoclonal isotype, are detected in patients with lymphoproliferative disorders. It is now established that > 90% of MCs are associated with HCV infection. Clinically, the spectrum of symptoms may range in severity from occasional purpuric eruptions to life-threatening features. In addition to the development of liver cirrhosis and hepatocellular carcinoma, the possible progression of HCV-positive CV patients to B-cell non-Hodgkin lymphoma (B-NHL) has been reported. The pathogenetic role played by HCV infection in the onset of B-NHL is suggested by regression of the latter following the achievement of a sustained virologic response (SVR). For several years, interferon-α alone or combined with ribavirin has been the standard of care. However, the rates of clinical, biochemical, and virologic responses have been low, and the occurrence of relapse frequent. The addition of rituximab has resulted in a higher rate of responses. With the advent of direct-acting antiviral agents, SVR has been achieved in ~ 95% of CV patients. However, in a minority of patients, despite SVR, CV may persist or reappear over variable lengths of time from the completion of therapy. The eventual appearance of B-NHL is also possible.

Changes in HCV Viremia following LDL Apheresis in a HCV Positive Patient with Familial Hypercholesterolemia

It has been suggested that hepatitis C virus (HCV) can be associated with beta-lipoprotein in human serum. According to this, the LDL receptor could promote endocytosis of such a virus. In the present study, we evaluated the changes in HCV viremia in a HCV positive patient with familial hypercholesterolemia, undergoing both selective (DALI System, Fresenius) and non-selective (plasma exchange) LDL apheresis. HCV-RNA levels did not decrease following selective LDL apheresis, on the contrary showed a random, odd variation pattern (from –35% to +72%). Conversely, plasma exchange steadily induced a drop in HCV viremia (–35/43%), to a lower extent than that of a totally intravascular plasmaprotein, i.e., alpha 2-macroglobulin (–53/54%). These data indicate that beta-lipoprotein may not function as a plasma carrier of HCV, at least in the present case. Moreover, a continuous, quantitatively unforeseeable circulation of HCV virions from the intravascular plasma compartment to other extravascular and intracellular sites, seems to occurr during an apheresis session.

Activation-induced cytidine deaminase in B cells of hepatits C virus-related cryoglobulinaemic vasculitis

Immunoglobulin variable region heavy chain (IgVH ) somatic gene diversification is instrumental in the transformation process that characterizes hepatitis C virus (HCV)-related B cell lymphoproliferative disorders. However, the extent to which activation-induced cytidine deaminase (AID), an enzyme essential for IgV gene somatic hypermutation (SHM), is active in cryoglobulinaemic vasculitis (CV) remains unclear. AID mRNA expression in the peripheral blood of 102 chronically hepatitis C virus (HCV)-infected patients (58 with and 44 without CV) and 26 healthy subjects was investigated using real-time reverse transcription-polymerase chain reaction (RT-PCR). The features of activation-induced cytidine deaminase (AID) protein and mRNA transcripts were explored in liver tissue biopsies and portal tracts isolated using laser capture microdissection. In chronically HCV-infected patients, AID mRNA expression was almost threefold higher in those with than in those without CV and sevenfold higher than in healthy subjects (median-fold: 6.68 versus 2.54, P = 0.03 and versus 0.95, P = 0.0003). AID transcript levels were significantly higher in polyclonal than in clonally restricted B cell preparations in either CV or non-CV patients (median-fold, 15.0 versus 2.70, P = 0.009 and 3.46 versus 1.58, P = 0.02, respectively). AID gene expression was found to be related negatively to age and virological parameters. AID protein was found in portal tracts containing inflammatory cells that, in several instances, expressed AID mRNA transcripts. Our data indicate that the aberrant expression of AID may reflect continuous B cell activation and sustained survival signals in HCV-related CV patients.

Comparison between the traditional and a rapid screening test for cryoimmunoglobulins detection

OBJECTIVES

A new rapid, automatic, and sensitive screening test useful to detect cryoglobulins in serum samples is proposed.

DESIGN AND METHODS

The increase of turbidity during the cryoglobulin aggregation was monitored spectrophotometrically in sera from 400 patients with clinical evidence of cryoglobulinemia related disorders and 100 controls. Results were correlated to those obtained by the traditional method.

RESULTS

Kinetics of the aggregation curves were described by their maximum turbidity increase, lag time, and slope. Despite a partial correspondence between the traditional and the rapid test, patients with symptomatic cryoglobulinemia showed turbidity values significantly higher than the determined cutoff. Moreover, a functional classification of cryoglobulins is proposed.

CONCLUSIONS

Due to its high reproducibility, operator independence, low cost, and results obtained within 2 hours, the rapid test can be used as a "real time" monitoring of cryoglobulinemia related diseases and for the evaluation of plasmapheresis efficacy.

Hepatic manifestations in hematological disorders

Liver involvement is often observed in several hematological disorders, resulting in abnormal liver function tests, abnormalities in liver imaging studies, or clinical symptoms presenting with hepatic manifestations. In hemolytic anemia, jaundice and hepatosplenomegaly are often seen mimicking liver diseases. In hematologic malignancies, malignant cells often infiltrate the liver and may demonstrate abnormal liver function test results accompanied by hepatosplenomegaly or formation of multiple nodules in the liver and/or spleen. These cases may further evolve into fulminant hepatic failure.

A randomized controlled trial of rituximab following failure of antiviral therapy for hepatitis C virus-associated cryoglobulinemic vasculitis

OBJECTIVE

To perform a randomized controlled trial of rituximab in patients with hepatitis C virus (HCV)-associated mixed cryoglobulinemic vasculitis.

METHODS

We conducted a single-center, open-label, randomized controlled trial of rituximab (375 mg/ m(2) /week for 4 weeks) compared to the best available therapy (maintenance or increase in immunosuppressive therapy) for HCV-associated cryoglobulinemic vasculitis in patients in whom antiviral therapy had failed to induce remission. The primary end point was disease remission at 6 months from study entry.

RESULTS

A total of 24 patients were enrolled (12 in each treatment group). Baseline disease activity and organ involvement were similar in the two groups. Ten patients in the rituximab group (83%) were in remission at study month 6, as compared with 1 patient in the control group (8%), a result that met the criterion for stopping the study (P < 0.001). The median duration of remission for rituximab-treated patients who reached the primary end point was 7 months. No adverse effects of rituximab on HCV plasma viremia or on hepatic transaminase levels were observed.

CONCLUSION

Rituximab was a well-tolerated and effective treatment in patients with HCV-associated cryoglobulinemic vasculitis in whom antiviral therapy failed to induce remission.

Dermatologic disorders and the liver

Chronic liver disease is associated with several cutaneous manifestations. Although many of these changes are nonspecific, some are associated with distinct liver diseases and correlate with the severity of hepatic pathology. Often the first clue to a liver disease is manifested through skin. Although cirrhosis is associated with spider nevi and palmar erythema, disorders can result in noncirrhotic cutaneous manifestations. It is important for physicians to be familiar with the spectrum of these manifestations, to recognize, help detect, and treat the underlying hepatic disease. This article reviews the medical literature and discusses the spectrum of dermatologic manifestations of liver disorders and their pathogenesis, significance, and treatment.

Management of hepatitis C virus-related mixed cryoglobulinemia

Mixed cryoglobulinemia is a chronic immune complex-mediated disease strongly associated with hepatitis C virus (HCV) infection. Mixed cryoglobulinemia is a vasculitis of small and medium-sized arteries and veins, due to the deposition of complexes of antigen, cryoglobulin and complement in the vessel walls. The main clinical features of mixed cryoglobulinemia vasculitis include the triad of palpable purpura, arthralgias, and weakness, and other pathological conditions such as glomerulonephritis, peripheral neuropathy, skin ulcers, and widespread vasculitis. The treatment of HCV-related mixed cryoglobulinemia is difficult due to the multifactorial origin and clinical polymorphism of the syndrome. It can be directed to eradicate the HCV infection, suppress the B-cell clonal expansion and cryoglobulin production, or ameliorate symptoms. The choice of the most appropriate treatment is strictly related to the assessment of disease activity, and to the extent and severity of organ involvement.

Vasculitic multiplex mononeuritis: polyarteritis nodosa versus cryoglobulinemic vasculitis

A 76-year-old female patient presented with a progressive motor-sensory multiplex mononeuritis (MM). Combined muscle and nerve biopsy showed the typical findings of a polyarteritis nodosa (PAN). Despite treatment with corticosteroids paresthesias increased and purpura of the legs newly appeared. Hepatitis screening revealed chronic hepatitis C-infection associated with cryoglobulinemia Type II (IgM-kappa Ig A). Finally, we diagnosed a hepatitis C-associated cryoglobulinemic vasculitis based on clinical and laboratory findings.

The infectious etiology of vasculitis

Infectious agents have been implicated in the etiopathogenesis of various vasculitides via numerous and overlapping mechanisms including direct microbial invasion of endothelial cells, immune complex mediated vessel wall damage and stimulation of autoreactive B and/or T cells through molecular mimicry and superantigens. While the causative role of hepatitis B virus in polyarteritis nodosa and hepatitis C virus in mixed cryoglobulinemia is clearly established, evidence for the association of other infectious agents with vasculitis, including human immunodeficiency virus, parvovirus B19, cytomegalovirus, varicella zoster virus, Staphylococcus aureus, rickettsiaceae, Treponema pallidum and Borrelia burgdorferi, among numerous others, is accumulating. The spectrum of association of infectious agents; bacteria, viruses and parasites, with systemic vasculitides, will be reviewed herewith.

Infectious serologies and autoantibodies in Wegener's granulomatosis and other vasculitides: novel associations disclosed using the Rad BioPlex 2200

In this study we assess the presence of antibodies against infectious agents as well as for a variety of autoantibodies in an attempt to establish associations between various vasculitides and infections in order to shed light on the etiopathogenesis of these diseases and perhaps implicate a potential cure. Sera from patients with Wegener's granulomatosis (WG), polyarteritis nodosa, microscopic polyangiitis, Churg Strauss, and giant cell arteritis were compared to healthy control sera. Serum samples were assessed, using the Bio-Rad BioPlex 2200, for the presence of Toxoplama gondii, cytomegalovirus (CMV), Epstein-Barr virus (EBV), Treponema pallidum, and Saccharomyces cerevisiae. Hepatitis B virus (HBV), hepatitis C virus (HCV), and anti-Helicobacter pylori antibodies were assessed by ELISA. In addition, sera were tested for a panel of antibodies associated with thrombophilia as well as various autoantibodies. The prevalence of antibodies toward HCV and H. pylori was significantly higher among patients with WG. IgG antibodies toward T. gondii and IgM antibodies toward CMV were significantly more common among WG patients than among controls. WG patients exhibited more antibodies toward EBV viral capsid antigen IgG and EBV early antigen IgG compared to sera from healthy controls. In WG, positive associations were disclosed between CMV IgG antibodies and the presence of gastrointestinal manifestations and renal involvement, and there was a higher Birmingham vasculitis activity score in association with elevated titers of EBV viral capsid antigen IgG antibodies. Otorhinolaryngeal manifestations were more common in those with positive IgG antibodies for EBV early antigen. Our results unveil novel associations between WG and various infectious agents, including HCV, H. pylori, T. gondii, CMV, and EBV. In addition to putative roles in initiation and exacerbation of the vasculitic process, it seems that these infectious agents also modulate the clinical phenotype of the disease.

Schistosoma mansoni coinfection could have a protective effect against mixed cryoglobulinaemia in hepatitis C patients

BACKGROUND/AIM

The association between mixed cryogloblinaemia and chronic hepatitis C virus (HCV) infection has been established. However, the factors underlying its great geographical heterogeneity of prevalence have not yet been identified. Concomitant HCV and Schistosoma mansoni infections are common in Egypt. Chronic helminthic infections have been found to decrease the incidence and manifestations of immune-related diseases. To date, no study has focused on the influence of S. mansoni coinfection on the risk of cryoglobulinaemia in hepatitis C patients.

METHODS

A cohort of 119 consecutively recruited chronic hepatitis C-infected patients was studied. Patients' sera were assessed for S. mansoni antibodies and cryoglobulins (CGs) were determined and characterized.

RESULTS

Cryoglobulins were detected in 18 of 119 patients (15.1%) included in this study. They were detected in 12 of 45 hepatitis C (26.7%) and six of 74 coinfected patients (8.1%), which was statistically significant, P=0.01. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were also found to be significantly lower in the CG-positive group compared with the CG-negative group, P=<0.01. CGs were detected in seven of 21 (33.3%) and in 11 of 98 (11.2%) hepatitis C female and male patients, respectively, indicating a significantly positive association with the female gender, P=0.02. A logistic regression adjusted for gender, AST and ALT showed that hepatitis C patients without schistosomal coinfection are more likely to have cryoglobulinaemia, odds ratio=4.12, 95% confidence interval=1.42-11.95.

CONCLUSION

There is an apparent protective effect of S. mansoni coinfection against mixed cryoglobulinaemia in chronic hepatitis C patients.

Hepatitis C virus-induced cryoglobulinemia

In this review we discuss the clinical manifestations, pathogenesis, and treatment of hepatitis C virus (HCV)-related cryoglobulinemia. HCV is a major cause of liver-related morbidity and is increasingly recognized as an instigator of B-cell lymphoproliferative disorders such as mixed cryoglobulinemia and non-Hodgkin lymphoma. Cryoglobulinemia is characterized by the clonal expansion of rheumatoid factor-expressing B cells in the liver, lymph nodes, and peripheral blood, resulting in the presence of cryoglobulins in the circulation. Cryoglobulins are cold-insoluble immune complexes containing rheumatoid factor, polyclonal IgG, and HCV RNA that precipitate and deposit on vascular endothelium, causing vasculitis in organs such as the skin, kidneys, and peripheral nerves. A subset of patients develops a low-grade lymphoma composed of B cells that are immunophenotypically similar to the expanded B cells seen in cryoglobulinemia. HCV-related B-cell lymphoproliferative disorders likely comprise a spectrum of disease, ranging from asymptomatic clonal B-cell expansions to pathogenic cryoglobulinemia and lymphoma. It is unclear how B cells become dysregulated during the course of chronic HCV infection, and continued patient-centered research is necessary to elucidate the pathogenesis of HCV-related B-cell dysregulation.

Prevalence of hepatitis B and C viruses in patients with lymphoproliferative disorders

The etiology of most lymphoproliferative disorders remains unclear, though several hypotheses have been proposed. One of the conjectured mechanisms is infection of a tumor clone by an oncologic virus. Recently, evidence has arisen implicating both hepatitis B and, even more so, hepatitis C viruses in the pathogenesis of lymphoproliferative disease. Based on this information, we surveyed the prevalence of hepatitis B and C virus in patients with lymphoproliferative disease. A total of 334 newly-diagnosed lymphoproliferative disease patients (200 males, 134 females) and 1,014 (133 females, 881 males) healthy controls were randomly recruited from the university blood bank. Serologic evaluation for hepatitis B and C viruses was conducted and confirmed using PCR analyses. Those with hepatitis B and/or C, controls, and subgroups of patients with lymphoproliferative disease were compared using Pearson Chi-square analysis. Among patients with lymphoid tumors, the seropositivity of HbsAg and/or anti-HCV was 8.7% (29/334), and among the controls 6.1% (49/802), however this difference did not achieve statistical significance (P = 0.23, OR: 1.36, 95% CI: 0.82-2.26). We found no significant gender- or age-related differences for either hepatitis B or C seropositivity. There were no significant differences between the seropositivity rates of hepatitis B, C, or both in either NHL or Hodgkin's lymphoma. However, in the diffuse large cell lymphoma and follicular lymphoma subgroups, the HbsAg seropositivity rate was significantly higher than that in the controls (P = 0.017, P = 0.048, respectively), as was the seropositivity rate for hepatitis C in those with diffuse B cell lymphoma versus controls (P = 0.008). We did not identify any significant difference in the combined prevalence of hepatitis B or C seropositivity between patients with lymphoproliferative disorders and controls. However, significant differences were revealed among certain patient subgroups versus the controls. These two viruses could play a role in the development of certain specific lymphoproliferative disorders. Nevertheless, larger epidemiological studies are necessary and should focus, particularly on specific patient subgroups.

Surgical treatment of superimposed nerve compressions in hepatitis C neuropathy

The plastic surgeon's usual involvement in patients with hepatitis C is most frequently limited to an inner city population with hand and forearm abscesses from intravenous drug use or to incidences of needle-stick injury in the operating room when the patient is hepatitis C positive. Hand surgeons and peripheral nerve surgeons often treat patients with underlying neuropathies who have superimposed overlying nerve compressions such as carpal tunnel syndrome. We have applied this experience to a patient with underlying peripheral neuropathy associated with Hepatitis C and clinical evidence of overlying lower extremity nerve compressions. We believe that she is the first successful surgical treatment of peripheral nerve compressions in a patient with hepatitis C-associated neuropathy, documented by noninvasive neurosensory testing.

Clonal expansion of immunoglobulin M+CD27+ B cells in HCV-associated mixed cryoglobulinemia

Hepatitis C virus (HCV) is associated with B-cell lymphoproliferative disorders such as mixed cryoglobulinemia (MC) and B-cell non-Hodgkin lymphoma (B-NHL). The pathogenesis of these disorders remains unclear, and it has been proposed that HCV drives the pro-liferation of B cells. Here we demonstrate that certain HCV(+)MC(+) subjects have clonal expansions of immunoglobulin M (IgM)(+)kappa(+)IgD(low/-)CD21(low)CD27(+) B cells. Using RT-PCR to amplify Ig from these singly sorted cells, we show that these predominantly rheumatoid factor-encoding V(H)1-69/J(H)4 and V(kappa)3-20 gene segment-restricted cells have low to moderate levels of somatic hypermutations. Ig sequence analysis suggests that antigen selection drives the generation of mutated clones. These findings lend further support to the notion that specific antigenic stimulation leads to B-cell proliferation in HCV MC and that chronic B-cell stimulation may set the stage for malignant transformation and the development of B-NHL. The finding that these hypermutated, marginal zone-like IgM(+)CD27(+) B cells are clonally expanded in certain subjects with MC offers insight into mechanisms of HCV-associated MC and B-cell malignancy. This study was registered at www.clinicaltrials.gov as NCT00219999.

HCV-related immunocytoma and type II mixed cryoglobulinemia-associated autoantigens

Hepatitis C virus (HCV) is a hepatotropic virus causing hepatocellular damage and chronic liver inflammation that progressively can lead to cirrhosis and hepatocellular carcinoma (HCC). HCV is also lymphotropic, as demonstrated by its capacity to replicate in lymphocytes, by the recurrent detection of organ- and non-organ-specific autoantibodies in HCV-infected patients, and by the strong association found between HCV infection and type II mixed cryoglobulinemic syndrome (MC-II). Moreover, accumulating data ascribe an etiopathogenetic role in the development of B cell non-Hodgkin's lymphomas (NHL) to HCV. All these findings account for the profound effect of HCV infection in the host's immune system. The unique virus-host interactions that culminate in the generation and sustained production of autoantibodies and cryoglobulins have not been delineated. It appears that chronic antigenic stimulation could cause the emergence of specific B cell clones that produce cryoglobulins; moreover, B cell activation and/or deregulation could originate as a result of HCV binding to CD81 tetraspanin or as a consequence of its ability to replicate in B cells. In a previous study we demonstrated that, in MC-II HCV-positive patients, cryoprecipitated monoclonal IgMs, and B cell receptors (BCR) of overexpanded B cell clones share the same combinatory region. Moreover, these IgMs were reactive against both the Fc region of human IgG and the HCV-NS3 antigen. NS3 and Fc epitopes have been idengified by epitope excision approach. One of the idengified NS3 epitopes has been used to immunize a mouse and the monoclonal antibody obtained showed the same cross-reactivity as patients' IgMs. The characterization of antigenic specificity of this antibody may be useful to idengify antigens that can stimulate B cell proliferation in HCV-infected individuals.

Infection and glomerulonephritis

Glomerular injury, occurring either as primary glomerular disease or as part of a systemic disease process, is usually a result of immune-mediated mechanisms. The morphologic reaction pattern has a diverse spectrum of appearance, ranging from normal by light microscopy in minimal change disease to crescentic forms of glomerulonephritis, with conspicuous disruption of the normal glomerular morphology. The mechanisms of glomerular immune deposit formation include trapping of circulating antigen-antibody complexes and the in situ formation of immune complexes within the glomerulus. While the majority of postinfectious immune-complex-mediated glomerulonephritides are believed to result from the deposition of circulating antigen-antibody complexes, preformed outside of the kidney and secondarily deposited in the kidney, the notion of forming in situ antigen-antibody complexes to either planted antigens or to integral structural components of the glomerulus, through "cross-reacting" autoimmune reactions, is gaining popularity in a variety of forms of glomerulonephritides. Patients with HIV infection may develop a spectrum of renal pathology, the glomerular manifestations of which include both antigen-antibody complex and nonimmune-complex-mediated pathogenetic mechanisms. Similarly, patients with Streptococcal infections, Hepatitis B virus, or Hepatitis C virus infection may develop a spectrum of glomerulonephritides, which are predominantly immune-complex-mediated. Therapy for glomerular diseases due to HIV, hepatitis B, or C virus infections remains a challenge.

HCV infection facilitates asymptomatic carotid atherosclerosis: preliminary report of HCV RNA localization in human carotid plaques

BACKGROUND

Clinical and experimental evidence suggests that hepatitis C virus (HCV) infection shows peculiar characteristics that strongly support a role in the development of atherosclerosis. We aimed to investigate whether (a) HCV infection can facilitate asymptomatic carotid lesions and (b) the presence of HCV RNA sequences can be shown in plaque tissues.

METHODS

The status of carotid arteries, studied as intima-media thickness (IMT) in carotid bifurcation and prevalence and severity of plaques in internal carotid artery, was investigated by high-resolution B-mode ultrasonography in 31 HCV seropositive (HCV+) and in 120 age-matched HCV seronegative (HCV-) subjects evaluated for cardiovascular risk factors. The atherosclerotic risk profile, inflammation markers and main liver function tests were also studied in all patients. HCV RNA sequences were investigated by highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) in plaque tissues and serum of 2 HCV+ patients who underwent carotid revascularization.

RESULTS

Genomic and antigenomic HCV RNA strands were evidenced within both the carotid plaque tissues examined. The prevalence of an IMT > 1 mm, but not the prevalence and severity of internal carotid plaques, was significantly higher (P < 0.001) in HCV+ than in HCV patients. The atherosclerotic risk profile for traditional and inflammatory factors did not differ between the HCV+ and HCV- groups. Main liver function tests did not differ between the two groups. HCV positivity was significantly associated with >1 mm IMT (P < 0.01) according to univariate analysis, and this association remained significant in multivariate regression analysis.

CONCLUSIONS

The novel finding of HCV RNA sequences within carotid plaques suggests a local pro-atherogenetic action of the virus inside the plaque. On the whole our data strongly support that HCV infection facilitates the occurrence of carotid atherosclerotic lesions.

Cryoglobulinemia related to hepatitis C virus infection

A causal link among hepatitis C virus (HCV) infection and essential mixed cryoglobulinemia, cryoglobulinemic glomerulonephritis, and vasculitis is strongly supported. HCV triggers autoimmune response in predisposed individuals that manifests as organ-specific and non-organ-specific autoantibodies and as polyclonal/monoclonal rheumatoid factor, which has a central role in causing damaging cryoglobulin and immune complex tissue levels. Immunologic events are mainly induced by HCV infection persistence, with excessive immune stimulation. Humoral immune dysfunction leads to autoantibodies and rheumatoid factor production with cryoglobulinemia, glomerulonephritis, vasculitis, neuropathy, and probably thyroiditis, and arthritis in rare cases. Cellular immune dysfunction leads to lymphocytic infiltration, proliferation, and cytokine production. Pegylated (or not) interferon-alpha in combination with ribavirin appears to be the treatment of choice for patients with symptomatic essential mixed cryoglobulinemia with or without glomerulonephritis. Novel treatment with rituximab is promising.

Severe hepatitis C virus-related cryoglobulinaemic sensory-motor polyneuropathy treated with pegylated interferon-a2b and ribavirin: clinical, laboratory and neurophysiological study

BACKGROUND/AIMS

Severe involvement of central and/or peripheral nervous system is a rare complication of hepatitis C virus (HCV)-related cryoglobulinaemia.

METHOD

Four patients with HCV-related type II/III cryoglobulinaemia (three males with genotype 1, one female with genotype 3) who presented with severe sensory-motor polyneuropathy, one with central nervous system involvement as well, were treated with pegylated IFNa-2b 1.5 microg/kg/week and ribavirin 10.6 mg/kg/daily for 48 weeks. Neurological evaluation involved detailed clinical motor and sensory scores/scales and neurophysiological studies before and after treatment.

RESULTS/CONCLUSION

Three out of four patients had undetectable serum HCV-RNA, normal levels of aminotransferases and substantially lower or undetectable levels of cryoglobulins at the end of treatment and at 24 weeks follow-up period. Treatment was well tolerated and all patients exhibited significant improvement of neuropathy based on solid clinical and laboratory criteria that was associated with the virological response.

Cryoglobulinemia is associated with steatosis and fibrosis in chronic hepatitis C

The relationship between cryoglobulin and severity of liver lesions is debated. No study has focused on the relationship between cryoglobulin, liver steatosis, and fibrosis. The aim of this study was to determine the relationship between cryoglobulins and liver lesions (necroinflammation, fibrosis, and steatosis) in patients with hepatitis C virus (HCV) infection. Four hundred and thirty-seven consecutive patients with untreated chronic hepatitis C who had been admitted for liver biopsy were included in the study. Risk factors for fibrosis and steatosis were assessed. The mean age was 50.9 +/- 13.8 years, and 49% were male. Cryoglobulin was present in 286 patients, 103 of whom had vasculitis. One hundred and eighty-six patients (43%) had steatosis greater than 10%, and 110 (25%) had advanced fibrosis (Metavir score F3-F4). On multivariate analysis, cryoglobulin increased by nearly threefold the risk of having advanced fibrosis and steatosis greater than 10%. Steatosis greater than 10% was associated with a higher body mass index (P < .001), HCV genotype 3 (P < .001), cryoglobulin (P = .002), and advanced liver fibrosis (P = .009). Advanced fibrosis (F3-F4) was associated with a higher level of gamma-glutamyltransferase (P = .04), cryoglobulin (P < .001), a high grade of necroinflammation (Metavir score A2-A3) (P < .001), and steatosis higher than 10% (P = .04). In conclusion, our study shows an independent association between cryoglobulin and steatosis as well as advanced fibrosis.

Pathogenic mechanisms in membranoproliferative glomerulonephritis

PURPOSE OF REVIEW

This review considers new information on the pathogenesis of a long recognized and poorly understood form of glomerular injury, membranoproliferative glomerulonephritis. This disease has received growing attention as it is the principal renal manifestation of hepatitis C virus infection, which has become pandemic worldwide.

RECENT FINDINGS

This review briefly describes three murine models of membranoproliferative glomerulonephritis suitable for pathogenesis studies. We consider recent evidence implicating innate immune mechanisms in immune and autoimmune-mediated glomerulonephritis, and recent data pointing to the alternative pathway of complement activation in the amplification of glomerulonephritic injury.

SUMMARY

Understanding the contribution of complement activation and innate immunity to the evolution of membranoproliferative glomerulonephritis promises to provide new therapeutic targets for this disease. Inhibitors of the complement cascade are already being tested in clinical trials as therapeutic interventions for some human glomerular diseases. Successful tests of this approach in membranoproliferative glomerulonephritis are still awaited. Our understanding of how the innate immune system modulates glomerulonephritis is still in an early stage, and future studies should be directed at identifying targets and specific interventions that may also benefit patients with this disease.

Extrahepatic immunological complications of hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is frequently associated with a number of extrahepatic complications. In the majority of cases the underlying pathogenetic mechanisms are immune mediated, as evidenced by the presence of circulating autoantibodies (mixed cryoglobulinemia), whereas for others a localized host cellular immune response is implicated (e.g. sialadenitis, lichen planus). In this review, the latest data on the pathogenesis and clinical manifestations of the most common autoimmune extrahepatic manifestations of chronic HCV infection are presented.

Hepatitis C virus drives the unconstrained monoclonal expansion of VH1-69-expressing memory B cells in type II cryoglobulinemia: a model of infection-driven lymphomagenesis

Chronic hepatitis C virus infection causes B cell lymphoproliferative disorders that include type II mixed cryoglobulinemia and lymphoma. This virus drives the monoclonal expansion and, occasionally, the malignant transformation of B cells producing a polyreactive natural Ab commonly encoded by the V(H)1-69 variable gene. Owing to their property of producing natural Ab, these cells are reminiscent of murine B-1 and marginal zone B cells. We used anti-Id Abs to track the stages of differentiation and clonal expansion of V(H)1-69(+) cells in patients with type II mixed cryoglobulinemia. By immunophenotyping and cell size analysis, we could define three discrete stages of differentiation of V(H)1-69(+) B cells: naive (small, IgM(high)IgD(high)CD38(+)CD27(-)CD21(high)CD95(-)CD5(-)), "early memory" (medium-sized, IgM(high)IgD(low)CD38(-)CD27(+)CD21(low)CD95(+)CD5(+)), and "late memory" (large-sized, IgM(low)IgD(low-neg)CD38(-)CD27(low)CD21(low-neg)CD5(-)CD95(-)). The B cells expanded in cryoglobulinemia patients have a "memory" phenotype; this fact, together with the evidence for intraclonal variation, suggests that antigenic stimulation by hepatitis C virus causes the unconstrained expansion of activated V(H)1-69(+) B cells. In some cases, these cells replace the entire pool of circulating B cells, although the absolute B cell number remains within normal limits. Absolute monoclonal V(H)1-69(+) B lymphocytosis was seen in three patients with cryoglobulinemia and splenic lymphoma; in two of these patients, expanded cells carried trisomy 3q. The data presented here indicate that the hepatitis C virus-driven clonal expansion of memory B cells producing a V(H)1-69(+) natural Ab escapes control mechanisms and subverts B cell homeostasis. Genetic alterations may provide a further growth advantage leading to an overt lymphoproliferative disorder.

How to diagnose and treat secondary forms of vasculitis

Vasculitis is considered to be secondary when it arises either in the context of a pre-existing connective tissue disease, as a result of direct infection with a limited range of organisms, especially viruses, or when it arises in response to exposure to a number of medications. Rheumatoid vasculitis is probably the most widely recognised form of secondary vasculitis, and in this article we review the incidence, clinical features and management of this condition. Infections may either trigger or cause some types of vasculitis. Drug therapy is a common cause of limited forms of vasculitis and may enhance our understanding of the mechanism of these diseases. The premature development of atherosclerosis in patients with existing connective tissue diseases or indeed primary vasculitis has been recognised for some time, and the underlying mechanisms are currently being studied. An appreciation of the complex and varied pathophysiology of secondary vasculitis may further our understanding of primary vasculitis.

Autoantibody Activity in Waldenström's Macroglobulinemia

Some monoclonal proteins from patients with Waldenstrom's macroglobulinemia (WM) or immunoglobulin (Ig) M monoclonal gammopathy of undetermined significance possess antigen-binding activity directed to autogenous or foreign antigens. These monoclonal IgM autoantibodies include cold agglutinins, mixed cryoglobulins, and antineural components. Because of the antigenantibody interaction, patients with these autoimmune syndromes often present with hemolytic anemia, mixed cryoglobulinemia, or peripheral neuropathy, respectively, at an earlier stage than patients with typical WM who do not have evident antibody activity. The presence of monoclonal macroglobulin autoreactive antibodies thus influences clinical presentation and natural history. Monoclonal IgM antibodies display polyreactivity to antigens of microbial origin in addition to autogenous antigens and may arise through T-independent as well as T-dependent pathways. Waldenstrom proteins with antibody activity appear to provide a link between autoimmunity, infection, and lymphoproliferative disease. Study of the antigens reacting with monoclonal IgMs may provide further insight into the pathogenesis of WM.

Cryoglobulinemia and progression of fibrosis in chronic HCV infection: cause or effect?

OBJECTIVES

Mixed cryoglobulinemia (MC) is the most common extrahepatic manifestation of HCV infection. The aim of this study is to determine the prevalence of MC in HCV infected Greek patients and to identify if it is associated with liver histology or the mode of HCV transmission.

METHODS

One hundred and twenty-six patients with chronic HCV infection were evaluated for the presence of serum cryoglobulins, autoantibodies and viral markers. One hundred and eighteen of them underwent liver biopsy and each specimen was evaluated according to the grading and staging system described by Ishak et al.

RESULTS

Cryoglobulins were detected in 37/126 (29.4%) HCV patients and cryocrit values ranged between 0.5 and 6.5%. Only two patients presented clear clinical manifestations of MC. In patients with MC, a higher grading (6.40+/-2.06 vs. 5.27+/-2.55, p=0.013) and staging score (3.71+/-1.45 vs. 2.83+/-1.84, p=0.007) was noted in liver biopsy compared to those without MC. Logistic regression analysis identified staging score (OR, 1.33; CI, 1.06-1.66, p=0.015) as the only independent variable associated with cryoglobulinemia. Correlation between the presence of cryoglobulins and the mode of HCV transmission was not found.

CONCLUSIONS

Greek patients with chronic HCV infection have high prevalence of cryoglobulinemia. A clear association between the presence of serum cryoglobulins and staging score of chronic hepatitis was found, with no difference in patients' age or the duration of infection. It is possible that cryoglobulinemia results in more rapid hepatic fibrosis in HCV infected patients.

Human monoclonal macroglobulins with antibody activity

Assays for specific antigen-binding activity were performed on sera from 172 patients with monoclonal macroglobulinemia defined by immunofixation electrophoresis. The sera were collected between 1970 and 2002. Mean IgM level was 1,409 mg/dL with a range from 70 to 6,800. Cryoglobulins were identified in 15.3% (26/170 sera: 12 trace, five single component, and nine mixed IgM-IgG). Rheumatoid factor (RF) was detected in 19 of 151 (12.6%) samples with titers ranging from 1:80 to 1:327,680. Among the nine mixed IgM-IgG cryos, eight were RF-positive and six of six displayed positivity for hepatitis C virus. Cold agglutinins (CA) were present in 8.5% (10/117) of sera with anti-I titers between 1:512 and 1:65,536. IgM binding to a series of glycosaminoglycan oligosaccharides, glycolipids, and glycoprotein antigens was found in 75 samples (43%). IgM binding to antigens having known associations to polyneuropathies occurred in 20 patients (12%). Antinuclear antibody (ANA) was documented in 10.7% (18/169) of sera. Anti-DNA activity was absent in all samples tested. Sera from 71% of patients with monoclonal macroglobulinemia in this series exhibited binding to autoantigens. Some of these immune complexes resulted in clinically significant manifestations. Our results suggest that many monoclonal immunoglobulins may be functional antibodies rather than "paraproteins." Characterization of antigen-binding activities may provide insight into the pathogenesis of monoclonal gammopathies.

Extrahepatic manifestations of hepatitis C infection

Hepatitis C virus (HCV) affects 1.8% of the American population, and approximately 38% of patients with HCV will manifest symptoms of at least 1 extrahepatic manifestation during the illness. Renal disease, neuropathy, lymphoma, and Sjögren syndrome with or without mixed cryoglobulinemia are all strongly associated with HCV infection. Porphyria cutanea tarda and diabetes have also been linked to HCV. Most extrahepatic manifestations of chronic HCV infection are immunological, and the chronic infection seems to be necessary for their development. The molecular study of the unique way in which the HCV virus interacts with the human immune system is beginning to provide plausible explanations of the pathogenic role of HCV in some of these syndromes, but many pathogenetic links remain completely obscure.

Prevalence and clinical significance of circulating cryoglobulins in HIV-positive patients with and without co-infection with hepatitis C virus

Although hepatitis C virus (HCV) is a recognized cause of circulating cryoglobulins, the role of human immunodeficiency virus (HIV) in the pathogenesis of cryoglobulinemia has not been investigated extensively. To evaluate the prevalence of circulating cryoglobulins and to assess the relationship with clinical and virological parameters, 162 HIV-positive subjects (84 anti-HCV(+)) were tested for cryoglobulins, C3, C4, RF, autoantibodies, HIV-viral titer, and CD4(+) count. Anti-HCV-positive subjects were tested for HCV-RNA, HCV-viral titer, and HCV genotype. All patients were examined for the presence of signs or symptoms of vasculitis and tested for cryoglobulins using a standard biochemical assay. Cryoglobulins were found in 30 (18.5%) cases. Of the 30 positive cases, 29 (96.7%) were anti-HCV-positive and 28 (93.3%) HCV-RNA-positive. The presence of cryoglobulins was significantly associated (P < 0.01) with HCV-RNA positivity (OR = 27), liver cirrhosis (OR = 16), decreased levels of C3 (OR = 8.6), C4 (OR = 13.6), increased levels of IgG and IgM (OR = 6.1 and 7.9, respectively), and RF positivity (OR = 6.3), but was unrelated to CD4(+) cell count, HIV viral load, diagnosis of AIDS, HCV viral load and the presence of autoantibodies. Interestingly, the presence of cryoglobulins was not significantly associated with signs and symptoms commonly associated with cryoglobulinemia. In conclusion, HIV infection does not seem to play a significant role in the production of circulating cryoglobulins, which strongly correlates with HCV co-infection and liver cirrhosis. Typical signs and symptoms of cryoglobulinemia do not correlate with the detection of circulating cryoglobulins in HIV and HCV patients.

Enhanced monocyte Th1 cytokine production in HCV-infected cryoglobulinemic patients

BACKGROUND/AIMS

The etiologic link between chronic hepatitis C virus (HCV) infection and mixed cryoglobulinemia is well established, while its prognostic significance within the context of HCV-related hepatitis is not as clear. Patients with an HCV-related cryoglobulinemic syndrome oft have mild liver disease, an aspect that can be influenced by an individual's Th1/Th2 orientation. Our goal was to document stigmata of differentiate cytokine production in this subgroup of patients.

METHODS

Fifteen patients with chronic HCV-related liver disease (CLD) and a cryoglobulinemic syndrome (CRYO) were compared to age/sex matched CLD controls with negative cryocrit. Cultured monocytes were stimulated with either Staphylococcus aureus (SAC) or lipopolysaccharide (LPS).

RESULTS

The protein concentrations of TNF-alpha and of the Th1-type cytokines interleukin (IL)-12 and IL-18 were significantly greater in the CRYO group, while IL-10 (a Th2 cytokine) levels were greater in the control group.

CONCLUSIONS

The clinical distinctiveness of the two groups was reflected at the cytokine level. The cryoglobulinemic patients studied showed a greater Th1 polarization than their cryoglobulin-negative counterparts. This enhanced production of Th1-type cytokines is seemingly not able to rid the host of infection but may account for a milder course of liver disease.

Viral RNA in nerve tissues of patients with hepatitis C infection and peripheral neuropathy

To assess the presence of viral ribonucleic acid (RNA) in nerve tissues of 15 patients with hepatitis C virus (HCV) infection and peripheral neuropathy with (11) or without (4) mixed cryoglobulinemia, nested reverse transcription-polymerase chain reaction (RT-PCR) was performed. Amplification of HCV-RNA was successful in 7 patients with and 3 without mixed cryoglobulinemia. This study demonstrates that the nested RT-PCR technique is a sensitive method to detect viral RNA in nerve tissue, and offers further evidence that in patients with HCV infection peripheral neuropathy can occur in the absence of mixed cryoglobulinemia.

Interferon-alpha and ribavirin treatment in patients with hepatitis C virus-related systemic vasculitis

OBJECTIVE

Hepatitis C virus (HCV)-related vasculitis may involve multiple organs, including the skin, kidneys, and nervous system, and may be life-threatening. Although HCV is increasingly recognized as a cause of systemic vasculitis, limited data are available regarding the optimal treatment of this potentially serious condition. Therefore, we retrospectively analyzed the response to treatment in patients with chronic hepatitis C complicated by systemic vasculitis who had received antiviral therapy with interferon-alpha (IFNalpha) and ribavirin.

METHODS

This retrospective study included 27 patients with systemic vasculitis and chronic HCV infection. Each patient had received treatment with IFNalpha and ribavirin for at least 6 months. The response to antiviral treatment was analyzed by comparing clinical, immunologic, and virologic data at the time of entry and during followup. Clinical response was defined according to the evolution of weight, arthralgia, nervous system, renal system, and cutaneous involvement. The virologic and immunologic responses were defined by the absence of HCV RNA and the absence of cryoglobulinemia, respectively, both 6 months after stopping antiviral therapy and at the end of followup.

RESULTS

Patients received IFNalpha for a mean +/- SD of 20 +/- 14 months and ribavirin (at a mean +/- SD dosage of 895 +/- 250 mg/day) for 14 +/- 12 months. Other treatments included low-dose corticosteroids and plasma exchange. After a mean +/- SD followup of 57 +/- 29 months, 25 of 27 patients are alive and are being followed up as outpatients. Because of the heterogeneity of anti-HCV treatments received, the main results were stratified according to patients with 6 months of followup after stopping antiviral treatment (group 1, n = 14) and those who were still undergoing antiviral therapy at the time of analysis (group 2, n = 13). Nine patients in group 1 had a sustained virologic response and were clinical and immunologic complete responders. Four patients in group 1 were virologic nonresponders, and 3 of these patients had partial clinical and immunologic responses. Overall, 10 patients in group 1 had a complete clinical and immunologic response of their vasculitis (all 9 of the sustained virologic responders and 1 of the 5 patients who remained viremic). At the end of followup, 7 patients in group 2 were negative for HCV RNA; 6 were complete clinical responders. Among the other 6 patients in group 2, who had persistent viremia, 4 had a partial clinical response. Among the patients in group 1, HCV RNA was more often undetectable and genotype 1 was less frequent in complete clinical responders compared with partial/nonresponders. Age, sex, clinical vasculitic involvement, mean duration or total cumulative dose of IFNalpha or ribavirin, and use of steroids or plasmapheresis did not differ significantly according to clinical response.

CONCLUSION

Treatment with IFNalpha and ribavirin can achieve a complete clinical response in most patients with HCV-related systemic vasculitis. Complete clinical response correlates with the eradication of HCV.