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Abstract

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. Acknowledgements
  7. REFERENCES

Objective

To evaluate the long-term efficacy of anti–hepatitis C virus (HCV) therapy in patients with HCV-associated mixed cryoglobulinemia (HCV-MC) vasculitis and to assess the factors associated with clinical remission of MC.

Methods

This was a single-center study of 72 consecutive patients who received treatment with IFN alfa-2b (3 million IU 3 times a week; n = 32 patients) or PEGylated IFN alfa-2b (PEG–IFN alfa-2b) (1.5 μg/kg/week; n = 40 patients), both in combination with oral ribavirin (600–1,200 mg/day), for at least 6 months. Logistic regression was used to assess factors associated with clinical remission of MC.

Results

The mean ± SD duration of followup after discontinuation of antiviral therapy was 39.7 ± 24.4 months. Eight deaths (11.1% of patients) occurred during the study, primarily as a result of cardiovascular disease, liver disease, or infection. A complete clinical response of the MC occurred in 45 patients (62.5%), a sustained virologic response occurred in 58.3%, and cryoglobulins cleared in 45.8%. Compared with patients treated with IFN alfa-2b plus ribavirin, those receiving PEG–IFN alfa-2b plus ribavirin had a higher sustained clinical (67.5% versus 56.3%), virologic (62.5% versus 53.1%), and immunologic (57.5% versus 31.3%) response, regardless of HCV genotype and viral load. In multivariate analyses, an early virologic response (odds ratio 3.53 [95% confidence interval 1.18–10.59]) was independently associated with a complete clinical response of MC. A glomerular filtration rate ≤70 ml/minute (odds ratio 0.18 [95% confidence interval 0.05–0.67]) was negatively associated with a complete clinical response of MC.

Conclusion

PEG–IFN alfa-2b plus ribavirin should be considered as induction therapy for HCV-MC vasculitis. An early virologic response and the absence of renal insufficiency are the key factors in the clinical response.

Chronic infection with hepatitis C virus (HCV) is the main cause of mixed cryoglobulinemia (MC), a potentially life-threatening, systemic vasculitis that may involve the skin, kidneys, and nervous system (1). The optimal therapeutic regimen for patients with HCV-related systemic vasculitis remains a subject of controversy. The treatment of HCV-associated MC (HCV-MC) vasculitis targets either the HCV viral trigger or downstream pathogenic events by means of less specific approaches, such as corticosteroids, immunosuppressants, or plasmapheresis (2).

Limited data are available regarding the treatment of patients with HCV-related systemic vasculitis. Monotherapy with interferon alfa (IFN alfa) is associated with a relatively poor response and a high relapse rate, especially in severe cases (3–6). Combination therapy with IFN alfa plus ribavirin provides much better short-term and long-term results (7–9). In our recent pilot study (10), PEGylated IFN alfa-2b (PEG–IFN alfa-2b) plus ribavirin achieved a higher rate of complete clinical response over a shorter treatment period than was previously reported with IFNα plus ribavirin treatment.

Apart from antiviral therapy, the use of corticosteroids, cyclophosphamide, and plasmapheresis may lead to life-threatening complications; in addition, they are difficult to manage in the long term and do not improve the manifestations of HCV-MC vasculitis (3–5, 11, 12). More recently, 3 groups of Italian investigators have reported the efficacy of treatment with rituximab, an anti-CD20 monoclonal antibody, in patients with HCV-MC vasculitis whose disease was resistant to IFNα monotherapy or who were intolerant of the treatment (13–15). However, one potential concern regarding the use of such therapy is that it has a propensity to worsen HCV viremia (13), which may lead to the development of more severe HCV-induced liver lesions and/or cryoglobulinemic relapses in ensuing years (15, 16).

The aims of the present study were to evaluate the long-term efficacy of anti-HCV therapy (i.e., with IFN alfa-2b plus ribavirin or PEG–IFN alfa-2b plus ribavirin) in a large cohort of MC patients and to assess the factors associated with clinical remission of MC. Our findings are presented herein.

PATIENTS AND METHODS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. Acknowledgements
  7. REFERENCES

Patients.

Seventy-two consecutive, unselected patients with HCV-MC vasculitis who were evaluated at the Department of Internal Medicine, Hôpital La Pitié-Salpêtrière, between 1997 and 2005 were included in the study. The patients had a serum cryoglobulin level >0.05 gm/liter on at least 2 occasions, which was associated with purpura, arthralgia (17), and sometimes with renal or neurologic involvement. All patients were positive for HCV RNA, and all had histologically proven chronic active liver disease. Inclusion criteria for the study were as follows: 1) chronic active HCV infection, 2) signs of MC vasculitis in the absence of any other condition known to cause vasculitis, 3) treatment with PEG-IFN alfa-2b plus ribavirin or IFN alfa-2b plus ribavirin for a minimum of 6 months, and 4) a minimum of 6 months of followup after discontinuation of the combination anti-HCV treatment. Exclusion criteria were the presence of either hepatitis B surface antigen or anti–human immunodeficiency virus antibodies.

Forty-six of the 72 patients (64%) had histologically confirmed systemic vasculitis. Neuromuscular biopsy specimens showed severe axonal degeneration and an inflammatory process involving the nerves in 26 of the patients. Renal biopsy specimens showed membranoproliferative glomerulonephritis in 17 of the patients. Skin biopsy specimens revealed leukocytoclastic vasculitis in 5 of the patients. Among the 46 patients who had biopsy-proven MC vasculitis, 2 of them had positive findings on biopsies of 2 different sites (skin and nerve in one and skin and kidney in the other). The remaining patients without histologic confirmation of systemic vasculitis presented with typical signs of “essential” MC vasculitis (i.e., arthralgia, asthenia, purpura of the lower extremities, and/or polyneuropathy) (17).

For each patient, clinical and biologic data were recorded at the time of the initial evaluation, at 3 months, at 12 months, at the end of combination antiviral treatment, at 6 months after the end of therapy, and at the end of followup. The clinical evaluation included age, sex, recent weight loss, neurologic (peripheral and/or central nervous system) involvement (impaired cognitive function and abnormal findings on magnetic resonance imaging of the brain), cutaneous involvement (Raynaud's phenomenon, purpura, distal ulcers), arthralgia, myalgia, sicca syndrome, gastrointestinal tract involvement (mesenteric microaneurysms and/or histologically confirmed vasculitis), renal involvement (proteinuria and/or a glomerular filtration rate [GFR] ≤70 ml/minute), and clinical signs of hepatic involvement. Laboratory evaluation included a complete blood cell count with differential cell count, serum chemistry profile, rheumatoid factor analysis, levels of the C4 fraction of complement, and cryoglobulin levels. The GFR was determined with the Cockcroft-Gault equation, as previously described (18). A 24-hour urine collection was also obtained in order to quantify daily levels of protein excretion.

Virologic and immunologic serum markers.

HCV antibodies were detected by 2 specific third-generation immunoassays (MonoLISA Anti-HCV Plus from Sanofi Pasteur Diagnostics, Marnes-la-Coquette, France; Axsym HCV version 3.0 from Abbott, Les Ulis, France). Serum HCV RNA was measured by reverse transcription–polymerase chain reaction (RT-PCR) assay (Amplicor HCV test; Roche Diagnostics, Neuilly-sur-Seine, France). HCV genotyping was performed using a second-generation line probe assay (LiPA; Innogenetics, Brussels, Belgium). Liver biopsy specimens were evaluated according to the previously validated Metavir scoring system (19). Cryoglobulins were measured as previously described (20). Cryoglobulins were classified according to the method described by Brouet et al (21) as either type II MC, which includes a monoclonal component, or type III MC, defined by the association of polyclonal immunoglobulins. The diagnosis of non-Hodgkin's lymphoma was based on World Health Organization criteria (22).

Treatment efficacy.

The response to treatment was analyzed by comparing clinical, virologic, and immunologic parameters at the initial evaluation, at 3 months, at 12 months, at the end of antiviral treatment, at 6 months after the end of therapy, and at the end of followup. Clinical response was defined by analyzing the evolution of the following main clinical signs: skin involvement (absence of purpura), peripheral neuropathy (clinical and electrophysiologic improvement on 2 successive examinations), renal involvement (normalization of serum creatinine level and disappearance of proteinuria), and the absence of arthralgia.

A complete clinical response was defined as improvement in all baseline clinical manifestations. A partial clinical response was defined as improvement in at least one-half of the baseline clinical manifestations. Patients who had neither a complete clinical response nor a partial clinical response were classified as nonresponders. Relapse was defined as the reappearance of clinical signs of vasculitis.

An early virologic response was defined as the absence of detectable serum HCV RNA 3 months after starting antiviral treatment. A sustained virologic response was defined as the absence of detectable serum HCV RNA 6 months after stopping antiviral treatment. Patients who had neither an early virologic response nor a sustained virologic response were classified as virologic nonresponders.

A complete immunologic response was defined as the absence of serum cryoglobulins. A partial immunologic response was defined as a decrease in the serum cryoglobulin level of >50% compared with baseline. Patients who had neither a complete immunologic response nor a partial immunologic response were classified as immunologic nonresponders.

Statistical analysis.

Quantitative variables were expressed as the mean ± SD. Comparisons between antiviral treatment groups (i.e., standard IFN alfa-2b plus ribavirin versus PEG–IFN alfa-2b plus ribavirin) were assessed with Wilcoxon's exact test and Fisher's exact test. Clinical, virologic, and immunologic complete responses were evaluated 12 months after the start of antiviral therapy. The association between outcome variables (i.e., death and clinical, virologic, and immunologic complete responses) and antiviral treatments were determined using Fisher's exact test, except for death which was determined with the log-rank test. Associations with a complete clinical response (6 months after the end of treatment) were determined with Fisher's exact test.

Continuous variables were dichotomized using median values (age, duration of HCV infection, HCV RNA level, alanine aminotransferase [ALT] level, cryoglobulin level, duration of anti-HCV therapy, and ribavirin dosage). Odds ratios (ORs) and their 95% confidence intervals (95% CIs) were also computed. Multivariate models were performed using multiple logistic regression. All factors with a P value lower than 0.1 in the univariate analyses were initially included. Factor selection was determined using a backward procedure based on the Akaike criteria. In model checking, we examined potential interactions and collinearity, and goodness of fit was evaluated using the method proposed by Le Cessie and Van Houwelingen (23). Comparisons of variables before and after antiviral therapy were performed using Wilcoxon's paired test and McNemar's test. All tests were 2-sided at the 0.05 significance level. Analyses were performed using the R statistical package (online at http://www.R-project.org).

RESULTS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. Acknowledgements
  7. REFERENCES

Characteristics of the HCV-MC vasculitis patients.

The main characteristics of the 72 patients with HCV-MC vasculitis are detailed in Tables 1 and 2. The patients had a mean age of 59.86 ± 14.08 years (range 31–84), and 37 (51.4%) of them were women. Clinical manifestations of MC included purpura in 51 patients (70.8%), peripheral neuropathy in 44 (61.1%), arthralgia in 30 (41.7%), renal involvement in 22 (30.6%), sicca syndrome in 13 (18.1%), gastrointestinal tract involvement in 6 (8.3%), central nervous system involvement in 3 (4.2%), Raynaud's phenomenon in 3 (4.2%), and leg ulcers in 1 (1.4%). Renal insufficiency (i.e., a GFR ≤70 ml/minute; range 11–70) was observed in 16 patients (22.2%). Twenty-two patients (30.5%) had proteinuria, and 17 had proteinuria ≥1 gm/24 hours. Nine patients (12.5%) had low-grade B cell non-Hodgkin's lymphoma (marginal zone lymphoma in 5 and lymphoplasmacytic lymphoma in 4). The mean cryoglobulin level was 1.15 gm/liter (range 0.05–7), with type II cryoglobulins in 51 patients (70.8%). The serum C4 level was low in 54 patients (75%), and 78.9% of patients had rheumatoid factor activity.

Table 1. Characteristics of the 72 HCV-MC vasculitis patients at baseline and at the end of followup*
ParameterBaselineEnd of followupP
  • *

    Rheumatoid factor (RF) data were available for 57 of the 72 patients. RF levels ≥15 IU/ml were considered positive. C4 levels <0.17 gm/liter were considered low. Except where indicated otherwise, values are the mean ± SD. HCV-MC = hepatitis C virus–associated mixed cryoglobulinemia; ALT = alanine aminotransferase.

Clinical   
 Purpura, no. (%)51 (70.8)7 (9.7)<0.001
 Peripheral neuropathy, no. (%)44 (61.1)14 (19.4)<0.001
 Arthralgia, no. (%)30 (41.7)6 (8.3)<0.001
 Renal involvement, no. (%)22 (30.6)13 (18)0.008
Virologic   
 HCV RNA positive, no. (%)72 (100)30 (41.6)<0.001
 ALT, IU/liter94 ± 5558 ± 33<0.001
 Abnormal ALT level, no. (%)55 (76.4)21 (29.2)<0.001
Immunologic   
 Cryoglobulin level, gm/liter1.15 ± 1.360.27 ± 0.63<0.001
 Cryoglobulin positive, no. (%)66 (91.6)41 (56.9)<0.001
 C4 complement level, gm/liter0.12 ± 0.070.21 ± 0.11<0.001
 Low C4 complement level, no. (%)54 (75)16 (22.2)<0.001
 RF level, IU/ml418.7 ± 744.5107.6 ± 183.2<0.001
 RF positive, no. (%)45 (78.9)37 (64.9)0.013
Table 2. Characteristics of all HCV-MC vasculitis patients and the 2 antiviral treatment groups at the end of therapy*
ParameterAll MC patients (n = 72)Patients taking antiviral treatmentsP
IFN alfa-2b plus ribavirin (n = 32)PEG–IFN alfa-2b plus ribavirin (n = 40)
  • *

    Except where indicated otherwise, values are the mean ± SD. HCV-MC = hepatitis C virus–associated mixed cryoglobulinemia; IFN = interferon; PEG = PEGylated; ALT = alanine aminotransferase; GI = gastrointestinal.

  • Liver necroinflammation and fibrosis were graded according to the Metavir scoring system.

  • Clinical, virologic, and immunologic responses were evaluated 12 months after the start of antiviral therapy.

Age, years59.86 ± 14.0862.31 ± 15.7857.9 ± 12.410.13
Female, no. (%) of patients37 (51.4)16 (50)21 (52.5)1
HCV related    
 Duration of HCV infection, years27.34 ± 9.6328.19 ± 11.226.73 ± 8.550.78
 HCV genotype 1, no. (%)44 (61.1)16 (51.6)28 (70)0.14
 HCV RNA, log copies/ml5.87 ± 0.655.92 ± 0.575.83 ± 0.720.44
 ALT, IU/liter93.6 ± 54.483.2 ± 39.8102 ± 63.00.38
 Liver necroinflammation score (0–3 scale)1.3 ± 0.81.4 ± 0.91.3 ± 0.70.6
 Liver fibrosis score (0–4 scale)1.9 ± 1.22.0 ± 1.11.8 ± 1.10.34
 Cirrhosis, no. (%)9 (12.5)4 (13.3)5 (12.5)1
MC related    
 Purpura, no. (%)51 (73.9)27 (87.1)24 (63.2)0.03
 Peripheral neuropathy, no. (%)44 (61.1)17 (53.1)27 (67.5)0.23
 Arthralgia, no. (%)30 (41.7)8 (25)22 (55)0.02
 Renal involvement, no. (%)22 (30.6)12 (37.5)10 (25)0.23
 Sicca syndrome, no. (%)13 (18.1)8 (25)5 (13.2)0.23
 Myalgia, no. (%)8 (11.1)3 (9.4)5 (12.5)0.73
 GI tract involvement, no. (%)6 (8.3)4 (12.5)2 (5)0.4
 Raynaud's phenomenon, no. (%)3 (4.2)2 (6.2)1 (2.5)0.58
 B cell lymphoma, no. (%)9 (12.5)4 (12.5)5 (12.5)1
 Cryoglobulin level, gm/liter1.15 ± 1.361.41 ± 1.490.93 ± 1.230.16
 Type II cryoglobulins, no. (%)51 (70.8)26 (83.9)25 (71.4)0.26
 Low C4 complement level, no. (%)54 (75)25 (78.1)29 (72.5)0.48
Treatment related    
 Duration of anti-HCV therapy, months16.63 ± 7.818.35 ± 10.013.25 ± 4.40.08
 Ribavirin dosage, mg/day915.9 ± 182.8875.9 ± 195.7945 ± 169.30.5
 Previous antiviral therapy, no. (%)20 (27.6)7 (21.9)13 (32.5)0.43
 Corticosteroids, no. (%)29 (40.3)15 (46.9)14 (35)0.34
 Plasmapheresis, no. (%)9 (12.5)8 (25)1 (2.5)0.01
 Immunosuppressants, no. (%)4 (5.6)4 (12.5)0 (0)0.03
 All adverse events, no. (%)39 (54.2)17 (53.1)22 (55)1
Outcome    
 Deaths, no. (%)8 (11.1)6 (18.8)2 (5)0.98
 Complete response, no. (%)    
  Clinical40 (55.5)12 (37.5)28 (70)0.009
  Virologic49 (68.0)19 (59.3)30 (75)0.20
  Immunologic33 (45.8)9 (28.1)24 (60)0.009

The source of HCV infection was a blood transfusion in 25 patients (34.7%), intravenous drug use in 13 (18.1%), and unknown in 34 (47.2%) patients. The distribution of HCV genotypes was genotype 1 in 44 (61.1%), genotype 2 in 10 (13.9%), genotype 3 in 8 (11.1%), genotype 4 in 6 (8.3%), and genotype 5 in 3 (4.2%). The mean ± SD HCV RNA level was 5.87 ± 0.65 log copies/ml (range 4.7–7.9). The mean ± SD ALT level was 93.6 ± 54.4 IU/liter. All patients had chronic active hepatitis, with a mean ± SD activity score of 1.3 ± 0.8 and a mean ± SD fibrosis score of 1.9 ± 1.2 according to the Metavir criteria. Nine patients (12.5%) had cirrhosis.

Treatment-related data and outcomes.

The main treatment-related data are summarized in Tables 1, 2, and 3. Among the 72 patients, 40 (55.6%) received subcutaneous PEG–IFN alfa-2b at a dosage of 1.5 μg/kg/week and 32 (44.5%) received standard IFN alfa-2b at a dosage of 3 millions IU 3 times/week for at least 6 months. Both groups also received oral ribavirin at a dosage of 600–1,200 mg/day. Patients seen prior to 2001 were treated with IFN alfa-2b plus ribavirin, whereas those seen in 2001 or later received PEG–IFN alfa-2b plus ribavirin. In cases of renal insufficiency, severe polyneuropathy, and/or life-threatening complications, patients were treated with corticosteroids (prednisone 0.5–1 mg/kg/day for 2 weeks, with a rapid taper to 10 mg/day within 6 weeks) (n = 29 [40.3%]), immunosuppressive drugs (cyclophosphamide or azathioprine) (n = 4 [5.6%]), and/or plasmapheresis (n = 9 [12.5%]). Fifty-two patients (72.2%) had not been treated prior to initiation of antiviral therapy. The 20 remaining patients had received first-line therapy with standard IFN alfa-2b (3 million IU 3 times/week) either alone (n = 7 in the IFN alfa-2b plus ribavirin group) or in combination with ribavirin (n = 13 in the PEG–IFN alfa-2b plus ribavirin group).

Table 3. Chronologic response to antiviral therapy in all HCV-MC vasculitis patients and in the 2 antiviral treatment groups*
 Complete response
ClinicalVirologicImmunologic
  • *

    Values are the number (%) of patients. HCV-MC = hepatitis C virus–associated mixed cryoglobulinemia; IFN = interferon; PEG = PEGylated.

At 3 months   
 All HCV-MC patients (n = 72)21 (29.2)41 (56.9)23 (31.9)
 Patients taking IFN alfa-2b plus ribavirin (n = 32)6 (18.8)16 (50)5 (15.6)
 Patients taking PEG–IFN alfa-2b plus ribavirin (n = 40)15 (37.5)25 (62.5)18 (45)
At 12 months   
 All HCV-MC patients (n = 72)40 (55.5)49 (68)33 (45.8)
 Patients taking IFN alfa-2b plus ribavirin (n = 32)12 (37.5)19 (59.3)9 (28.1)
 Patients taking PEG–IFN alfa-2b plus ribavirin (n = 40)28 (70)30 (75)24 (60)
At the end of therapy   
 All HCV-MC patients (n = 72)44 (61.1)50 (69.4)33 (45.8)
 Patients taking IFN alfa-2b plus ribavirin (n = 32)15 (46.8)20 (62.5)9 (28.1)
 Patients taking PEG–IFN alfa-2b plus ribavirin (n = 40)29 (72.5)30 (75)24 (60)
At the end of followup   
 All HCV-MC patients (n = 72)45 (62.5)42 (58.3)33 (45.8)
 Patients taking IFN alfa-2b plus ribavirin (n = 32)18 (56.3)17 (53.1)10 (31.3)
 Patients taking PEG–IFN alfa-2b plus ribavirin (n = 40)27 (67.5)25 (62.5)23 (57.5)

Following antiviral therapy (Table 1), purpura resolved in 86.3% of cases (P < 0.001), arthralgia resolved in 80% (P < 0.001), peripheral neuropathy in 68.2% (P < 0.001), and renal involvement resolved in 40.9% (P = 0.008). The main virologic parameters (i.e., HCV RNA and ALT) improved significantly. The cryoglobulin level decreased from a mean of 1.15 gm/liter to 0.27 gm/liter (P < 0.001) (Figure 1), the C4 complement level normalized in 38 of 54 patients (70.4%) (P < 0.001), and rheumatoid factor disappeared in 17.8% of patients (P = 0.01). There was an association between the clearance of cryoglobulins and both rheumatoid factor (P = 0.003) and normalization of the C4 level (P = 0.01).

thumbnail image

Figure 1. Immunologic parameters in patients with hepatitis C virus–associated mixed cryoglobulinemia vasculitis at baseline and at the end of followup (EOF). A, Cryoglobulin level. B, C4 complement level. C, Rheumatoid factor (RF) activity. Data are shown as box plots. Each box represents the 25th to 75th percentiles. Lines inside the boxes represent the median. Whiskers represent the highest and lowest values.

Download figure to PowerPoint

The mean ± SD duration of followup was 39.7 ± 24.4 months after discontinuing antiviral therapy (57.0 ± 23.8 months in the IFN alfa-2b plus ribavirin group and 25.5 ± 13.5 months in the PEG–IFN alfa-2b plus ribavirin group). At the end of followup, 45 patients (62.5%) were complete clinical responders, 42 (58.3%) had a sustained virologic response, and 33 (45.8%) had a complete immunologic response (Table 3).

A reappearance of HCV RNA was observed in 8 patients (11.1%) a median of 2 months after discontinuing therapy (range 1–3 months). Six of these 8 patients had a relapse of MC vasculitis. Eight deaths occurred during the study. Three patients died of cardiovascular disease, 2 died of hepatocarcinoma, 2 died of liver failure, and 1 died of sepsis.

Comparison of PEG–IFN alfa-2b with standard IFN alfa-2b.

Table 2 summarizes the main outcomes after antiviral therapy with PEG–IFN alfa-2b plus ribavirin versus standard IFN alfa-2b plus ribavirin. The mean duration of antiviral therapy was 13.25 ± 4.4 months in the PEG–IFN alfa-2b plus ribavirin group and 18.35 ± 10.0 months in the IFN alfa-2b plus ribavirin group. The duration of therapy and the decision to stop the treatment were based on the clinical response. At baseline, virologic and clinical characteristics were not significantly different except for arthralgia and purpura. After 3 months of antiviral therapy (Table 3), 41 of the patients (56.9%) were virologic responders, 21 (29.2%) were clinical responders, and 23 (31.9%) were immunologic responders. In comparison to IFN alfa-2b plus ribavirin therapy, PEG–IFN alfa-2b plus ribavirin therapy showed a higher rate of virologic (62.5% versus 50%), clinical (37.5% versus 18.8%), and immunologic (45% versus 15.6%) responses.

Six months after discontinuing antiviral therapy (at the end of followup), 42 of the patients (58.3%) were virologic responders, 45 (62.5%) were clinical responders, and 33 (45.8%) were immunologic responders. Patients treated with PEG–IFN alfa-2b plus ribavirin showed a higher rate of virologic (62.5% versus 53.1%), clinical (67.5% versus 56.3%) and immunologic (57.5% versus 31.3%) response than those receiving IFN alfa-2b plus ribavirin. A partial immunologic response was observed in 14 of 32 (43.8%) patients treated with IFN alfa-2b plus ribavirin and in 14 of 40 (35%) of those receiving PEG–IFN alfa-2b plus ribavirin. Compared with standard IFN alfa-2b plus ribavirin, there was a trend toward a shorter duration of anti-HCV therapy (13.25 months versus 18.35 months), less frequent use of corticosteroids (35% versus 46.9%) and a lower rate of death (5% versus 18.8%) with PEG–IFN alfa-2b plus ribavirin. Plasmapheresis and immunosuppressive drugs were less likely to be used in association with PEG–IFN alfa-2b plus ribavirin.

Factors associated with complete clinical response.

Table 4 summarizes the factors associated with a complete clinical response. Among the 72 treated HCV-MC vasculitis patients, 45 (62.5%) were complete clinical responders, 20 (27.8%) were partial responders, and 7 (9.7%) were nonresponders. Complete clinical response correlates with the eradication of HCV. Among the complete clinical responders, 66.6% had an early virologic response, and 73.3% had a sustained virologic response. Among the 12 patients with necrotizing vasculitis (i.e., polyarteritis nodosa–like HCV vasculitis [24]), 8 of them (66.7%) had a complete clinical response, as compared with 37 of the 60 patients (61.7%) without necrotizing arteritis.

Table 4. Factors associated with complete clinical response of HCV-MC vasculitis*
ParameterTotal no. of patientsNo. (%) with CRUnivariate analysisMultivariate analysis
OR (95% CI)POR (95% CI)P
  • *

    HCV-MC = hepatitis C virus–associated mixed cryoglobulinemia; CR = complete response; OR = odds ratio; 95% CI = 95% confidence interval; ALT = alanine aminotransferase; GFR = glomerular filtration rate; GI = gastrointestinal; IFN = interferon; PEG = PEGylated.

  • Liver necroinflammation and fibrosis were graded according to the Metavir scoring system.

Age, years      
 ≤603821 (55.3)1   
 >603424 (70.6)1.92 (0.66–5.84)0.23  
Sex      
 Male3518 (51.4)1 1 
 Female3727 (73)2.52 (0.86–7.7)0.092.2 (0.74–6.52)0.16
Duration of HCV infection, years      
 ≤20115 (45.5)1   
 >202719 (70.4)2.77 (0.53–15.43)0.27  
HCV genotype      
 Others2718 (66.7)1   
 14427 (61.4)0.8 (0.25–2.4)0.8  
HCV RNA, log copies/ml      
 ≤65031 (62)1   
 >62214 (63.6)1.07 (0.34–3.54)1  
ALT, IU/liter      
 ≤804425 (56.8)1   
 >802820 (71.4)1.88 (0.62–6.08)0.32  
Liver necroinflammation      
 Grades A0–A14128 (68.3)1   
 Grades A2–A32915 (51.7)0.5 (0.17–1.48)0.21  
Liver fibrosis      
 Grades F0–F24832 (66.7)1   
 Grades F3–F42211 (50)0.51 (0.16–1.59)0.2  
Purpura      
 Absent188 (44.4)1   
 Present5135 (68.6)2.69 (0.79–9.55)0.09  
Peripheral neuropathy      
 Absent2815 (53.6)1   
 Present4430 (68.2)1.84 (0.62–5.5)0.22  
Arthralgia      
 Absent4222 (52.4)1   
 Present3023 (76.7)2.94 (0.96–9.96)0.05  
Renal involvement      
 Absent5036 (72)1   
 Present229 (40.9)0.27 (0.08–0.87)0.02  
Renal insufficiency, GFR ≤70 ml/minute      
 Absent5640 (71.4)1 1 
 Present165 (31.2)0.19 (0.04–0.69)0.010.16 (0.05–0.67)0.01
Proteinuria ≥1 gm/24 hours      
 Absent5538 (69.1)1   
 Present177 (41.2)0.32 (0.09–1.11)0.05  
Sicca syndrome      
 Absent5733 (57.9)1   
 Present1311 (84.6)3.93 (0.75–39.75)0.11  
Myalgia      
 Absent6441 (64.1)1   
 Present84 (50)0.57 (0.1–3.34)0.46  
GI tract involvement      
 Absent6640 (60.6)1   
 Present65 (83.3)3.21 (0.33–159.41)0.4  
Raynaud's phenomenon      
 Absent6943 (62.3)1   
 Present32 (66.7)1.21 (0.06–74.02)1  
B cell lymphoma      
 Absent6339 (61.9)1   
 Present96 (66.7)1.23 (0.24–8.29)1  
Cryoglobulin level, gm/liter      
 ≤0.703217 (53.1)1   
 >0.703223 (71.9)2.23 (0.71–7.3)0.2  
Mixed cryoglobulin type      
 Type II5132 (62.7)1   
 Type III159 (60)0.89 (0.24–3.56)1  
Duration of anti-HCV therapy, months      
 ≤1474 (57.1)1   
 >146541 (63.1)1.28 (0.17–8.26)1  
Antiviral treatment      
 IFN alfa-2b plus ribavirin3218 (56.2)1   
 PEG–IFN alfa-2b plus ribavirin4027 (67.5)1.6 (0.55–4.71)0.34  
Ribavirin dosage, mg/day      
 <1,0002916 (55.2)1   
 ≥1,0004027 (67.5)1.67 (0.56–5.07)0.32  
Corticosteroids      
 Absent4331 (72.1)1   
 Present2914 (48.3)0.37 (0.12–1.08)0.05  
Plasmapheresis      
 Absent6341 (65.1)1   
 Present94 (44.4)0.43 (0.08–2.25)0.28  
Immunosuppressants      
 Absent6844 (64.7)1   
 Present41 (25)0.19 (0–2.46)0.15  
Adverse events related to therapy      
 Absent3323 (69.7)1   
 Present3922 (56.4)0.57 (0.19–1.65)0.33  
Immunologic CR at 3 months      
 Absent4932 (65.3)1   
 Present2313 (56.5)0.69 (0.22–2.17)0.6  
Virologic CR at 3 months      
 Absent3115 (48.4)1 1 
 Present4130 (73.2)2.86 (0.97–8.78)0.053.53 (1.18–10.59)0.02

In univariate analyses, factors associated with a complete clinical response were the presence of arthralgia (OR 2.94 [95% CI 0.96–9.96]), and an early virologic response (OR 2.86 [95% CI 0.97–8.78]). Factors negatively associated with a complete clinical response were renal involvement (OR 0.27 [95% CI 0.08–0.87]), a GFR ≤70 ml/minute (OR 0.19 [95% CI 0.04–0.69]), proteinuria ≥1 gm/24 hours (OR 0.32 [95% CI 0.09–1.11]), and corticosteroid use (OR 0.37 [95% CI 0.12–1.08]). In multivariate analyses, an early virologic response (OR 3.53 [95% CI 1.18–10.59]) and a GFR ≤70 ml/minute (OR 0.18 [95% CI 0.05–0.67]) were independently associated with a complete clinical response of MC.

Course of the main parameters according to the virologic response.

Compared with values before antiviral therapy (Table 5), patients with a sustained virologic response had a significant decrease in the cryoglobulin level (mean ± SD 1.1 ± 1.2 versus 0.1 ± 0.2 gm/liter; P < 0.001) and the proteinuria level (4.4 ± 2.3 versus 0.6 ± 0.9 gm/24 hours; P = 0.002) at the end of followup. Regardless of the virologic response, no significant changes in the mean serum creatinine level or the mean GFR were seen. A significant decrease in the ALT level was observed in sustained virologic responders at the end of followup (mean ± SD 95.7 ± 62.5 versus 46.3 ± 25.9 IU/liter; P < 0.001).

Table 5. Changes in the main immunologic, renal, and liver parameters in HCV-MC vasculitis patients, by virologic response to therapy*
 Sustained virologic respondersVirologic nonresponders
BaselineEnd of followupPBaselineEnd of followupP
  • *

    Values are the mean ± SD. HCV-MC = hepatitis C virus–associated mixed cryoglobulinemia; %Δ = percentage of variation between parameters at baseline and end of followup; ALT = alanine aminotransferase.

Cryoglobulin, gm/liter1.1 ± 1.20.1 ± 0.2−91<0.0011.0 ± 1.50.5 ± 0.9−500.002
Glomerular filtration rate, ml/minute43.0 ± 25.566.2 ± 33.2+540.0751.4 ± 21.355.3 ± 26.0+80.29
Serum creatinine, μmoles/liter133.3 ± 53.2118.5 ± 45.3−110.24175.0 ± 80.9189.1 ± 161.1+80.35
Proteinuria, gm/24 hours4.4 ± 2.30.6 ± 0.9−860.0024.1 ± 3.22.2 ± 3.1−460.14
ALT, IU/liter95.7 ± 62.546.3 ± 25.9−52<0.00190.8 ± 41.673.8 ± 36.3−190.11

Tolerance of therapy.

Treatment was well tolerated in 33 of the patients (45.8%). In the 39 remaining patients, side effects included fatigue (47.2%), fever (37.5%), anemia (33.3%), myalgia (25%), neutropenia (20%), depression (15.2%), thrombocytopenia (5%), pruritus (4.1%), and alopecia (2.7%). The rates of adverse events were similar in the IFN alfa-2b plus ribavirin group (53.1%) and the PEG–IFN alfa-2b plus ribavirin group (55%). No therapy interruptions were needed. A dosage reduction of antiviral therapy was required in 11 patients, all of which were for hematologic indications.

DISCUSSION

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. Acknowledgements
  7. REFERENCES

Our results show overall rates of complete clinical and virologic responses of HCV-MC vasculitis in 62.5% of patients treated with PEG–IFN alfa-2b plus ribavirin and in 58% of patients treated with IFN alfa-2b plus ribavirin. Clearance of cryoglobulins was noted in 45.8% of patients. Clinical and virologic responses were closely correlated. Previous studies found different clinical response rates with antiviral therapy in terms of the manifestations of vasculitis (i.e., cutaneous 85–100%, neural 25–50%, and renal 25–50%) (7–9). In the present study, we observed a complete improvement in purpura in 86.3% of patients, neuropathy in 68.2%, and renal involvement in 40.9%. The proportion of HCV-MC vasculitis patients reporting any adverse events to anti-HCV therapy was 54.2%. This was similar to the proportions previously reported in HCV-infected patients without MC (25, 26). The most frequent adverse events observed were fatigue, fever, cytopenia, and myalgia. However, no therapy interruptions were needed. A similar rate of adverse events was seen with IFN alfa-2b plus ribavirin and PEG–IFN alfa-2b plus ribavirin treatment.

Consistent with the findings of our previous study (10), the treatment duration was ∼13 months for all genotypes in the PEG–IFN alfa-2b and ribavirin group. HCV-MC vasculitis is a more challenging disease to treat than HCV infection without cryoglobulinemia and usually justifies longer treatment periods (7). Compared with IFN alfa-2b plus ribavirin, patients treated with PEG–IFN alfa-2b plus ribavirin had higher sustained clinical (67.5% versus 56.2%) and virologic (62.5% versus 53.1%) responses, regardless of HCV genotype and viral load. The proportion of patients with a complete immunologic response was significantly higher in those taking PEG–IFN alfa-2b plus ribavirin (57.5% versus 31.2%). Clearance of cryoglobulins is a major goal of therapy in MC, since recurrence of vasculitis, sometimes in association with B cell lymphoma, has been reported in patients with persistent cryoglobulins despite successful treatment of HCV (27). Strikingly, the early response to antiviral therapy was nearly 2 times higher with PEG–IFN alfa-2b plus ribavirin than with IFN alfa-2b plus ribavirin. This may explain the lower duration of therapy with PEG–IFN alfa-2b plus ribavirin. Similarly, patients treated with PEG–IFN alfa-2b plus ribavirin received corticosteroids, plasmapheresis, and immunosuppressive drugs less frequently than the other treatment group. These findings are of particular importance since corticosteroids and cytotoxic agents are associated with considerable morbidity. This sparing effect is likely to be clinically meaningful.

This large cohort of HCV-MC vasculitis patients enabled us to assess factors predictive of complete clinical response. In multivariate analyses, an early virologic response increased by nearly 4-fold the odds of achieving sustained clinical remission. Thirty of 45 patients (66.7%) with negative HCV RNA by 3 months of antiviral combination therapy experienced clinical remission. An early virologic response (3 months) to IFNα-based therapy is well known in HCV-infected patients without extrahepatic complications. More than 90% of patients who do not have an early virologic response to PEG–IFN alfa plus ribavirin by week 12 will ever have a sustained virologic response (25, 26). Compared with patients with chronic HCV without MC, those with cryoglobulinemia vasculitis had a similar rate of early virologic response to PEG–IFN alfa-2ab plus ribavirin (64% versus 62.5%, respectively) (26). According to previous reports patients with HCV-MC vasculitis may remain in clinical remission despite the persistence of viremia (6, 7, 28, 29). In the present study, 26.7% (12 of 45) of the complete clinical responders were not sustained virologic responders. However, 7 of the 12 patients exhibited a significant reduction of their viral load (>2 log copies/ml). Besides its antiviral activity, IFNα also has antiproliferative and immunomodulatory properties (30), which may account for the clinical response in the 5 remaining patients.

HCV-MC vasculitis patients with a GFR ≤70 ml/minute were 5.6 times less likely to be complete clinical responders. Only one-third of these patients achieved a complete clinical response. In contrast, proteinuria ≥1 gm/24 hours did not modify the response to antiviral therapy. A significant decrease in proteinuria was observed in sustained virologic responders, whereas no significant change in the serum creatinine level was seen. Nephropathy is a major cause of morbidity and mortality in MC (11, 31). However, data on the treatment of patients with cryoglobulinemic glomerulonephritis are scarce. Consistent with our results, 2 other studies showed a loss of proteinuria in sustained viral responders treated with IFNα plus ribavirin (29, 32). Ribavirin clearance is dependent on renal function, and in a small study of patients with HCV-associated glomerulonephritis conducted by Bruchfeld et al (32), the ribavirin dosage was modified and the concentration was controlled; however, no significant changes in renal function were noted in MC patients following anti-HCV therapy, regardless of the virologic response to treatment. Kidney injury could result from the fixation of circulating immune complexes containing HCV antibodies, HCV antigens, and complement on glomerular capillaries in the mesangium (33). In a recent study, Rossi et al (34) showed an improvement in serum creatinine levels and a decrease in renal injury in 3 patients, with persistence of glomerular lesions on the second renal biopsy after antiviral treatment withdrawal. We suggest that deposition of immune complexes leads to definitive glomerular lesions. Therefore, early treatment with antiviral agents is needed before definitive sclerosis occurs.

Corticosteroids and immunosuppressive drugs were not associated with an improved clinical outcome of MC as compared with antiviral therapy alone. However, this study was not designed to assess their efficacy in HCV-MC vasculitis, since only patients who had more severe disease (renal insufficiency, severe polyneuropathy, and/or life-threatening complications) received additional therapy with corticosteroids and, less commonly, immunosuppressive agents. In 2 previous controlled studies (3, 5), corticosteroid treatment alone or in addition to IFN did not improve the response of HCV-related vasculitic manifestations as compared with antiviral therapy. Corticosteroids in combination with cytotoxic agents may be useful initially for the control of life-threatening organ involvement while awaiting the generally slow response to antiviral treatments.

More recently, data on the efficacy of rituximab, an anti-CD20 monoclonal antibody, have been reported in patients with HCV-MC vasculitis (13–16). It appears that rituximab is very efficacious against cryoglobulin production and its clinical consequences (i.e., inflammatory vascular lesions). However, those studies did not allow conclusions to be drawn concerning the efficacy of anti-CD20 monoclonal antibody on peripheral neuropathy and nephropathy (13–15). The lack of efficacy in the clearance of HCV virus as well as the potential increase in HCV viral load emphasize the need for combined antiviral therapy to block the HCV infection trigger.

In summary, the findings of the present study underscore the idea that PEG–IFN alfa-2b plus ribavirin should be considered for induction therapy in patients with HCV-MC vasculitis. Inducing a sustained virologic and clinical response and minimizing the use of immunosuppressive drugs are the main goals in the treatment of patients with HCV-MC vasculitis. Although this approach affords a satisfactory response rate, additional therapy (i.e., anti-CD20 monoclonal antibody or new immunosuppressive agents) may be needed in MC patients with renal insufficiency and/or without an early virologic response.

Acknowledgements

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. Acknowledgements
  7. REFERENCES

We thank P. Ghillani-Dalbin for help with the immunologic data.

REFERENCES

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. Acknowledgements
  7. REFERENCES
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