The expanding spectrum of HCV-related cryoglobulinemic vasculitis: a narrative review

Evolution of Cryoglobulinemia in Direct-Acting Antiviral-Treated Asian Hepatitis C Patients With Sustained Virological Responses: A 4-Year Prospective Cohort Study

Background

How cryoglobulinemia evolves after sustained virological response (SVR) following direct-acting antiviral (DAA) treatment in Asian hepatitis C virus (HCV)-infected patients remains elusive.

Methods

A prospective cohort study was conducted in 422 Taiwanese patients (358 completed DAA therapy and 353 experienced SVRs). Serum cryoglobulins were surveyed at baseline and every 3-6 months posttherapy.

Results

Of 422, 227 (53.8%) had cryoglobulinemia, 8 (1.89%) had cryoglobulinemic vasculitis. Of 227, 54 (23.8%), 57 (25.1%) and 116 (51.1%) had 1, 2 and 3 cryoglobulins, respectively; those with 3 cryoglobulins had the highest alanine aminotransferase, immunoglobulin G (IgG) and fibrosis-4 index. During a 4-year follow-up, among SVR patients, cryoglobulinemia rates decreased from 56.4% to 15.4%, single cryoglobulin rates increased (21.6% to 63.9%) and 3 cryoglobulin rates decreased (55.7% to 11.1%). Compared with baseline values, among SVR patients with baseline cryoglobulinemia, complement component 4 levels increased, and IgG and IgM levels decreased until 48 weeks posttherapy for those without posttherapy cryoglobulinemia. All 8 cryoglobulinemic vasculitis patients exhibited SVRs; 5 (62.5%) achieved complete clinical response 12 weeks posttherapy, of whom, 2 (40%) experienced clinical relapse 24~48 weeks posttherapy. Baseline IgM levels were associated with posttherapy cryoglobulinemia in SVR patients (cut-off values at 12, 24, 48 weeks and 4 years posttherapy: 130, 105, 118 and 168 mg/dL, respectively).

Conclusions

Among DAA-treated SVR patients, in 4 years, cryoglobulinemia rates decreased from 56.4% to 15.4%, multiple cryoglobulin rates decreased, cryoglobulinemia signals reversed, 62.5% of cryoglobulinemic vasculitis patients achieved complete clinical response (40% had relapse), and baseline IgM levels indicated posttherapy cryoglobulinemia.

Interactive Impacts from Hepatitis C Virus Infection and Mixed Cryoglobulinemia on Complement Levels

BACKGROUND/AIM

How hepatitis C virus (HCV) infection and mixed cryoglobulinemia interactively affect complement levels remains elusive, and we aimed to elucidate it.

METHODS

A prospective cohort study of 678 consecutive chronic HCV-infected (CHC) patients was conducted. Of 678, 438 had completed a course of anti-HCV therapy and 362 had achieved a sustained virological response (SVR). The baseline and 24-week post-therapy variables including complement levels and mixed cryoglobulinemia status were surveyed.

RESULTS

At baseline, lower complement component 3 (C3) and component 4 (C4) levels were noted in patients with than those without mixed cryoglobulinemia. The differences between pre-therapy (in 678 CHC patients) and 24-week post-therapy (in 362 SVR patients) factors associated with C3 levels were interferon λ3 (IFNL3) genotype, triglycerides, cirrhosis, and estimated glomerular filtration rate; the different associations with C4 levels were cirrhosis, sex and high sensitivity C-reactive protein. Compared with baseline, SVR patients without pre- and post-therapy mixed cryoglobulinemia had increased C3 levels, and SVR patients with pre-therapy mixed cryoglobulinemia had increased C4 levels. Lower C3 levels were noted in SVR patients with than those without post-therapy mixed cryoglobulinemia.

CONCLUSIONS

HCV might affect C3 levels through IFNL3 genotype, triglycerides, cirrhosis, and renal function; and affect C4 with a link to sex, inflammation, and cirrhosis. That C3 levels decreased in CHC patients without mixed cryoglobulinemia or in SVR patients with post-therapy mixed cryoglobulinemia, and C4 levels decreased in CHC patients with mixed cryoglobulinemia, suggested that mixed cryoglobulinemia and HCV infection antagonistically and synergistically decrease C3 and C4 levels, respectively.

Antibody Responses in Hepatitis C Infection

Antibody responses in hepatitis C virus (HCV) have been a rather mysterious research topic for many investigators working in the field. Chronic HCV infection is often associated with dysregulation of immune functions particularly in B cells, leading to abnormal lymphoproliferation or the production of autoantibodies that exacerbate inflammation and extrahepatic diseases. When considering the antiviral function of antibody, it was difficult to endorse its role in HCV protection, whereas T-cell response has been shown unequivocally critical for natural recovery. Recent breakthroughs in the study of HCV and antigen-specific antibody responses provide important insights into viral vulnerability to antibodies and the immunogenetic and structural properties of the neutralizing antibodies. The new knowledge reinvigorates HCV vaccine research by illuminating a new path for the rational design of vaccine antigens to elicit broadly neutralizing antibodies for protection.

Prevalence of cryoglobulinemia and cryoglobulinemic vasculitis in chronically HCV-infected Brazilian patients

INTRODUCTION AND OBJECTIVES

Cryoglobulinemia is one of the most frequent extrahepatic manifestations of chronic hepatitis C virus (HCV) infection and it may evolve to cryoglobulinemic vasculitis (CryoVas) which is a systemic vasculitis that affects small-sized vessels. The objective of this study was to evaluate the prevalence of cryoglobulinemia and CryoVas in HCV patients in São Paulo, Brazil.

MATERIALS AND METHODS

A cross-sectional study was conducted and included sixty-eight viremic HCV patients, without HIV or hepatitis B coinfection. A thorough clinical and laboratory evaluation was performed including the detection of serum cryoglobulins and measurement of serum complement components. The classification criteria for CryoVas were applied.

RESULTS

The study population comprised mainly women (61.8%) with long term HCV infection (median 11.0 years). Advanced hepatic fibrosis was detected in 20.6% (14/68) of cases. Cryoglobulins were detected in 48.5% (33/68) of HCV-patients with type III cryoglobulinemia being the most frequent. CryoVas was present in 10.3% (7/68) and the main manifestations were peripheral neuropathy (85.7%), palpable purpura (42.8%), arthralgias (42.8%) and renal involvement (42.8%). Life-threatening manifestations were rare. Low hemolytic C2, C4 and total hemolytic complement (CH100) levels were common findings in the cryoglobulinemia group. Low C4 levels were independently associated with the development of CryoVas.

CONCLUSION

A high prevalence of cryoglobulinemia and CryoVas was found in Brazilian HCV-patients. CryoVas patients mostly presented non-life-threatening manifestations, especially peripheral neuropathy. Complement abnormalities were common in patients with cryoglobulinemia and low serum C4 levels were associated with CryoVas.

Impact of mixed cryoglobulinemia on patients with spontaneous hepatitis C virus clearance: A 13-year prospective cohort study

BACKGROUND

The prevalence and associations of mixed cryoglobulinemia (MC) in patients with spontaneous clearance of hepatitis C virus (HCV) remain elusive.

MATERIALS AND METHODS

A 13-year prospective cohort study of patients with spontaneous HCV clearance was conducted in a tertiary care centre. Baseline characteristics, incident cardiovascular and neurologic events and cancers were analysed.

RESULTS

Of 104 consecutive patients (mean age: 54.08 years old; females: 71 [68%]), 37 (34.6%) had MC and 6 (5.8%) had cirrhosis. MC (+) patients were more female (86% vs 58%, P = .002), had higher rate of cirrhosis (14% vs 1.5%, P = .012), higher levels of Immunoglobulin G (IgG; P = .001), IgM (P = .002) and fibrosis-4 (FIB-4) (P = .004), but lower levels of complement C4 (P = .034) than the MC (-) patients. Female gender (95% confidence interval [CI] of odds ratio: 1.402-26.715), levels of IgG (1.000-1.004), IgM (1.009-1.037) and FIB-4 (1.217-3.966) were independently associated with MC. Baseline rheumatoid factor (RF) levels were independently associated with incident cancer (95% CI hazard ratio [HR]: 1.001-1.030 [HR: 1.015], P = .039). With a cut-off value of 11.3 IU/mL, RF levels significantly predicted incident cancer (area under curve: 0.865, P = .002). No different cumulative incidences of cardiovascular and neurologic events, cancers or mortalities were identified between MC (+) and MC (-) patient.

CONCLUSIONS

Approximately 1/3 of patients with spontaneous HCV clearance yielded MC, which harboured similar characteristics of MC in patients with chronic hepatitis C. Despite the negligible role of MC in the prognosis of patients with spontaneous HCV clearance, the connection between RF and incident cancer demands further investigation.

Cryoglobulinemic Vasculitis Masquerading as Bilateral Carpal Tunnel Syndrome

Cryoglobulinemic vasculitis (CV) is a systemic inflammatory syndrome involving small- to medium-sized vessels. Almost half of hepatitis C-infected patients have detectable cryoglobulins levels, but only very few develop clinical manifestations. In this case report, we bring forth a diagnostic challenge of CV. A 52-year-old man with untreated hepatitis C (high viral load), diabetes mellitus, hypertension, and chronic kidney disease 4 (CKD) with solitary left kidney presented with one month of bilateral hand pain that started in his right hand, progressed to involve the left with numbness more on the palmer aspects and lateral three fingers. Physical exam was significant for bilateral positive Phalen and Tinel's sign. CV occurs due to precipitation of immune complexes within the vessels. Palpable purpura, arthralgia, and weakness have been described as the core symptoms of CV. However, progressive acute to subacute neuropathy, especially bilateral, should raise concerns for vasculitic neuropathy.

CD5/CD20 expression on circulating B cells in HCV-related chronic hepatitis and mixed cryoglobulinemia

The role of CD5⁺ B cells in patients with HCV infection and HCV-related disorders, including mixed cryoglobulinemia (MC), has been addressed in previous reports with conflicting results. We established a correlation between CD5/CD20 expression on circulating B lymphocytes, characterizing monoclonal B cell lymphocytosis (MBL), and clinical features in a cohort of 45 patients with chronic HCV hepatitis [without MC: 23 patients (MC- group); with MC: 22 patients (MC+ group)], and 45 HCV-negative healthy subjects as controls. By flow cytometry analysis, three B cells phenotypes were singled out: 1) CD5⁺CD20^dim (CLL-like phenotype); 2) CD5⁺CD20^bright (atypical phenotype); and 3) CD5^-CD20⁺ phenotype. CD5⁺CD20^bright cells were reduced in MC- patients (p=0.049). CD5⁺CD20^dim B cells were significantly higher in group B than in the control group (p=0.003). ROC curve analysis in MC+ patients showed the highest positive likelihood ratio at ≥7.35% (p=0.008) for CLL-like phenotype and at ≤63.6% (p=0.03) for the CD5^-CD20⁺ B cell phenotype. HCV infection was associated with a higher frequency of CLL-like (odds ratio=16, p=0.002) and a lower frequency of atypical (odds ratio: 3.1, p=0.02) and CD5^-CD20⁺ (odds ratio: 11, p=0.01) phenotypes. The association with higher levels of CLL-like phenotype progressively increased from group of MC- patients (odds ratio: 9.3, p=0.04) to the group of MC+ patients (odds ratio: 25.1, p=0.0003). CONCLUSIONS: The occurrence of a CLL-like pattern may allow to identify HCV-infected patients at risk of developing MC and eventually non-Hodgkin lymphoma, who should require a closer surveillance and a longer follow-up.

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.

[Chronic hepatitis C virus infection: An internist's opinion (Part 1)]

Hepatitis C virus (HCV) infection results in not only chronic hepatitis and subsequent complications as liver cirrhosis and hepatocellular carcinoma, but also in a significant number of other diseases, the so-called extrahepatic manifestations of chronic HCV infection. This is because of viral hepatotropicity and lymphotropicity. The most striking example of the course of chronic HCV infection, in which the infectious and inflammatory processes are concurrent with autoimmune disorders and carcinogenesis, is mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma. The pathogenesis of these diseases is based on the clonal expansion of B cells, which occurs under their prolonged stimulation with the virus or viral proteins. Part 1 of this review is devoted to the analysis of a correlation of chronic HCV infection with lymphoproliferative and autoimmune disorders, as well as its association with kidney injury.

Interferon-free therapy in hepatitis C virus mixed cryoglobulinaemia: a prospective, controlled, clinical and quality of life analysis

BACKGROUND

Cryoglobulinaemic vasculitis (CV) is a lymphoproliferative disorder related to hepatitis C virus (HCV) infection; anti-viral therapy is the first therapeutic option. CV can be incapacitating, compromising the patients' quality of life (QoL). In a controlled study, interferon-based therapy was associated with a lower virological response in vasculitic patients than in patients without vasculitis. Limited, uncontrolled data on direct-acting anti-virals are available.

AIM

To evaluate safety, clinical efficacy, virological response and the impact of interferon-free treatment on QoL in HCV patients with and without mixed cryoglobulinaemia (MC).

METHODS

We prospectively studied HCV patients with cryoglobulinaemia (with vasculitis-CV- and without vasculitis-MC-) and without cryoglobulinaemia (controls), treated with direct-acting anti-virals. Hepato-virological parameters, CV clinical response and impact on QoL were assessed.

RESULTS

One hundred and eighty-two HCV patients were recruited (85 with CV, 54 with MC and 43 controls). A sustained virological response at 12 weeks (SVR12) was achieved in 166 (91.2%) patients (77/85 CV, 48/54 MC, 41/43 controls). In CV SVR patients, cryocrit levels progressively decreased and clinical response progressively improved, reaching 96.7%, 24 weeks after treatment. QoL, baseline physical and mental component summaries were lower in the CV group compared to the other groups (P < 0.05). Scores improved in all groups, and significantly in CV patients after SVR.

CONCLUSIONS

No significant differences in SVR rates were recorded between cryoglobulinaemic patients and controls and a high clinical and immunological efficacy was confirmed in CV, supporting the role of interferon-free therapy as the first therapeutic option. Interestingly, CV patients had worse baseline QoL than other HCV-positive groups and interferon-free therapy was effective in significantly increasing QoL, suggesting the important role of direct-acting anti-viral-based therapy in improving CV's individual and social burden.

Sofosbuvir-daclatasvir improves hepatitis C virus-induced mixed cryoglobulinemia: Upper Egypt experience

BACKGROUND AND AIMS

Hepatitis C virus (HCV) infection is associated with extrahepatic manifestations such as cryoglobulinemia and accounts for up to 90% of all cases of mixed cryoglobulinemia (MC). The present study aimed to evaluate the effect of sofosbuvir-daclatasvir therapy on symptomatic HCV-related MC and sustained virologic response (SVR) achievement.

PATIENTS AND METHODS

This prospective cohort study was carried out on 120 patients with chronic HCV infection, clinically suspected to have MC, but only 63 of whom were positive for cryoglobulins. HCV-MC patients were treated with sofosbuvir 400 mg and daclatasvir 60 mg once daily for 3 months. The serum cryoglobulins levels, complement 3 (C3), complement 4 (C4) (using ELISA assay kits) and rheumatoid factor (RF) (using immunoturbidimetric assay kit), were measured in the included HCV infected patients (to confirm HCV-MC diagnosis), in addition to quantitave HCV-RNA assays, using real time PCR. All these measurements have been done before stating therapy and 12, 24 weeks post-therapy for assessments of immunological recovery, viral load and SVR.

RESULTS

Significant increase in the serum cryoglobulin levels and RF with significant decrease in C3 and C4 serum levels were detected in only 63 out of 120 included HCV infected patients, upon whom the study has been completed. They showed significant decrease in their mean cryoglobulin levels from 41.47 µg/mL ±12.32 SD to 5.12 µg/mL ±3.59 SD then to 5.09 µg/mL ±3.02 SD, 12 to 24 weeks post-therapy respectively (p<0.001), with significant decline in RF concentrations and rise in C3 and C4 serum levels approaching the normal values. There were improvements in the presenting HCV-MC clinical manifestations in variable degrees, ranging from 5 (71.42%) in patients with glomerulonephritis to 62 (98.4%) in patients with purpura. Eighty-seven percent of the included patients showed complete response (clinical, virological and immunological recovery) and 13% showed partial response (virological and immunological recovery without clinical improvement of cryoglobulinemia associated manifestations).

CONCLUSION

A combined therapy of sofosbuvir 400 mg and daclatasvir 60 mg once daily for 3 months was associated with a significant decrease in serum cryoglobulin levels and appears as a reasonable treatment option for HCV-associated MC.

The Complement System and C1q in Chronic Hepatitis C Virus Infection and Mixed Cryoglobulinemia

The complement system bridges innate and adaptive immunity against microbial infections, with viral infection being a major trigger. Activation of the classical, alternative, and lectin pathways have been reported in chronic hepatitis C virus (HCV) infection and/or cryoglobulinemia. HCV infection leads to dysregulation of complement-mediated immune responses. Clinical and experimental evidence support involvement of complement in intra- and extrahepatic manifestations of HCV infection, such as liver fibrosis and type II cryoglobulinemia. In this review, we summarize studies that have investigated the interplay between HCV and the complement system to establish chronic infection and autoimmunity, as well as the association between HCV pathogenesis and abnormal complement profiles. Several unanswered questions are highlighted which suggest additional informative lines of investigation.

Treatment for hepatitis C virus-associated mixed cryoglobulinaemia

BACKGROUND

Hepatitis C virus (HCV)-associated mixed cryoglobulinaemia is the manifestation of an inflammation of small and medium-sized vessels produced by a pathogenic IgM with rheumatoid factor activity generated by an expansion of B-cells. The immune complexes formed precipitate mainly in the skin, joints, kidneys or peripheral nerve fibres. Current therapeutic approaches are aimed at elimination of HCV infection, removal of cryoglobulins and also of the B-cell clonal expansions. The optimal treatment for it has not been established.

OBJECTIVES

This review aims to look at the benefits and harms of the currently available treatment options to treat the HCV-associated mixed cryoglobulinaemia with active manifestations of vasculitis (cutaneous or glomerulonephritis).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 30 November 2017 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs looking at interventions directed at treatment of HCV-associated cryoglobulinaemic vasculitis (immunosuppressive medications and plasma exchange therapy) have been included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the retrieved titles and abstracts. Authors of included studies were contacted to obtain missing information. Statistical analyses were performed using random effects models and results expressed as risk ratio (RR) or mean difference (MD) with 95% confidence interval (CI). The planned primary outcomes were kidney disease, skin vasculitis, musculoskeletal symptoms, peripheral joint arthralgia, peripheral neuropathies, liver involvement, interstitial lung involvement, widespread vasculitis and death. Other planned outcomes were: therapy duration, laboratory findings, adverse effects, antiviral therapy failure, B-cell lymphoma, endocrine disorders and costs of treatment.

MAIN RESULTS

Ten studies were included in the review (394 participants). None of them evaluated direct-acting antivirals. Seven studies were single-centre studies and three were multicentre. The duration of the studies varied from six to 36 months. The risk of bias was generally unclear or low. Three different interventions were examined: use of rituximab (3 studies, 118 participants); interferon (IFN) (IFN compared to other strategies (5 studies, 223 participants); six IFN months versus one year (1 study, 36 participants), and immunoadsorption apheresis versus only immunosuppressive therapy (1 study, 17 participants).The use of rituximab may slightly improve skin vasculitis (2 studies, 78 participants: RR 0.57, 95% CI 0.28 to 1.16; moderate certainty evidence) and made little of no difference to kidney disease (moderate certainty evidence). In terms of laboratory data, the effect of rituximab was uncertain for cryocrit (MD -2.01%, 95% CI -10.29% to 6.27%, low certainty evidence) and HCV replication. Rituximab may slightly increase infusion reactions compared to immunosuppressive medication (3 studies, 118 participants: RR 4.33, 95%CI 0.76 to 24.75, moderate certainty evidence) however discontinuations of the treatment due to adverse reactions were similar (3 studies, 118 participants: RR 0.97, 95% CI 0.22 to 4.36, moderate certainty evidence).Effects of lFN on clinical symptoms were evaluated only in narrative results. When laboratory parameters were assessed, IFN made little or no difference in levels of alanine transaminase (ALT) at six months (2 studies, 39 participants: MD -5.89 UI/L, 95%CI -55.77 to 43.99); rheumatoid factor activity at six months (1 study, 13 participants: MD 97.00 UI/mL, 95%CI -187.37 to 381.37), or C4 levels at 18 months (2 studies, 49 participants: MD -0.04 mg/dL, 95%CI -2.74 to 2.67). On the other hand, at 18 months IFN may probably decrease ALT (2 studies, 39 participants: MD -28.28 UI/L, 95%CI -48.03 to -8.54) and Ig M (-595.75 mg/dL, 95%CI -877.2 to -314.3), but all with low certainty evidence. One study reported infusion reactions may be higher in IFN group compared to immunosuppressive therapy (RR 27.82, 95%CI 1.72 to 449.18), and IFN may lead to higher discontinuations of the treatment due to adverse reactions (4 studies, 148 participants: RR 2.32, 95%CI 0.91 to 5.90) with low certainty evidence. Interferon therapy probably improved skin vasculitis (3 studies, 95 participants: RR 0.60, 95% CI 0.36 to 1.00) and proteinuria (2 studies, 49 participants: MD -1.98 g/24 h, 95% CI -2.89 to -1.07), without changing serum creatinine at 18 months (2 studies, 49 participants: MD -30.32 μmol/L, 95%CI -80.59 to 19.95).Six months versus one year treatment with IFN resulted in differences terms of the maintenance of the response, 89% of patients in the six months group presented a relapse and only 11% maintained a long-term response at one year, while in the one year group only 78% relapsed and long-term response was observed in 22%. The one-year therapy was linked to a higher number of side-effects (severe enough to cause the discontinuation of treatment in two cases) than the six-month schedule.One study reported immunoadsorption apheresis had uncertain effects on skin vasculitis (RR 0.44, 95% CI 0.05 to 4.02), peripheral neuropathies (RR 2.70, 95%CI 0.13 to 58.24), and peripheral joint arthralgia (RR 2.70, 95%CI 0.13 to 58.24), cryocrit (MD 0.01%, 95%CI -1.86 to 1.88) at six months, and no infusion reactions were reported. However when clinical scores were evaluated, they reported changes were more favourable in immunoadsorption apheresis with higher remission of severe clinical complications (80% versus 33%, P = 0.05) compared to immunosuppressive treatment alone.In terms of death, it was not possible to present a pooled intervention effect estimate because most of the studies reported no deaths, or did not report death as an outcome.

AUTHORS' CONCLUSIONS

To treat HCV-associated mixed cryoglobulinaemia, it may be beneficial to eliminate HCV infection by using antiviral treatment and to stop the immune response by using rituximab. For skin vasculitis and for some laboratory findings, it may be appropriate to combine antiviral treatment with deletion of B-cell clonal expansions by using of rituximab. The applicability of evidence reviewed here is limited by the absence of any studies with direct-acting antivirals, which are urgently needed to guide therapy.

Cryoglobulins: An update on detection, mechanisms and clinical contribution

Cryoglobulins are immunoglobulins precipitating in cold condition. They are classified in 3 types according to the Brouet classification and may lead to vasculitis of small and medium size vessels. Vasculitis is related to vessel obstruction by monoclonal cryoglobulin aggregates in type I cryoglobulins and immune complex deposition in type II and III mixed cryoglobulins. This phenomenon is favored by low temperature, especially in skin, joints, and peripheral nerves, or increased cryoglobulin concentration in kidneys. For their detection, collection and clotting at 37°C are critical pre-analytical conditions. Cryoglobulin characterization and quantification are important to identify the underlying disease. Since detection and identification of cryoglobulins lack standardization, a protocol for such detection, characterization and quantification is proposed.

Effectiveness and cost of hepatitis C virus cryoglobulinaemia vasculitis treatment: From interferon-based to direct-acting antivirals era

BACKGROUND

The net benefits of new hepatitis C virus (HCV) direct-acting antiviral drugs (DAA) in patients with cryoglobulinaemia vasculitis (CryoVas) are unknown.

OBJECTIVE

To analyse the effectiveness and cost of all treatments used for HCV-CryoVas in the DAA vs pre-DAA era.

METHODS

A chart review of all HCV-CryoVas patients who received antivirals from 1993 to 2016 in a tertiary centre was performed. Treatment effectiveness was analysed for clinical, immunological and virological responses. Cost analyses included anti-HCV treatments, non-antiviral drugs, plasmapheresis, dialysis and hospitalizations. We compared main data in the pre-DAA vs DAA period.

RESULTS

About 201 HCV-CryoVas patients were included (women, 53.2%; mean age, 59.2 years; Metavir score F3-F4, 36.7%; genotype 1, 64.2%). Patients in the DAA era (n=27) compared to those in the pre-DAA era (n=174) showed higher rates of clinical (96.3% vs. 78.6%), immunological (89.5% vs. 77.1%), and sustained virological response (75.0% vs. 42.8%). Death rate was 14.8% vs. 24.4% respectively. In the DAA compared to pre-DAA era, mean cost of anti-HCV drugs increased from 11 855 to 57 632 € while mean CryoVas-related cost decreased for both hospitalizations (from 33 510 to 21 347€) and non-antiviral treatments (from 17 347 to 11 397€).

CONCLUSION

Improved antiviral efficacy of HCV drugs in the DAA era led to increased clinical and immunological efficacy and a lower death rate. Use of DAAs was associated to higher costs for HCV drugs while costs related to both hospitalizations and non-antiviral treatments decreased.

Hepatitis C Virus-Associated Aortitis Caused by Type I Cryoglobulins

Chronic hepatitis C virus infection (HCV) can present with cryoglobulinemic vasculitis, which is primarily associated with type II/III cryoglobulins. Type I cryoglobulins are usually seen in lymphoproliferative disease, and large vessel involvement with this type of vasculitis is rare. A 70-year-old man with chronic HCV presented with abdominal pain, leukocytosis, and rash. Computed tomography angiography showed thickening of the abdominal aorta consistent with large-vessel vasculitis. He was found to have type I cryoglobulinemia and was treated with corticosteroids and ledipasvir/sofosbuvir with rapid resolution of his aortitis. This case emphasizes the need to recognize HCV as a potential etiology of large-vessel vasculitis.

Viral-Associated GN: Hepatitis C and HIV

Viruses are capable of inducing a wide spectrum of glomerular disorders that can be categorized on the basis of the duration of active viremia: acute, subacute, or chronic. The variable responses of the adaptive immune system to each time period of viral infection results mechanistically in different histologic forms of glomerular injury. The unique presence of a chronic viremic carrier state with either hepatitis C (HCV) or HIV has led to the opportunity to study in detail various pathogenic mechanisms of viral-induced glomerular injury, including direct viral infection of renal tissue and the development of circulating immune complexes composed of viral antigens that deposit along the glomerular basement membrane. Epidemiologic data show that approximately 25%-30% of all HIV patients are coinfected with HCV and 5%-10% of all HCV patients are coinfected with HIV. This situation can often lead to a challenging differential diagnosis when glomerular disease occurs in this dual-infected population and requires the clinician to be familiar with the clinical presentation, laboratory workup, and pathophysiology behind the development of renal disease for both HCV and HIV. Both of these viruses can be categorized under the new classification of infection-associated GN as opposed to being listed as causes of postinfectious GN as has previously been applied to them. Neither of these viruses lead to renal injury after a latent period of controlled and inactive viremia. The geneses of HCV- and HIV-associated glomerular diseases share a total dependence on the presence of active viral replication to sustain renal injury so the renal disease cannot be listed under "postinfectious" GN. With the new availability of direct-acting antivirals for HCV and more effective combined antiretroviral therapy for HIV, successful remission and even regression of glomerular lesions can be achieved if initiated at an early stage.

Direct-acting antiviral agents in the therapy of hepatitis C virus-related mixed cryoglobulinaemia: a single-centre experience

BACKGROUND

The efficacy and safety of direct-acting antiviral agents (DAAs) were evaluated in a cohort of prospectively enrolled patients with hepatitis C virus (HCV)-related mixed cryoglobulinaemia (MC), an immune complex-mediated vasculitis of small and medium vessels in which the pathogenetic role of HCV has been clearly established.

METHODS

Twenty-two patients received DAAs. Clinical and laboratory features were recorded at baseline, every 4 weeks until the end of treatment (EoT), and 12 weeks afterwards. Primary efficacy endpoints were (a) sustained virological response 12 weeks after therapy completion (SVR12), (b) regression of symptomatology (clinical response) and (c) cryoglobulin disappearance or cryocrit reduction ≥50% (immunological response). Complete response (CR) was defined as the occurrence of all three primary endpoints; partial response (PR) was defined as the occurrence of SVR12, with or without either immunological or clinical response; and no response was defined as missing the achievement of all three endpoints.

RESULTS

All patients reached SVR12. Compared with basal values, mean cryocrit values were significantly decreased at EoT and SVR12. A significant reduction of alanine transaminase and a parallel increase of complement component C4 levels were also detected. Rheumatoid factor activity was significantly reduced at EoT but not at SVR12. At SVR12, a CR was established in 14 patients (63.7%) and a PR in 8 patients (36.3%). In one patient with small lymphocytic lymphoma, the tumour progressed despite viral clearance. Mild adverse events were recorded in nine patients (40.9%).

CONCLUSIONS

The response rates induced by the use of DAAs in patients with MC were remarkably higher than those previously achieved with pegylated interferon-α/ribavirin, with or without rituximab. A much longer follow-up is desirable to achieve useful information in terms of persistent viral clearance and clinical response.

Gastrointestinal aspects of vasculitides

Systemic vasculitides are caused by inflammation of blood vessels and can affect any organ and any part of the gastrointestinal tract, hepatic and biliary system, as well as the pancreas. These disorders can cause a wide array of gastrointestinal manifestations, from asymptomatic elevated transaminase levels and mild abdominal pain to potentially life-threatening bowel perforations and peritonitis. A diagnosis based solely on gastrointestinal symptoms is challenging as these manifestations are not specific. Conversely, diagnostic and therapeutic delays can be rapidly detrimental. In this article, we review the epidemiology, characteristics and management of the main gastrointestinal manifestations of systemic vasculitides, including polyarteritis nodosa and antineutrophil cytoplasm antibody-associated vasculitides, as well as isolated vasculitides limited to the gastrointestinal tract.