Virus-driven autoimmunity and lymphoproliferation: the example of HCV infection

HCV chronic infection is characterized by possible development of both hepatic and extrahepatic manifestations. The infection by this both hepatotropic and lymphotropic virus is responsible for polyoligoclonal B-lymphocyte expansion, leading to several immune-mediated disorders. Mixed cryoglobulinemia syndrome that in some cases may evolve to frank B-cell non-Hodgkin’s lymphoma is the prototype of HCV-driven autoimmune and lymphoproliferative disorders. The HCV oncogenic potential has been suggested by several clinicoepidemiological and laboratory studies; it includes hepatocellular carcinoma, B-cell non-Hodgkin’s lymphoma and papillary thyroid cancer. The definition HCV syndrome refers to the complex of HCV-driven diseases; these latter are characterized by heterogeneous geographical distribution, suggesting a role of other important genetic and/or environmental cofactors. The natural history of HCV syndrome is the result of a multifactorial and multistep pathogenetic process, which may evolve from mild manifestations to systemic autoimmune disorders, and less frequently to malignant neoplasias. The present updated review analyzes the clinical and pathogenetic aspects of the main HCV-associated diseases.     

Systemic sclerosis and cryoglobulinemia: Our experience with overlapping syndrome of scleroderma and severe cryoglobulinemic vasculitis and review of the literature

Objective

Systemic sclerosis (SSc) is an immune-mediated disorder characterized by multiple organ fibrotic alterations and diffuse microangiopathy. The SSc can be associated with other connective tissue diseases and less frequently with systemic vasculitides, including cryoglobulinemic vasculitis (CV). The aim of the present study was to investigate the prevalence of CV in a large series of SSc patients.

Methods

The presence of serum cryoglobulins was detected in 246 SSc patients (24 M and 222 F, age 61 ± 13.5 SD years, disease duration 9.3 ± 6.7 SD years); the observed clinico-serological findings, in particular the presence of SSc–CV overlapping syndrome, were carefully analyzed and compared with previous data reported in the literature.

Results

The presence of circulating cryoglobulins was found in 7/246 (2.8%) of SSc patients; namely, 2 subjects only trace amounts of cryoglobulins, while 5 (2%) showed mixed cryoglobulinemia (type II, IgG-IgMk), low C4, rheumatoid factor seropositivity, and hepatitis C virus infection. Among SSc patients with serum mixed cryoglobulins, 4 (1.6%) developed a clinically overt CV, while the other one was totally asymptomatic with regard to typical vasculitic manifestations. Patients with SSc–CV overlapping syndrome had limited cutaneous SSc with serum anticentromere antibodies, pulmonary hypertension, clinico-serological features of HCV-related CV, and non-healing skin ulcers of the lower limbs. In all cases, the diagnosis of SSc preceded the clinical onset of CV, from 3 to 17 years. The treatment with rituximab was useful on skin ulcers of lower limb in 2/3 patients; however, the overall clinical outcome of the four SSc–CV patients was unusually severe: one with very severe skin ulcers complicated by gangrene required bilateral through-the knee amputation, the other three subjects died because of severe heart failure, and in two cases because of untreatable pulmonary hypertension.In the literature, the prevalence of mixed cryoglobulinemia in scleroderma patients is quite rare (range 0.3–2%); while, the association of SSc with clinically overt CV is only anecdotally described, always in the absence of HCV infection.

Conclusion

The SSc–CV overlapping syndrome described here is characterized by markedly severe vascular manifestations responsible for very poor prognosis; these peculiar clinical manifestations suggest a synergic activity of typical scleroderma microangiopathy and cryoglobulinemic vasculitis.     

Rituximab as a Therapeutic Tool in Severe Mixed Cryoglobulinemia

Type II mixed cryoglobulinemia (MC) is a systemic vasculitis, associated in most cases with hepatitis C virus (HCV) infection, sustained by proliferation of oligoclonal cells. Systemic B cell depletion and clinical remission can be achieved in non-Hodgkin lymphoma by human/mouse chimeric monoclonal antibody that specifically reacts with the CD20 antigen (rituximab). Similar effects could be expected in type II MC. Twelve patients, mean age 61.9 years (range 37–76), 11 with HCV infection genotype 2a2c (4 cases) or 1b (6 cases) and 3 (1 case) and symptomatic type II MC with systemic manifestations, including renal involvement, marrow clonal restriction, large necrotizing ulcers, and polyneuropathy, were considered eligible for rituximab therapy because of resistance or intolerance to conventional therapy or important bone marrow infiltration. Rituximab was administered intravenously at a dose of 375 mg/m² on days 1, 8, 15, and 22. Two more doses were administered 1 and 2 months later. No other immunosuppressive drugs were added. Response was evaluated by assessing the changes in clinical signs, symptoms, and laboratory parameters. Levels of proteinuria, hematuria, erythrocyte sedimentation rate, cryocrit, rheumatoid factor, and IgM decreased while C4 values increased and HCV viral load remained stable during short- and medium-term observation. Bone marrow abnormalities were found to reverse to normal. Constitutional symptoms disappeared or ameliorated. No acute or delayed side effects were seen. Based on this experience and a number of reports published in the last 5 years, Rituximab appears to be a safe and effective therapeutic option in symptomatic patients with HCV-associated MC with signs of systemic vasculitis.     

HCV核心抗原C33肽单克隆抗体的研制与初步鉴定

用ＨＣＶ核心抗原（３３肽）与鼠血清白蛋白交联后免疫ＢＡＬＢ／ｃ小鼠，用杂交瘤技术获得有实用价值的２株ＭｃＡｂ。此两株ＭｃＡｂ除与免疫抗原有较强的抗原－抗体反应外，与ＨＣＶ核心抗原ＣＰ１０也有很好的反应；但与ＨＣＶＮＳ３、ＮＳ５及核心区ＣＰ９抗原无反应性。在竞争ＥＬＩＳＡ中，对抗ＨＣＶ－ＩｇＧ阳性血清有较好的抑制作用。将此两株ＭｃＡｂ用于慢性丙型肝炎病人肝活检免疫组化研究，获得较为满意的结果。     

低剂量利妥昔单抗治疗温抗体型自身免疫性溶血性贫血的系统评价

目的标准剂量利妥昔单抗(RTX)(375 mg/m2/周×4)已成为难治复发温抗体型自身免疫性溶血性贫血(w AIHA)的首选二线治疗。尽管如此,低剂量RTX治疗w AIHA的疗效仍值得探讨。方法通过对PUBMED数据库和CNKI数据库的文献检索,本研究共纳入13项临床研究,对172例患者进行系统评价。结果低剂量RTX(100 mg/周×4)治疗w AIHA总反应率达到87.8%,其中完全缓解(CR)率62.8%,部分缓解(PR)率25%。由于病例数少,各组报道复发率差异较大,从0~62.5%不等,复发后再治疗仍有有效病例报道。无严重不良反应。结论低剂量RTX治疗w AIHA安全有效,不良反应少。     

血清丙型肝炎病毒抗原的免疫酶斑点法检测

目的建立一种可筛查早期HCV感染者的简单快捷方法。方法制备特异性的抗HCV核心蛋白和抗HCVNS3的单克隆抗体(mAb)酶标记物,应用免疫酶斑点法检测各种类型肝炎患者和正常人血清中的HCV-Ag,并与双抗体夹心ELISA检测HCV-Ag及RT-PCR检测HCVRNA的结果进行比较。结果免疫酶斑点法检测表明,HCV-Ag的检出率在抗HCV抗体阳性、乙肝和非甲非戊肝炎患者中,分别为15.4%(8/52)、1.73%(19/1099)和1.03%(1/97);在81例甲肝和67例戊肝患者及50例正常人中均未检出。免疫酶斑点法与双抗体夹心ELISA及RT-PCR的检测的结果没有显著性差异,但其与RT-PCR检测结果有一定的相关性。结论免疫酶斑点法特异性强,操作简便快捷,不需要特殊仪器设备,为HCV的早期诊断和常规筛查提供了有效的方法。     

Cryoprecipitate of patients with cryoglobulinemic glomerulonephritis contains molecules of the lectin complement pathway

Serological and histological studies were carried out to explore the role of the lectin complement pathway in the pathogenesis of cryoglobulinemic glomerulonephritis. Sixteen patients with mixed cryoglobulinemia type II with glomerulonephritis (GN) were enrolled. All cases had hepatitis C virus (HCV) infection. The serum concentration of mannose-binding lectin (MBL) was significantly higher in the GN patients than in the normal controls according to ELISA (P < 0.01). IgG, IgM, C1q, C4d, HCV envelope antigen, MBL, and MBL-associated serine protease-1 (MASP-1) could be visualized in the cryoprecipitate of the 16 patients by Dot blot assay. Renal biopsy specimens obtained from 3 patients were examined by immunohistochemistry, and the glomeruli strongly stained for IgG, IgM, MBL, MASP-1, C4d, C3c, and C3d in a fringe-like pattern. The pattern of HCV constituent deposition was partially fringe-like. The complement profiles of the 16 cases were distinctive; briefly, the serum levels of C1q, C2, and C3 were reduced, although the levels of circulating regulatory proteins (C1-inhibitor, factor H, and factor I) were in the normal range. The serum C4 level was significantly reduced. These results indicate that immune complex formation involves molecules of the lectin pathway and leads to organ damage in cryoglobulinemic glomerulonephritis.     

Antiviral therapy of symptomatic HCV‐associated mixed cryoglobulinemia: Meta‐analysis of clinical studies

Hepatitis C virus (HCV) infection may be associated with extra‐hepatic illness including mixed cryoglobulinemia. Evidence on HCV‐related mixed cryoglobulinemia in the non‐transplantation setting exists even if its appropriate management remains unclear. The cornerstone of treatment for symptomatic HCV‐associated mixed cryoglobulinemia is antiviral therapy but little is known about its activity. A systematic review of the literature with a meta‐analysis of clinical studies was performed in order to assess efficacy and safety of combination antiviral therapy for symptomatic HCV‐associated mixed cryoglobulinemia in non‐immunosuppressed individuals. The random effects model of DerSimonian and Laird was used, with heterogeneity and sensitivity analyses. The primary outcome was sustained virological response (as a measure of efficacy), and the secondary outcome was the rate of patients stopping (or dose reducing) antiviral agents (as a measure of tolerability). Ten clinical studies (300 unique patients) were identified; the rate of baseline kidney involvement ranged between 4% and 39%. The summary estimate of frequency of sustained viral response was 0.42 with a 95% confidence interval (CI) of 0.31; 0.54 (random effects model). Significant heterogeneity occurred (P = 0.00001; I² = 77.6%). Stratified analysis showed higher efficacy in those studies using combination therapy with pegylated—than conventional IFN; the summary estimate of sustained viral response being 0.52 (95% CI, 0.40; 0.63) and 0.32 (95% CI, 0.15; 0.49), respectively. There was good association between viral and clinical response, weighted K 0.634 (95% CI, 0.455; 0.814), by a meta‐analysis at individual level on a subset of reports (n = 3; 74 unique patients). The summary estimate of frequency of patients stopping (or dose reducing) antiviral agents was 0.15 (95% CI, 0.08; 0.21); no heterogeneity occurred (P = 0.05; I² = 51%). In summary, combination antiviral therapy (pegylated IFN plus ribavirin) gives satisfactory response in more than the half of patients with symptomatic mixed cryoglobulinemia associated with HCV. HCV‐related mixed cryoglobulinemia is uncommon in developed countries and this clearly hampers randomized controlled clinical trials aimed to evaluate efficacy and safety of antiviral therapy in non‐immunosuppressed individuals. J. Med. Virol. 85: 1019–1027, 2013. © 2013 Wiley Periodicals, Inc.     

High prevalence of HBV and HCV infection among intravenous drug users in Korea

Although intravenous drug users are a well-known route of hepatitis C virus (HCV) and hepatitis B virus (HBV) transmission, there is no data on the prevalence of HBV and HCV infection among intravenous drug users in Korea. In order to describe the prevalence of HBV and HCV infection, and to determine HCV genotypes in the population, serum samples were collected from 107 intravenous drug users during 2005-2006. Fifty-seven percent (n = 61) were HCV RNA positive and 51% (n = 55) were HBV DNA positive. Co-infection of HBV and HCV were found in 23% (n = 25). HCV genotypes 1b, 2a/2c, 2, 2b, and 3a were found in 38% (n = 23), 44% (n = 27), 8% (n = 5), 2% (n = 1), and 3% (n = 2), respectively. Moreover, mixed infections of genotypes 1b and 2a/2c were found in 5% (n = 3). When the number of patients with HCV genotype 1b compared with that of patients with genotype 2a/2c, HBV DNA titer was not significantly different by independent t-test (t = -0.881, P = 0.392 > 0.05) between the two patient groups. These results suggest that the prevalence of HBV and HCV infection among intravenous drug users is high showing over 50% in Korea and a strategic prevention program should be performed in this group to prevent further infection into local community.     

Clinicopathological features of cryoglobulinemic glomerulonephritis associated with HBV infection: a retrospective analysis of 8 cases in China

Aims: We retrospectively analyzed clinicopathologic features of 8 cases of hepatitis B virus-associated glomerulonephritis with hyaline thrombi, to confirm the diagnosis of cryoglobulinemic glomerulonephritis (CRYGN) associated with HBV infection. Methods: Retrospective analysis was carried out with demographic information, clinical manifestations, laboratory parameters, pathological and prognostic features. Results: The median age of 8 patients was 30.5 years (range, 21-75 years), including 6 males and 2 femles (M:F = 3:1). One patient had Raynaud’s syndrome. Cryoglobulin testing was performed in 4 cases of our series, and 3 cases had elevated cryocrit (>256). Serum C4 decreased in all detected cases. Histopathologically, all cases showed hyaline thrombi occluded in capillary lumina; Co-deposit of IgG, IgM, IgA, Fib, C3d, C4d, C1q, HBsAg and HBcAb were identified in hyaline deposit/hyaline thrombi with polyclonal Igκ and Igλ staining. Ultrastructural examination confirmed the hyaline thrombi to be huge electron-dense bodies, which were a homogeneous texture. Conclusions: The results suggest that 8 cases in the series are CRYGN associated with HBV infection. The incidence of CRYGN associated HBV was extremely low. Our series suggested that prognosis of CRYGN associated HBV was better in patients with mild symptoms, but it was poor in elder patients with severe vasculitis.     

Incidence of HCV infection in French hemodialysis units: a prospective study

A large prospective study was carried out from 1997 to 2000 in 25 French hemodialysis units including 1,323 patients to determine the incidence of hepatitis C virus (HCV) infection. Monthly testing of alanine aminotransferase (ALT) activity, and assessment of HCV RNA and anti-HCV antibodies if the ALT activity was elevated, identified 14 new infections in 7 different units, giving an incidence of 0.4% new HCV infections per year. Molecular analyses and epidemiological data indicated that five patients became infected with HCV outside the unit where they were dialyzed, while the nine remaining patients acquired HCV from infected patients on dialysis during the same shift at the same unit. HCV was cleared in six of the seven (85.7%) patients with acute hepatitis C who were given standard doses of alpha-interferon (alpha-IFN). The persistence of nosocomial transmission of HCV in hemodialysis units emphasizes the need to implement infection control practices. Identifying new infections is crucial because alpha-IFN treatment results in long term clearance of HCV RNA in a large proportion of patients.     

Analysis of antibodies from HCV elite neutralizers identifies genetic determinants of broad neutralization

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B cell activating factor (BAFF) in the natural history of chronic hepatitis C virus liver disease and mixed cryoglobulinaemia

B cell activating factor (BAFF) plays a crucial role in the process of development, maturation and activation of B lymphocytes. Chronic hepatitis C virus (HCV) infection is characterized by multiple B cell disorders. It is a major cause of type II mixed cryoglobulinaemia (MC). We measured serum BAFF levels in several clinical situations to elucidate the potential role of BAFF in chronic HCV infection. We used a commercially available solid phase enzyme-linked immunosorbent assay. We estimated serum BAFF in stored sera from uninfected controls (n = 8), patients with chronic hepatitis B virus infection HBV (n = 5) and chronic HCV infection with (n = 16) and without mixed cryoglobulinaemia (n = 14). In two patients with HCV and MC we correlated BAFF with HCV RNA after pegylated interferon (peg-I). We correlated serum BAFF levels at baseline and at 12 weeks with treatment response: sustained virological response SVR (n = 5), non-responders (n = 6) and relapsers (n = 2). Finally, we estimated BAFF levels after complete depletion of B cells with rituximab in patients with chronic HCV with MC (n = 3). Serum levels of BAFF were increased in chronic HCV with MC, but not in chronic HBV infection, suggesting an association between BAFF and cryoglobulinaemia. Peg-I increased BAFF levels in serum and this paralleled HCV RNA very closely. Serum BAFF levels at week 12 of therapy with peg-I and R were significantly higher in responders than non-responders. Finally, B cell depletion was associated with markedly increased levels of BAFF.     

Factors predisposing to the occurrence of cryoglobulinemia in two cohorts of Egyptian and Japanese patients with chronic hepatitis C infection: ethnic and genotypic influence

The association between cryoglobulinemia and hepatitis C virus (HCV) infection has been reported. However, the factors underlying its wide variation of occurrence have not yet been well identified. To investigate this, cryoglobulinemia was studied in four cohorts of Egyptian and Japanese patients. Fifty Egyptian patients with chronic hepatitis C, infected with genotype 4 (the predominant HCV genotype in Egypt), were compared with 50 age- and sex-matched Japanese patients, infected with HCV genotype 1b (the predominant HCV genotype in Japan). Thirty-two Egyptian and 30 age- and sex-matched Japanese patients with chronic hepatitis B were included as controls. All patients were noncirrhotic. Antinuclear antibody (ANA), immunoglobulins (Ig), and cryoglubulins were assessed. Results showed a significantly higher prevalence of cryoglobulinemia in chronic hepatitis C Japanese genotype 1b (40%) as compared with Egyptian genotype 4 (14%), P = 0.003, while no difference was found between Japanese (17%) and Egyptian chronic hepatitis B controls (13%). Symptomatic cryoglobulinemia was more prevalent in the Japanese than in the Egyptian chronic hepatitis C group (10% vs. 4%), but the difference was not statistically significant. Univariate analysis showed no association between cryoglobulinemia and either age, sex, alanine aminotransferase level, or HCV viral load in Japanese or Egyptian patients, while the mean IgM level was significantly higher in the cryoglobulin-positive than in the cryoglobulin-negative chronic hepatitis C patients in each group (P = 0.003 and 0.017, respectively). Cryoglobulinemia was found to be significantly associated with both high IgG level (P = 0.020), and positive ANA (P < 0.001) in Japanese patients with chronic hepatitis C, genotype 1b but not in Egyptians with genotype 4. Multivariate analysis showed that the only factors predisposing to cryoglobulinemia were Japanese ethnicity with HCV genotype1b (P = 0.002, OR = 2.56), high IgM level of >245 mg/dl (P = 0.018, OR = 2.05) and female gender (P = 0.040, OR = 1/0.66). In conclusion, cryoglobulinemia is prevalent in Japanese patients with chronic hepatitis C infected with genotype 1b, but cryoglobulinemia is not common in Egyptians with HCV genotype 4. Although it was not possible to evaluate ethnicity and HCV genotype separately in this study, HCV genotype 1b appears to predispose more to cryoglobulinemia than does genotype 4. Female gender and high serum IgM level were also related.     

Clinical significance of hepatitis C viral RNA status and its correlation to antibodies to structural HCV antigens in anti-HCV reactive patients with normal liver tests

Extensive serological testing and HCV RNA determination by RT-PCR was performed in serum, PBMCs, and liver tissue in thirteen anti-HCV reactive patients with persistently normal liver tests. Absolute concordance in the status of HCV RNA between serum, PBMCs, and liver was noted. Five patients were HCV RNA positive but only three had mild histological changes. Eight patients were HCV RNA negative in all three sites and had virtually normal liver histology. Patterns of reactivity in RIBA™ 2.0 strip immunoblot assay did not differentiate viremic from nonviremic patients. ELISA testing using multiple individual HCV recombinant antigens from the structural and non-structural regions of HCV demonstrated mean antibody titers to the structural antigens, in particular HCV E2 antibodies, to be significantly lower in HCV RNA negative patients. The status of HCV RNA in the serum appears to infer the status of HCV RNA in the liver and PBMCs in patients with persistently normal liver tests. Patients with persistently normal liver tests and undetectable HCV RNA have probably spontaneously cleared HCV infection. © 1996 Wiley-Liss, Inc.     

Relationship between the hepatitis C viral load and the serum interferon concentration during the first week of peginterferon‐alpha‐2b‐ribavirin combination therapy

In chronic hepatitis C virus (HCV) infections, the current standard of care (combination therapy with pegylated alpha interferon (PEG‐IFNα) and ribavirin) is only effective in around 50% of cases. The aim of the present study was to analyze the relationship between the HCV load and the PEG‐IFN concentration during the first week of treatment. Fifteen treatment‐naive patients with chronic hepatitis C infection (genotypes 1, 2, 3, and 4) underwent PEG‐IFNα‐2b/ribavirin combination therapy. Blood samples were collected before the first injection (T₀) and then at different time points until the next injection a week later. The PEG‐IFN concentration and the HCV load were assayed. The serum interferon concentration peaked 2 days after the first injection (mean value for the study population; T_max = 40.9 hr; C_max = 490 pg/ml) and a trough in viral load was seen at day 3. The PEG‐IFNα‐2b concentration decreased from day 2 to day 7, enabling a viral rebound in all patients. The change in viral load between day 0 and day 3 differed significantly according to whether the patients were responders at week 12 (Δlog d₀/d₃ = 2.729 ± 1.419 log₁₀ IU/ml) or not (Δlog d₀/d₃ = 1.102 ± 0.472 log₁₀ IU/ml). Our results emphasize the potential clinical importance of achieving viral decay immediately after initiation of interferon–ribavirin combination therapy. J. Med. Virol. 82:1640–1646, 2010. 2010 Wiley‐Liss, Inc.     

HCV infection in a patient with hyper-IgM syndrome

The association between an acquired form of hyper-IgM syndrome and a chronic hepatitis C virus (HCV) infection in a 71-year-old female patient is described. Both diseases were diagnosed at the age of 58 years. She was started on intramuscular and then intravenous immunoglobulin replacement therapy. HCV RNA was detected in 1992. The patient remained in well-balanced clinical condition until 1994, when total and specific anti-HCV IgM levels increased and the patient developed an IgM monoclonal gammopathy. Adherent cells and B cells were HCV RNA positive, while T cells were HCV RNA negative. Anti-IgM reactivity was specifically directed to the core antigen of the HCV. The patient we describe showed a picture of a late-onset form of hypogammaglobulinemia with a progressive increase in IgM antibodies, possibly due to the concomitant HCV infection. It is possible that the immunodeficiency might also result from the HCV infection, with formation of specific antibodies belonging to the IgM class, and that the worsening of the clinical condition may be directly related to the persistent viral infection.