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Hepatitis C virus and lymphoma Semra Paydas ∗ Cukurova University, Faculty of Medicine, Dept of Oncology, 01330 Adana, Turkey Accepted 14 October 2014
Contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the most common extra-hepatic manifestation of HCV? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is risk of NHL in cases with HCV? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Which test is more useful to determine the prevalence of HCV in cases with lymphoma? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the route of HCV transmission? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the pathogenetic role of HCV in NHL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the clinical/pathological/genotypic properties of HCV related NHL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anti-viral treatment for HCV associated NHL: when and whom? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Management of DLBCL associated with HCV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potential benefits/harms of rituximab and anti-viral using in cases with HCV associated NHL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reviewers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Abstract Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus and is a global health problem. Cirrhosis and hepatocellular cancer are the most common complications of HCV. Association between HCV and B cell non-Hodgkin lymphomas (B-NHL) has been shown in epidemiological studies in the last 20 years. High prevalence of HCV infection among patients with NHL has been reported in the early 1990s by Ferri in Italy and this association has been confirmed in later studies. Geographically, HCV related NHL is highly variable and chronic rather than cleared HCV infection is required for lymphomagenesis. Although anti-HCV antibody test is the most commonly used technique in epidemiological studies, HCV-RNA is more useful test to detect the association between HCV and NHL. The optimal management of HCV related NHL is not clear. However, anti-viral treatment may be sufficient for cases with low grade and/or asymptomatic lymphomas, while immuno-chemotherapy is necessary, in spite of probable hepatic toxicity, in cases with high grade lymphomas. © 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Lymphoma; HCV; Aggressive/indolent lymphoma; HCV prognostic score; Sustained viral response; Rituximab, Immuno-chemotherapy
1. Introduction Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus [1,2] HCV is a global health problem ∗
Tel.: +90 322 3386060 3142; fax: +90 322 3387320. E-mail address: [email protected]
affecting 3% of the world population and 180 million people are infected with HCV [3,4]. Cirrhosis and hepatocellular cancer are the most common complications of HCV [5]. However, HCV related health problems are not limited to the liver, hematological problems like type II mixed cryoglobulinemia (MC) or B-NHL may be seen in cases infected with HCV. In the last 20 years epidemiological studies have shown
http://dx.doi.org/10.1016/j.critrevonc.2014.10.008 1040-8428/© 2014 Elsevier Ireland Ltd. All rights reserved.
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a relationship between B-NHL and HCV. MC is the most commonly documented extrahepatic disorder in cases with HCV. Strong associations between HCV and MC have been shown to exist using serological and molecular techniques [6–8]. The biologic rational for an etiological relationship between HCV and B-NHL is based on epidemiological data and clinical observations [9]. High prevalence of HCV infection among patients with NHL has been reported in the early 1990s by Ferri et al. [10]. Geographically, HCV related NHL is highly variable. In a systematic review, prevalence of HCV infection has been evaluated among over 6000 cases in Europe, America and Asia. High HCV prevalence has been found especially in Southern and Eastern Europe, Japan and Southern United States. This is due to different HCV prevalence in these countries, ranging from 1–2% to more than 10% [11]. It is clear that chronic rather than cleared HCV infection is required for lymphomagenesis and chronic antigenic stimulation driven by chronic infection leads to lymphoma [12]. For this reason HCV-RNA is a more useful test to detect the association between HCV and NHL.
2. What is the most common extra-hepatic manifestation of HCV? The associatıon between HCV and NHL has been described firstly by Pozzatto and Ferri [13,14]. Large number of studies reported by Mele, Duberg and Anderson confirmed the Italian studies [15–17]. Very high prevalence of (as high as 100%) HCV has been found in type II MC [18]. Although only a minority of the HCV (+) patients show symptomatic MC, for example vasculitis, the circulating cryoglobulin reach up to 50% of the infected patients [19]. Epidemiologic studies on HCV-MC show large differences in the geographic distribution: higher prevalence in Southern Europe compared with Northern Europe or USA. It is clear that the presence of mixed cryoglobulin in HCV (+) patients may increase the risk for NHL. A thirty-five fold increased risk for NHL has been shown in HCV (+) patients with symptomatic MC in a multicenter Italian study [20]. Approximately 8–10% of patients with HCV-MC progress to overt NHL. Even after HCV eradication, HCV-MC patients may remain at increased risk to develop B-NHL [21].
3. What is risk of NHL in cases with HCV? In the last 20 years etiologic association between HCV and NHL has been reported in many studies. At the beginning in epidemiologic studies, it has been found a strong association between HCV and indolent lymphoma, but later studies have shown also increased risk for aggressive lymphoma. The most common association between HCV and NHL has been reported from Italy. In two of these studies, a three fold increased risk of low grade lymphoma has been reported [15,22]. Four fold increased risk of follicular
lymphoma has been reported from US [23]. Goldman from Egypt reported 4.4 and 3.3 fold increased risk for marginal zone lymphoma and follicular lymphoma, respectively [24]. Interestingly, a 5.2 fold increased risk of lymphoplasmacytic lymphoma has been reported from Denmark [25]. Additionally, DANVIR cohort study from Denmark showed 29.97 fold increased risk of NHL during first year of follow up [26]. Although the HCV related NHLs seem to be lower in countries with lower HCV prevalence, long-term cohort studies showed again higher prevalence of HCV related NHL in some countries. Striking geographic variation about HCV and NHL suggests that genetic and/or environmental factors are involved in the pathogenesis. For these reasons large scale studies and meta analyses have been performed and reported. However, studies showing strong associations between HCV and NHL have been included in these meta-analyses for example Italy, Egypt and Japan [24,27,28]. On the other hand there is a strict difference for HCV prevalence between Northern and Southern countries of Europe; HCV prevalence is 0.1–1%, 0.2–1.2% and 2–5% in Northern, Central and Southern Europe, respectively [9,29]. Some theories have been proposed to explain the geographic differences in the association of HCV with B-NHL: (1) Differences in the HCV carrier population with Northern European countries in which transmission is via intravenous drug use. Transmission, however, is mixed in Southern Europe: intravenous drug abuse in younger and iatrogenic transmission is more frequent in olders. (2) Long lasting infection in Southern sites may be a cause for the development of NHL. (3) There is controversy about the NHL occurrence and certain genotypes have not been included in low prevalence countries. (4) Most importantly patients with low grade lymphoma cases had longer duration of viral infection while patients with diffuse large B cell lymphoma (DLBCL) had a shorter duration of infection [3,30]. There are three meta-analyses about HCV associated NHL. First, analysis has been published in 2003 and HCVMC, 43 studies and 5542 cases have been included in this report. OR has been found to be 10.8. It has been found an association between lymphoplasmacytic lymphoma subtype and mean HCV prevalence has been found to be 13% in cases with NHL [18]. In this analysis, in 10 case-control studies, HCV prevalence has been found to be 17% and 1.5% in cases with NHL and healthy controls, respectively [31,20]. Second, meta-analysis has been published by Matsuo [32]. In this analysis 23 studies and 4049 cases and 1.813.480 controls have been included and OR has been found as 5.7. In this meta-analysis lymphoma cell type and HCV relationship has been evaluated and it has not been found an association between HCV and lymphoma subtype [32]. Third, meta-analysis has been published by Dal Maso [33]. Fifteen case-control and three prospective studies and 4678 cases
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Table 1 Meta-analyses and International extranodal lymphoma consortium results about NHL risk in patients with HCV. Author
Publication year
Number of studies
Number of cases
OR for NHL
OR for NHL subtype
Reference
Gispert Matsua Dal Maso International extranodal lymphoma consortium
2003 2004 2006 2008
43 23 18 7
5542 4049 4678 4784
10.8 5.7 2.5 1.78
LPL No association No association LPL: 2.99MZL:2.47DLBCL:2.24
[18] [32] [33] [34]
Abbreviations: OR, odds ratio; NHL, non-Hodgkin lymphoma; LPL, lymphoplasmacytic lymphoma; MZL, marginal zone lymphoma; DLBCL, diffuse large B cell lymphoma.
have been included in these analysis. Relative risk has been found as 2.5 and again no difference was found between lymphoma subtypes in this report [33]. Pooled analysis of data from the International Lymphoma Epidemiology Consortium covered 7 studies and 4784 cases and indicated a 1.78 fold increased risk of NHL. HCV infection has been detected in 172 NHL cases (3.6%) and 169 controls (2.7%) and OR has been found as 2.99 for lymphoplasmacytic lymphoma, 2.47 for marginal zone lymphoma, and 2.24 for DLBCL [34]. Table 1 shows the results of the three meta-analyses and extranodal lymphoma epidemiology consortium for NHL risk in cases with HCV. In a report, subgroups of NHL have been evaluated and no clear association has been found between HCV and BNHL subtypes either indolent or aggressive [35]. However, some case-control studies showed higher risk of aggressive lymphomas compared to indolent lymphomas. Morton et al. recently published an interesting analysis. They investigated HBV, HCV and risk of NHL in solid organ transplant receivers and they found that hepatitis viral infection status at the time of transplantation was not related with NHL risk [36].
4. Which test is more useful to determine the prevalence of HCV in cases with lymphoma? An important point for different results for the association between HCV and NHL is the method used to determine the HCV infection. The detection of HCV antibodies without HCV-RNA analysis may underestimate the true rate of HCV infection in patients with NHL. This is due to the abnormal HCV antibody response both quantitatively and qualitatively in cases with NHL [37]. We performed three studies to detect the prevalence of HCV in Turkey. In our first study, anti-HCV antibody prevalence was evaluated in 228 cases with lymphoproliferative disorders. Nine of 98 cases with NHL had anti-HCV antibody and prevalence was found to be 10% [38]. In our second study, anti-HCV antibody was studied in 223 cases and we found anti-HCV positivity in 18 cases (8.1%). This prevalence was compared with donor population and OR and corrected OR were found to be 34.56 and 19.07, respectively. Additionally, HCV-RNA was studied in 67 of
these 223 samples. In this study HCV-RNA was detected in 21 of these cases (31.3%). This and some other studies suggested that HCV-RNA is more beneficial for the detection of HCV infection in these immune-suppressed cases [39–43]. In our third study, RT-PCR was used to detect the HCV-RNA both in serum and tissue samples. HCV-RNA was detected in 11 of 30 tissue samples (37%) while HCV-RNA and anti-HCV antibody were detected in only 7 (23.3%) and 3 (10%) serum samples of these 30 cases, respectively [44]. In another study considering HCV-RNA, HCV prevalence was found to be associated with diffuse large B cell lymphoma (OR: 2.19) and HCV-RNA was found to be more frequently associated with NHL than anti-HCV antibodies. This finding is related with impaired antibody production in these cases [12]. In a population based study from US, HCVRNA was found in 3.9 and 2.1% of the patients and controls, respectively and it has been found 2.46 fold increased risk for follicular lymphoma, 3.99 fold increased risk for marginal zone lymphoma and 2.04 fold increased risk for MALT lymphoma [45]. No relationship was found between anti-HCV antibodies and increased risk of NHL (OR: 2.2) in a casecontrol study from a Danish–Swedish population. Analysis restricted to HCV-RNA indicated that OR was 1.7 in this population [25]. In another Swedish study increased risk of NHL was found to be restricted to only HCV-RNA positive cases [26]. Serum samples from eight European countries, between 1998 and 2004, HCV-RNA positivity was found to be related with 1.42 fold increased risk of NHL. This was lower than the studies which HCV detected by anti-HCV antibody [12].
5. What is the route of HCV transmission? HCV is a single stranded RNA virus without DNA intermediate in its replicative cycle, so integration of HCV nucleic acid sequences into host genome seems unlikely. Therefore, it cannot be considered a typical oncogenic virus but it can exert its oncogenic potential indirectly by contributing to the modulator effects of the host immune system [46,47]. In fact, viral transmission routes are important in the development of NHL related HCV. Intravenous drug use transmission is the predominant route among
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Fig. 1. Pathogenesis of HCV related lymphoproliferative disorders. Reprinted from reference [56].
younger population in the Northern countries while iatrogenic transmission is important in older population in the Southern countries [48].
6. What is the pathogenetic role of HCV in NHL? It has been suggested that HCV can exert a chronic stimulus on the immune system, which facilitates the development and selection of abnormal clones and this scenario looks like the role of H Pylori for MALT lymphomas [49]. The regression of HCV related B-NHL following anti-viral treatment represents the etiologic association between HCV and lymphomas. It has been reported complete or partial responses after anti-viral therapy in HCV (+) cases but not in HCV (−) patients [9,50–52]. In early 1990s, HCV-RNA has been demonstrated in serum/plasma and liver tissues and also in peripheral blood mononuclear cells of patients with HCV [53,54]. Peripheral blood cells serve as reservoirs for persistent HCV infection. Long lasting HCV infection in B cells may cause to lymphoproliferative disorders [55]. It has been proposed that sustained antigenic stimulation of B cell compartment has a role in viral lymphotrophism [56]. Fig. 1 shows the steps for lymphomagenesis after antigenic stimulation. Viral lymphotropism has been suggested with the presence of viral replication in lymphatic cells [53]. HCV infection in bone marrow has been shown by Galli in 100% and 43% of the patients with or without MC, respectively [57]. It has been shown that HCV-E2 protein interacts with CD81
which is also present on the B cell surface. This binding is responsible for sustained polyclonal B cell activation lowering the B cell activation threshold [58,59]. Fig. 2 shows the role of connections between HCV proteins, CD81-E2, chromosomal aberrations, apoptotic inhibition, cytokines and chronic antigenic stimulation. HCV-CD81 interaction plays a central role for virus adaptation to the human host [59]. Lai used an in vitro model for HCV infection in B cell and showed the enhanced mutation rate of Ig genes [60]. The study showed the dramatically increased copy of activation induced cytidine deaminase (AID) in the B cells in HCV infected patients. HCV enhances AID expression by NFKB activation through the expression of viral core proteins. It has been found 100 fold increased levels of AID mRNA levels in CD19 (+) cells. This finding shows that HCV infects peripheral blood CD19 (+) cells and this is the reservoir during HCV infection in humans: suggesting HCV infects and may replicate in B cells [61]. These findings suggest that inappropriate expression of AID acts as a DNA mutator which enhances genetic susceptibility to mutagenesis [55]. Fig. 3 shows the role of activation induced cytidine deaminase (AID) in the B cells in HCV infected patients. This finding suggests that AID activation may be a factor in the lymphomagenic process mediated by HCV. Also significantly higher expression of several lymphomagenesis related genes have been shown in patients with HCV [19]. In transgenic mice expressing the full HCV genome in B cells was established by Tsuhiyama and 25% incidence of diffuse large B cell lymphoma within 600 days of birth was shown [62]. Oncogenic potential and lymphotrophism of different HCV genotypes are variable
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Fig. 2. The role of connections between HCV proteins, CD81-E2, chromosomal aberrations, apoptosis inhibition, cytokines and chronic antigenic stimulation. Reprinted from reference [56].
Fig. 3. The role of activation induced cytidine deaminase (AID) in the B cells in HCV infected patients. Reprinted from reference [55].
and results are conflicting [63–66]. Although HCV does not directly transform human B cells in vitro, transgenic mice expressing the full HCV genome in B cells spontaneously develop B cell lymphomas in vivo [67]. The most commonly investigated genetic aberration is t(14:18) and this is associated with type II or monoclonal MC. The presence of this translocation in MC has been found to be correlated with the overexpression of the anti-apoptotic Bcl-2/Bax ratio. Abnormal B cell clones following effective anti-viral treatment and in some cases a new expansion of the same clones have been shown [68]. Aneuploidy and chromosomal instability and reduced expression of retinoblastoma have been reported in HCV-infected patients [69,70]. Some cytokines and chemokines including CXCL10, CXCL13 are important in B cell trafficking and have been found to be increased in serum of MC patients [26]. High levels of B cell activator factor (BAFF or BLyS) is essential for B cell development/survival and has been found to be higher in HCV patients with lymphoproliferative disorders [71].
Recently Ng et al. looked for B cell receptors expressed by HCV associated lymphomas and interestingly they found that these lymphomas use a restricted immunoglobulin variable region gene repertoire. Also they found no evidence for their binding to the HCV antigens. With these results they suggested that most of the HCV associated lymphomas do not arise from B cells eliminating the virus [72]. It is very well known that miRNAs are important in pathogenesis of many malignant and inflammatory disorders. Among miRNAs, miR-26b has been shown to be downregulated in HCV (+) lymphomas as compared to HCV (−) splenic marginal zone lymphomas. This finding suggests a possible speculative mechanism in malignant lymphoma [45]. Additionally, in recent times it has been shown the possible contribution of NF-KB signaling and down regulation of miR-26b in the development of HCV associated B cell lymphomas in transgenic mice [73]. miRNA profile has been studied in HCV associated DLBCL in a comprehensive study and has been found decreased expression of miR-138-5p and increased expression of miR-147-a, miR-147b and miR-5115p and these alterations have been found to be poor prognostic factors in HCV related DLBCL [74]. These results suggest that miRNA profiles are related with clinical and pathological parameters and have a potential for therapeutic opportunity in HCV associated with DLBCL in near future. In summary as proposed for the last two decades, sustained HCV-driven antigenic stimulation plays a key role in inducing B cell clonal expansion and indicates a mechanism of HCV-related lymphomagenesis. Lymphatic follicles in the
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liver in HCV infection is the main site for B cell clonal expansion [75]. Intra-hepatic B cell clones are associated with extrahepatic manifestations of HCV. During the multi-step lymphomagenic process, chromosomal aberrations and other genetic aberrations occur [76].
7. What is the clinical/pathological/genotypic properties of HCV related NHL? It is not clear which lymphoma subtype is more prevalent in cases with HCV infection. The most frequently described subtypes are marginal zone lymphoma especially splenic marginal zone lymphoma, lymphoplasmacytic lymphoma and DLBCL [77]. Clinical data of patients with HCV related lymphoma is variable in different series. In some series more aggressive behavior, including extranodal involvement, higher LDH, and older age have been found to be increased in HCV related lymphoma, but other studies did not find such relationship [30,78–85]. Liver involvement was more common in patients with active infection and was seen in one fourth of the cases with hepatitis or cirrhosis at diagnosis. This finding suggests that active viral infection may be related with lymphomagenesis in the liver [78]. In some series, splenomegaly was found to be more frequent as compared to HCV (−) patients. The cause of this finding was portal hypertension due to impaired liver circulation in HCV infected patients. The other cause may be related with transformation from marginal zone lymphoma. An important point is the association between HCV genotypes and B-NHL. In most studies, no link has been found between specific viral genotypes and B-NHL. However, we know that this point has not been addressed in many of the studies and in some of these studies association has been evaluated more carefully [35]. Genotype II has been found to be important for the development of lymphoma [83]. In another study genotype Ib has been found to be most prevalent subtype and OR for the development of NHL has been found as 4.2 while OR was 2.9 for whole group [12]. Luppi documented an unexpectedly lower prevalence of HCV genotype 1b/3 in patients with B-NHL. In contrast the prevalence of genotypes 2a/3 and 2b/4 were found to be higher in B-NHL [84]. These findings suggest that some HCV genotypes are more lymphomagenic. Another interesting point is the duration of HCV infection and subtype of lymphoma. Pallicelli reported a higher prevalence of genotype 1 and shorter duration of HCV infection in cases with DLBCL as compared to higher prevalence of genotype 2 and longer duration of HCV infection in patients with indolent-low grade lymphoma. It is known that HCV genotype 2 is related with longer duration of viral infection. It has been speculated that it may induce a persistent chronic immune-stimulation of B cells over time. In contrast, direct lymphocyte transformation for HCV genotype 1 in aggressive lymphomas may occur on the basis of the shorter duration of viral exposure [79].
8. Anti-viral treatment for HCV associated NHL: when and whom? Anti-viral treatment (AVT) has been found to be effective in low grade lymphomas. Interestingly HCV infected patients treated by interferon and achieved sustained viral response (SVR) had a lower rate of lymphoma than who had not received AVT. This finding suggests that AVT may be preventive for lymphomagenesis in HCV infected patients. New anti-viral drugs may be attractive at this situation [85,86,87,88]. Subcutaneous pegylated intereferon alpha 2a, 180 g weekly plus oral ribavirin (800, 1000 and 1200 mg daily dose have been recommended for patients 85 kg, respectively) is the therapy of choice in these cases. Erythropoietin alpha 2a 40.000 IU weekly subcutaneously has been added in cases if hemoglobin level decreased by more than 2 g. Duration of treatment has been recommended as 1 year in patients HCV genotype 1 or 4, and 6 months for patients genotype 2 or 3. Definition of response to anti-viral treatment is important: SVR has been defined as HCV RNA negativity (
ARTICLE IN PRESS
Critical Reviews in Oncology/Hematology xxx (2014) xxx–xxx
Hepatitis C virus and lymphoma Semra Paydas ∗ Cukurova University, Faculty of Medicine, Dept of Oncology, 01330 Adana, Turkey Accepted 14 October 2014
Contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the most common extra-hepatic manifestation of HCV? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is risk of NHL in cases with HCV? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Which test is more useful to determine the prevalence of HCV in cases with lymphoma? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the route of HCV transmission? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the pathogenetic role of HCV in NHL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What is the clinical/pathological/genotypic properties of HCV related NHL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anti-viral treatment for HCV associated NHL: when and whom? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Management of DLBCL associated with HCV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potential benefits/harms of rituximab and anti-viral using in cases with HCV associated NHL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reviewers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
00 00 00 00 00 00 00 00 00 00 00 00 00
Abstract Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus and is a global health problem. Cirrhosis and hepatocellular cancer are the most common complications of HCV. Association between HCV and B cell non-Hodgkin lymphomas (B-NHL) has been shown in epidemiological studies in the last 20 years. High prevalence of HCV infection among patients with NHL has been reported in the early 1990s by Ferri in Italy and this association has been confirmed in later studies. Geographically, HCV related NHL is highly variable and chronic rather than cleared HCV infection is required for lymphomagenesis. Although anti-HCV antibody test is the most commonly used technique in epidemiological studies, HCV-RNA is more useful test to detect the association between HCV and NHL. The optimal management of HCV related NHL is not clear. However, anti-viral treatment may be sufficient for cases with low grade and/or asymptomatic lymphomas, while immuno-chemotherapy is necessary, in spite of probable hepatic toxicity, in cases with high grade lymphomas. © 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Lymphoma; HCV; Aggressive/indolent lymphoma; HCV prognostic score; Sustained viral response; Rituximab, Immuno-chemotherapy
1. Introduction Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus [1,2] HCV is a global health problem ∗
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affecting 3% of the world population and 180 million people are infected with HCV [3,4]. Cirrhosis and hepatocellular cancer are the most common complications of HCV [5]. However, HCV related health problems are not limited to the liver, hematological problems like type II mixed cryoglobulinemia (MC) or B-NHL may be seen in cases infected with HCV. In the last 20 years epidemiological studies have shown
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a relationship between B-NHL and HCV. MC is the most commonly documented extrahepatic disorder in cases with HCV. Strong associations between HCV and MC have been shown to exist using serological and molecular techniques [6–8]. The biologic rational for an etiological relationship between HCV and B-NHL is based on epidemiological data and clinical observations [9]. High prevalence of HCV infection among patients with NHL has been reported in the early 1990s by Ferri et al. [10]. Geographically, HCV related NHL is highly variable. In a systematic review, prevalence of HCV infection has been evaluated among over 6000 cases in Europe, America and Asia. High HCV prevalence has been found especially in Southern and Eastern Europe, Japan and Southern United States. This is due to different HCV prevalence in these countries, ranging from 1–2% to more than 10% [11]. It is clear that chronic rather than cleared HCV infection is required for lymphomagenesis and chronic antigenic stimulation driven by chronic infection leads to lymphoma [12]. For this reason HCV-RNA is a more useful test to detect the association between HCV and NHL.
2. What is the most common extra-hepatic manifestation of HCV? The associatıon between HCV and NHL has been described firstly by Pozzatto and Ferri [13,14]. Large number of studies reported by Mele, Duberg and Anderson confirmed the Italian studies [15–17]. Very high prevalence of (as high as 100%) HCV has been found in type II MC [18]. Although only a minority of the HCV (+) patients show symptomatic MC, for example vasculitis, the circulating cryoglobulin reach up to 50% of the infected patients [19]. Epidemiologic studies on HCV-MC show large differences in the geographic distribution: higher prevalence in Southern Europe compared with Northern Europe or USA. It is clear that the presence of mixed cryoglobulin in HCV (+) patients may increase the risk for NHL. A thirty-five fold increased risk for NHL has been shown in HCV (+) patients with symptomatic MC in a multicenter Italian study [20]. Approximately 8–10% of patients with HCV-MC progress to overt NHL. Even after HCV eradication, HCV-MC patients may remain at increased risk to develop B-NHL [21].
3. What is risk of NHL in cases with HCV? In the last 20 years etiologic association between HCV and NHL has been reported in many studies. At the beginning in epidemiologic studies, it has been found a strong association between HCV and indolent lymphoma, but later studies have shown also increased risk for aggressive lymphoma. The most common association between HCV and NHL has been reported from Italy. In two of these studies, a three fold increased risk of low grade lymphoma has been reported [15,22]. Four fold increased risk of follicular
lymphoma has been reported from US [23]. Goldman from Egypt reported 4.4 and 3.3 fold increased risk for marginal zone lymphoma and follicular lymphoma, respectively [24]. Interestingly, a 5.2 fold increased risk of lymphoplasmacytic lymphoma has been reported from Denmark [25]. Additionally, DANVIR cohort study from Denmark showed 29.97 fold increased risk of NHL during first year of follow up [26]. Although the HCV related NHLs seem to be lower in countries with lower HCV prevalence, long-term cohort studies showed again higher prevalence of HCV related NHL in some countries. Striking geographic variation about HCV and NHL suggests that genetic and/or environmental factors are involved in the pathogenesis. For these reasons large scale studies and meta analyses have been performed and reported. However, studies showing strong associations between HCV and NHL have been included in these meta-analyses for example Italy, Egypt and Japan [24,27,28]. On the other hand there is a strict difference for HCV prevalence between Northern and Southern countries of Europe; HCV prevalence is 0.1–1%, 0.2–1.2% and 2–5% in Northern, Central and Southern Europe, respectively [9,29]. Some theories have been proposed to explain the geographic differences in the association of HCV with B-NHL: (1) Differences in the HCV carrier population with Northern European countries in which transmission is via intravenous drug use. Transmission, however, is mixed in Southern Europe: intravenous drug abuse in younger and iatrogenic transmission is more frequent in olders. (2) Long lasting infection in Southern sites may be a cause for the development of NHL. (3) There is controversy about the NHL occurrence and certain genotypes have not been included in low prevalence countries. (4) Most importantly patients with low grade lymphoma cases had longer duration of viral infection while patients with diffuse large B cell lymphoma (DLBCL) had a shorter duration of infection [3,30]. There are three meta-analyses about HCV associated NHL. First, analysis has been published in 2003 and HCVMC, 43 studies and 5542 cases have been included in this report. OR has been found to be 10.8. It has been found an association between lymphoplasmacytic lymphoma subtype and mean HCV prevalence has been found to be 13% in cases with NHL [18]. In this analysis, in 10 case-control studies, HCV prevalence has been found to be 17% and 1.5% in cases with NHL and healthy controls, respectively [31,20]. Second, meta-analysis has been published by Matsuo [32]. In this analysis 23 studies and 4049 cases and 1.813.480 controls have been included and OR has been found as 5.7. In this meta-analysis lymphoma cell type and HCV relationship has been evaluated and it has not been found an association between HCV and lymphoma subtype [32]. Third, meta-analysis has been published by Dal Maso [33]. Fifteen case-control and three prospective studies and 4678 cases
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Table 1 Meta-analyses and International extranodal lymphoma consortium results about NHL risk in patients with HCV. Author
Publication year
Number of studies
Number of cases
OR for NHL
OR for NHL subtype
Reference
Gispert Matsua Dal Maso International extranodal lymphoma consortium
2003 2004 2006 2008
43 23 18 7
5542 4049 4678 4784
10.8 5.7 2.5 1.78
LPL No association No association LPL: 2.99MZL:2.47DLBCL:2.24
[18] [32] [33] [34]
Abbreviations: OR, odds ratio; NHL, non-Hodgkin lymphoma; LPL, lymphoplasmacytic lymphoma; MZL, marginal zone lymphoma; DLBCL, diffuse large B cell lymphoma.
have been included in these analysis. Relative risk has been found as 2.5 and again no difference was found between lymphoma subtypes in this report [33]. Pooled analysis of data from the International Lymphoma Epidemiology Consortium covered 7 studies and 4784 cases and indicated a 1.78 fold increased risk of NHL. HCV infection has been detected in 172 NHL cases (3.6%) and 169 controls (2.7%) and OR has been found as 2.99 for lymphoplasmacytic lymphoma, 2.47 for marginal zone lymphoma, and 2.24 for DLBCL [34]. Table 1 shows the results of the three meta-analyses and extranodal lymphoma epidemiology consortium for NHL risk in cases with HCV. In a report, subgroups of NHL have been evaluated and no clear association has been found between HCV and BNHL subtypes either indolent or aggressive [35]. However, some case-control studies showed higher risk of aggressive lymphomas compared to indolent lymphomas. Morton et al. recently published an interesting analysis. They investigated HBV, HCV and risk of NHL in solid organ transplant receivers and they found that hepatitis viral infection status at the time of transplantation was not related with NHL risk [36].
4. Which test is more useful to determine the prevalence of HCV in cases with lymphoma? An important point for different results for the association between HCV and NHL is the method used to determine the HCV infection. The detection of HCV antibodies without HCV-RNA analysis may underestimate the true rate of HCV infection in patients with NHL. This is due to the abnormal HCV antibody response both quantitatively and qualitatively in cases with NHL [37]. We performed three studies to detect the prevalence of HCV in Turkey. In our first study, anti-HCV antibody prevalence was evaluated in 228 cases with lymphoproliferative disorders. Nine of 98 cases with NHL had anti-HCV antibody and prevalence was found to be 10% [38]. In our second study, anti-HCV antibody was studied in 223 cases and we found anti-HCV positivity in 18 cases (8.1%). This prevalence was compared with donor population and OR and corrected OR were found to be 34.56 and 19.07, respectively. Additionally, HCV-RNA was studied in 67 of
these 223 samples. In this study HCV-RNA was detected in 21 of these cases (31.3%). This and some other studies suggested that HCV-RNA is more beneficial for the detection of HCV infection in these immune-suppressed cases [39–43]. In our third study, RT-PCR was used to detect the HCV-RNA both in serum and tissue samples. HCV-RNA was detected in 11 of 30 tissue samples (37%) while HCV-RNA and anti-HCV antibody were detected in only 7 (23.3%) and 3 (10%) serum samples of these 30 cases, respectively [44]. In another study considering HCV-RNA, HCV prevalence was found to be associated with diffuse large B cell lymphoma (OR: 2.19) and HCV-RNA was found to be more frequently associated with NHL than anti-HCV antibodies. This finding is related with impaired antibody production in these cases [12]. In a population based study from US, HCVRNA was found in 3.9 and 2.1% of the patients and controls, respectively and it has been found 2.46 fold increased risk for follicular lymphoma, 3.99 fold increased risk for marginal zone lymphoma and 2.04 fold increased risk for MALT lymphoma [45]. No relationship was found between anti-HCV antibodies and increased risk of NHL (OR: 2.2) in a casecontrol study from a Danish–Swedish population. Analysis restricted to HCV-RNA indicated that OR was 1.7 in this population [25]. In another Swedish study increased risk of NHL was found to be restricted to only HCV-RNA positive cases [26]. Serum samples from eight European countries, between 1998 and 2004, HCV-RNA positivity was found to be related with 1.42 fold increased risk of NHL. This was lower than the studies which HCV detected by anti-HCV antibody [12].
5. What is the route of HCV transmission? HCV is a single stranded RNA virus without DNA intermediate in its replicative cycle, so integration of HCV nucleic acid sequences into host genome seems unlikely. Therefore, it cannot be considered a typical oncogenic virus but it can exert its oncogenic potential indirectly by contributing to the modulator effects of the host immune system [46,47]. In fact, viral transmission routes are important in the development of NHL related HCV. Intravenous drug use transmission is the predominant route among
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Fig. 1. Pathogenesis of HCV related lymphoproliferative disorders. Reprinted from reference [56].
younger population in the Northern countries while iatrogenic transmission is important in older population in the Southern countries [48].
6. What is the pathogenetic role of HCV in NHL? It has been suggested that HCV can exert a chronic stimulus on the immune system, which facilitates the development and selection of abnormal clones and this scenario looks like the role of H Pylori for MALT lymphomas [49]. The regression of HCV related B-NHL following anti-viral treatment represents the etiologic association between HCV and lymphomas. It has been reported complete or partial responses after anti-viral therapy in HCV (+) cases but not in HCV (−) patients [9,50–52]. In early 1990s, HCV-RNA has been demonstrated in serum/plasma and liver tissues and also in peripheral blood mononuclear cells of patients with HCV [53,54]. Peripheral blood cells serve as reservoirs for persistent HCV infection. Long lasting HCV infection in B cells may cause to lymphoproliferative disorders [55]. It has been proposed that sustained antigenic stimulation of B cell compartment has a role in viral lymphotrophism [56]. Fig. 1 shows the steps for lymphomagenesis after antigenic stimulation. Viral lymphotropism has been suggested with the presence of viral replication in lymphatic cells [53]. HCV infection in bone marrow has been shown by Galli in 100% and 43% of the patients with or without MC, respectively [57]. It has been shown that HCV-E2 protein interacts with CD81
which is also present on the B cell surface. This binding is responsible for sustained polyclonal B cell activation lowering the B cell activation threshold [58,59]. Fig. 2 shows the role of connections between HCV proteins, CD81-E2, chromosomal aberrations, apoptotic inhibition, cytokines and chronic antigenic stimulation. HCV-CD81 interaction plays a central role for virus adaptation to the human host [59]. Lai used an in vitro model for HCV infection in B cell and showed the enhanced mutation rate of Ig genes [60]. The study showed the dramatically increased copy of activation induced cytidine deaminase (AID) in the B cells in HCV infected patients. HCV enhances AID expression by NFKB activation through the expression of viral core proteins. It has been found 100 fold increased levels of AID mRNA levels in CD19 (+) cells. This finding shows that HCV infects peripheral blood CD19 (+) cells and this is the reservoir during HCV infection in humans: suggesting HCV infects and may replicate in B cells [61]. These findings suggest that inappropriate expression of AID acts as a DNA mutator which enhances genetic susceptibility to mutagenesis [55]. Fig. 3 shows the role of activation induced cytidine deaminase (AID) in the B cells in HCV infected patients. This finding suggests that AID activation may be a factor in the lymphomagenic process mediated by HCV. Also significantly higher expression of several lymphomagenesis related genes have been shown in patients with HCV [19]. In transgenic mice expressing the full HCV genome in B cells was established by Tsuhiyama and 25% incidence of diffuse large B cell lymphoma within 600 days of birth was shown [62]. Oncogenic potential and lymphotrophism of different HCV genotypes are variable
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Fig. 2. The role of connections between HCV proteins, CD81-E2, chromosomal aberrations, apoptosis inhibition, cytokines and chronic antigenic stimulation. Reprinted from reference [56].
Fig. 3. The role of activation induced cytidine deaminase (AID) in the B cells in HCV infected patients. Reprinted from reference [55].
and results are conflicting [63–66]. Although HCV does not directly transform human B cells in vitro, transgenic mice expressing the full HCV genome in B cells spontaneously develop B cell lymphomas in vivo [67]. The most commonly investigated genetic aberration is t(14:18) and this is associated with type II or monoclonal MC. The presence of this translocation in MC has been found to be correlated with the overexpression of the anti-apoptotic Bcl-2/Bax ratio. Abnormal B cell clones following effective anti-viral treatment and in some cases a new expansion of the same clones have been shown [68]. Aneuploidy and chromosomal instability and reduced expression of retinoblastoma have been reported in HCV-infected patients [69,70]. Some cytokines and chemokines including CXCL10, CXCL13 are important in B cell trafficking and have been found to be increased in serum of MC patients [26]. High levels of B cell activator factor (BAFF or BLyS) is essential for B cell development/survival and has been found to be higher in HCV patients with lymphoproliferative disorders [71].
Recently Ng et al. looked for B cell receptors expressed by HCV associated lymphomas and interestingly they found that these lymphomas use a restricted immunoglobulin variable region gene repertoire. Also they found no evidence for their binding to the HCV antigens. With these results they suggested that most of the HCV associated lymphomas do not arise from B cells eliminating the virus [72]. It is very well known that miRNAs are important in pathogenesis of many malignant and inflammatory disorders. Among miRNAs, miR-26b has been shown to be downregulated in HCV (+) lymphomas as compared to HCV (−) splenic marginal zone lymphomas. This finding suggests a possible speculative mechanism in malignant lymphoma [45]. Additionally, in recent times it has been shown the possible contribution of NF-KB signaling and down regulation of miR-26b in the development of HCV associated B cell lymphomas in transgenic mice [73]. miRNA profile has been studied in HCV associated DLBCL in a comprehensive study and has been found decreased expression of miR-138-5p and increased expression of miR-147-a, miR-147b and miR-5115p and these alterations have been found to be poor prognostic factors in HCV related DLBCL [74]. These results suggest that miRNA profiles are related with clinical and pathological parameters and have a potential for therapeutic opportunity in HCV associated with DLBCL in near future. In summary as proposed for the last two decades, sustained HCV-driven antigenic stimulation plays a key role in inducing B cell clonal expansion and indicates a mechanism of HCV-related lymphomagenesis. Lymphatic follicles in the
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liver in HCV infection is the main site for B cell clonal expansion [75]. Intra-hepatic B cell clones are associated with extrahepatic manifestations of HCV. During the multi-step lymphomagenic process, chromosomal aberrations and other genetic aberrations occur [76].
7. What is the clinical/pathological/genotypic properties of HCV related NHL? It is not clear which lymphoma subtype is more prevalent in cases with HCV infection. The most frequently described subtypes are marginal zone lymphoma especially splenic marginal zone lymphoma, lymphoplasmacytic lymphoma and DLBCL [77]. Clinical data of patients with HCV related lymphoma is variable in different series. In some series more aggressive behavior, including extranodal involvement, higher LDH, and older age have been found to be increased in HCV related lymphoma, but other studies did not find such relationship [30,78–85]. Liver involvement was more common in patients with active infection and was seen in one fourth of the cases with hepatitis or cirrhosis at diagnosis. This finding suggests that active viral infection may be related with lymphomagenesis in the liver [78]. In some series, splenomegaly was found to be more frequent as compared to HCV (−) patients. The cause of this finding was portal hypertension due to impaired liver circulation in HCV infected patients. The other cause may be related with transformation from marginal zone lymphoma. An important point is the association between HCV genotypes and B-NHL. In most studies, no link has been found between specific viral genotypes and B-NHL. However, we know that this point has not been addressed in many of the studies and in some of these studies association has been evaluated more carefully [35]. Genotype II has been found to be important for the development of lymphoma [83]. In another study genotype Ib has been found to be most prevalent subtype and OR for the development of NHL has been found as 4.2 while OR was 2.9 for whole group [12]. Luppi documented an unexpectedly lower prevalence of HCV genotype 1b/3 in patients with B-NHL. In contrast the prevalence of genotypes 2a/3 and 2b/4 were found to be higher in B-NHL [84]. These findings suggest that some HCV genotypes are more lymphomagenic. Another interesting point is the duration of HCV infection and subtype of lymphoma. Pallicelli reported a higher prevalence of genotype 1 and shorter duration of HCV infection in cases with DLBCL as compared to higher prevalence of genotype 2 and longer duration of HCV infection in patients with indolent-low grade lymphoma. It is known that HCV genotype 2 is related with longer duration of viral infection. It has been speculated that it may induce a persistent chronic immune-stimulation of B cells over time. In contrast, direct lymphocyte transformation for HCV genotype 1 in aggressive lymphomas may occur on the basis of the shorter duration of viral exposure [79].
8. Anti-viral treatment for HCV associated NHL: when and whom? Anti-viral treatment (AVT) has been found to be effective in low grade lymphomas. Interestingly HCV infected patients treated by interferon and achieved sustained viral response (SVR) had a lower rate of lymphoma than who had not received AVT. This finding suggests that AVT may be preventive for lymphomagenesis in HCV infected patients. New anti-viral drugs may be attractive at this situation [85,86,87,88]. Subcutaneous pegylated intereferon alpha 2a, 180 g weekly plus oral ribavirin (800, 1000 and 1200 mg daily dose have been recommended for patients 85 kg, respectively) is the therapy of choice in these cases. Erythropoietin alpha 2a 40.000 IU weekly subcutaneously has been added in cases if hemoglobin level decreased by more than 2 g. Duration of treatment has been recommended as 1 year in patients HCV genotype 1 or 4, and 6 months for patients genotype 2 or 3. Definition of response to anti-viral treatment is important: SVR has been defined as HCV RNA negativity (
