Hepatitis C virus infection and B-cell non-Hodgkin's lymphomas: more than a simple association

Prevalence and clinical consequences of Hepatitis C virus infection in patients undergoing hematopoietic stem cell transplantation

Hepatitis C virus (HCV) infection is a significant cause of morbidity and mortality among hematopoietic stem cell transplant (HCT) recipients. In Brazil, its occurrence in HCT recipients remains undetermined. We now report on HCV prevalence in HCT recipients and its clinical consequences. The medical records of all HCT recipients seen at Hospital das Clinicas, Sao Paulo University Medical School, from January 2010 to January 2020 were reviewed to determine HCV serostatus. A retrospective analysis of medical charts was undertaken on all seropositive cases to determine HCV genotype, presence of liver fibrosis, co-infections with other viruses, previous treatments, and clinical evolution of liver pathology after HCT. Of the 1,293 HCT recipients included in the study, seven (0.54%) were HCV antibody-positive and five (0.39%) were also viremic for HCV-RNA. Four of these individuals had moderate to severe liver fibrosis (METAVIR F2/F3) and one was cirrhotic. Two of the viremic patients developed acute liver dysfunction following transplantation. All patients had their acute episode of liver dysfunction resolved with no further complications. Four of the viremic patients were treated for HCV infection with direct acting agents (DAA). Information regarding HCV treatment was lacking for one of the viremic HCV patients due to loss of follow up. Sustained anti-virologic responses were observed in three cases after the use of DAA. The detection of HCV in hematological adults undergoing HCT and its successful treatment with DAA highlight the necessity of testing for HCV both prior to and following transplantation.

Clearance of Hepatitis C Virus (HCV) Is Associated With Improved Outcomes in HCV-Associated Lymphoma

BACKGROUND

Improved hepatitis C virus (HCV) clearance due to directly acting antiviral agents has led to remarkably improved outcomes of indolent HCV-associated non-Hodgkin lymphoma (NHL). The impact of directly acting antivirals on the outcomes of aggressive NHL is still under investigation. Characteristics of HCV-associated NHL in black patients are not well characterized. We report outcomes of HCV-associated NHL compared to their HCV-negative counterparts in a predominantly black population.

PATIENTS AND METHODS

Patients with lymphoma between January 2007 and December 2017 were retrospectively studied. Depending on presence or absence of HCV RNA, patients were grouped into HCV positive (HCV⁺) and HCV negative (HCV^-) cohorts. Depending on virologic clearance (VC), HCV⁺ were classified into HCV⁺ with VC and HCV⁺ without VC. Overall response rate (ORR), complete response, overall survival (OS), and progression-free survival (PFS) of HCV⁺ patients with and without VC were compared to HCV^- patients.

RESULTS

Of 397 patients with lymphoma, 40 had HCV. Black comprised 90% of HCV⁺ patients. Diffuse large B-cell lymphoma was most frequent (47%) in the HCV⁺ group. HCV⁺ patients without VC had significantly worse OS and PFS compared to HCV^- patients. There were no differences in ORR, complete response, PFS, and OS of HCV⁺ patients with VC and HCV^- patients. These results were consistent in subgroups of diffuse large B-cell lymphoma and aggressive lymphoma.

CONCLUSION

HCV clearance is positively associated with lymphoma outcomes in black patients. Patients who clear HCV have noninferior outcomes to HCV^- patients, while those who fail to clear HCV have significantly worse outcomes.

Hepatitis C virus infection and non-hepatocellular malignancies in the DAA era: A systematic review and meta-analysis

BACKGROUND AND AIMS

Direct antiviral agents have greatly improved therapeutic options for chronic hepatitis C. Indeed, former "difficult-to-treat" patients can now be treated and can achieve sustained response. Hepatitis C virus (HCV) is associated with hepatocellular carcinoma and with B-cell non-Hodgkin lymphoma (B-NHL). Other malignancies have been reported to be associated with HCV infection albeit with various grades of evidence. Antineoplastic treatment is often reduced or suspended in HCV-positive cancer patients to avoid "HCV reactivation." In this setting, antiviral therapy combined with antineoplastic protocols may improve the outcome. For this reason, we conducted a systematic review and a meta-analysis to update the association between HCV infection and non-hepatocellular malignancies, and to shed light on the effects exerted by antiviral treatment on the natural history of oncological diseases.

METHODS

Relevant studies were identified by searching PUBMED, EMBASE and MEDLINE up to 1 August 2018. Pooled risk estimates were calculated with random-effects models according to PRISMA guidelines.

RESULTS

A total of 58 studies were included in the analysis: 27 studies of the association between HCV and B-NHL(OR 3.36; 95% CI 2.40-4.72;P < 0.00001);13 studies of the association between sustained virological response and progression-free survival (PFS) in B-NHL patients(OR 9.34; 95% CI 4.90-17.79; P < 0.00001); 13 studies of the association between HCV and intrahepatic-cholangio-carcinoma (OR 3.95;95% CI 2.25-6.94; P < 0.00001); and 5 studies of the association between HCV infection and pancreatic adeno-carcinoma(OR 1.60; 95% CI:1.25-2.04; P = 0.0002).

CONCLUSIONS

This study updates the strong association between B-NHL and HCV infection, confirms the association between HCV and non-hepatocellular tumours, and demonstrates a very strong association between viral eradication and a better outcome of HCV-positive B-NHL.

Efficacy and safety of new direct antiviral agents in hepatitis C virus-infected patients with diffuse large B-cell non-Hodgkin's lymphoma

The association of hepatitis C virus (HCV) with non-Hodgkin's lymphoma (NHL) has been demonstrated throughout the world. The new interferon-free direct antiviral agents (DAAs) showed high efficacy and safety, and preliminary data seem to confirm their activity on low-grade NHL. The question arises as whether or not-and how-to treat the HCV-positive patients suffering from diffuse large B-cell lymphomas (DLBCLs). The aim of this observational study was to evaluate whether DAA antiviral treatment of DLBCL/HCV-infected patients in concomitance with chemotherapy is a safe and effective option. Twenty (13 males and 7 females) HCV genotype 1b-positive subjects, undergoing chemotherapy for DLBCL, were enrolled between June 2015 and December 2015. After informed consent, all patients underwent antiviral therapy (AVT) with sofosbuvir/ledipasvir and chemotherapy (14 rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone and 6 cyclophosphamide, doxorubicin, vincristine, and prednisone) for DLBCL. Complete hematological (Revised European-American Lymphoma classification, Ann Arbor, and International Prognostic Index [IPI] scores) and hepatological (viral markers, liver stiffness, and biochemical parameters) evaluations were made. A historical retrospective cohort of 101 DLBCL/HCV-positive patients not undergoing AVT was enrolled for comparison. DAA-treated and untreated patients were similar for sex distribution, IPI score, and NHL stage, and differed for age (older in treated), chemotherapy and use of AVT. Overall survival (OS) and disease-free survival (DFS) were evaluated among a 52-week of follow-up. No statistical difference was found in OS after 52 weeks (P = 0.122), whereas a statistically significant higher DFS was achieved in treated patients (P = 0.036). At the multivariate analysis, only IPI score and AVT were independently correlated with a better DFS. No differences in adverse events were reported.

CONCLUSION

DAA treatment in concomitance with chemotherapy was shown to be safe and effective in influencing remission of aggressive lymphomas in HCV patients. (Hepatology 2018;67:48-55).

Polyclonal and monoclonal B lymphocytes response in HCV-infected patients treated with direct-acting antiviral agents

Hepatitis C virus (HCV) chronic infection can be associated with extrahepatic manifestations such as mixed cryoglobulinaemia and lymphoproliferative disorders that are endowed with increased rates of morbidity and all-cause mortality. In this study, we used flow cytometry to evaluate the effect of interferon-free antiviral treatment on peripheral blood lymphocytes in HCV-infected patients with or without associated lymphoproliferative disorders. Flow cytometry analysis of peripheral blood lymphocytes was performed at baseline and at the end of treatment. In HCV-infected patients with lymphoproliferative disorders, we evaluated immunoglobulin (Ig) light chain κ/λ ratio variations as a measure of monoclonal B-cell response to antiviral therapy. Healthy volunteers were enrolled as controls. A total of 29 patients were included, nine with and 20 without lymphoproliferative disorders. Sustained virological response was achieved in 29 of 29 patients. We observed a significant reduction in the B-cell compartment (39% global reduction) in eight of nine HCV-infected patients with lymphoproliferative disorders after viral clearance. We recognized the same trend, even if less pronounced, in HCV-infected patients without lymphoproliferative disorders (9% global reduction). Among HCV-infected patients with lymphoproliferative disorders, three showed an improvement/normalization of the immunoglobulin light chain ratio, whereas in the remaining six patients monoclonal B cells persisted to be clonally restricted even 1 year after the end of treatment. Our data show that DAAs treatment can be effective in reducing the frequency of pathological B cells in the peripheral blood of HCV-infected patients affected by HCV-associated lymphoproliferative disorders; however, monoclonal populations can persist after viral eradication.

Hepatitis C virus-associated B-cell non-Hodgkin's lymphomas: what do we know?

Epidemiological studies have shown an increased risk of developing B-cell lymphomas in patients with chronic hepatitis C virus (HCV) infection. There is, however, a great geographic variability and it remains unclear whether additional environmental and genetic factors are involved or whether the international discrepancies represent simply a consequence of the variable prevalence of HCV infection in different countries. Other confounding factors may affect the comparability of the different studies, including the method of HCV assessment, the selection of normal controls, the lymphoma classification used and the year of publication. The most convincing evidence for a causal relationship comes from the observation, mainly limited to some indolent subtypes, of B-cell lymphoma regressions after successful HCV eradication with antiviral treatment. Yet, the molecular mechanism of HCV-induced lymphomagenesis are mainly hypothetical. According to most plausible models, lymphoma growth is a consequence of continuous antigenic stimulation induced by the chronic viral infection. This review will summarize the current knowledge on HCV-associated lymphomas and their management.

Emerging role of infectious etiologies in the pathogenesis of marginal zone B-cell lymphomas

Extranodal marginal zone B-cell lymphomas of the mucosa-associated lymphoid tissue (MALT) arise from lymphoid populations that are induced by chronic inflammation in extranodal sites. The most frequently affected organ is the stomach, where MALT lymphoma is incontrovertibly associated with a chronic gastritis induced by a microbial pathogen, Helicobacter pylori. Gastric MALT lymphoma therefore represents a paradigm for evaluating inflammation-associated lymphomagenesis, which may lead to a deeper understanding of a possible etiologic association between other microorganisms and nongastric marginal zone lymphomas. Besides infectious etiology, chronic inflammation caused by autoimmune diseases, such as Sjögren syndrome or Hashimoto thyroiditis, can also carry a significant risk factor for the development of marginal zone lymphoma. In addition to the continuous antigenic drive, additional oncogenic events play a relevant role in lymphoma growth and progression to the point at which the lymphoproliferative process may eventually become independent of antigenic stimulation. Recent studies on MALT lymphomas have in fact demonstrated genetic alterations affecting the NF-κB) pathway, a major signaling pathway involved in many cancers. This review aims to present marginal zone lymphoma as an example of the close pathogenetic link between chronic inflammation and tumor development, with particular attention to the role of infectious agents and the integration of these observations into everyday clinical practice. See all articles in this CCR Focus section, "Paradigm Shifts in Lymphoma."

Hepatitis C virus-associated B-cell non-Hodgkin lymphomas

Epidemiological studies have demonstrated an increased risk of developing B-cell lymphomas in patients with chronic hepatitis C virus (HCV) infection. However, the strength of the association shows great geographic discrepancies, with higher relative risk in countries with high HCV prevalence. It remains unclear whether additional environmental and genetic factors are involved or if the international variability is simply a consequence of the variable infection prevalence. Therefore, a causal relationship remains controversial. Other confounding factors may affect the comparability of the different studies, including the method of HCV assessment, the selection of normal controls, the lymphoma classification used, and the year of publication. The most convincing proof is the observation, mainly limited to some indolent subtypes, of B-cell lymphoma regressions after HCV eradication with IFN and ribavirin. However, the molecular mechanisms of the HCV-induced lymphomagenesis are mainly hypothetical. According to the model considered to be most plausible, lymphoma growth is a consequence of the continuous antigenic stimulation of the B-cell immunologic response induced by the chronic viral infection. This review summarizes the current epidemiological and biological evidence of a role of HCV in lymphomagenesis, describing the putative mechanisms for a causative relationship. The clinical characteristics and management difficulties of the HCV-associated lymphomas are also discussed. HCV treatment with IFN cannot be given safely in concomitance with cytotoxic lymphoma treatment because of hematological and liver toxicity. However, novel and better tolerated antiviral regimens are under development and will hopefully make the treatment of both lymphoma and hepatitis easier in the future.

Waldenström macroglobulinemia in hepatitis C: case report and review of the current literature

Background. Recent literature has associated hepatitis C virus with the development of non-Hodgkin lymphoma. Hepatitis C virus infection appears to promote lymphoproliferation, providing a plausible mechanism for a causative association; however, despite prior reports of patients with comorbid hepatitis C infection and Waldenström macroglobulinemia, the literature is in disagreement regarding whether there exists an association between these two conditions. Case Presentation. This case report describes a 57-year-old African-American male with chronic hepatitis C infection and cryoglobulinemia who presented with several episodes of transient confusion and paralysis and was found to have symptomatic hyperviscosity. The recognition of his condition was facilitated by characteristic findings on ophthalmologic examination. He was subsequently diagnosed with Waldenström macroglobulinemia on bone marrow biopsy. Conclusions. An up to date, comprehensive review of the literature suggests an association between hepatitis C and Waldenström macroglobulinemia. Data on optimal treatment of patients with comorbid hepatitis C infection and Waldenström macroglobulinemia is limited. We have provided a comprehensive review of previously explored treatment options to guide management of other similar patients. Our patient has since been treated with repeated plasmapheresis with a plan to pursue antiviral therapy.

Primary T-cell lymphoma of liver

Primary hepatic lymphoma (PHL) is rare and represents approximately 0.016% of all cases of non-Hodgkin's lymphoma (NHL). The majority of these are B-cell NHL of diffuse large B-cell type. Primary T-cell lymphoma constitutes approximately 5-10% of all PHLs arising in the liver, 90% being B-cell type. Peripheral T-cell lymphoma, γδ hepatosplenic T-cell lymphoma and αβ hepatosplenic T-cell lymphoma are the common T-cell lymphomas involving hepatic parenchyma. We encountered a case presenting with gross hepatomegaly extending beyond umbilicus, mild ascites, pedal oedema, icterus and dyspnoea. Haemogram showed moderate anaemia with counts. Bone marrow aspiration showed erythroid hyperplasia with dimorphic anaemia. There was no evidence of atypical lymphoid cells in peripheral blood of bone marrow. We present a rare case of primary T-cell lymphoma presenting as primary liver involvement without splenomegaly, lymphadenopathy, bone marrow or peripheral blood involvement.

Antiviral therapy after complete response to chemotherapy could be efficacious in HCV-positive non-Hodgkin's lymphoma

BACKGROUND/AIMS

Prevalence of HCV infection in non-Hodgkin's lymphoma is high. The impact of antiviral therapy on the natural history of this subgroup of lymphomas after a successful chemotherapy regimen is still an argument of debate.

METHODS

We retrospectively examined 343 chemotherapy-treated patients referred to our centre for five consecutive years. Clinical and histological characteristics, disease free-survival (DFS) and overall-survival (OS) were compared in HCV-positive (69/343) and HCV-negative (274/343) patients. Twenty-five HCV-positive patients received antiviral treatment following chemotherapy discontinuation. Uni- and multivariate analyses were performed.

RESULTS

20% of lymphomas were HCV-positive. Indolent histology was prevalent in the HCV-positive group (p<0.05); no significant differences in OS or DFS were found between the two groups; in HCV-positive subjects, antiviral therapy, was associated with a longer DFS (p<0.05); none of the HCV-positive subjects who achieved a virological response experienced any lymphoma relapse; 29% of non responders did; at multivariate analysis, the independent factors related to a better clinical outcome were: indolent histology at the onset of lymphoma and antiviral therapy.

CONCLUSIONS

Antiviral treatment in HCV-positive non-Hodgkin's lymphoma may be an important strategy to reinforce the results of a successful chemotherapy regimen; further studies are needed to validate this combined approach.

High prevalence of hepatitis B virus infection in patients with B-cell non-Hodgkin's lymphoma in Korea

This study assessed the association of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection with non-Hodgkin's lymphoma in a highly HBV-endemic area. The prevalence of either HBV or HCV infection in 235 patients with non-Hodgkin's lymphoma was compared with that of an age- and sex-matched hospital control group of 235 patients. The prevalence of HBV infection was higher in B-cell non-Hodgkin's lymphoma (15.5%) than control (8.1%), but the prevalence of HCV infection in the non-Hodgkin's lymphoma patients (2.1%) and control group (3%) was similar. HBV prevalence increased significantly with age in the B-cell non-Hodgkin's lymphoma patients. The presence of HBV proteins and DNA in lymphoma tissues and peripheral blood mononuclear cells (PBMCs) from HBV-infected non-Hodgkin's lymphoma patients was also investigated using immunohistochemistry and PCR. HBV DNA was frequently detected in PBMCs from HBV-infected non-Hodgkin's lymphoma patients, but HBV antigens were not. Therefore, HBV infection, but not HCV infection, was associated with B-cell non-Hodgkin's lymphoma in Korea, suggesting a possible role for HBV in the development of non-Hodgkin's lymphoma.

Extrahepatic manifestations of Hepatitis C Virus infection: a general overview and guidelines for a clinical approach

Hepatitis C Virus is associated with a wide series of extrahepatic manifestations. Based on available data the link between the virus and some of these extrahepatic diseases is only suggested and needs further confirmation. Hepatitis C Virus-related lymphoproliferative disorders, whose prototype is mixed cryoglobulinaemia, represent the most closely related extrahepatic manifestations of Hepatitis C Virus. Other Hepatitis C Virus-associated disorders include nephropathies, thyreopathies, sicca syndrome, idiopathic pulmonary fibrosis, porphyria cutanea tarda, lichen planus, diabetes, chronic polyarthritis, cardiopathy and atherosclerosis. A pathogenetic link between Hepatitis C Virus and some extrahepatic manifestations was confirmed by their responsiveness to antiviral therapy, which is now deemed the first therapeutic option to consider. By contrast, there are diseases where treatment with interferon was ineffective or dangerous. The aim of the present paper is to outline the most recent evidence concerning extrahepatic disorders that are possibly associated with Hepatitis C Virus infection. Special emphasis will be given to discussion of the most appropriate clinical approaches to be adopted in order to diagnose, treat (possibly prevent) and follow-up extrahepathic diseases in patients with Hepatitis C Virus infection.

Interleukin-10 - 1082 GG polymorphism influences the occurrence and the clinical characteristics of hepatitis C virus infection

BACKGROUND/AIMS

In this study, we determined the genotypic and allelic frequencies of the Interleukin (IL)-10(-1082G/A) IL-10(-592A/C), and IL-10(-819C/T) polymorphisms, and their association with the risk to develop B cell Non Hodgkin Lymphoma (NHL) in hepatitis virus C (HCV) carriers.

RESULTS

Genetic polymorphisms in the IL-10 gene promoter were studied in 250 consecutive patients with B-cell NHL with no clinical and/or laboratory findings of cryoglobulinemia, 142 NHL/HCV- and 108 NHL/HCV+ with chronic hepatitis (CH), 120 consecutive subjects with HCV-related CH, and 110 age, sex-matched healthy blood donors. The frequency of the IL-10(-1082GG) genotype vs remaining genotypes (IL-10(-1082GA/AA)) was higher in NHL/HCV+ patients than HCV-related CH patients (P=0.0002, OR=2.89, CI: 1.62-5.15) and in NHL/HCV+ than NHL/HCV- patients (P=0.0001, OR=2.99, CI: 1.72-5.19). Moreover, the IL-10(-1082GG) genotype was more prevalent in indolent NHL/HCV+ cases than aggressive NHL/HCV+ (P=0.0004, OR=4.97, CI: 2.10-11.79). Finally, we confirmed that IL-10(-1082GG) genotype is associated with higher IL-10 production compared to AA homozygous (P=0.037).

CONCLUSIONS

The high IL-10 production, due to IL-10(-1082GG) genotype, influences the clinical expression of the HCV infection by increasing susceptibility to develop NHL and might contribute to the indolent form of the disease.

Effect of hepatitis C virus core protein on the molecular profiling of human B lymphocytes

Hepatitis C virus (HCV) core protein features many intriguing properties and plays a pivotal role in cellular immunity, cell growth, apoptosis, cell transformation, and eventually in tumor development. However, the role of B cells, the primary players in the humoral immune response, during HCV infection is largely unknown. To explore the molecular effects of HCV core on human B cells, we conducted gene expression profiling of serial RNA samples from B cells that were infected with adenovirus harboring full-length HCV core protein and beta-galactosidase as a reference using a microarray platform containing 22,149 human oligo probes. The entire experiment was performed in duplicate in B lymphocytes that were isolated from two individual donors and incubated for up to 3 days after infection with adenovirus expressing HCV core protein to identify dynamic gene expression patterns. Differential expression of representative genes was validated by quantitative RT-PCR. We found that HCV core significantly inhibited B-lymphocyte apoptosis. We showed a dramatic downregulation of MHC class II molecules in B cells expressing HCV core, whereas the expression of immunoglobulin genes was not significantly altered. Moreover, genes associated with leukemia and B-lymphoma were consistently upregulated by HCV core. In contrast, downregulation of caspase-1 and caspase-4 was found to be associated with core's ability to prevent B-lymphocyte apoptosis. In summary, we have identified several clusters of genes that are differentially expressed in human B lymphocytes expressing HCV core, suggesting a potential impairment of antigen processing and presentation, which may provide more insights into HCV infection in B lymphocytes.

Mucosa-associated lymphoid tissue (MALT) lymphoma

OBJECTIVES

To review the pathogenesis of MALT lymphoma, and the associations with antigenic stimulation, presentation, and unique treatment.

DATA SOURCES

Research and review articles and textbooks.

CONCLUSION

MALT lymphoma is a heterogeneous but unique pathologic form of extranodal B-cell non-Hodgkin's lymphoma. The gastrointestinal tract is the most common site of disease, but involvement of multiple other organ systems has been reported. In the case of gastric MALT lymphomas, H. pylori has been highly implicated as the stimulating agent. Treatment strategies for early disease involve eradication of H. pylori when it is involved and/or radiotherapy, which alone may result in cure of this lymphoma. Chemotherapy is used in more advanced or resistant disease.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play a significant role in the education of patients about this unique malignancy and follow-up regarding compliance with therapy. Attention to social needs of the patients is critical.

The epidemiology of non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) includes a group of more than 20 different malignant lymphoproliferative diseases that originate from lymphocytes. Rates of NHL have increased dramatically over the past few decades, although the rate of increase has recently slowed. It is now the sixth most common cancer in Australia. Globally, it is somewhat more common in men than in women, and rates are highest in North America and Australia. The causes of the increase in NHL rates are largely unknown. The best described risk factor for NHL is immune deficiency; rates of NHL are greatly increased, with relative risks of 10-100 or more, in people with immune deficiency associated with immune suppressive therapy after transplantation, HIV/AIDS, and congenital conditions. In addition, some NHL subtypes are associated with specific infections. These include immune-deficiency-associated central nervous system NHL (Epstein-Barr virus); gastric mucosa-associated lymphoid tissue NHL (Helicobacter pylori); adult T-cell leukemia/lymphoma (human T-lymphotrophic virus type 1) and body cavity-based lymphoma (human herpesvirus 8). However, these specific infections account for a very small proportion of total NHL incidence. In addition to immune deficiency and infection, other immune-related conditions are increasingly being recognised as related to NHL risk. Specific autoimmune conditions, including rheumatoid arthritis, systemic lupus erythema, Sjogren's syndrome, psoriasis and coeliac disease are associated with moderately increased risk of NHL. On the other hand, allergic and atopic conditions and their correlates such as early birth order, appear to be associated with a decreased risk of NHL.A variety of other exposures are less strongly related to NHL risk. These include occupational exposures, including some pesticides, herbicides, and solvents. Recently, two studies have reported that sun exposure is associated with a decreased risk of NHL. Smoking appears to be weakly positively associated with risk of follicular NHL, and alcohol intake is associated with a decreased risk of NHL. The pooled analysis of several case-control studies of NHL risk that are currently in the field promises to help clarify which of these risk factors are real, and will contribute to the elucidation of the mechanisms of how disorders of the immune system, and other factors, are related to NHL risk.

Mitogen-induced upregulation of hepatitis C virus expression in human lymphoid cells

Considering growing evidence indicating that hepatitis C virus (HCV) replicates in lymphoid cells, establishment of a reliable and sensitive method for detection of HCV in these cells may provide means for monitoring the infection and the efficacy of sterilizing antiviral therapy. In this study, conditions for ex vivo augmentation and detection of the HCV genome in peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis C (CHC) or after a sustained virological response (SVR) to antiviral treatment were assessed. Following stimulation with combinations of mitogens and/or cytokines, PBMCs and, in certain cases, affinity-purified T and B cells were examined for HCV positive- and negative-strand RNA by using RT-PCR followed by nucleic acid hybridization, while the presence of viral NS3 protein was determined by flow cytometry. HCV RNA augmentation was assessed by quantification of Southern and dot-blot hybridization signals. The results showed that treatment of peripheral lymphoid cells with mitogens stimulating T- and B-cell proliferation and with cytokines supporting their growth significantly increased HCV RNA detection in patients with both CHC and SVR. This enhancement was up to 100-fold for the HCV genome and fivefold for the NS3 protein compared with untreated cells. In conclusion, HCV RNA can be readily detected in circulating lymphoid cells in progressing hepatitis C and following SVR after ex vivo cell stimulation. As such, this method offers a new investigative tool to study HCV lymphotropism and to monitor virus presence during the course of HCV infection.

Autoantibody Activity in Waldenström's Macroglobulinemia

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

Lymphoproliferative disorders in chronic hepatitis C

Chronic hepatitis C virus (HCV) infection is associated with the development of lymphoproliferative disorders (LPDs). The aim of this investigation was to determine the prevalence and characterization of monoclonal gammopathy and benign and malignant LPDs in individuals with chronic hepatitis C. A total of 233 subjects diagnosed with chronic hepatitis C (male/female ratio: 131/102, median age; 49 years) were studied. Serum and urine were examined for the presence of a monoclonal gammopathy. A bone marrow aspirate and biopsy was obtained in individuals with a monoclonal gammopathy. Thirty-two patients (13.7%, 32 of 233) had a monoclonal gammopathy; 75% of them were benign and were not associated with malignant disorders (24 of 32) while 25% were associated with malignant LPDs or a plasma cell disorder (eight of 32). Two additional subjects without monoclonal gammopathy were diagnosed as having a malignant LPDs. The prevalence of malignant LPDs/plasma cell disorder in individuals with HCV-induced chronic liver disease was 4.3%. No difference was found in terms of disease duration, HCV genotype, viral load, alanine aminotransferase level or histopathologic score between the subjects with or without a monoclonal gammopathy. The presence of mixed cryoglobulinaemia was strongly associated with the presence of an underlying malignant disorder. Hence a monoclonal gammopathy is found in 14% of patients with chronic hepatitis C and is associated with malignant B-cell LPD in more than a quarter of such patients. The prevalence of LPDs in individuals with HCV-induced chronic liver disease is greater than that of the normal healthy population.

Hepatitis C virus persistence after spontaneous or treatment-induced resolution of hepatitis C

It is presumed that resolution of hepatitis C, as evidenced by normalization of liver function tests and disappearance of hepatitis C virus (HCV) RNA from serum, as determined by conventional laboratory assays, reflects virus eradication. In this study, we examined the expression of the HCV genome in the sera, peripheral blood mononuclear cells (PBMC), and, on some occasions, monocyte-derived dendritic cells (DC) long after resolution of hepatitis C by using a highly sensitive reverse transcription (RT)-PCR-nucleic acid hybridization (RT-PCR-NAH) assay. The samples obtained from 16 randomly selected patients (5 with spontaneous and 11 with treatment-induced resolution), monitored for up to 5 years, were studied by qualitative and semiquantitative RT-PCR-NAH and by real-time RT-PCR to detect the HCV RNA positive strand. The replicative HCV RNA negative strand was examined in PBMC after culture with a T-cell proliferation stimulating mitogen. The findings show that HCV RNA was carried in the convalescent-phase sera and/or PBMC in all 16 individuals investigated. Also, DC from six of seven patients were reactive for the HCV genome. Importantly, traces of the HCV RNA negative strand, suggesting progressing virus replication, were detected in the majority of mitogen-stimulated PBMC, including four samples collected 5 years after recovery. Sequencing of the HCV 5' untranslated region fragment revealed genotype 1b in four of nine individuals examined and genotypes 1a and 2a in three and two patients, respectively. These results imply that HCV RNA can persist at very low levels in the serum and peripheral lymphoid cells and that an intermediate replicative form of the HCV genome can persist in PBMC for many years after apparently complete spontaneous or antiviral therapy-induced resolution of chronic hepatitis C.