Pathogenetic mechanisms of hepatitis C virus-induced B-cell lymphomagenesis

A multicentric and nationwide predictive study role of T cell sub-population in the prevalence and prognosis of cryoglobulinemia among genotype 4 chronic hepatitis C patients

The infection caused by the hepatitis C virus (HCV) is a significant global health concern. The prevailing genotype of HCV in Egypt is 4a, commonly referred to as GT-4a. A significant proportion exceeding 50% of patients infected with HCV experience extrahepatic manifestations (EHMs), encompassing a diverse range of clinical presentations. These manifestations, including essential mixed cryoglobulinemia (MC), can serve as initial and solitary indicators of the disease. The complete understanding of the pathogenesis of EHM remains unclear, with autoimmune phenomena being recognized as the primary causative factor. In this study, we examined the predictive significance of T-cell subpopulations in relation to the occurrence and prognosis of cryoglobulinemia in HCV patients. A total of 450 CHC genotype four treatment naïve patients were enrolled in this analytic cross-sectional study after thorough clinical, laboratory, and radiological examinations. All patients underwent laboratory investigations, including testing for cryoglobulin antibodies and measurements of CD4 and CD8 levels; two groups were described according to their test results: Group 1 consists of patients who have tested positive for cryoglobulin antibodies and Group 2 consists of patients who have tested negative for cryoglobulin antibodies. The exclusion criteria encompassed individuals with HIV infection or chronic HBV infection. Additionally, pelvi-abdominal ultrasonography was performed. Our study included 450 treatment naïve CHC patients (59% male, mean age 50.8 years). The patients were categorized according to their cryoglobulin antibodys test results into two groups: group A, CHC patients with cryoglobulin antibodies (Abs) negative (364 patients), and group B, CHC patients with cryoglobulin Ab positive (86 patients). Group B demonstrated a higher average age, elevated international normalized ratio, more prolonged duration of HCV infection, lower albumin, higher alanine aminotransferase, higher aspartate aminotransferase, higher bilirubin, lower CD8, lower CD4, and lower CD4:CD8 ratio. In contrast, 27 out of 86 (31.40%) patients in group B had symptoms; 85.8% had purpura and arthralgia, 74.3% had paresthesias, 86.7% had weakness, and 12.2% had non-Hodgkin's lymphoma. The levels of CD4 and CD8 were found to be decreased in chronic HCV patients with MC. T-cell subpopulation serves as a reliable indicator for assessing the prevalence and prognosis of MC in individuals with genotype 4 chronic hepatitis C. However, additional research is needed to further understand the development and spread of various emerging infectious diseases. Nevertheless, it is noteworthy that a critical threshold may exist beyond which EHM reaches a point of no return.

Distinct clinical features and prognostic factors of hepatitis C virus-associated non-Hodgkin's lymphoma: a systematic review and meta-analysis

BACKGROUND

Increasing evidence suggests that hepatitis C virus (HCV) infection is associated with non-Hodgkin's lymphoma (NHL). However, no clear consensus has been reached about the clinical features and effective treatment of HCV-associated NHL patients. We therefore performed a systematic review and meta-analysis to explore the clinical characteristics and effectiveness of antiviral treatment or rituximab administration among NHL patients with HCV infection.

METHODS

Eight electronic databases, including PubMed, OVID, EMBASE, Cochrane Library, ClinicalTrials, WANFANG, CNKI, and VIP, were searched for eligible studies up to July 31, 2021. The hazard ratio (HR) or odds ratio (OR) corresponding to the 95% confidence interval (CI) was calculated to estimate the outcomes. Publication bias was assessed by Egger's and Begg's tests. Statistical analysis was performed with RevMan 5.4 software and Stata version 15.

RESULTS

There were 27 shortlisted articles out of a total of 13,368 NHL patients included in the current meta-analysis. Our results demonstrated that NHL patients with HCV infection had a significantly shorter overall survival (OS: HR 1.89; 95% CI 1.42-2.51, P < 0.0001) and progression-free survival (PFS: HR 1.58; 95% CI 1.26-1.98, P < 0.0001), a lower overall response rate (ORR: OR 0.58, 95% CI 0.46-0.73, P < 0.00001) and a higher incidence of hepatic dysfunction during chemotherapy (OR 5.96; 95% CI 2.61-13.62, P < 0.0001) than NHL patients without HCV infection. HCV-positive NHL patients exhibited an advanced disease stage, an elevated level of LDH, a high-intermediate and high IPI/FLIPI risk as well as a higher incidence of spleen and liver involvement. Moreover, antiviral treatment prolonged survival (OS: HR 0.38; 95% CI 0.24-0.60, P < 0.0001), reduced disease progression [PFS/DFS (disease-free survival): HR 0.63; 95% CI 0.46-0.86, P = 0.003] and reinforced the treatment response (ORR: OR 2.62; 95% CI 1.34-5.11, P = 0.005) among the HCV-infected NHL patients. Finally, rituximab administration was associated with a favourable OS, while liver cirrhosis and low levels of albumin predicted a poor OS for HCV-positive NHL patients.

CONCLUSIONS

The current study provided compelling evidence about an inferior prognosis and distinct clinical characteristics among HCV-associated NHL patients. Antiviral treatment and rituximab-containing regimens were shown to be efficacious in improving the clinical outcomes of NHL patients with HCV infection.

Heterogeneity and coexistence of oncogenic mechanisms involved in HCV-associated B-cell lymphomas

The association of HCV-infection with B-lymphomas is supported by the regression of most indolent/low-grade lymphomas following anti-viral therapy. Studies on direct and indirect oncogenic mechanisms have elucidated the pathogenesis of HCV-associated B-lymphoma subtypes. These include B-lymphocyte proliferation and sustained clonal expansion by HCV-envelope protein stimulation of B-cell receptors, and prolonged HCV-infected B-cell growth by overexpression of an anti-apoptotic BCL-2 oncogene caused by the increased frequency of t(14;18) chromosomal translocations in follicular lymphomas. HCV has been implicated in lymphomagenesis by a "hit-and-run" mechanism, inducing enhanced mutation rate in immunoglobulins and anti-oncogenes favoring immune escape, due to permanent genetic damage by double-strand DNA-breaks. More direct oncogenic mechanisms have been identified in cytokines and chemokines in relation to NS3 and Core expression, particularly in diffuse large B-cell lymphoma. By reviewing genetic alterations and disrupted signaling pathways, we intend to highlight how mutually non-contrasting mechanisms cooperate with environmental factors toward progression of HCV-lymphoma.

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

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

Spectrum of bone marrow morphologic findings in hepatitis C patients with and without prior liver transplantation

INTRODUCTION

Cytopenia is a common hematologic finding in patients with HCV infection. Only a few studies have addressed bone marrow (BM) morphologic findings in these patients. No systemic study has been performed in these patients with liver transplantation (LT).

METHODS

We retrospectively examined BMs in 49 hepatitis C patients with and without prior LT (n = 19 and n = 30).

RESULTS

Among the patients with an available complete blood count (n = 46), the majority of them presented with cytopenia involving one or multiple cell lineages including unicytopenia (13%, n = 6), bicytopenia (31%, n = 14), and pancytopenia (43%, n = 20). Examination of the BM revealed a wide spectrum of morphologic findings ranging from benign reactive processes to overt malignant processes which included myeloid, lymphoid, and plasma cell neoplasms. The severity of cytopenia was not correlated with cirrhosis or antiviral therapy. However, the severity of cytopenia was partly correlated with splenomegaly or LT (P < 0.05).

CONCLUSIONS

Cytopenia is a common finding in hepatitis C patients. Hypersplenism or LT has an adverse impact on some blood cell counts. Lastly, hepatitis C patients present with a wide spectrum of BM findings including malignant neoplasms, which indicates a diagnostic value of BM examination in these patients.

Proliferative Glomerulonephritis With Monoclonal IgG1κ Deposits in a Hepatitis C Virus-Positive Patient

Hepatitis C virus infection is associated with several glomerular diseases, most commonly cryoglobulinemic glomerulonephritis, which is typically secondary to type II mixed cryoglobulinemia. We present a patient with hepatitis C virus infection and cryoglobulinemic glomerulonephritis secondary to type I (monoclonal) cryoglobulinemia that is likely related to a concurrent hepatitis C virus infection-associated lymphoproliferative disorder. We list the differential diagnosis of cryoglobulinemic glomerulonephritis. Additionally, the case draws attention to the possibility that, rarely, even clinically undetectable "occult" B-cell lymphoproliferative disorders may result in significant kidney disease.

Peripheral T-cell and NK cell lymphoproliferative disorders: cell of origin, clinical and pathological implications

T-cell lymphoproliferative disorders are a heterogeneous group of neoplasms with distinct clinical-biological properties. The normal cellular counterpart of these processes has been postulated based on functional and immunophenotypic analyses. However, T lymphocytes have been proven to be remarkably capable of modulating their properties, adapting their function in relationship with multiple stimuli and to the microenvironment. This impressive plasticity is determined by the equilibrium among a pool of transcription factors and by DNA chromatin regulators. It is now proven that the acquisition of specific genomic defects leads to the enforcement/activation of distinct pathways, which ultimately alter the preferential activation of defined regulators, forcing the neoplastic cells to acquire features and phenotypes distant from their original fate. Thus, dissecting the landscape of the genetic defects and their functional consequences in T-cell neoplasms is critical not only to pinpoint the origin of these tumors but also to define innovative mechanisms to re-adjust an unbalanced state to which the tumor cells have become addicted and make them vulnerable to therapies and targetable by the immune system. In our review, we briefly describe the pathological and clinical aspects of the T-cell lymphoma subtypes as well as NK-cell lymphomas and then focus on the current understanding of their pathogenesis and the implications on diagnosis and treatment.

Successful and Safe Long-Term Standard Antiviral Therapy in a Patient with "Explosive" Immune Response in Course of HCV-Related Liver Cirrhosis

Hepatitis C virus (HCV) has been recognized to be both a hepato- and lymphotropic virus. HCV lymphotropism represents an essential detail in the pathogenesis of virus-related autoimmune and lymphoproliferative disorders, ranging from clonal expansion of B-cells with organ and non-organ-specific autoantibody production up to overt non-Hodgkin’s lymphoma along a continuous step-by-step model of B-cell lymphomagenesis, where the intermediated mixed cryoglobulinemia could be considered as a stage of suppressible antigen-driven lymphoproliferation. The HCV long-lasting extrahepatic replicative state generates an abnormal systemic immunological response, including rheumatoid factor (RF) and cryo- and non-cryoprecipitable immune complexes, as well as clinical manifestations, comprising dermatitis, polyarthralgias and arthritis, pulmonary disease, aplastic anemia, glomerulonephritis and vasculitis. The mechanism of these extra-hepatic disorders is thought of as linked to immune complex disease, but their pathogenesis is poorly clarified. Immune-suppressive treatment could induce high-level hepatitis C viremia and impair hepatic disease. We report a female patient, whose chronic HCV-related liver cirrhosis with associated explosive, but oligosymptomatic lymphoproliferative immune response, i.e., RF beyond three thousand times the upper of normal range (unr), type II cryoglobulinemia with cryocrit 40% and monoclonal gammopathy IgM-k, has been successfully and safely treated by long-lasting (sixty-six months) combined antiviral therapy (pegylated interferon alfa and ribavirin), at moderate and tapering dose regimen, prolonged for nearly 24 months after the first viral suppression. At the last follow-up (fifty-one months), the patient was showing very-long term antiviral response, progressive decline of secondary immune activation and absence of significant side-effects. Further research is required to fully verify the real impact on therapeutic choice/regimen.

Virus-induced preferential antibody gene-usage and its importance in humoral autoimmunity

It is known that even the adaptive components of the immune system are based on genetic traits common to all individuals, and that diversity is shaped by the lifelong contacts with different non-self antigens, including those found on infectious pathogens. Besides the individual differences, some of these common traits may be more prone to react against a given antigen, and this may be exploited by the infectious pathogens. Indeed, viral infections can deregulate immune response by subverting antibody (Ab) gene usage, leading to the overexpression of specific Ab subfamilies. This overexpression often results in a protective antiviral response but, in some cases, also correlates with a higher likelihood of developing humoral autoimmune disorders. These aspects of virus-induced autoimmunity have never been thoroughly reviewed, and this is the main purpose of this review. An accurate examination of virus specific Ab subfamilies elicited during infections may help further characterize the complex interplay between viruses and the humoral immune response, and be useful in the design of future monoclonal antibody (mAb)-based anti-infective prophylactic and therapeutic strategies.

Hepatitis C virus syndrome: A constellation of organ- and non-organ specific autoimmune disorders, B-cell non-Hodgkin's lymphoma, and cancer

The clinical course of chronic hepatitis C virus (HCV) infection is characterized by possible development of both liver and extrahepatic disorders. The tropism of HCV for the lymphoid tissue is responsible for several immune-mediated disorders; a poly-oligoclonal B-lymphocyte expansion, commonly observed in a high proportion of patients with HCV infection, are responsible for the production of different autoantibodies and immune-complexes, such as mixed cryoglobulins. These serological alterations may characterize a variety of autoimmune or neoplastic diseases. Cryoglobulinemic vasculitis due to small-vessel deposition of circulating mixed cryoglobulins is the prototype of HCV-driven immune-mediated and lymphoproliferative disorders; interestingly, in some cases the disease may evolve to frank malignant lymphoma. In addition, HCV shows an oncogenic potential as suggested by several clinico-epidemiological and laboratory studies; in addition to hepatocellular carcinoma that represents the most frequent HCV-related malignancy, a causative role of HCV has been largely demonstrated in a significant percentage of patients with isolated B-cells non-Hodgkin's lymphomas. The same virus may be also involved in the pathogenesis of papillary thyroid cancer, a rare neoplastic condition that may complicate HCV-related thyroid involvement. Patients with HCV infection are frequently asymptomatic or may develop only hepatic alteration, while a limited but clinically relevant number can develop one or more autoimmune and/or neoplastic disorders. Given the large variability of their prevalence among patients' populations from different countries, it is possible to hypothesize a potential role of other co-factors, i.e., genetic and/or environmental, in the pathogenesis of HCV-related extra-hepatic diseases.

Case report of acute-on-chronic liver failure secondary to diffuse large B-cell lymphoma

Acute liver failure is a rare presentation of hematologic malignancy. Acute on chronic liver failure (ACLF) is a newly recognized clinical entity that describes acute hepatic decompensation in persons with preexisting liver disease. Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin’s lymphoma (NHL) with increasing incidence in older males, females and blacks. However, it has not yet been reported, to present with acute liver failure in patients with preexisting chronic liver disease due to human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infection. We describe a case of ACLF as the presenting manifestation of DLBCL in an elderly black man with HIV/HCV co-infection and prior Hodgkin’s disease in remission for three years. The rapidly fatal outcome of this disease is highlighted as is the distinction of ACLF from decompensated cirrhosis. Due to the increased prevalence of HIV/HCV co-infection in the African American 1945 to 1965 birth cohort and the fact that both are risk factors for chronic liver disease and NHL we postulate that the incidence of NHL presenting as ACLF may increase.

Hepatitis C virus and lymphoma

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.

Non-Hodgkin lymphoma and hepatitis C: where we are and what next?

The association between hepatitis C virus and certain B-cell non-Hodgkin lymphomas, such as marginal zone lymphomas, is supported by epidemiological studies. The exact pathogenetic mechanism is still unknown but both chronic antigenic stimulation and viral lymphotropism may contribute to the evolution of the malignant clone. Furthermore, the hematologic response following hepatitis C antiviral treatment suggests that the virus may have an etiologic role. Interferon and ribavirin based treatment proved to be successful in small case series of hepatitis C virus associated splenic lymphoma with villous lymphocytes, therefore, it is suggested that antiviral treatment could be an alternative to chemo-immunotherapy. In the near future new more potent direct acting antivirals will make interferon free treatments possible. It is still an open question whether these new short-course regimens are also effective in the treatment of associated lymphomas and what is the importance of the lymphoid reservoir in eliminating HCV.

Hepatitis C virus infection and kidney transplantation in 2014: what's new?

Chronic hepatitis C virus (HCV) infection remains an important health problem, which is associated with deleterious consequences in kidney transplant recipients. Besides hepatic complications, several extrahepatic complications contribute to reduced patient and allograft survival in HCV-infected kidney recipients. However, HCV infection should not be considered as a contraindication for kidney transplantation because patient survival is better with transplantation than on dialysis. Treatment of HCV infection is currently interferon-alpha (IFN-α) based, which has been associated with higher renal allograft rejection rates. Therefore, antiviral treatment before transplantation is preferable. As in the nontransplant setting, IFN-free treatment regimens, because of their greater efficacy and reduced toxicity, currently represent promising and attractive therapeutic options after kidney transplantation as well. However, clinical trials will be required to closely evaluate these regimens in kidney recipients. There is also a need for prospective controlled studies to determine the optimal immunosuppressive regimens after transplantation in HCV-infected recipients. Combined kidney and liver transplantation is required in patients with advanced liver cirrhosis. However, in patients with cleared HCV infection and early cirrhosis without portal hypertension, kidney transplantation alone may be considered. There is some agreement about the use of HCV-positive donors in HCV-infected recipients, although data regarding posttransplant survival rates are controversial.

Serum levels of immunoglobulin free light chains in patients with chronic hepatitis C presenting cryoglobulinemia

Hepatitis C virus (HCV) infects B-lymphocytes, provokes cellular dysfunction and causes lymphoproliferative diseases such as cryoglobulinemia and non-Hodgkin's B-cell lymphoma. In the present study, we investigated the serum levels of kappa and lambda free light chains (FLC) of immunoglobulins and the kappa/lambda FLC ratio in Brazilian patients with chronic HCV infection and cryoglobulinemia. We also analyzed the immunochemical composition of the cryoglobulins in these patients. Twenty-eight cryoglobulinemic HCV patients composed the target group, while 37 HCV patients without cryoglobulinemia were included as controls. The median levels of kappa and lambda FLC were higher in patients with cryoglobulinemia compared to controls (p = 0.001 and p = 0.003, respectively), but the kappa/lambda FLC ratio was similar in patients with and without cryoglobulinemia (p > 0.05). The median FLC ratio was higher in HCV patients presenting with advanced fibrosis of the liver compared to HCV patients without fibrosis (p = 0.004). Kappa and lambda FLC levels were strongly correlated with the IgA, IgG and IgM levels in the patients with cryoglobulinemia. In patients without cryoglobulinemia, the kappa FLC level was only correlated with the IgG level, whereas the lambda FLC were weakly correlated with the IgA, IgG and IgM levels. An immunochemical pattern of mixed cryoglobulins (MC), predominantly IgM, IgG, IgA and kappa light chain, was verified in these immune complexes. We concluded that HCV-infected patients presenting cryoglobulinemia have vigorous polyclonal B-lymphocyte activation due to chronic HCV infection and persistent immune stimulation.

Hepatitis C virus (HCV) infection of peripheral blood mononuclear cells in patients with type II cryoglobulinemia

OBJECTIVES

Type II cryoglobulinemia is a common extrahepatic manifestation of chronic hepatitis C virus (HCV) infection. The mechanisms behind its development are unclear, but could be related to direct infection of the immune cells.

METHODS

Peripheral blood mononuclear cells from 18 patients with type II cryoglobulinemia were separated into CD3+ (T cells), CD19+ (B cells) and CD14+ (monocytes) and analyzed for the presence of negative strand HCV RNA, which is a viral replicative intermediate, and for the presence of HCV non-structural protein 3 (NS3). Control group consisted of 182 consecutive chronic hepatitis C patients prior to initiation of antiviral therapy.

RESULTS

Negative strand HCV RNA was detected in PBMC from six (33.3%), patients and in 15 (8.2%) controls (p < 0.01). Negative strand was most frequently detected in B cells (3 patients), followed by T cells (2 patients), and monocytes (2 patients). One patient was positive both in CD3+ and CD14+ cells. NS3 protein was detected in six (33.3%) patients; five were positive in T cells, three in B cells, and another three were positive in monocytes. Two patients were positive in all analyzed cell subpopulation and one patient was positive in CD14+ and CD19+ cells, but not in CD3+ cells. Altogether, 11 patients (61.1%) were positive either for the negative strand HCV RNA or NS3 protein in at least one of the analyzed cell compartments.

CONCLUSION

Our findings of common presence of viral replication in cells of the immune system suggest that direct HCV infection could play a role in the etiology of cryoglobulinemia.

Immunity and hepatitis C: a review

Hepatitis C virus (HCV) is a major cause of chronic hepatitis and hepatocellular carcinoma worldwide. Due to shared transmission routes, the prevalence of HCV is especially high among individuals infected with HIV. HIV uninfected individuals spontaneously clear HCV approximately 30 % of the time, while the rate of control in HIV infected individuals who subsequently acquire HCV is substantially lower. In addition, complications of HCV are more frequent in those with HIV infection, making liver disease the leading cause of non-AIDS-related death in HIV infected individuals. This review summarizes recent advances in understanding the role of the innate and adaptive immune responses to HCV in those with and without HIV. Further defining the interaction between hepatitis C and the host immune system will potentially reveal insights into HCV pathogenesis and the host's ability to prevent persistent infection, as well as direct the development of vaccines.