Hepatitis C virus-Epstein-Barr virus interaction in patients with AIDS

Carcinogenic mechanisms of virus-associated lymphoma

The development of lymphoma is a complex multistep process that integrates numerous experimental findings and clinical data that have not yet yielded a definitive explanation. Studies of oncogenic viruses can help to deepen insight into the pathogenesis of lymphoma, and identifying associations between lymphoma and viruses that are established and unidentified should lead to cellular and pharmacologically targeted antiviral strategies for treating malignant lymphoma. This review focuses on the pathogenesis of lymphomas associated with hepatitis B and C, Epstein-Barr, and human immunodeficiency viruses as well as Kaposi sarcoma-associated herpesvirus to clarify the current status of basic information and recent advances in the development of virus-associated lymphomas.

Pre-stimulation of CD81 expression by resting B cells increases proliferation following EBV infection, but the overexpression of CD81 induces the apoptosis of EBV-transformed B cells

Hepatitis C virus (HCV) E2 protein binds to CD81, which is a component of the B cell co-stimulatory complex. The E2-CD81 interaction leads to B cell proliferation, protein tyrosine phosphorylation and to the hypermutation of immunoglobulin genes. Epidemiological studies have reported a high prevalence of B cell non-Hodgkin lymphoma (NHL) in HCV-positive patients, suggesting a potential association between HCV and Epstein-Barr virus (EBV) in the genesis of B lymphocyte proliferative disorders. In the present study, in order to investigate the association between EBV and HCV in B cells, we created an in vitro EBV-induced B cell transformation model. CD81 was gradually overexpressed during transformation by EBV. B cells isolated from HCV-positive patients grew more rapidly and clumped together earlier than B cells isolated from healthy donors following EBV infection. Pre-stimulation of CD81 expressed by resting B cells with anti-CD81 monoclonal antibody (mAb) or HCV E2 accelerated the generation of lymphoblastoid cell lines (LCLs) by EBV infection. These cells proliferated prominently through the early expression of interleukin-10 and intracellular latent membrane protein (LMP)-l. By contrast, the overexpression of CD81 on EBV-transformed B cells by anti-CD81 mAb or HCV E2 protein induced apoptosis through reactive oxygen species (ROS)-mediated mitochondrial dysfunction. These results suggest that the engagement of CD81 expressed by B cells has differential effects on B cell fate (proliferation or apoptosis) according to EBV infection and the expression level of CD81.

Epstein-Barr virus and Interleukin-28B polymorphism in the prediction of response to interferon therapy in hepatitis C patients

BACKGROUND AND STUDY AIMS

In chronic hepatitis C virus (HCV), viral and host factors are known to be predictors for anti-viral therapy. IL-28B genotype strongly influences treatment outcome, while Epstein-Barr virus (EBV) co-infection could accelerate the course of chronic HCV infection. This study was conducted to assess whether EBV co-infection adds to the predictive value of IL-28B.

PATIENTS AND METHODS

A total of 105 patients with chronic HCV were classified according to their response to treatment into two groups: 38 sustained virological responders (SVRs) and 67 nonresponders (NRs). Collected sera at baseline and follow-up (FUP) were used for assessing EBV antibodies by enzyme-linked immunosorbent assay (ELISA) and the expression of EBV genes (BNLF-1, BZLF-1, and EBER-2) by polymerase chain reaction (PCR). Collected peripheral blood was used for detecting IL-28B rs.12979860 single-nucleotide polymorphism.

RESULTS

Regarding IL-28B genotype frequencies, a significant difference (p=0.003) was observed between SVRs (C/C=51.4%, C/T=48.6%, T/T=0%) and NRs (C/C=25%, C/T=55%, T/T=20%). On assessing EBV infection at baseline and FUP, it was found that 61% and 55% were positive, respectively, with no significant difference between SVRs and NRs. As for anti-viral capsid antigen (VCA) antibodies, the NRs had significantly higher baseline anti-VCA immunoglobulin M (IgM) levels than SVRs (p=0.01). While FUP anti-Epstein-Barr nuclear antigen-1 (EBNA-1) IgG reported a significant decline within SVR patients (p=0.02), neither baseline nor FUP anti-VCA IgG levels showed a statistically significant viral response. Finally, on comparing EBV markers with CC versus CT and TT genotypes, it was found that FUP anti-VCA IgG levels were significantly increased in CC genotype (p=0.003).

CONCLUSION

Interleukin-28B polymorphism could be a possible predictor of response to pegylated interferon/ribavirin therapy (PEG-IFN/RBV). Furthermore, co-infection with EBV did not affect the response to IFN-based therapy in HCV-infected patients.

Hepatitis C virus infection and risk of posttransplantation lymphoproliferative disorder among solid organ transplant recipients

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation. Hepatitis C virus (HCV) infection has been linked to increased risk of lymphoma among immunocompetent individuals. We therefore investigated the association between HCV infection and PTLD in a retrospective cohort study of all individuals in the United States who received their first solid organ transplant from 1994 to 2005 (N = 210 763) using Scientific Registry of Transplant Recipients data. During follow-up, 1630 patients with PTLD were diagnosed. HCV prevalence at transplantation was 11.3%. HCV infection did not increase PTLD risk in the total cohort (Cox regression model, hazard ratio [HR] = 0.84; 95% confidence interval [CI] 0.68-1.05), even after adjustment for type of organ transplanted, indication for transplantation, degree of HLA mismatch, donor type, or use of immunosuppression medications. Additional analyses also revealed no association by PTLD subtype (defined by site, pathology, cell type, and tumor Epstein-Barr virus [EBV] status). HCV infection did increase PTLD risk among the 2.8% of patients (N = 5959) who were not reported to have received immunosuppression maintenance medications prior to hospital discharge (HR = 3.09; 95% CI, 1.14-8.42; P interaction = .007). Our findings suggest that HCV is not a major risk factor for PTLD, which is consistent with the model in which an intact immune system is necessary for development of HCV-related lymphoproliferation.

Hepatocellular lymphoepithelioma-like carcinoma associated with epstein barr virus: a hitherto unrecognized entity

OBJECTIVE

Lymphoepithelioma-like carcinoma (LELC) is an undifferentiated carcinoma with a dense lymphoid stroma. It has been reported in diverse organs and shows variable association with Epstein-Barr virus (EBV). Only a few EBV positive cases have been observed in the hepatobiliary system, all of which were considered to be cholangiocarcinomas. We report a unique case of hepatocellular LELC arising in a cirrhotic liver with EBV demonstrated in the tumor cells.

METHODS AND RESULTS

A 39-year-old Hispanic female underwent an orthotopic liver transplant for end stage liver disease secondary to chronic hepatitis C. A high-grade hepatocellular carcinoma with a dense lymphocytic infiltrate was found in the explant as well as in a portal lymph node. Three months posttransplant, the patient developed numerous hepatic nodules with enlarged periaortic and portacaval lymph nodes. Biopsy of the hepatic nodules showed a recurrent hepatocellular carcinoma devoid of a dense lymphocytic infiltrate. Both the primary and recurrent tumors were positive for EBV by molecular studies. The patient eventually expired from liver failure over a 6-week period.

CONCLUSION

This case represents the first report of EBV-positive hepatocellular LELC. It is particularly interesting given the precipitous clinical outcome, which was possibly related to immunosuppresive therapy.