Xiaoyong Zhang

Hepatitis due to Reactivation of Hepatitis B Virus in Endemic Areas Among Patients With Hepatitis C Treated With Direct-acting Antiviral Agents

&NA; Hepatitis due to reactivation of hepatitis B virus (HBV) has been reported in patients treated with direct‐acting antiviral (DAA) agents for chronic hepatitis C virus infection. We performed an observational study to determine the incidence of and factors associated with hepatitis in 327 patients receiving pan‐oral DAA agents for HCV infections in areas endemic for HBV in China. Ten patients were positive for hepatitis B surface antigen (HBsAg), and 124 patients had occult HBV infection. HBV reactivation was determined by measuring HBV DNA and HBsAg status in serial serum samples collected every 2 weeks during DAA treatment and then every 4 weeks after treatment until week 12. In the total study population, 10 patients (3.1%) had hepatitis; 3 cases were associated with HBV reactivation (1 case not in the icteric phase, 1 case in the icteric phase, and 1 case with liver failure) and 7 from other causes. Testing positive for HBsAg before DAA treatment was a strong risk factor for developing hepatitis during treatment (hazard ratio, 15.0; P < .001).

Chemokine (C‐X‐C motif) ligand 13 promotes intrahepatic chemokine (C‐X‐C motif) receptor 5+ lymphocyte homing and aberrant B‐cell immune responses in primary biliary cirrhosis

The serologic hallmark of primary biliary cirrhosis (PBC) is the presence of high titer, and specific anti-mitochondrial antibodies (AMA). Interestingly, although there is no global immune defect in patients with PBC, there is widespread dysregulated B cell function, including increased sera levels of IgM and enhanced B cell responses to CpG stimulation. The mechanisms involved in this B cell dysfunction have remained unknown. To address this issue, we focused on identifying the frequencies of B cell subsets in patients with PBC and the mechanisms that lead to B cell dysregulation, including the relationships with CXCR5+CD4+T cells. Herein we report that elevations of both serum and intrahepatic IL-21 were found in patients with PBC and, in particular, promoted B cell proliferation, STAT3 phosphorylation and AMA production in vitro. More importantly, upon stimulation with rPDC-E2, CXCR5+CD4+T cells in PBC produced higher levels of IL-21 than healthy controls. Additionally, sorted CXCR5+CD4+T cells increased production of AMA by autologous CD19+B cells. Indeed, elevated expression of intrahepatic CXCL13, a key chemokine of CXCR5+ cells, was uniquely found within the portal tracts in PBC, accompanied by infiltrates of CD4+, CXCR5+, CD19+, and CD38+ cells. In conclusion, CXCL13 promotes aggregation of CD19+B cells and CXCR5+CD4+T cells, which directs the aberrant AMA response via IL-21. These data have implications for potential immunotherapy and also reflect the unique lymphoid biology in the liver of PBC.The serological hallmark of primary biliary cirrhosis (PBC) is the presence of high titer and specific antimitochondrial antibodies (AMAs). Although there is no global immune defect in patients with PBC, there is widespread dysregulated B‐cell function, including increased sera levels of immunoglobulin M and enhanced B‐cell responses to cytosine‐phosphate‐guanine stimulation. The mechanisms involved in this B‐cell dysfunction have remained unknown. To address this issue, we focused on identifying the frequencies of B‐cell subsets in patients with PBC and the mechanisms that lead to B‐cell dysregulation, including the relationships with chemokine (C‐X‐C motif) receptor 5 (CXCR5)+CD4+T cells. Herein, we report that elevations of both serum and intrahepatic interleukin‐21 (IL‐21) were found in patients with PBC and, in particular, promoted B‐cell proliferation, signal transducer and activator of transcription 3 phosphorylation and AMA production in vitro. More important, upon stimulation with recombinant E2 subunit of pyruvate dehydrogenase complex, CXCR5+CD4+T cells in PBC produced higher levels of IL‐21 than healthy controls. Additionally, sorted CXCR5+CD4+T cells increased production of AMAs by autologous CD19+B cells. Indeed, elevated expression of intrahepatic chemokine (C‐X‐C motif) ligand 13 (CXCL13), a key chemokine of CXCR5+ cells, was uniquely found within the portal tracts in PBC, accompanied by infiltrates of CD4+, CXCR5+, CD19+, and CD38+ cells. Conclusion: CXCL13 promotes aggregation of CD19+B cells and CXCR5+CD4+T cells, which directs the aberrant AMA response by IL‐21. These data have implications for potential immunotherapy and also reflect the unique lymphoid biology in liver of PBC. (Hepatology 2015;61:1998‐2007)

Off-Treatment Hepatitis B Virus (HBV) DNA Levels and the Prediction of Relapse After Discontinuation of Nucleos(t)ide Analogue Therapy in Patients With Chronic Hepatitis B: A Prospective Stop Study

BackgroundnThe optimal management remains unknown after nucleos(t)ide analogue (NA) discontinuation in patients with chronic hepatitis B (CHB). This prospective study investigated the role of off-treatment viral kinetics in predicting relapse after discontinuation of NA therapy.nnnMethodsnA total of 82 noncirrhotic Asian patients with CHB who discontinued NA therapy according to international guidelines were prospectively followed. Patients with a hepatitis B virus (HBV) DNA level of >2000 IU/mL and an alanine aminotransferase (ALT) level of >2 times the upper limit of normal (clinical relapse) were retreated.nnnResultsnSixty patients were HBV envelope antigen (HBeAg) positive at the start of treatment, and 22 were HBeAg negative. Clinical relapse developed in 28 patients (2-year rates, 31% among HBeAg-positive patients and 53% among HBeAg-negative patients). Age of ≤35 years (hazard ratio [HR], 0.37; P = .026) and end-of-treatment HBsAg level of ≤200 IU/mL (HR, 0.39; P = .078) were independently associated with lower relapse rates. A high risk of biochemical relapse (defined as an ALT level of >2 times the upper limit of normal) was observed if the HBV DNA level was >200000 IU/mL when the level was initially elevated, compared with HBV DNA levels of >2000 to ≤200000 IU/mL (HR, 8.42; P < .001). The risk of biochemical relapse was also high in patients with persistent elevation in the HBV DNA level (confirmed to be >2000 IU/mL within 3 months), compared with the group with transient elevation (HR, 6.87; P < .001).nnnConclusionsnAfter NA discontinuation, a lower relapse rate was observed in younger patients and in those with low end-of-treatment HBsAg levels. The level and persistence of off-treatment elevated HBV DNA levels were useful in the prediction of a subsequent biochemical relapse and may thus be used to guide off-treatment management.

Elevated Expression of Chemokine CXCL13 in Chronic Hepatitis B Patients Links to Immune Control during Antiviral Therapy

C–X–C-chemokine ligand 13 (CXCL13), the ligand for C–X–C chemokine receptor type 5 (CXCR5), is a major regulator of B-cell trafficking and plays an integral role in age-dependent clearance of hepatitis B virus (HBV) in the mouse model. However, the expression and function of CXCL13 in patients with chronic hepatitis B (CHB) remain unknown. By use of liver cell subpopulations isolated from CHB patients, we found that CXCL13 mRNA was abundantly expressed in Kupffer cells (KCs), but not in primary hepatocytes, liver sinusoidal endothelial cells, and hepatic stellate cells. Interestingly, KC isolated from HBV-positive liver had much higher level of CXCL13 expression than non-HBV-infected controls. And its expression was induced by toll-like receptor 3 ligand poly I:C stimulation. Moreover, intense expression of CXCL13 protein and accumulation of CD4+ T and B cells were evident in follicular-like structures in the liver tissue of CHB patients, which indicated its chemotactic effect on CXCR5+ CD4+ cells and B cells. Consistently, the levels of serum CXCL13 were significantly higher in the CHB patients than in healthy controls. Furthermore, CXCL13 concentration was increased in the complete response (CR) group during weeks 0–12 and did not change significantly during the course of telbivudine treatment, compared with the patients who didn’t achieve CR. In conclusion, the HBV-related increase of CXCL13 production in KC and serum CXCL13 level during telbivudine treatment might be associated with immune control of chronic HBV infection.

Predictors of sustained virologic response after discontinuation of nucleos(t)ide analog treatment for chronic hepatitis B.

Background/Aims: The aim of this study was to identify the predictors for relapse after discontinuation of oral nucleos(t)ide analog treatment for chronic hepatitis B (CHB). Patients and Methods: We evaluated patients who were receiving long-term, regular antiviral therapy with nucleos(t)ide analogs, and subsequently achieved the discontinuation criteria from the Asia-Pacific guideline. After they voluntarily discontinued the drug therapy, data were prospectively collected to observe the potential virologic relapse, and the parameters that predicted recurrence were analyzed. Results: Sixty-five patients met the inclusion criteria, and were included in this study. Twenty-eight patients relapsed, and the accumulative recurrence rates at the 3-month, 6-month, and 1-year follow-ups were 13.85%, 32.31%, and 49.23%, respectively. There was no difference in the accumulative recurrence rate 12 months after discontinuation among patients who were positive or negative for the hepatitis B e antigen (HBeAg) before they received the medication. Logistic regression analysis revealed that the time to complete response, age at discontinuation, and HBsAg levels at discontinuation affected the rate of relapse. Conclusions: Among patients who received orally administrated nucleos(t)ide analogs, serum levels of HBsAg, age at discontinuation, and the time to complete response might be used as a guide to discontinue treatment. Among younger patients, those with low serum HBsAg levels, and those with an earlier complete response, the risk of relapse is lower and discontinuation is much safer.

Lower Expression of MicroRNA-155 Contributes to Dysfunction of Natural Killer Cells in Patients with Chronic Hepatitis B

MicroRNAs have been reported to be regulated in different ways in a variety of liver diseases. As a key modulator of cellular function in both innate and adaptive immunity, the role of miR-155 in chronic hepatitis B virus infection remains largely unknown. Here, we investigated the expression and function of miR-155 in chronic hepatitis B (CHB) patients. It was found that miR-155 expression in peripheral blood mononuclear cells (PBMCs) was lower in CHB patients than healthy controls (HC). Among CHB infection, immune-active (IA) patients with abnormal alanine aminotransferase (ALT) levels had relatively higher miR-155 expression in PBMCs and serum than immune-tolerant carriers, but were comparable to inactive carriers. Moreover, there was a positive correlation between miR-155 expression and ALT levels in CHB patients. Particularly, miR-155 expression in natural killer (NK) cells was significantly downregulated in IA patients compared with HC. Inversely, suppressor of cytokine signaling 1 (SOCS1), a target of miR-155, was upregulated in NK cells of IA patients. Overexpression of miR-155 in NK cells from IA patients led to a decrease in SOCS1 expression and an increase of IFN-γ production. Finally, accompanied by the normalization of ALT, miR-155 expression in PBMCs gradually decreased during telbivudine or peg-IFN-α-2a therapy. Interestingly, higher miR-155 expression at baseline was associated with better response to telbivudine therapy, but not peg-IFN-α-2a. In conclusion, our data suggested that miR-155 downregulation in NK cells of IA patients impaired IFN-γ production by targeting SOCS1, which may contribute to immune dysfunction during CHB infection. Additionally, baseline miR-155 expression could predict the treatment response to telbivudine therapy.

TCRγδ+CD4−CD8− T Cells Suppress the CD8+ T-Cell Response to Hepatitis B Virus Peptides, and Are Associated with Viral Control in Chronic Hepatitis B

The immune mechanisms underlying failure to achieve hepatitis B e antigen (HBeAg) seroconversion associated with viral control in chronic hepatitis B (CHB) remain unclear. Here we investigated the role of CD4−CD8− T (double-negative T; DNT) cells including TCRαβ+ DNT (αβ DNT) and TCRγδ+ DNT (γδ DNT) cells. Frequencies of circulating DNT cell subsets were measured by flow cytometry in a retrospective cohort of 51 telbivudine-treated HBeAg-positive CHB patients, 25 immune tolerant carriers (IT), 33 inactive carriers (IC), and 37 healthy controls (HC). We found that γδ DNT cell frequencies did not significantly change during treatment, being lower at baseline (Pu200a=u200a0.019) in patients with HBeAg seroconversion after 52 weeks of antiviral therapy (nu200a=u200a20) than in those without (nu200a=u200a31), and higher in the total CHB and IT than IC and HC groups (P<0.001). αβ DNT cell frequencies were similar for all groups. In vitro, γδ DNT cells suppressed HBV core peptide-stimulated interferon-γ and tumor necrosis factor-α production in TCRαβ+CD8+ T cells, which may require cell–cell contact, and could be partially reversed by anti-NKG2A. These findings suggest that γδ DNT cells limit CD8+ T cell response to HBV, and may impede HBeAg seroconversion in CHB.

IL-21 receptor signaling is essential for control of hepatocellular carcinoma growth and immunological memory for tumor challenge

ABSTRACT Hepatocellular carcinoma (HCC) is a typical inflammation-associated cancer. IL-21 regulates both innate and adaptive immune responses and has key roles in antitumor and antiviral responses. However, the role of IL-21 in HCC development is poorly defined. In the current study, we explored the role of IL-21R signaling in HCC growth by using IL-21R knockout mice and HCC mouse models. We discovered that IL-21R signaling deficiency promoted HCC growth in tumor-bearing mice. We showed that IL-21R deletion reduced T cells infiltration and activation as well as their function but increased the accumulation of myeloid-derived suppressor cells in tumor tissues to enhance HCC growth. Furthermore, loss of IL-21R signaling in tumor-bearing mice resulted in an imbalance of the systemic immune system characterized by decreased antitumor immune cells and increased immunosuppressive cells in the spleen and lymph nodes. In addition, we revealed that IL-21R signaling is critical for the expansion of antitumor immune cells in the memory immune response to tumor rechallenge. Finally, we showed that the transcriptional levels of IL-21 in the peritumoral region and IL-21R within the tumor are associated with survival and recurrence of HCC patients. In conclusion, our study demonstrates that IL-21R signaling is essential for controlling the development of HCC and immunological memory response to tumor challenge.

Pre-Activation of Toll-Like Receptor 2 Enhances CD8+ T-Cell Responses and Accelerates Hepatitis B Virus Clearance in the Mouse Models

Toll-like receptors (TLRs) play a crucial role in activation of innate immunity, which is essential for inducing effective adaptive immune responses. Our previous studies have shown that toll-like receptor 2 (TLR2) is required to induce effective virus-specific T-cell responses against hepatitis B virus (HBV) in vivo. However, the contribution of TLR2 activation to adaptive immunity and HBV clearance remains to be clarified. In this study, we explored the hydrodynamic injection (HI) mouse models for HBV infection and examined how the TLR2 agonist Pam3CSK (P3C) influences HBV control and modulates HBV-specific T-cell response if applied in vivo. We found that TLR2 activation by P3C injection leads to the rapid but transient production of serum proinflammatory factors interleukin-6 and tumor necrosis factor-α and activation of CD8+ T cells in vivo. Then, the anti-HBV effect and HBV-specific T-cell immunity were investigated by TLR2 activation in the mouse models for persistent or acute HBV infections using HBV plasmids pAAV-HBV1.2 and pSM2, respectively. Both P3C application at early stage and pre-activation promoted HBV clearance, while only TLR2 pre-activation enhanced HBV-specific T-cell response in the liver. In the mouse model for acute HBV infection, P3C application had no significant effect on HBV clearance though P3C significantly enhanced the HBV-specific T-cell response. Collectively, TLR2 pre-activation enhances HBV-specific T-cell responses and accelerates HBV clearance in HI mouse models. Thus, the modulation of host immune status by TLR2 agonists may be explored for immunotherapeutic strategies to control HBV infection.

Serum Level of Antibodies Against Hepatitis B Core Protein Is Associated With Clinical Relapse After Discontinuation of Nucleos(t)ide Analogue Therapy.

BACKGROUND & AIMS: Levels of antibodies against the hepatitis B virus (HBV) core protein (anti‐HBc) have been associated with response to nucleos(t)ide analogue and (peg)interferon therapy in patients with chronic HBV infection. We performed a prospective study to determine whether the total serum level of anti‐HBc level (immunoglobulins M and G) is associated with clinical relapse after discontinuation of nucleos(t)ide analogue‐based therapy. METHODS: We collected data from patients with chronic HBV infection who discontinued nucleos(t)ide analogue therapy according to pre‐specified stopping criteria, recruited from November 2012 through July 2016 at an academic hospital in Guangzhou, China. Patients were followed through February 2017. We performed comprehensive biochemical and virologic tests at every visit, and anti‐HBc was quantified for 2 years after treatment cessation (at baseline and weeks 4, 8, 12, 24, 48, and 96). The primary endpoint was clinical relapse, defined as level of HBV DNA >2000 IU/mL and level of alanine aminotransferase more than 2‐fold the upper limit of normal—these were also the criteria for retreatment. RESULTS: We followed 100 patients (71% positive for HB e antigen [HBeAg] at the start of nucleos(t)ide analogue therapy, 43% treated with entecavir or tenofovir) for a median of 2.5 years after stopping therapy. Clinical relapse occurred in 39 patients (in 46% of patients at year 4 after discontinuation). High level of anti‐HBc at the end of treatment (hazard ratio [HR], 0.31 per log IU/mL; P = .002) and low level of HB surface antigen (HBsAg) at the end of treatment (HR, 1.71 per log IU/mL; P = .032) were associated with a reduced risk of clinical relapse after adjusting for age, start of nucleos(t)ide analogue therapy, HBeAg‐status, and consolidation therapy duration. At year 4, 21% of patients with anti‐HBc levels at the end of treatment ≥1000 IU/mL developed a clinical relapse compared to 85% of patients with levels <100 IU/mL (P < .001). An HBsAg level at the end of treatment ≤100 IU/mL was associated with a reduced risk of relapse (HR 0.30; P = .045). However, 82% of patients had levels of HBsAg above 100 IU/mL; for these patients, level of anti‐HBc at the end of treatment could be used to determine the risk of relapse (HR 0.39 per log IU/mL; P = .005). CONCLUSION: In a median 2.5‐year follow‐up study of patients with chronic HBV infection who stopped nucleos(t)ide analogue therapy, total serum level of anti‐HBc at the end of treatment was associated with risk of clinical relapse. Serum level of anti‐HBc might be used to select patients suitable for discontinuing nucleos(t)ide analogue therapy.