Serum IL-21 levels associated with chronic hepatitis B and hepatitis B-related liver failure

Review of the potential value of serum interleukin levels as prognostic biomarkers of liver failure

Liver failure (LF) is prevalent in China and is characterized by complex pathogenesis, challenging clinical management, poor prognosis, and rising incidence and mortality rates. The immune status is an important factor affecting LF prognosis. Interleukins (Ils) are a type of cytokine that act and interact with multiple cells, including immune cells. These signaling molecules play important roles in intercellular information transmission, including the regulation of immune cells; mediation of the activation, proliferation, and differentiation of T and B cells; and orchestration of the inflammatory response. To date, many studies have explored the correlation between IL expression and liver disease prognosis, but few studies have evaluated Ils as the prognostic biomarkers of LF. This article reviews the potential use of Ils as the prognostic biomarkers of LF. Particularly, it evaluates the predictive values of IL-21, IL-22, and IL-31, the three often overlooked yet promising prognostic biomarkers, in predicting susceptibility to LF. Harnessing biomarkers for early prognostic insights can facilitate tailored treatment strategies and enhance patient survival. Thus, this article focuses on the identification of IL-21, IL-22, and IL-33 as biomarkers in preclinical and clinical studies on LF and reviews their role as biomarkers in the pathogenesis and diagnosis of LF.

Interleukin-21 receptor signaling promotes metabolic dysfunction-associated steatohepatitis-driven hepatocellular carcinoma by inducing immunosuppressive IgA+ B cells

BACKGROUND

Dysregulation of immune surveillance is tightly linked to the development of metabolic dysfunction-associated steatohepatitis (MASH)-driven hepatocellular carcinoma (HCC); however, its underlying mechanisms remain unclear. Herein, we aimed to determine the role of interleukin-21 receptor (IL-21R) in MASH-driven HCC.

METHODS

The clinical significance of IL-21R was assessed in human HCC specimens using immunohistochemistry staining. Furthermore, the expression of IL-21R in mice was assessed in the STAM model. Thereafter, two different MASH-driven HCC mouse models were applied between IL-21R-deficient mice and wild type controls to explore the role of IL-21R in MASH-driven HCC. To further elucidate the potential mechanisms by which IL-21R affected MASH-driven HCC, whole transcriptome sequencing, flow cytometry and adoptive lymphocyte transfer were performed. Finally, flow cytometry, enzyme-linked immunosorbent assay, immunofluorescent staining, chromatin immunoprecipitation assay and western blotting were conducted to explore the mechanism by which IL-21R induced IgA+ B cells.

RESULTS

HCC patients with high IL-21R expression exhibited poor relapse-free survival, advanced TNM stage and severe steatosis. Additionally, IL-21R was demonstrated to be upregulated in mouse liver tumors. Particularly, ablation of IL-21R impeded MASH-driven hepatocarcinogenesis with dramatically reduction of lipid accumulation. Moreover, cytotoxic CD8+ T lymphocyte activation was enhanced in the absence of IL-21R due to the reduction of immunosuppressive IgA+ B cells. Mechanistically, the IL-21R-STAT1-c-Jun/c-Fos regulatory axis was activated in MASH-driven HCC and thus promoted the transcription of Igha, resulting in the induction of IgA+ B cells.

CONCLUSIONS

IL-21R plays a cancer-promoting role by inducing IgA+ B cells in MASH-driven hepatocarcinogenesis. Targeting IL-21R signaling represents a potential therapeutic strategy for cancer therapy.

Cytokine profiles and virological markers highlight distinctive immune statuses, and effectivenesses and limitations of NAs across different courses of chronic HBV infection

PURPOSE

The characteristics of cytokine/chemokine(CK) profiles across different courses of chronic hepatitis B virus infection and the effects of NAs antiviral therapy on cytokine profiles remain unclear.

METHODS

This report provides evidence from 383 patients with chronic HBV infection. The Luminex multiple cytokine detection technology was used to detect CK profiles. The predictive power of CKs across course of disease was assessedusing univariate analyses and with receiver operating characteristic (ROC) curves.

RESULTS

Compared to healthy control (HC), expression levels of interleukin 6 (IL)-6, IL-8, IL-21, matrix metalloproteinases (MMP)-2 and tumor necrosis factor receptor (TNFR)-1 showed a significant increasing trend during chronic HBV infection. IL-23 and IL-33 increased respectively in chronic hepatitis B patients (CHB). interferon (IFN)-gamma and TNF-α changed significantly only in liver cirrhosis (LC) patients. Whereas, myeloid-related markers decreased dramatically in those with hepatocellular carcinoma (HCC). The ROC result suggests that combining IL-6, IL-8, CXCL9 and CXCL13 into a nomogram has closely correlation with HCC during chronic HBV infection. In addition, nucleotide analogues (NAs) antiviral treatments are capable of recoveringnormal liver functions and significantly reducing the viral loads, however, they seem to have a limited effect in changing CKs, especially specific antiviral factors.

CONCLUSION

The differential CK and virological markers may serve as potential indicators of distinct immune statuses in chronic HBV infection. They also underscore the varying efficacy and limitations of NAs antiviral therapies. This next step would to break new ground in the optimization of current anti-HBV treatment programs although this requires further research.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

Serum Interleukins as Potential Prognostic Biomarkers in HBV-Related Acute-on-Chronic Liver Failure

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is relatively common in China and has complex pathogenesis, difficult clinical treatment, and poor prognosis. Immune status is an important factor affecting ACLF prognosis. Interleukins are a family of secreted lymphocyte factors that interact with a host of cell types including immune cells. These signaling molecules play important roles in transmitting information; regulating immune cells; mediating the activation, proliferation, and differentiation of T and B cells; and modulating inflammatory responses. Many studies have investigated the correlation between interleukin expression and the prognosis of HBV-ACLF. This review focuses on the potential use of interleukins as prognostic biomarkers in HBV-ACLF. References were mainly identified through PubMed and CNKI search, including relevant studies published until December 2021. We have summarized reports of several promising diagnostic interleukin biomarkers that predict susceptibility to HBV-ACLF. The use of biomarkers to understand early prognosis can help devise different therapeutic measures and improve patient survival. Ongoing research on prognostic biomarkers of HBV-ACLF is promising, and future preclinical and clinical studies are warranted.

Cytokines and Chemokines in HBV Infection

Chronic hepatitis B virus (HBV) infection remains a leading cause of hepatic inflammation and damage. The pathogenesis of chronic hepatitis B (CHB) infection is predominantly mediated by persistent intrahepatic immunopathology. With the characterization of unique anatomical and immunological structure, the liver is also deemed an immunological organ, which gives rise to massive cytokines and chemokines under pathogenesis conditions, having significant implications for the progression of HBV infection. The intrahepatic innate immune system is responsible for the formidable source of cytokines and chemokines, with the latter also derived from hepatic parenchymal cells. In addition, systemic cytokines and chemokines are disturbed along with the disease course. Since HBV is a stealth virus, persistent exposure to HBV-related antigens confers to immune exhaustion, whereby regulatory cells are recruited by intrahepatic chemokines and cytokines, including interleukin-10 and transforming growth factor β, are involved in such series of causal events. Although the considerable value of two types of available approved treatment, interferons and nucleos(t)ide analogues, effectively suppress HBV replication, neither of them is sufficient for optimal restoration of the immunological attrition state to win the battle of the functional or virological cure of CHB infection. Notably, cytokines and chemokines play a crucial role in regulating the immune response. They exert effects by directly acting on HBV or indirectly manipulating target immune cells. As such, specific cytokines and chemokines, with a potential possibility to serve as novel immunological interventions, combined with those that target the virus itself, seem to be promising prospects in curative CHB infection. Here, we systematically review the recent literature that elucidates cytokine and chemokine-mediated pathogenesis and immune exhaustion of HBV infection and their dynamics triggered by current mainstream anti-HBV therapy. The predictive value of disease progression or control and the immunotherapies target of specific major cytokines and chemokines in CHB infection will also be delineated.

Serum IL-21 levels predict HBeAg decline during rescue therapy in patients with partial response to nucleos(t)ide analogues

To investigate whether IL-21 levels predict treatment outcomes of salvage therapy among patients with suboptimal response (SOR) to nucleos(t)ide analogues (NAs), serum IL-21 levels were measured in a prospective cohort of hepatitis B e antigen (HBeAg)-positive patients with SOR to antiviral therapy. The patients switched therapy to entecavir (ETV) with or without adefovir (ADV) for 104 weeks. IL-21 levels at treatment week 12 in patients who achieved HBeAg loss with undetectable levels of hepatitis B virus (HBV)-DNA at week 104 were the primary endpoint and the results were compared with those of corresponding patients without such an endpoint. Furthermore, IL-21 levels at treatment week 12 in patients who achieved an HBeAg-level decline at week 104 were assessed as the secondary endpoint. Among 24 enrolled patients with SOR to ADV (n=21), telbivudine (n=2) or ETV (n=1), the median (10-90th percentile) levels of HBeAg, HBV-DNA and ALT at baseline were 2.7 (0.2-3.1) log₁₀ S/CO, 5.2 (3.5-7.5) log₁₀ IU/ml and 0.9 (0.5-3.1) upper limit of normal, respectively. Comparison of the patients with and without HBeAg loss at week 104 indicated that their mean IL-21 levels did not significantly differ at week 12 (63.0±14.4 vs. 55.9±10.5 pg/ml; P=0.26). In the secondary endpoint analyses of patients with and without HBeAg level decline, the elevated levels of IL-21 at the first 12 weeks were significantly higher in the decline group (15.6±8.3 vs. 3.1±13.2 pg/ml; P=0.03). Following adjustment for confounding factors, the elevated levels of IL-21 from baseline to week 12 independently predicted an HBeAg level decline at week 104 (odds ratio=1.137, R²=0.23; P=0.047). In conclusion, the serum IL-21 levels at the first 12 weeks during the salvage therapy independently predicted HBeAg level decline at treatment week 104 in patients with SOR to NAs (ClinicalTrials.gov identifier: NCT01829685; date of registration, April 2013).

Elevated serum A20 is associated with severity of chronic hepatitis B and A20 inhibits NF-κB-mediated inflammatory response

A20 is a powerful suppressor for inflammatory response. This study aims to determine A20 level in patients with chronic hepatitis B (CHB), and analyze its association with the disease severity. The role of A20 in inflammatory response was further investigated in vivo and in vitro. Our results showed significantly higher A20 in both serum and liver tissues in CHB patients than in health controls. Serum A20 level was positively correlated with ALT, AST and TNF-α. To induce hepatitis with inflammation and liver injury, mice were injected intraperitoneally with D-galactosamine (D-GalN), resulting in rapid increase of A20 in serum and liver tissues. Consistently, HepG2 and Huh-7 cells exposed to Lipopolysaccharide (LPS) or D-GalN were promoted to express A20. Moreover, overexpression or knockdown of A20 inhibited or increased TNF-α secretion separately. A20 significantly reduced pro-inflammatory cytokines expression and down-regulated phospho-IκBα and phospho-p65 in both cells. In conclusion, elevated A20 expression is involved in the severity of CHB, suggesting A20 to be a possible serological biomarker for the disease prognosis. Additionally, the inflammatory response is attenuated by A20 through inhibiting NF-κB activity, which partially contributes to the hepato-protective function of this molecule. Thus, up-regulating A20 might be a potential strategy for preventing the progress of CHB.

Identification of the novel 3' UTR sequences of human IL-21 mRNA as potential targets of miRNAs

Hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma worldwide. However, the strategy of HBV to escape from the host immune system remains largely unknown. In this study, we examined extracellular vesicles (EVs) secreted from human hepatocytes infected with HBV. EVs includeing exosomes are nano-size vesicles with proteins, mRNAs, and microRNAs (miRNAs), which can be transmitted to different cells. We found that 104 EV associated miRNAs were increased in hepatocytes more than 2-fold by HBV infection. We then selected those that were potentially implicated in immune regulation. Among them, five HBV-induced miRNAs were found to potentially target multiple sequences in the 3'UTR of IL-21, a cytokine that induces anti-viral immunity. Moreover, expression of a reporter gene with the 3' UTR of human IL-21 mRNA was suppressed by the five miRNAs individually. Finally, IL-21 expression in cloned human T cells was down-regulated by the five miRNAs. Collectively, this study identified the novel 3' UTR sequences of human IL-21 mRNA and potential binding sites of HBV-induced EV-miRNAs.

Interleukin-21 Is Associated with Early Antiviral Response in Patients with Hepatitis B e Antigen-Positive Chronic Hepatitis B and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) becomes a characteristic of liver disease. Interleukin-21 (IL-21) plays an important role in the control of chronic hepatitis B (CHB). We aimed to investigate the relationship between IL-21 and early (24 weeks) viral response (EVR) to antiviral therapy in patients with coexistence of CHB and NAFLD (CHB + NAFLD). A prospective study was carried out in hepatitis B e antigen (HBeAg)-positive CHB + NAFLD and CHB patients receiving Entecavir for initial antiviral therapy, by recording demographic, anthropometric, and clinical data at baseline 12 and 24 weeks. Univariate analysis, correlation analysis, and receiver operating characteristic curve (ROC) were applied to find related factors with EVR. Forty CHB + NAFLD patients and 20 CHB patients entered final analysis. At baseline, IL-21, triglyceride (TG), cholesterol (CHOL), glutanyltransferase (GGT), body mass index (BMI), and computed tomography (CT) ratio of liver/spleen showed significant difference between the 2 groups. Although no significant difference was found, EVR rates was lower in CHB + NAFLD than CHB (75% vs. 90%, P = 0.053). Baseline IL-21 was associated with BMI, CT ratio of liver/spleen, TG, CHOL, and HBeAg level in CHB + NAFLD patients, whose IL-21, alanine aminotransferase, aspartate aminotransferase, CHOL, BMI, and CT ratio of liver/spleen at baseline was associated with EVR. Only the level of IL-21 exhibited significant increase from 0 to 12 weeks, while the change line of other associated factors was nearly parallel between EVR group and non-EVR group. ROC discovered the level of IL-21 at 12 weeks implied a strong predictive value for EVR. We deduced that IL-21 was associated with EVR, and the elevated level of IL-21 at treatment week 12 can predict EVR in CHB + NAFLD patients.