Innate-like Cytotoxic Function of Bystander-Activated CD8+ T Cells Is Associated with Liver Injury in Acute Hepatitis A.

Acute hepatitis A (AHA) involves severe CD8+ T cell-mediated liver injury. Here we showed during AHA, CD8+ T cells specific to unrelated viruses became activated. Hepatitis A virus (HAV)-infected cells produced IL-15 that induced T cell receptor (TCR)-independent activation of memory CD8+ T cells. TCR-independent activation of non-HAV-specific CD8+ T cells were detected in patients, as indicated by NKG2D upregulation, a marker of TCR-independent T cell activation by IL-15. CD8+ T cells derived from AHA patients exerted innate-like cytotoxicity triggered by activating receptors NKG2D and NKp30 without TCR engagement. We demonstrated that the severity of liver injury in AHA patients correlated with the activation of HAV-unrelated virus-specific CD8+ T cells and the innate-like cytolytic activity of CD8+ T cells, but not the activation of HAV-specific T cells. Thus, host injury in AHA is associated with innate-like cytotoxicity of bystander-activated CD8+ T cells, a result with implications for acute viral diseases.

Loss of Krüppel-like factor-10 facilitates the development of chemical-induced liver cancer in mice.

BACKGROUND: Krüppel-like factor 10 (KLF10) is involved in a positive feedback loop that regulates transforming growth factor ß (TGFß) signaling, and TGFß plays an important role in the pathogenesis of liver disease. Here, we investigated whether KLF10 deletion affects the development of liver fibrosis and hepatocellular carcinoma (HCC). METHODS: We induced KLF10 deletion in C57BL/6 mice. Liver fibrosis was induced by feeding a diet high in fat and sucrose (high-fat diet [HFD]), whereas HCC was produced by intraperitoneal administration of N-diethylnitrosamine (DEN). An in vitro experiment was performed to evaluate the role of KLF10 in the cancer microenvironment using Hep3B and LX2 cells. An immunohistochemical study of KLF10 expression was performed using human HCC samples from 60 patients who had undergone liver resection. RESULTS: KLF10 deletion resulted in an increased DEN-induced HCC burden with significant upregulation of SMAD2, although loss of KLF10 did not alter HFD-induced liver fibrosis. DEN-treated mice with KLF10 deletion exhibited increased levels of mesenchymal markers (N-cadherin and SNAI2) and tumor metastasis markers (matrix metalloproteinases 2 and 9). KLF10 depletion in Hep3B and LX2 cells using siRNA was associated with increased invasiveness. Compared with co-culture of KLF10-preserved Hep3B cells and KLF10-intact LX2 cells, co-culture of KLF10-preserved Hep3B cells and KLF10-depleted LX2 cells resulted in significantly enhanced invasion. Low KLF10 expression in resected human HCC specimens was associated with poor survival. CONCLUSION: The results of this study suggest that loss of KLF10 facilitates liver cancer development with alteration in TGFß signaling.

Baseline and on-treatment HBcrAg levels as predictors of HBeAg seroconversion in chronic hepatitis B patients treated with antivirals.

HBeAg seroconversion is an important treatment endpoint. We aimed to identify predictors of seroconversion using serum HBsAg and hepatitis B core-related antigen (HBcrAg) in HBeAg-positive patients treated with nucleos(t)ide analogs (NAs). Data and samples from 70 HBeAg-positive patients treated with entecavir or tenofovir between January 2007 and December 2017 were retrospectively analysed. The mean follow-up period was 11 years. The predictive power for HBeAg seroconversion of HBcrAg levels at baseline and 2 years after antiviral therapy was determined using receiver operating curve analysis. Twenty-one patients (30%) achieved HBeAg seroconversion at a mean of 28 (range, 12-84) months after antiviral treatment. The median baseline HBcrAg and HBsAg levels were 6.9(5.7-7.0) vs. 5.8(5.5-6.5) log10 U/mL (p = .006), 4.9(4.5-5.1) vs. 4.5(4.1-5.0) log10 IU/mL (p = .044) in the no seroconversion group and seroconversion group, respectively. In the multivariate analysis, the serum HBcrAg levels at baseline and 2 years after antiviral therapy were predictive factors for HBeAg seroconversion ([HR]; 0.326; [CI], 0.111-0.958; p = .042 and HR, 0.4555; CI, 0.211-0.984; p = .045). HBcrAg levels≤6.5log10 U/mL at baseline and ≤5.3log10 U/mL at 2 years after antiviral therapy had sensitivities of 53.1% and 69.8%, specificities of 95.2% and 70.6%, positive predictive values of 82.6% and 50.0%, and negative predictive values of 82.6% and 84.5%, respectively, with AUROCs of 0.712 (95%CI, 0.596-0.830) and 0.745 (95%CI, 0.599-0.891) for predicting HBeAg seroconversion. In chronic hepatitis B patients treated with NAs, HBcrAg levels≤6.5log10 U/mL at baseline and ≤5.3log10 U/mL at 2 years after antiviral therapy were useful predictive factors of HBeAg seroconversion.

The care cascade for hepatitis C virus and prognosis of chronic hepatitis C patients treated with antiviral agents in a tertiary hospital.

BACKGROUND: Some studies have analyzed the frequency of HCV RNA testing and actual treatment among anti-HCV positive patients in Korea, which has a low prevalence of HCV infection. This study aimed to analyze the diagnosis process, treatment results, and prognosis according to care cascade in patients who are anti-HCV positive. METHODS: Three thousand two hundred fifty-three anti-HCV positive patients presented to a tertiary hospital between January 2005 and December 2020. The number of patients who underwent HCV RNA testing, treatment, and proportion of sustained virologic response (SVR) according to the type of antivirals was investigated. We investigated the cumulative incidence of hepatocellular carcinoma (HCC) and liver cirrhosis. RESULTS: Of a total of 3,253 people, 1,177 (36.2%) underwent HCV RNA testing and 858 (72.9%) were positive for HCV RNA. 494 (57.6%) of HCV RNA positive patients received antiviral treatment, and 443 (89.7%) of initiated hepatitis C treatment experienced SVR. Of the 421 treated patients, 16 (14.2%) developed HCC. The cumulative incidence of HCC at 15 years was significantly different according to the presence of liver cirrhosis (10/83, 29.5% vs. 6/338, 10.8%, p < 0.001). The cumulative incidences of HCC or liver cirrhosis did not show significant differences according to the presence of SVR12 (14/388, 13.2% vs. 2/33, 52.5%, p = 0.084, 21/319, 15.0%, vs. 3/22, 28.7%, p = 0.051). CONCLUSIONS: Owing to the introduction of direct-acting antivirals, high SVR12 was achieved, but the proportion of anti-HCV positive patients who received HCV RNA testing and treatment was not high. HCC surveillance after SVR12 is recommended for chronic hepatitis C patients with cirrhosis.

Similar risk of kidney function decline between tenofovir alafenamide and besifovir dipivoxil maleate in chronic hepatitis B.

BACKGROUND AND AIMS: Although tenofovir alafenamide (TAF) and besifovir dipivoxil maleate (BSV) are potent antiviral agents in the treatment of chronic hepatitis B (CHB) infection, their renal safety profiles have not been previously compared. This study compared the risk of kidney function decline among patients with treatment-naïve CHB treated with TAF or BSV. METHODS: This multicenter, retrospective, longitudinal cohort study included 556 patients with treatment-naïve CHB treated with TAF (n = 366) or BSV (n = 190) between November 2017 and August 2021. The primary outcome was chronic kidney disease (CKD) progression, defined as an increase in CKD stage by at least one stage for at least three consecutive months. RESULTS: 1:1 Propensity score matching yielded 154 patients in each treatment group. The mean estimated glomerular filtration rate (eGFR) was 100.4 vs. 100.3 ml/min/1.73 m2 in the TAF and BSV groups respectively. A total of 25 patients developed a progression in CKD stage ≥1, of which 13 and 12 patients were from the TAF and BSV treated groups respectively (3.1 vs. 3.3 per 1000 person-years; p = .751). The unadjusted hazard ratio for risk of progression in CKD stage ≥1 of the BSV group (vs. the TAF group) was 1.13 (95% confidence interval, 0.50-2.58; p = .758). This association persisted even after adjusting for potential confounders. Virological, serological and biochemical responses were also similar between the two treatment groups (all p > .05). CONCLUSIONS: TAF and BSV showed a similar risk of kidney function decline in patients with treatment-naïve CHB. Further prospective randomized studies are warranted for validation.

Anti-HBc IgG Levels: A Predictor of HBsAg Seroclearance in Chronic Hepatitis B Patients with Nucleos(t)ide Analogue-Induced HBeAg Seroclearance.

BACKGROUND/AIMS: We investigated the efficiency of the indirect ratio of anti-HBc IgG at predicting HBsAg seroclearance in patients with nucleos(t)ide analogue (NA)-induced HBeAg seroclearance. METHODS: We performed a retrospective study that included 366 chronic hepatitis B patients (March 2007 to December 2016) at a single tertiary hospital. These patients were HBsAg seropositive, and experienced NA-induced HBeAg seroclearance. The indirect ratio of light absorbance of anti-HBc IgG levels were measured with chemiluminescent microparticle immunoassay using the Architect Anti-HBc assay (Abbott Laboratories, IL, USA) as a qualitative method prior to antiviral therapy. We calculated the cumulative incidences of HBsAg seroclearance based on the anti-HBc IgG levels. RESULTS: After a 10-year follow-up, 48 patients experienced HBsAg seroclearance (13.1%). Thirty-three of 179 patients who had an indirect ratio of light absorbance of anti-HBc IgG < 11 RLU (relative light unit) showed HBsAg seroclearance (18.4%); 15 of 187 patients who had an indirect ratio of light absorbance of anti-HBc IgG ≥ 11 RLU showed HBsAg seroclerance (8.0%) (p = 0.003). In multivariate analysis, age, and ALT at the time of HBeAg seroclearance were predictors of HBsAg seroclearance. Especially, the relative risk of HBsAg seroclearance in patients with baseline anti-HBc IgG levels < 11 RLU was 2.213 (95% CI, 1.220-4.014), compared to that in patients with higher levels of anti-HBc IgG at baseline (p = 0.009). CONCLUSION: Using an indirect method for anti-HBc IgG levels, baseline anti-HBc IgG levels (< 11RLU), age (≥ 50 years), and ALT (≥ 40 IU/L) might be associated with HBsAg seroclearance in patients with NA-induced HBeAg seroclearance.

Effects of Statin Use on the Development and Progression of Nonalcoholic Fatty Liver Disease: A Nationwide Nested Case-Control Study.

INTRODUCTION: The use of statins in nonalcoholic fatty liver disease (NAFLD) may reduce cardiovascular morbidity, although their effect on NAFLD itself is not well known. We aimed to investigate the role of statins on the development of de novo NAFLD and progression of significant liver fibrosis. METHODS: This study included 11,593,409 subjects from the National Health Information Database of the Republic of Korea entered in 2010 and followed up until 2016. NAFLD was diagnosed by calculating fatty liver index (FLI), and significant liver fibrosis was evaluated using the BARD score. Controls were randomly selected at a ratio of 1:5 from individuals who were at risk of becoming the case subjects at the time of selection. RESULTS: Among 5,339,901 subjects that had a FLI < 30 and included in the non-NAFLD cohort, 164,856 subjects eventually had NAFLD developed. The use of statin was associated with a reduced risk of NAFLD development (adjusted odds ratio [AOR] 0.66; 95% confidence interval [CI] 0.65-0.67) and was independent of associated diabetes mellitus (DM) (with DM: AOR 0.44; 95% CI 0.41-0.46, without DM: AOR 0.71; 95% CI 0.69-0.72). From 712,262 subjects with a FLI > 60 and selected in the NAFLD cohort, 111,257 subjects showed a BARD score ≥ 2 and were defined as liver fibrosis cases. The use of statins reduced the risk of significant liver fibrosis (AOR 0.43; 95% CI 0.42-0.44), independent of DM (with DM: AOR 0.31; 95% CI 0.31-0.32, without DM: AOR 0.52; 95% CI 0.51-0.52). DISCUSSION: In this large population-based study, statin use decreased the risk of NAFLD occurrence and the risk of liver fibrosis once NAFLD developed.

An Alternatively Spliced Sirtuin 2 Isoform 5 Inhibits Hepatitis B Virus Replication from cccDNA by Repressing Epigenetic Modifications Made by Histone Lysine Methyltransferases.

Sirtuin 2 (Sirt2), an NAD+-dependent protein deacetylase, deacetylates tubulin, AKT, and other proteins. Previously, we showed that Sirt2 isoform 1 (Sirt2.1) increased replication of hepatitis B virus (HBV). Here, we show that HBV replication upregulates the expression of Sirt2 primary and alternatively spliced transcripts and their respective isoforms, 1, 2, and 5. Since Sirt2 isoform 5 (Sirt2.5) is a catalytically inactive nuclear protein with a spliced-out nuclear export signal (NES), we speculated that its different localization affects its activity. The overexpression of Sirt2.5 reduced expression of HBV mRNAs, replicative intermediate DNAs, and covalently closed circular DNA (cccDNA), an activity opposite that of Sirt2.1 and Sirt2.2. Unlike the Sirt2.1-AKT interaction, the Sirt2.5-AKT interaction was weakened by HBV replication. Unlike Sirt2.1, Sirt2.5 activated the AKT/GSK-3ß/ß-catenin signaling pathway very weakly and independently of HBV replication. When the NES and an N-terminal truncated catalytic domain were added to the Sirt2.5 construct, it localized in the cytoplasm and increased HBV replication (like Sirt2.1 and Sirt2.2). Chromatin immunoprecipitation assays revealed that more Sirt2.5 was recruited to cccDNA than Sirt2.1. The recruitment of histone lysine methyltransferases (HKMTs), such as SETDB1, SUV39H1, EZH2, and PR-Set7, and their respective transcriptional repressive markers, H3K9me3, H3K27me3, and H4K20me1, to cccDNA also increased in Sirt2.5-overexpressing cells. Among these, the Sirt2.5-PR-Set7 and -SETDB1 interactions increased upon HBV replication. These results demonstrate that Sirt2.5 reduces cccDNA levels and viral transcription through epigenetic modification of cccDNA via direct and/or indirect association with HKMTs, thereby exhibiting anti-HBV activity.IMPORTANCE Sirt2, a predominant cytoplasmic α-tubulin deacetylase, promotes the growth of hepatocellular carcinoma; indeed, HBV replication increases Sirt2 expression, and overexpression of Sirt2 is associated with hepatic fibrosis and epithelial-to-mesenchymal transition. Increased amounts of Sirt2 isoforms 1, 2, and 5 upon HBV replication might further upregulate HBV replication, leading to a vicious cycle of virus replication/disease progression. However, we show here that catalytically inactive nuclear Sirt2.5 antagonizes the effects of Sirt2.1 and Sirt2.2 on HBV replication, thereby inhibiting cccDNA level, transcription of cccDNA, and subsequent synthesis of replicative intermediate DNA. More Sirt2.5 was recruited to cccDNA than Sirt2.1, thereby increasing epigenetic modification by depositing transcriptional repressive markers, possibly through direct and/or indirect association with histone lysine methyltransferases, such as SETDB1, SUV39H1, EZH2, and/or PR-Set7, which represses HBV transcription. Thus, Sirt2.5 might provide a functional cure for HBV by silencing the transcription of HBV.

Risk assessment of hepatocellular carcinoma and liver-related events using ultrasonography and transient elastography in patients with chronic hepatitis B.

Cirrhosis has prognostic value. We investigated whether the combined use of ultrasonography (US) and transient elastography (TE) to diagnose cirrhosis is beneficial for the risk assessment of hepatocellular carcinoma (HCC) and liver-related events in patients with chronic hepatitis B (CHB). A total of 9300 patients with CHB who underwent US and TE in two institutions between 2006 and 2018 were enrolled. TE value ≥13 kPa was set to indicate cirrhosis. Patients were divided into four groups: US(+)TE(+) (cirrhosis by US and TE), US(+)TE(-) (cirrhosis by US, but not by TE), US(-)TE(+) (cirrhosis by TE, but not by US) and US(-)TE(-) (non-cirrhosis by US and TE).The patients were predominantly male (n = 5474, 58.9%) with a mean age of 47.5 years. The proportions of patients with cirrhosis diagnosed by US and TE were 17.2% (n = 1595) and 13.2% (n = 1225), respectively. The proportion of patients with discordant results in diagnosing cirrhosis by US and TE was 18.7% (n = 1740). During follow-up (median: 60.0 months), HCC and liver-related events developed in 481 (5.2%) and 759 (8.2%) patients, respectively. The cumulative incidence rates of HCC and liver-related events were highest in the US(+)TE(+) group, intermediate-high in the US(-)TE(+) group, intermediate-low in the US(+)TE(-) group and lowest in the US(-)TE(-) group (overall p < .001). Cirrhosis assessed using US and TE was a major predictor of HCC and liver-related event development in patients with CHB. Cirrhosis assessed using TE seemed better in predicting HCC or liver-related events than using US, when cirrhosis diagnosis was discordant by US and TE.

Real-world systemic sequential therapy with sorafenib and regorafenib for advanced hepatocellular carcinoma: a multicenter retrospective study in Korea.

Background/Aims Regorafenib has been approved as a second-line systemic therapy for hepatocellular carcinoma (HCC) patients after the phase III RESORCE trial. This study analyzed real-world data to assess the clinical effectiveness and safety of regorafenib compared to the RESORCE trial. Methods This multicenter cohort study included HCC patients treated with regorafenib after sorafenib (n = 133). We evaluated the time to progression (TTP), progression-free survival (PFS), overall survival (OS), and safety in patients receiving regorafenib along with the predictors of prognosis. Results The median age was 60 years and 81.2% patients were men. Hepatitis B virus infection (68.4%) was the commonest etiology. Most patients were classified as Child-Pugh A (98.5%) and had extrahepatic metastasis (84%) and vascular invasion (45.1%). This study demonstrated similar characteristics apart from more frequent hepatitis B etiology and more vascular or extrahepatic involvement compared with the RESORCE trial. An objective response rate of 12.5% was obtained for response assessment (n = 112); the disease control rate was 34.8%. Thirty-eight patients died during follow-up. With regorafenib, the median OS, PFS, and TTP were 10.0, 2.7, and 2.6 months, respectively. In the exploratory analysis after sorafenib administration, the median OS was 25.8 months. The rate of response and survival were comparable to those in the RESORCE trial. Child-Pugh score > 5, alpha-fetoprotein > 400 ng/ml, and TTP for sorafenib ≥ median were independently associated with OS. Conclusions This real-word regorafenib study showed comparable effectiveness and safety to the RESORCE trial. Regorafenib improves the prognosis of patients with prolonged TTP during previous sorafenib therapy.

Efficacy and safety of selective internal radiation therapy with yttrium-90 for the treatment of unresectable hepatocellular carcinoma.

BACKGROUND: This retrospective analysis was undertaken to evaluate the efficiency of SIRT with Y-90 microspheres and determined prognostic factors affecting patients with unresectable HCC. METHODS: A total of 97 patients diagnosed with unresectable HCC who underwent SIRT with Y-90 microspheres. Patient survival was assessed using the Kaplan-Meier method, and prognostic factors affecting survival were assessed using log-rank tests and Cox proportional hazards regression. RESULTS: Among the 97 patients (90 males, mean age 60.4 ± 12.3 years) who underwent SIRT, the median clinical follow-up was 16.4 (1.8-62) months. The median overall survival (OS) was 23.9 ± 2.4 months. Tumor response according to the Modified RECIST in patients followed up beyond 6 months included a complete response (CR) to treatment in 12 patients (18.8%), partial response (PR) in 23 (35.8%), stable disease (SD) in 8 (12.5%), and progressive disease (PD) in 21 (32.8%). Factors associated with longer OS included age > 65 years, BCLC stage B, tumor size < 5 cm, tumor burden < 25%, and tumor response (CR/PR). In multivariate analysis, unilobar disease and objective tumor response (CR/PR) were predictors of longer OS. CONCLUSION: SIRT was an effective treatment for unresectable HCC. Unilobar disease before SIRT and tumor response (CR/PR) were positive prognostic factors.

Direct-Acting Antivirals Improve Treatment Outcomes in Patients with Hepatitis C Virus-Related Hepatocellular Carcinoma Treated with Transarterial Chemoembolization: A Nationwide, Multi-center, Retrospective Cohort Study.

BACKGROUND AND AIMS: The influence of direct-acting antivirals (DAAs) on chronic hepatitis C (CHC)-related hepatocellular carcinoma (HCC) remains controversial. We investigated the effect of eradicating CHC using DAAs on treatment outcomes in patients with CHC-related HCC treated with transarterial chemoembolization (TACE). METHODS: This nationwide, multi-center, retrospective study recruited patients with CHC-related HCC treated with TACE as the first-line anti-cancer treatment, and who achieved a sustained virological response (SVR) using DAAs (DAA group) between 2006 and 2017. Patients achieving an SVR following interferon-based treatment (IFN group) and those without treatment (control group) were also recruited for comparison. RESULTS: A total of 425 patients were eligible for the study. Of these, 356 (83.8%), 26 (6.1%), and 43 (10.1%) were allocated to the control, IFN, and DAA groups, respectively. A multivariate analysis showed that liver cirrhosis, segmental portal vein thrombosis, and larger maximal tumor size independently predicted an increased risk of progression (all p < 0.05), whereas, the DAA group (vs. IFN and control groups) independently predicted a reduced risk of progression (hazard ratio (HR) = 0.630, 95% confidence interval 0.411-0.966, p = 0.034). The cumulative incidence rate of HCC progression in the DAA group was significantly lower than that in the IFN and control groups (p = 0.033, log-rank test). In addition, the DAA group (vs. IFN and control groups) was independently associated with a reduced risk of mortality (p = 0.042). CONCLUSIONS: DAA treatment provided significantly prolonged progression-free survival in patients with CHC-related HCC treated with TACE compared to that in patients administered IFN or no treatment.

Discontinuation of nucleos(t)ide analogues is not associated with a higher risk of HBsAg seroreversion after antiviral-induced HBsAg seroclearance: a nationwide multicentre study.

OBJECTIVE: Direct comparison of the clinical outcomes between nucleos(t)ide analogue (NA) discontinuation versus NA continuation has not been performed in patients with chronic hepatitis B who achieved HBsAg-seroclearance. Whether NA discontinuation was as safe as NA continuation after NA-induced surface antigen of HBV (HBsAg) seroclearance was investigated in the present study. DESIGNS: This multicentre study included 276 patients from 16 hospitals in Korea who achieved NA-induced HBsAg seroclearance: 131 (47.5%) discontinued NA treatment within 6 months after HBsAg seroclearance (NA discontinuation group) and 145 (52.5%) continued NA treatment (NA continuation group). Primary endpoint was HBsAg reversion and secondary endpoints included serum HBV DNA redetection and development of hepatocellular carcinoma (HCC). RESULTS: During follow-up (median=26.9 months, IQR=12.2-49.2 months), 10 patients (3.6%) experienced HBsAg reversion, 6 (2.2%) showed HBV DNA redetection and 8 (2.9%) developed HCC. Compared with NA continuation, NA discontinuation was not associated with HBsAg reversion in both univariable (HR=0.45, 95% CI=0.12 to 1.76, log-rank p=0.24) and multivariable analyses (adjusted HR=0.65, 95% CI=0.16 to 2.59, p=0.54). The cumulative probabilities of HBsAg reversion at 1, 3 and 5 years were 0.8%, 2.3% and 5.0% in the NA discontinuation group, and 1.5%, 6.3% and 8.4% in the NA continuation group, respectively. NA discontinuation was not associated with higher risk of either HBV redetection (HR=0.83, 95% CI=0.16 to 4.16, log-rank p=0.82) or HCC development (HR=0.53, 95% CI=0.12 to 2.23, log-rank p=0.38). CONCLUSION: The discontinuation of NA was not associated with a higher risk of either HBsAg reversion, serum HBV DNA redetection or HCC development compared with NA continuation among patients who achieved HBsAg seroclearance with NA.

Human liver CD8+ MAIT cells exert TCR/MR1-independent innate-like cytotoxicity in response to IL-15.

BACKGROUND & AIMS: Mucosal-associated invariant T (MAIT) cells, the most abundant innate-like T cells in the human liver, can be activated by cytokines during viral infection without TCR stimulation. Here, we examined the mechanisms underlying TCR/MR1-independent innate-like cytotoxicity of cytokine-activated liver MAIT cells. We also examined the phenotype and function of MAIT cells from patients with acute viral hepatitis. METHODS: We obtained liver sinusoidal mononuclear cells from donor liver perfusate during liver transplantation and examined the effect of various cytokines on liver MAIT cells using flow cytometry and in vitro cytotoxicity assays. We also obtained peripheral blood and liver-infiltrating T cells from patients with acute hepatitis A (AHA) and examined the phenotype and function of MAIT cells using flow cytometry. RESULTS: IL-15-stimulated MAIT cells exerted granzyme B-dependent innate-like cytotoxicity in the absence of TCR/MR1 interaction. PI3K-mTOR signaling, NKG2D ligation, and CD2-mediated conjugate formation were critically required for this IL-15-induced innate-like cytotoxicity. MAIT cells from patients with AHA exhibited activated and cytotoxic phenotypes with higher NKG2D expression. The innate-like cytotoxicity of MAIT cells was significantly increased in patients with AHA and correlated with serum alanine aminotransferase levels. CONCLUSIONS: Taken together, the results demonstrate that liver MAIT cells activated by IL-15 exert NKG2D-dependent innate-like cytotoxicity in the absence of TCR/MR1 engagement. Furthermore, the innate-like cytotoxicity of MAIT cells is associated with liver injury in patients with AHA, suggesting that MAIT cells contribute to immune-mediated liver injury. LAY SUMMARY: Immune-mediated liver injury commonly occurs during viral infections of the liver. Mucosal-associated invariant T (MAIT) cells are the most abundant innate-like T cells in the human liver. Herein, we have identified a mechanism by which MAIT cells circumvent conventional T cell receptor interactions to exert cytotoxicity. We show that this innate-like cytotoxicity is increased during acute hepatitis A virus infection and correlates with the degree of hepatocyte injury.

Predictive score for hepatocellular carcinoma after hepatitis B e antigen loss in patients treated with entecavir or tenofovir.

The risk of developing hepatocellular carcinoma (HCC) after hepatitis B e antigen seroclearance (ESC) remains unclear. We established and validated a new risk prediction model for HCC development after ESC in patients with chronic hepatitis B (CHB) receiving antiviral therapy (AVT). Between 2006 and 2016, 769 patients (training cohort) and 1,061 patients (validation cohort) with CHB who experienced ESC during AVT using entecavir (ETV) or tenofovir disoproxil fumarate (TDF) were recruited. In the multivariate analysis, male sex (hazard ratio [HR] = 2.092; 95% confidence interval [CI] = 1.152-3.800), cirrhosis (HR = 5.141; 95% CI = 2.367-11.167) and fibrosis-4 index (FIB-4) of >3.25 (HR = 2.070; 95% CI = 1.184-3.620) were the independent risk factors for HCC development (all P < .05). Accordingly, a novel HCC-ESCAVT model was developed (1x[sex: male = 1, female = 0] + 3x(cirrhosis = 1, noncirrhosis = 0) + 1x(FIB-4: >3.25 = 1, ≤3.25 = 0). The cumulative risk for HCC development was significantly different among the risk groups based on the HCC-ESCAVT category (0-1, 2-4 and 5 for the low-, intermediate- and high-risk groups, respectively) (overall P < .001, log-rank test). The area under the receiver operating characteristic curve (AUC) for predicting HCC development 3, 5 and 10 years after ESC was 0.791, 0.771 and 0.790, respectively (all P < .05). The predictive value of the HCC-ESCAVT model was similar in the validation cohort (AUC = 0.802, 0.774 and 0.776 at 3, 5 and 10 years, respectively; all P < .05). Hence, we have developed and validated a new HCC-ESCAVT model for HCC development, which includes male sex, cirrhosis and FIB-4 of >3.25 as constituent variables.

Cumulative incidence of hepatocellular carcinoma and hepatitis B surface antigen Seroclearance after Nucleos(t) ide analogue-induced hepatitis B e antigen Seroclearance.

BACKGROUND: Hepatitis B e antigen (HBeAg) seroclearance has been considered as the treatment endpoint in HBeAg-positive patients with chronic hepatitis B (CHB). Although HBeAg seroclearance has been accomplished, some aspects are yet unclear. We investigated the cumulative incidence of hepatocellular carcinoma (HCC) and evaluated hepatitis B surface antigen (HBsAg) seroclearance in patients undergoing nucleos(t) ide analogue (NA)-induced HBeAg seroclearance. METHODS: In this retrospective cohort study, 203 patients with CHB were HBsAg and HBeAg seropositive before NA (entecavir or tenofovir) treatment. All patient who experienced NA -induced HBeAg seroclearance were recruited. Patients with documented HBeAg seroclearance were followed-up every 6 months. Baseline characteristics and laboratory results were recorded. RESULTS: The mean age at HBeAg seroclearance was 40 years (range, 20-84), and the mean follow-up duration was 5 years (range, 2-11). The cumulative incidence of HCC was 1.5 to 11.5% at 1 to 8 years after HBeAg seroclearance. Cirrhosis was the only significant factor for HCC development (hazard ratio [HR], 24.651; confidence interval [CI], 3.018 to 201.365; P = 0.003). The cumulative incidence of HBsAg seroclearance was 3.5 to 18.7% after 1 to 8 years from HBeAg seroclearance. CONCLUSIONS: A significant proportion of patients developed HCC after NA-induced HBeAg seroclearance. The presence of liver cirrhosis at the time of HBeAg seroclearance serves as an independent factor for HCC development. Some patients with NA-induced HBeAg seroclearance achieved HBsAg seroclearance.

Aromatase Inhibitors and Newly Developed Nonalcoholic Fatty Liver Disease in Postmenopausal Patients with Early Breast Cancer: A Propensity Score-Matched Cohort Study.

BACKGROUND: Unlike tamoxifen, the relationship between aromatase inhibitor use in postmenopausal patients with breast cancer and nonalcoholic fatty liver disease (NAFLD) has not been delineated. MATERIALS AND METHODS: A retrospective analysis of 253 patients with early breast cancer without baseline NAFLD and treated with nonsteroidal aromatase inhibitors was performed. Among them, 220 patients were matched for sex, age, and menstruation status with healthy patients, and the prevalence of NAFLD was compared. NAFLD was determined by hepatic steatosis index in the absence of other known liver diseases. The presence of significant liver fibrosis in patients with NAFLD was determined noninvasively by AST-platelet ratio index, FIB-4 score, and NAFLD fibrosis score (NFS). RESULTS: Postmenopausal patients with breast cancer undergoing treatment with aromatase inhibitors had higher prevalence of NAFLD independent of body mass index (BMI) and underlying diabetes mellitus (DM). Although the aromatase inhibitor group showed higher fibrotic burden by NFS, independent of BMI and DM, the proportion of advanced fibrosis did not show statistically significant differences between AI-treated patients and the healthy patients. Those with abnormal baseline fasting glucose levels are suggested to have increased risk of NAFLD development after aromatase inhibitor treatment. In addition, patients with NAFLD developed after aromatase inhibitor use had significantly lower disease-free survival than those without NAFLD, although there was no significant difference in overall survival. CONCLUSION: Results of this study suggest that inhibition of estrogen synthesis in postmenopausal women undergoing treatment with aromatase inhibitors could increase the risk of NAFLD, which might have some influence on the prognosis of patients with breast cancer. IMPLICATIONS FOR PRACTICE: Unlike tamoxifen, the role of aromatase inhibitor treatment use in postmenopausal patients with breast cancer in development of fatty liver is not well known. In this propensity-matched cohort study, postmenopausal patients with breast cancer treated with aromatase inhibitors had increased risk of nonalcoholic fatty liver disease compared with healthy women after menopause, independent of obesity and diabetes mellitus. The results show possible adverse influence of the newly developed fatty liver on breast cancer disease-free survival and suggest a necessity for further validation. Fatty liver may need to be considered as an adverse event for aromatase inhibitor treatment.

Tumor Necrosis Factor-producing T-regulatory Cells Are Associated With Severe Liver Injury in Patients With Acute Hepatitis A.

BACKGROUND AND AIMS: CD4+CD25+Foxp3+ T-regulatory (Treg) cells control immune responses and maintain immune homeostasis. However, under inflammatory conditions, Treg cells produce cytokines that promote inflammation. We investigated production of tumor necrosis factor (TNF) by Treg cells in patients with acute hepatitis A (AHA), and examined the characteristics of these cells and association with clinical factors. METHODS: We analyzed blood samples collected from 63 patients with AHA at the time of hospitalization (and some at later time points) and 19 healthy donors in South Korea. Liver tissues were collected from patients with fulminant AHA during liver transplantation. Peripheral blood mononuclear cells were isolated from whole blood and lymphocytes were isolated from liver tissues and analyzed by flow cytometry. Cytokine production from Treg cells (CD4+CD25+Foxp3+) was measured by immunofluorescence levels following stimulation with anti-CD3 and anti-CD28. Epigenetic stability of Treg cells was determined based on DNA methylation patterns. Phenotypes of Treg cells were analyzed by flow cytometry and an RORγt inhibitor, ML-209, was used to inhibit TNF production. Treg cell suppression assay was performed by co-culture of Treg-depleted peripheral blood mononuclear cells s and isolated Treg cells. RESULTS: A higher proportion of CD4+CD25+Foxp3+ Treg cells from patients with AHA compared with controls produced TNF upon stimulation with anti-CD3 and anti-CD28 (11.2% vs 2.8%). DNA methylation analysis confirmed the identity of the Treg cells. TNF-producing Treg cells had features of T-helper 17 cells, including up-regulation of RORγt, which was required for TNF production. The Treg cells had reduced suppressive functions compared with Treg cells from controls. The frequency of TNF-producing Treg cells in AHA patients' blood correlated with their serum level of alanine aminotransferase. CONCLUSIONS: Treg cells from patients with AHA have altered functions compared with Treg cells from healthy individuals. Treg cells from patients with AHA produce higher levels of TNF, gain features of T-helper 17 cells, and have reduced suppressive activity. The presence of these cells is associated with severe liver injury in patients with AHA.

Selective deletion of hepatocyte platelet-derived growth factor receptor α and development of liver fibrosis in mice.

BACKGROUND: Platelet-derived growth factor receptor α (PDGFRα) expression is increased in activated hepatic stellate cells (HSCs) in cirrhotic liver, while normal hepatocytes express PDGFRα at a negligible level. However, cancerous hepatocytes may show upregulation of PDGFRα, and hepatocellular carcinoma is preceded by chronic liver injury. The role of PDGFRα in non-cancerous hepatocytes and liver fibrosis is unclear. We hypothesized that upon liver injury, PDGFRα in insulted hepatocytes contributes to liver fibrosis by facilitating intercellular crosstalk between hepatocytes and HSCs. METHODS: Hepatocytes were isolated from normal and thioacetamide (TAA)-induced cirrhotic livers for assessment of PDGFRα expression. Conditional knock-out (KO) C57BL/6 mice, in which PDGFRα was selectively deleted in hepatocytes, were generated. Liver fibrosis was induced by injecting TAA for 8 weeks. Hep3B cells were transfected with a small interfering RNA (siRNA) (PDGFRα or control) and co-cultured with LX2 cells. RESULTS: PDGFRα expression was increased in hepatocytes from fibrotic livers compared to normal livers. Conditional PDGFRα KO mice had attenuated TAA-induced liver fibrosis with decreased HSC activation and proliferation. Immunoblot analyses revealed decreased expression of phospho-p44/42 MAPK in TAA-treated KO mice; these mice also showed almost complete suppression of the upregulation of mouse double minute 2. Although KO mice exhibited increased expression of transforming growth factor (TGF)-ß and Smad2/3, this was compensated for by increased expression of inhibitory Smad7. LX2 cells co-cultured with PDGFRα siRNA-infected Hep3B cells showed decreased PDGFRα, α smooth muscle actin, collagen α1(I), TGFß, and Smad2/3 expression. LX2/PDGFRα-deleted hepatocyte co-culture medium showed decreased PDGF-BB and PDGF-CC levels. CONCLUSIONS: Deletion of PDGFRα in hepatocytes attenuated the upregulation of PDGFRα in HSCs after TAA treatment, resulting in decreased liver fibrosis and HSC activation. This suggests that in the event of chronic liver injury, PDGFRα in hepatocytes plays an important role in liver fibrosis by affecting PDGFRα expression in HSCs.

The clinical implication of single nucleotide polymorphisms in deoxycytidine kinase in chronic hepatitis B patients treated with lamivudine.

Deoxycytidine kinase (dCK) is a critical enzyme involved in intracellular phosphorylation of lamivudine (LAM) to its active triphosphates. We conducted this study to determine dCK polymorphisms in Koreans and to evaluate whether the discovered single nucleotide polymorphisms (SNPs) were associated with treatment outcomes in chronic hepatitis B (CHB) patients treated with LAM. The full-length dCK gene was sequenced from 24 healthy volunteers and 24 patients with CHB. One hundred twenty-seven patients with CHB who were followed-up for at least 24 months after LAM treatment were enrolled. Virological response as determined by undetectable HBV DNA was defined as a good drug response. Primary non-response at 6 months and virological breakthrough within 12 months were defined as a poor drug response. Six novel dCK SNPs were found (-2052C/A, IVS3 - 46G/del, IVS4 + 40G/T, IVS5 + 39T/C, IVS5 - 72A/T, and 966-975T10/T11). In particular, two promoter SNPs, namely -360C/G and -201C/T, were in full linkage disequilibrium. These two SNPs had a higher allele frequency than previously reported in Caucasian, Japanese, and Chinese (26% vs. 2%, 13.1%, and 15.6%, respectively). There was no significant difference between treatment response groups in terms of the distributions of SNP genotypes or allele frequencies. However, there was significant difference in the allele frequency of -360G/-201T between HBeAg seroclearance group and HBeAg non-seroclearance group (P = 0.045). In conclusion, six novel dCK SNPs were discovered. Two promoter SNPs, namely -360C/G and -201C/T, were more frequent in Koreans than other populations. In particular, HBeAg-positive patients with the -360G/-201T haplotype may help HBeAg seroclearance in response to LAM therapy.