Single-cell landscape of functionally cured chronic hepatitis B patients reveals activation of innate and altered CD4-CTL-driven adaptive immunity.

BACKGROUND & AIMS: Hepatitis B surface antigen (HBsAg) loss or functional cure (FC) is considered the optimal therapeutic outcome for patients with chronic hepatitis B (CHB). However, the immune-pathological biomarkers and underlying mechanisms of FC remain unclear. In this study we comprehensively interrogate disease-associated cell states identified within intrahepatic tissue and matched PBMCs (peripheral blood mononuclear cells) from patients with CHB or after FC, at the resolution of single cells, to provide novel insights into putative mechanisms underlying FC. METHODS: We combined single-cell transcriptomics (single-cell RNA sequencing) with multiparametric flow cytometry-based immune phenotyping, and multiplexed immunofluorescence to elucidate the immunopathological cell states associated with CHB vs. FC. RESULTS: We found that the intrahepatic environment in CHB and FC displays specific cell identities and molecular signatures that are distinct from those found in matched PBMCs. FC is associated with the emergence of an altered adaptive immune response marked by CD4 cytotoxic T lymphocytes, and an activated innate response represented by liver-resident natural killer cells, specific Kupffer cell subtypes and marginated neutrophils. Surprisingly, we found MHC class II-expressing hepatocytes in patients achieving FC, as well as low but persistent levels of covalently closed circular DNA and pregenomic RNA, which may play an important role in FC. CONCLUSIONS: Our study provides conceptually novel insights into the immuno-pathological control of HBV cure, and opens exciting new avenues for clinical management, biomarker discovery and therapeutic development. We believe that the discoveries from this study, as it relates to the activation of an innate and altered immune response that may facilitate sustained, low-grade inflammation, may have broader implications in the resolution of chronic viral hepatitis. IMPACT AND IMPLICATIONS: This study dissects the immuno-pathological cell states associated with functionally cured chronic hepatitis B (defined by the loss of HBV surface antigen or HBsAg). We identified the sustained presence of very low viral load, accessory antigen-presenting hepatocytes, adaptive-memory-like natural killer cells, and the emergence of helper CD4 T cells with cytotoxic or effector-like signatures associated with functional cure, suggesting previously unsuspected alterations in the adaptive immune response, as well as a key role for the innate immune response in achieving or maintaining functional cure. Overall, the insights generated from this study may provide new avenues for the development of alternative therapies as well as patient surveillance for better clinical management of chronic hepatitis B.

Switching to or Add-on Peginterferon in Patients on Nucleos(t)ide Analogues for Chronic Hepatitis B: The SWAP RCT.

BACKGROUND & AIMS: The optimal therapeutic strategy in nucleoside analogue (NA) experienced chronic hepatitis B (CHB) using peginterferon is still unclear; hence we explored a switch to or add-on peginterferon strategy versus continued NA. METHODS: We conducted a randomized controlled trial of CHB patients on NA >12 months with HBV DNA(-) randomized to switch or add-on peginterferon-alpha2b (1.5 µg/kg/weekly) for 48 weeks versus continuing NA (controls) (allocation 2:2:1; Clinicaltrial.gov: NCT01928511) in tertiary Singapore hospitals. The primary composite endpoint at week 72 was hepatitis B e antigen (HBeAg) loss or quantitative HBsAg (qHBsAg) >1 log IU/mL reduction, and secondary endpoints were HBsAg loss, HBsAg seroconversion, qHBsAg <200 IU/mL, qHBsAg <100 IU/mL, HBV DNA(-), viral relapse, and safety. Analysis was by intention-to-treat (ITT). RESULTS: A total of 253 patients (controls 51, switch 103, add-on 99) were randomized. The primary ITT endpoint was achieved in 3.9% of controls, 33.3% of switch, and 26.7% of add-on (P < .0001, switch/add-on versus controls). HBsAg loss occurred in 0% of controls, 7.8% of switch, and 10.1% of add-on (ITT, P < .001, switch/add-on versus controls). HBeAg(+) patients on peginterferon had higher HBeAg loss than controls but poor HBsAg responses, whereas HBeAg(-) patients on peginterferon achieved better HBsAg responses than controls. Reduction in qHBsAg in HBeAg(+) was 0.14 log IU/mL versus 0.51 log IU/mL in HBeAg(-) (P < .0001) in peginterferon-treated patients. Clinical relapse was higher in switch (13.6% overall, 27% in HBeAg(+)) versus 1% add-on and 0% controls. Adverse events were typically interferon-related symptoms, with one death (myocardial infarction unrelated to therapy). CONCLUSIONS: ITT analysis showed that either peginterferon strategies were superior to NA for the primary endpoint and HBsAg loss, but add-on peginterferon is preferred to switch due to improved safety and similar efficacy. ClincialTrials.gov number: NCT01928511.

Roux-en-Y or Billroth II Reconstruction After Radical Distal Gastrectomy for Gastric Cancer: A Multicenter Randomized Controlled Trial.

OBJECTIVE: The aim of the study was to compare the clinical symptoms between Billroth II (B-II) and Roux-en-Y (R-Y) reconstruction after distal subtotal gastrectomy (DG) for gastric cancer. BACKGROUND: Surgery is the mainstay of curative treatment for gastric cancer. The technique for reconstruction after DG remains controversial. Both B-II and R-Y are popular methods. METHODS: This is a prospective multicenter randomized controlled trial. From October 2008 to October 2014, 162 patients who underwent DG were randomly allocated to B-II (n = 81) and R-Y (n = 81) groups. The primary endpoint is Gastrointestinal (GI) Symptoms Score 1 year after surgery. We also compared the nutritional status, extent of gastritis on endoscopy, and quality of life after surgery between the 2 procedures at 1 year. RESULTS: Operative time was significantly shorter for B-II than for R-Y [mean difference 21.5 minutes, 95% confidence interval (95% CI) 3.8-39.3, P = 0.019]. The B-II and R-Y groups had a peri-operative morbidity of 28.4% and 33.8%, respectively (P = 0.500) and a 30-day mortality of 2.5% and 1.2%, respectively (P = 0.500). GI symptoms score did not differ between R-Y versus B-II reconstruction (mean difference -0.45, 95% CI -1.21 to 0.31, P = 0.232). R-Y resulted in a lower median endoscopic grade for gastritis versus B-II (mean difference -1.32, 95% CI -1.67 to -0.98, P < 0.001). We noted no difference in nutritional status (R-Y versus B-II mean difference -0.31, 95% CI -3.27 to 2.65, P = 0.837) and quality of life at 1 year between the 2 groups too. CONCLUSION: Although BII is associated with a higher incidence of heartburn symptom and higher median endoscopic grade for gastritis, BII and RY are similar in terms of overall GI symptom score and nutritional status at 1 year after distal gastrectomy.

Extensive peritoneal lavage after curative gastrectomy for gastric cancer (EXPEL): study protocol of an international multicentre randomised controlled trial.

Peritoneal recurrence after gastrectomy for gastric cancer is common and the prognosis is dismal. Recent evidence suggests that extensive peritoneal lavage with large volume of normal saline after surgery before abdominal closure can reduce the risk of peritoneal recurrence and improve overall survival. This study aims to evaluate the benefit of extensive intraoperative peritoneal lavage. This is a prospective, open-label, multicentre randomised controlled trial involving 15 international centres in China, Korea, Japan, Malaysia and Singapore. Patients with cT3/4 stomach cancer undergoing curative resection are randomised to either extensive peritoneal lavage (10 l of saline) or standard lavage (≤2 l of saline). The primary outcome is overall survival and secondary outcomes include disease-free survival and peritoneal recurrence. The minimum sample size is 600 subjects with 300 per arm completing 3 years follow-up. The data will be analysed on an intention-to-treat basis, assuming a two-sided test with a 5% level of significance.

Longer examination time improves detection of gastric cancer during diagnostic upper gastrointestinal endoscopy.

BACKGROUND & AIMS: It is not clear how the duration of upper endoscopy affects the detection of cancer or premalignant lesions that increase the risk for gastric cancer. We investigated whether the length of time spent performing esophagogastroduodenoscopy (EGD) affects the detection of important pathologic features of the stomach. METHODS: We collected data from 837 symptomatic patients, during a 3-month period in 2010, who underwent a first diagnostic EGD at a tertiary university hospital in Singapore. Endoscopists were classified as fast or slow based on the mean amount of time it took them to perform a normal EGD examination. We used logistic regression to compare between groups the numbers of intestinal metaplasias, gastric atrophies, dysplasias, and cancers detected, using histologic analysis of biopsy samples collected during endoscopy as the standard. RESULTS: Of 224 normal endoscopies, the mean duration was 6.6 minutes (range, 2-32 min). When we used 7 minutes as the cut-off time, 8 endoscopists were considered to have short mean examination times (mean duration, 5.5 ± 2.1 min; referred to as fast endoscopists), and 8 endoscopists were considered to have long mean examination times (mean duration, 8.6 ± 4.2 min; referred to as slow endoscopists). Eleven cancers and 81 lesions considered to pose risks for cancer were detected in 86 patients; 1.3% were determined to be cancer, 1.0% were determined to be dysplasia, and 8.7% were determined to be intestinal metaplasia and/or gastric atrophy. Slow endoscopists were twice as likely to detect high-risk lesions as fast endoscopists (odds ratio, 2.50; 95% confidence interval, 1.52-4.12), regardless of whether they were endoscopy staff or trainees. The slow endoscopists also detected 3-fold more neoplastic lesions (cancer or dysplasia; odds ratio, 3.42; 95% confidence interval, 1.25-10.38). CONCLUSIONS: Endoscopists with mean EGD examination times longer than 7 minutes identified a greater number of high-risk gastric lesions than faster endoscopists. Examination time may be a useful indicator of quality assessment for upper endoscopy. Studies are required to test these findings in different populations.

Quantitative HBeAg is a strong predictor of HBeAg loss among patients receiving pegylated interferon.

BACKGROUND: HBeAg loss is an important endpoint for antiviral therapy in chronic hepatitis B (CHB), however there are no reliable biomarkers to identify patients who will respond to the addition of pegylated interferon to nucleos(t)ide analogue (NA) therapy. AIM: To evaluate the use of serum biomarkers to predict HBeAg loss. METHODS: HBeAg positive CHB participants on NAs who switched-to or added-on 48 weeks pegylated interferon alpha2b (clinicaltrial.gov NCT01928511) were evaluated at week 72 for HBeAg loss. The predictive ability of qHBeAg, qHBsAg, HBV RNA and clinical variables for HBeAg loss were investigated. RESULTS: HBeAg loss occurred in 15/55 (27.3%) participants who completed 48 weeks of pegylated interferon. There was a lower baseline qHBeAg (1.18 IU/mL [2.27] versus 10.04 IU/mL [24.87], P = 0.007) among participants who lost HBeAg. Baseline qHBeAg (OR = 0.15, 95% CI 0.03-0.66, P = 0.01) and detectable HBV DNA at baseline (OR = 25.00, 95% CI 1.67-374.70, P = 0.02) were independent predictors of HBeAg loss. In addition, on-treatment qHBeAg was also a strong predictor of HBeAg loss (OR = 0.39, 95% CI 0.18-0.81, P = 0.012). The models combining detectable baseline HBV DNA with baseline (C-statistic 0.82) and on-treatment (C-statistic 0.83) had good accuracy for predicting HBeAg loss. A rise in qHBeAg ≥ 10 IU/ml was a predictor of flare (ALT ≥ 120 U/ml) on univariable analysis but not after adjustment for treatment arm. CONCLUSIONS: Baseline and on-treatment qHBeAg is a useful biomarker that can identify participants on NA therapy who may benefit from adding or switching to pegylated interferon.

Endoscopic tri-modal imaging improves detection of gastric intestinal metaplasia among a high-risk patient population in Singapore.

BACKGROUND: Detection of pre-neoplastic gastric mucosal changes and early gastric cancer (EGC) by white-light endoscopy (WLE) is often difficult. In this study we investigated whether combined autofluorescence imaging (AFI) and narrow band imaging (NBI) can improve detection of pre-neoplastic lesions and early gastric cancer in high-risk patients. PATIENTS AND METHODS: Chinese patients who were 50-years-old or above with dyspepsia were examined by both high-resolution WLE and combined AFI followed by NBI (AFI-NBI), consecutively in a prospective randomized cross-over setting, by two experienced endoscopists. The primary outcome was diagnostic ability of the two methods for patients with pre-neoplastic lesions such as intestinal metaplasia (IM) and mucosal atrophy. RESULTS: Sixty-five patients were recruited. One patient with large advanced gastric cancer was found and excluded from the analysis. Among the remaining 64 patients, 38 (59%) had IM; of these, 26 (68%) were correctly identified by AFI-NBI (sensitivity 68%, specificity 23%) and only 13 (34%) by WLE (sensitivity 34%, specificity 65%). AFI-NBI detected more patients with IM than did WLE (p=0.011). Thirty-one patients (48%) had mucosal atrophy. Ten patients (32%) were identified by AFI-NBI (sensitivity 32%, specificity 79%) and four patients (13%) by WLE (sensitivity 13%, specificity 88%) (p=0.100). No dysplasia or EGC was found. CONCLUSION: AFI-NBI identified significantly more patients with IM than did WLE. Our result warrants further studies to define the role of combined AFI-NBI endoscopy for detection of precancerous conditions.

Bayesian analysis of cytokines and chemokine identifies immune pathways of HBsAg loss during chronic hepatitis B treatment.

Our objective was to examine differences in cytokine/chemokine response in chronic hepatitis B(CHB) patients to understand the immune mechanism of HBsAg loss (functional cure) during antiviral therapy. We used an unbiased machine learning strategy to unravel the immune pathways in CHB nucleo(t)side analogue-treated patients who achieved HBsAg loss with peg-interferon-α(peg-IFN-α) add-on or switch treatment in a randomised clinical trial. Cytokines/chemokines from plasma were compared between those with/without HBsAg loss, at baseline, before and after HBsAg loss. Peg-IFN-α treatment resulted in higher levels of IL-27, IL-12p70, IL-18, IL-13, IL-4, IL-22 and GM-CSF prior to HBsAg loss. Probabilistic network analysis of cytokines, chemokines and soluble factors suggested a dynamic dendritic cell driven NK and T cell immune response associated with HBsAg loss. Bayesian network analysis showed a dominant myeloid-driven type 1 inflammatory response with a MIG and I-TAC central module contributing to HBsAg loss in the add-on arm. In the switch arm, HBsAg loss was associated with a T cell activation module exemplified by high levels of CD40L suggesting T cell activation. Our findings show that more than one immune pathway to HBsAg loss was found with peg-IFN-α therapy; by myeloid-driven Type 1 response in one instance, and T cell activation in the other.

Comparative biomarkers for HBsAg loss with antiviral therapy shows dominant influence of quantitative HBsAg (qHBsAg).

BACKGROUND: Biomarkers such as quantitative HBsAg (qHBsAg), quantitative hepatitis B virus (HBV) core-related antigen (qHBcrAg) and HBV RNA may be useful in predicting HBsAg loss in patients with chronic hepatitis B (CHB) undergoing antiviral therapy. AIM(S): Our study evaluated qHBsAg, HBV RNA and qHBcrAg as a posthoc analysis of a randomized clinical trial of peginterferon±NA to determine their utility in predicting HBsAg loss. METHODS: CHB patients who completed therapy with 48weeks peginterferon alpha2b ± nucleoside analogue therapy (clinicaltrial.gov NCT01928511) were evaluated at week 72 for HBsAg loss. The predictive ability of qHBsAg, qHBcrAg, HBV RNA and other variables were investigated by univariate and multivariate logistic models for HBeAg-negative patients by odds ratios, area under the curve (AUC), sensitivity, specificity, and positive and negative likelihood ratios (LR). RESULTS: HBsAg loss occurred in 15/114(13%) HBeAg-negative CHB patients who completed 48 weeks of peginterferon. At baseline, qHBsAg was superior to HBcrAg and HBV RNA with AUC 0.916, 0.649 and 0.542, respectively. Using multivariate analysis, the model comprising treatmentarm, age, gender, baseline qHBsAg, HBcrAg and HBV RNA, weeks 4 & 8 qHBsAg had the highest AUC(0.98), but the univariate model with week 8 qHBsAg <70 IU/mL had AUC 0.96. Hence, the contributions of variables other than qHBsAg were marginal. HBV RNA and qHBcrAg were weak predictors of HBsAg loss. Kinetics of the novel markers showed only qHBsAg had a good relationship with HBsAg loss while HBV RNA had a marginal relationship and HBcrAg did not change at all, and none had a good relationship with viral rebound. CONCLUSIONS: On-treatment biomarker predictors were better than baseline ones, and the best predictor of HBsAg loss at 72 weeks was week 8 qHBsAg <70 IU/mL.

Acquired Resistance to FGFR Inhibitor in Diffuse-Type Gastric Cancer through an AKT-Independent PKC-Mediated Phosphorylation of GSK3ß.

Preclinical models of diffuse-type gastric cancer (DGC) that reliably predict clinical activity of novel compounds are lacking. To overcome the problem of poor tumor cellularity in DGC, we used cells from malignant ascites to establish DGC patient-derived xenograft (PDX) models that recapitulate the primary cancer. Cells in PDX model GAGA6 with FGFR2 amplification were sensitive to AZD4547, a potent FGFR inhibitor that is being clinically evaluated for FGFR-aberrant cancer types. Intermittent in vivo treatment of GAGA6 tumors with AZD4547 gave rise to PDX tumors with acquired resistance to AZD4547, GAGA6-R. Surprisingly, there were no mutations in the FGFR2 gene in GAGA6-R, negating gatekeeper mutations as a mechanism of drug resistance. Phosphorylation of FGFR2 and downstream signaling molecules AKT/PKB and MAPK/ERK remained inhibited by AZD4547. Further analysis of signaling pathways identified AKT-independent phosphorylation and inhibition of GSK3ß as a mechanism of drug resistance in GAGA6-R cells. Treatment of GAGA6-R cells with protein kinase C (PKC) inhibitor H7 in combination with AZD4547 led to dephosphorylation and activation of GSK3ß with concomitant downregulation of MCL-1 and BCL-XL. Combined treatment with AZD4547 and H7 in vitro synergistically enhanced cell death in GAGA6-R but not GAGA6 cells. Furthermore, midostaurin, a multikinase inhibitor with PKC-inhibiting activity, in part reversed resistance of GAGA6-R tumor to AZD4547 in vivo Our results suggest that upon challenge with FGFR inhibitors, FGFR2-amplified tumors that are highly dependent on FGFR2 signaling for survival rapidly develop resistance by switching to a PKC-mediated inhibition of GSK3ß to gain a survival advantage. Mol Cancer Ther; 17(1); 232-42. ©2017 AACR.

CD44v8-10 is a cancer-specific marker for gastric cancer stem cells.

The surface marker CD44 has been identified as one of several markers associated with cancer stem cells (CSC) in solid tumors, but its ubiquitous expression in many cell types, including hematopoietic cells, has hindered its use in targeting CSCs. In this study, 28 paired primary tumor and adjacent nontumor gastric tissue samples were analyzed for cell surface protein expression. Cells that expressed pan-CD44 were found to occur at significantly higher frequency in gastric tumor tissues. We identified CD44v8-10 as the predominant CD44 variant expressed in gastric cancer cells and verified its role as a gastric CSC marker by limiting dilution and serial transplantation assays. Parallel experiments using CD133 failed to enrich for gastric CSCs. Analyses of another 26 primary samples showed significant CD44v8-10 upregulation in gastric tumor sites. Exogenous expression of CD44v8-10 but not CD44 standard (CD44s) increased the frequency of tumor initiation in immunocompromised mice. Reciprocal silencing of total CD44 resulted in reduced tumor-initiating potential of gastric cancer cells that could be rescued by CD44v8-10 but not CD44s expression. Our findings provide important functional evidence that CD44v8-10 marks human gastric CSCs and contributes to tumor initiation, possibly through enhancing oxidative stress defense. In addition, we showed that CD44v8-10 expression is low in normal tissues. Because CD44 also marks CSCs of numerous human cancers, many of which may also overexpress CD44v8-10, CD44v8-10 may provide an avenue to target CSCs in other human cancers.