Faculty Bibliography

The discovery of environmentally specific genetic effects is crucial to the understanding of complex traits, such as susceptibility to noise-induced hearing loss (NIHL). We describe the first genome-wide association study (GWAS) for NIHL in a large and well-characterized population of inbred mouse strains, known as the Hybrid Mouse Diversity Panel (HMDP). We recorded auditory brainstem response (ABR) thresholds both pre and post 2-hr exposure to 10-kHz octave band noise at 108 dB sound pressure level in 5-6-wk-old female mice from the HMDP (4-5 mice/strain). From the observation that NIHL susceptibility varied among the strains, we performed a GWAS with correction for population structure and mapped a locus on chromosome 6 that was statistically significantly associated with two adjacent frequencies. We then used a "genetical genomics" approach that included the analysis of cochlear eQTLs to identify candidate genes within the GWAS QTL. In order to validate the gene-by-environment interaction, we compared the effects of the postnoise exposure locus with that from the same unexposed strains. The most significant SNP at chromosome 6 (rs37517079) was associated with noise susceptibility, but was not significant at the same frequencies in our unexposed study. These findings demonstrate that the genetic architecture of NIHL is distinct from that of unexposed hearing levels and provide strong evidence for gene-by-environment interactions in NIHL.

BACKGROUND & AIMS: GS-4774 is a heat-inactivated, yeast-based, T-cell vaccine designed to elicit hepatitis B virus (HBV)-specific T-cell responses. We evaluated the safety, tolerability and efficacy of GS-4774 in patients with chronic HBV infection. METHODS: In this phase II study, 178 patients with chronic HBV infection and no cirrhosis who were virally suppressed on an oral antiviral (OAV) for 1 year were randomized (1:2:2:2) to continue OAV alone or receive OAV plus GS-4774 2, 10, or 40 yeast units (YU) subcutaneously every 4 weeks until week 20. OAV was continued for the remainder of the study. Efficacy was measured by decline in serum hepatitis B surface antigen (HBsAg) from baseline to week 24. RESULTS: Baseline characteristics were similar across groups (mean age, 45-50 years; male, 62-74%; Asian, 68-80%; hepatitis B e antigen (HBeAg)-positive, 24-26%; mean HBsAg, 2.5-3.1 log10 IU/ml). There were no significant differences between groups in mean HBsAg declines from baseline to week 24 or 48. Five HBeAg-positive patients receiving GS-4774 experienced HBeAg loss vs. none in the control group. Three GS-4774 40 YU-treated patients had HBsAg declines 0.5 log10 IU/ml, but no patient experienced loss of serum HBsAg. No virologic breakthrough occurred. Injection site reactions were the most frequent adverse event (AE), and there were no treatment discontinuations. CONCLUSIONS: GS-4774 was well tolerated, but did not provide significant reductions in serum HBsAg in virally suppressed patients with chronic hepatitis B. Efficacy of GS-4774 in treatment naive patients remains to be determined. LAY SUMMARY: GS-4774 is a therapeutic vaccine designed to improve the immune response against hepatitis B virus (HBV) in patients who already have chronic infection with HBV. In this study, GS-4774 was safe and well tolerated in patients with chronic HBV infection receiving oral antiviral therapy, but did not result in a clinical benefit. Combination approaches with other agents, and evaluation in other populations of patients with HBV are ongoing to determine if GS-4774 might have a therapeutic benefit.

OBJECTIVES: Data from the United States are lacking regarding the impact of entecavir (ETV) on the risk of hepatocellular carcinoma (HCC). Our aim is to determine whether treatment with ETV is associated with a reduced HCC risk by calculating the expected HCC incidence based on the Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B (REACH-B) model and comparing it with the observed HCC incidence. METHODS: The incidence of HCC in US patients treated with ETV between 2005 and 2013 in a retrospective cohort was obtained. The predicted HCC incidence was calculated using the REACH-B model. The standardized incidence ratios (SIRs) were calculated as a ratio of observed over predicted HCC cases. RESULTS: Of 841 patients, 646 (65% male, 84% Asian, median age 47 years, 36% hepatitis B e antigen positive, 9.4% with cirrhosis) met the inclusion criteria. Over a median follow-up of 4 years, 17 (2.6%) cases of HCC were diagnosed, including 8 out of 61 (13.1%) patients with cirrhosis and 9 out of 585 (1.5%) without cirrhosis. Compared with those without HCC, the 17 patients with HCC were older at 53 years vs. 47 years and more likely to have cirrhosis at 47.1% vs. 8.4%. Among patients without cirrhosis, the observed HCC incidence was significantly lower than predicted by the fourth year (SIR, 0.37; 95% confidence interval: 0.166-0.82). A sensitivity analysis that comprised all patients, including those with cirrhosis, showed that at the maximum follow-up time of 8.2 years, a significantly lower than predicted HCC incidence was noted with an SIR of 0.56 (95% confidence interval: 0.35-0.905). CONCLUSIONS: Based on the REACH-B model, long-term ETV therapy was associated with a lower than predicted HCC incidence. However, the risk of HCC persisted, and careful HCC surveillance remains warranted despite the anti-viral treatment.Am J Gastroenterol advance online publication, 21 June 2016; doi:10.1038/ajg.2016.257.

BACKGROUND: Few data are available regarding the use of tenofovir disoproxil fumarate (TDF) during pregnancy for the prevention of mother-to-child transmission of hepatitis B virus (HBV). METHODS: In this trial, we included 200 mothers who were positive for hepatitis B e antigen (HBeAg) and who had an HBV DNA level higher than 200,000 IU per milliliter. Participants were randomly assigned, in a 1:1 ratio, to receive usual care without antiviral therapy or to receive TDF (at an oral dose of 300 mg per day) from 30 to 32 weeks of gestation until postpartum week 4; the participants were followed until postpartum week 28. All the infants received immunoprophylaxis. The primary outcomes were the rates of mother-to-child transmission and birth defects. The secondary outcomes were the safety of TDF, the percentage of mothers with an HBV DNA level of less than 200,000 IU per milliliter at delivery, and loss or seroconversion of HBeAg or hepatitis B surface antigen at postpartum week 28. RESULTS: At delivery, 68% of the mothers in the TDF group (66 of 97 women), as compared with 2% in the control group (2 of 100), had an HBV DNA level of less than 200,000 IU per milliliter (P<0.001). At postpartum week 28, the rate of mother-to-child transmission was significantly lower in the TDF group than in the control group, both in the intention-to-treat analysis (with transmission of virus to 5% of the infants [5 of 97] vs. 18% [18 of 100], P=0.007) and the per-protocol analysis (with transmission of virus to 0 vs. 7% [6 of 88], P=0.01). The maternal and infant safety profiles were similar in the TDF group and the control group, including birth-defect rates (2% [2 of 95 infants] and 1% [1 of 88], respectively; P=1.00), although more mothers in the TDF group had an increase in the creatine kinase level. After the discontinuation of TDF, alanine aminotransferase elevations above the normal range occurred more frequently in mothers in the TDF group than in those in the control group (45% [44 of 97 women] vs. 30% [30 of 100], P=0.03). The maternal HBV serologic outcomes did not differ significantly between the groups. CONCLUSIONS: In a cohort of HBeAg-positive mothers with an HBV DNA level of more than 200,000 IU per milliliter during the third trimester, the rate of mother-to-child transmission was lower among those who received TDF therapy than among those who received usual care without antiviral therapy. (Funded by Gilead Sciences; ClinicalTrials.gov number, NCT01488526.).

BACKGROUND: Entecavir (ETV) has been shown to be safe and efficacious in randomised controlled trials in highly selected patients with hepatitis B virus (HBV) infection. AIM: To determine the safety and effectiveness of ETV in 'real-world' HBV patients in the United States (US). METHODS: Treatment-naive HBV patients >/=18 years old who received ETV for >/=12 months between 2005 and 2013 were included in a retrospective, cohort study. Rates of ALT normalisation, undetectable HBV DNA, HBeAg and HBsAg loss/seroconversion, adverse events (AE) and clinical outcomes were evaluated. RESULTS: Of 841 patients, 658 [65% male, 83% Asian; median age 47 years] met the inclusion criteria. 36% were HBeAg+ and 9.3% cirrhotic. 89% had abnormal ALT. Baseline median HBV DNA was 5.8 log 10 IU/mL. Median duration of ETV treatment was 4 years. Rates of ALT normalisation at 1, 3 and 5 years were 37.2%, 48.7% and 56.2% in HBeAg+ and 39.6%, 46.8% and 55.6% in HBeAg- patients. HBV DNA was undetectable at 1, 3 and 5 years in 34.6%, 64.7% and 84.6% in HBeAg+ patients, and 81.9%, 90.3% and 96.2% in HBeAg patients. Five-year cumulative probability of HBeAg loss and seroconversion was 46% and 33.7% and HBsAg loss was 4.6%. ETV was discontinued due to adverse events in 1.2% of patients. Hepatic decompensation occurred in 0.8%, liver cancer in 2.7% and death in 0.6%. CONCLUSION: Entecavir treatment was safe in a large cohort of US patients, but ALT normalisation and hepatitis B virus DNA suppression rates were lower than previously reported in clinical trials.

Hepatitis B virus (HBV), a leading cause of cirrhosis and liver cancer, is a serious health threat, and prevention of HBV transmission is an important part of the strategy to alleviate infection and its outcomes. Hepatitis Bvirus can be vertically transmitted from mothers to fetuses during childbirth, and infants who are untreated can consequently develop chronic infection. This study aimed to assess the utility of tenofovir, a nucleotide analog and HBVpolymerase inhibitor, to prevent mother-to-child transmission ofHBV during pregnancy. A randomized controlled trial was designed to test the efficacy and safety of tenofovir therapy in mothers with HBV DNA levels greater than 200,000 IU/mL. Participants (HBeAg-positive) in a 1: 1 ratio were randomly assigned with or without an oral dose of 300 mg tenofovir daily starting from 30 to 32 weeks of gestation until postpartum week 4. The pregnant mothers and mother-infant dyads were evaluated every 4 weeks for any adverse events and at 4, 12, 24, and 28 weeks postpartum for laboratory results. The rates of mother-to-child transmission and birth defects with or without tenofovir exposure were the primary outcomes, whereas the secondary outcomes included the percentage of mothers with HBV DNA levels less than 200,000 IU/mL at delivery and the percentage of mothers with HBeAg or HBsAg loss or seroconversion at postpartum week 28. The median HBV DNA level was significantly lower at delivery in the tenofovir group compared with the control group (4.7 log10 IU/mL [interquartile range, 4.1-5.3] vs 8.0 log10 IU/mL [interquartile range, 7.5-8.3], P < 0.001). Also, 66 of 97 mothers in the tenofovir group (68%; 95% confidence interval, 59-77) had HBV DNA levels less than 200,000 IU/mL compared with 2 of 100 mothers in the control group (2%; 95% confidence interval, 0-6) at delivery (P < 0.001). In an intention-to-treat analysis, the rate of mother-to-child transmission was significantly lower in infants born tomothers in the tenofovir group (5%) than those in the control group (18%, P = 0.007). When only those women who complied with treatment were examined, the rates of vertical transmission were 0% in the tenofovir group versus 7% in the control group (P = 0.01). With regard to maternal adverse events, 2 significant differences were detected. A higher frequency of an elevation in the creatine kinase level among mothers in the tenofovir group than those in the control group (7% vs 0%, P = 0.006) and higher frequency of elevations in the alanine aminotransferase levels in the tenofovir group compared with the control group (45% vs 30%, P = 0.03) were observed. There were no significant differences between both groups with regard to congenital anomalies or infant growth. The study concluded that the rate of mother-to-child HBV transmission was lower among mothers who received tenofovir therapy than those who did not

The clinical course for chronic hepatitis B (CHB) patients with normal ALT and with or without minimal histologic activity remains unclear. We assessed frequency, amplitude, disease activities, and associated factors of ALT and/or AST flares in this subpopulation. Forty-seven consecutive treatment naive Asian patients with CHB were enrolled from two liver clinics between December 2003 and January 2013, who had normal baseline ALT by routine clinical biochemical testing performed 6 weeks before or after the liver biopsy. We defined a flare as elevation of ALT/AST above the upper limit of normal of ALT/AST. The mean follow-up was 37.6 (CI = 12, 88) months, and the mean age at entry into the study was 43.3 (CI = 19, 65); 22/47 (46.8%) were males; 15/45 (33.3%), HBeAg+; 68.1% had stage 0-1 fibrosis; 63.8% had grade 0-1 inflammation. During follow-up, 13/47 (27.7%) cases developed ALT flare at least once in a mean of 13.5 (CI = 2, 43) months after liver biopsy; ALT flare was not associated with baseline ALT level, fibrosis stage, inflammation grade, hepatitis B virus (HBV) DNA load, HBeAg status, HBV genotype, HBV precore and basal core promoter mutations. 11/13 (84/6%) of ALT flares resolved during follow-up. 13/13 (100%) of ALT flares met AASLD treatment criteria, but only 6/13 (46.2%) were on HBV treatment. Serum ALT and/or AST flares occur frequently in CHB carriers who initially presented with normal ALT during pretreatment period. Thus, regular follow-up is warranted despite status of ALT/AST. No clinical factors were found to be associated with ALT flares.

Background: Pre-core and/or basal core promoter mutations are frequently detected in HBeAg(-) CHB patients, but little is known about the clinical significance of their presence in HBeAg(+) patients. Methods We performed a 2 center cross-sectional study on treatment-naive CHB patients. Clinical characteristics were compared between HBeAg(+) and HBeAg(-) cohorts with mutation analysis. In addition, patients with and without PC/BCP mutations in HBeAg (+) cohort were compared. Results We enrolled 267 consecutive patients with obtainable mutation analysis in 2 centers. Of 177 HBeAg(+) patients, 6(3.39%) were genotype A, 65(36.72%) genotype B, 104(58.76%) genotype C, 1(0.57%) genotype B/C, and 1(0.57%) genotype C/D. Of 90 HBeAg(-) patients, 1(1.11%) were genotype A, 50(55.56%) genotype B, 37(41.11%) genotype C and 2(2.22%) genotype D. When compared to HBeAg(-) patients, HBeAg(+) patients were significantly younger in mean age (37.93 vs. 44.40; P<0.001), had higher levels of mean ALT (108.93+/-169.50 vs 59.41+/-90.29 U/mL; P0.001), higher levels of mean HBV DNA (7.50+/-1.48 vs 5.10+/-1.44 log₁₀ copies/mL; P0.001) and lower frequency of detectable PC/ BCP mutations (60.45% vs. 93.33%; P< 0.001), but had significantly higher percentage of cases with BCP when mutations were detected (37.85%, vs. 22.22%; P = 0.013). Among HBeAg(+) patients, 61% (107/177) had detectable PC/BCP and their clinical features are shown on Table 1. When compared to those with wild type, HBeAg(+) patients with PC/ BCP were significantly older in mean age, had higher mean ALT levels and lower mean HBV DNA levels. Conclusions In treatment-naive HBeAg(+) patients, up to 60% had PC/BCP mutants. These patients presented with distinct clinical characteristics when compared to HBeAg(+) cases with wild type or HBeAg(-) patients. Further studies are needed to substantiate the clinical significance of PC/BCP in HBeAg(+) patients as it may impact the natural history or treatment response in such patients. (Table Presented)