Scott Bowden

Serum hepatitis B surface antigen and hepatitis B e antigen titers: disease phase influences correlation with viral load and intrahepatic hepatitis B virus markers.

Although threshold levels for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) titers have recently been proposed to guide therapy for chronic hepatitis B (CHB), their relationship to circulating hepatitis B virus (HBV) DNA and intrahepatic HBV replicative intermediates, and the significance of emerging viral variants, remains unclear. We therefore tested the hypothesis that HBsAg and HBeAg titers may vary independently of viral replication in vivo. In all, 149 treatment‐naïve CHB patients were recruited (HBeAg‐positive, n = 71; HBeAg‐negative, n = 78). Quantification of HBeAg and HBsAg was performed by enzyme immunoassay. Virological characterization included serum HBV DNA load, HBV genotype, basal core promoter (BCP)/precore (PC) sequence, and, in a subset (n = 44), measurement of intrahepatic covalently closed circular DNA (cccDNA) and total HBV DNA, as well as quantitative immunohistochemical (IHC) staining for HBsAg. In HBeAg‐positive CHB, HBsAg was positively correlated with serum HBV DNA and intrahepatic cccDNA and total HBV DNA (r = 0.69, 0.71, 0.76, P < 0.01). HBeAg correlated with serum HBV DNA (r = 0.60, P < 0.0001), although emerging BCP/PC variants reduced HBeAg titer independent of viral replication. In HBeAg‐negative CHB, HBsAg correlated poorly with serum HBV DNA (r = 0.28, P = 0.01) and did not correlate with intrahepatic cccDNA nor total HBV DNA. Quantitative IHC for hepatocyte HBsAg confirmed a relationship with viral replication only in HBeAg‐positive patients. Conclusion: The correlation between quantitative HBsAg titer and serum and intrahepatic markers of HBV replication differs between patients with HBeAg‐positive and HBeAg‐negative CHB. HBeAg titers may fall independent of viral replication as HBeAg‐defective variants emerge prior to HBeAg seroconversion. These findings provide new insights into viral pathogenesis and have practical implications for the use of quantitative serology as a clinical biomarker. (HEPATOLOGY 2010)

Hepatitis B surface antigen levels during the natural history of chronic hepatitis B: A perspective on Asia

BACKGROUND & AIMS Data from clinical trials suggest a potential role for on-treatment monitoring of serum HBsAg titres during interferon-alpha (pegIFN) therapy in predicting virological responses. However, baseline HBsAg titres during the natural history of chronic hepatitis B (CHB) have not been well-characterized. We aimed to define the serum HBsAg titres during the different phases of CHB in a cohort of Asian patients infected with either genotype B or C HBV. METHODS Two-hundred and twenty patients were classified into immune-tolerant (IT), immune-clearance (IC), non/low-replicative (LR) or hepatitis B e antigen negative hepatitis (ENH) phases. Serum HBsAg was quantified using the ARCHITECT platform (Abbott Laboratories, Chicago, USA). Correlation of HBsAg titre with HBV DNA and serum ALT within each phase of infection was performed. RESULTS Median HBsAg titres were different between each phase of CHB (p=0.001): IT (4.53 log(10)IU/ml), IC (4.03 log(10)IU/ml), LR (2.86 log(10)IU/ml), and ENH (3.35 log(10)IU/ml). HBsAg titres were highest in the IT phase, and lowest in the LR phase. In general, median HBsAg titres were similar between genotypes B and C HBV. Serum HBsAg titres only correlated with HBV viral load in the IC phase. No correlation between the serum HBsAg level and ALT was observed. CONCLUSIONS This study demonstrated significant differences in median baseline serum HBsAg titres across the different phases of CHB. These results provide further insight into the HBV viral life cycle in the setting of the various phases of CHB. Baseline HBsAg quantification may help refine future treatment algorithms for both immune-modulator therapy and oral nucleos(t)ide analogue therapy.

Tenofovir disoproxil fumarate rescue therapy following failure of both lamivudine and adefovir dipivoxil in chronic hepatitis B

Objective To determine the efficacy of tenofovir disoproxil fumarate (TDF) in adults with chronic hepatitis B virus (HBV) infection who had previously failed lamivudine (LAM) and had significant viral replication (HBV DNA >105 copies/ml if HBeAg positive, >104 copies/ml if HBeAg negative) despite at least 24 weeks of treatment with adefovir dipivoxil (ADV). Design A prospective open-label study of TDF 300 mg daily. Patients receiving combination ADV/LAM prior to baseline were switched to TDF/LAM. Setting Multiple tertiary referral centres. Methods Sixty patients were enrolled. The median age was 48.5 years (range 21–80), 46 (77%) were male and 40 (67%) were HBeAg positive. Thirty-eight patients (63%) were switched from ADV to TDF, the remainder from ADV/LAM to TDF/LAM. At baseline, substitutions conferring resistance to LAM or ADV were present in 20 patients (33%) and 17 patients (28%), respectively. The median baseline viral load was 5.33 log10 IU/ml (range 2.81–8.04). Patients initially treated with TDF monotherapy with persistent viral replication at or after 24 weeks were switched to TDF/LAM. The main outcome measures were change in HBV viral load from baseline and percentage of patients achieving an undetectable viral load (<15 IU/ml). Results Results are reported at 96 weeks of treatment. One patient discontinued TDF at 10 days due to rash. The time-weighted change in viral load from baseline to week 12 was −2.19 log10 IU/ml overall. The median change in HBV DNA from baseline to weeks 12, 24, 48 and 96 was −2.86, −3.23, −3.75 and −4.03 log10 IU/ml, respectively. At 48 and 96 weeks, 27/59 (46%) and 38/59 (64%) patients achieved a HBV DNA <15 IU/ml. The response was independent of baseline LAM therapy or mutations conferring ADV resistance. Conclusions In heavily pretreated patients with a high rate of genotypic resistance, TDF retains significant activity against HBV although this appears diminished in comparison with studies of naïve patients.

Asian Pacific Association for the Study of the Liver consensus statements on the diagnosis, management and treatment of hepatitis C virus infection.

Co-chairs: GW McCaughan, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia M Omata, Tokyo University Hospital, Tokyo, Japan Faculty Members: D Amarapurkar, Bombay Hospital, Mumbai, India S Bowden, Victorian Infectious Diseases Reference Laboratories, Melbourne, Australia WC Chow, Singapore General Hospital, Singapore A Chutaputti, Pramongkutklao Hospital, Bangkok, Thailand G Dore, National Center in HIV Epidemiology and Clinical Research, Sydney, Australia E Gane, NZ Liver Transplant Unit, Auckland, New Zealand R Guan, Mount Elizabeth Medical Center, Singapore SS Hamid, The Aga Khan University, Karachi, Pakistan W Hardikar, Royal Children’s Hospital, Melbourne, Australia CK Hui, Queen Mary Hospital, University of Hong Kong, Hong Kong, China W Jafri, The Aga Khan University, Karachi, Pakistan J-D Jia, Beijing Friendship Hospital, Capital Medical University, Beijing, China M-Y Lai, National Taiwan University Hospital, Taiwan L Wei, Peking University Peoples Hospital, Beijing, China N Leung, The Chinese University of Hong Kong, Hong Kong, China T Piratvisuth, Prince of Songkla University, Hat Yai, Thailand S Sarin, GB Pant Hospital, Delhi, India J Sollano, University Santo Tomas Hospital, Manilla, Philippines R Tateishi, University of Tokyo Hospital, Tokyo Japan

A randomized trial of combination hepatitis B therapy in HIV/HBV coinfected antiretroviral naïve individuals in Thailand

Coinfection with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) is associated with considerable liver disease morbidity and mortality. Emerging HIV epidemics in areas of high HBV endemicity such as Asia are expanding the population with HIV/HBV coinfection. Limited randomized trial data exist to support current guidelines for HBV combination therapy in HIV/HBV coinfection. The objective of this prospective randomized clinical trial was to compare the strategy of HBV monotherapy with lamivudine (LAM) or tenofovir disoproxil fumarate (TDF) versus HBV combination therapy with LAM/TDF in antiretroviral‐naïve HIV/HBV‐coinfected subjects in Thailand. Thirty‐six HIV/HBV‐coinfected subjects initiating highly active antiretroviral therapy (HAART) were randomized to either LAM (arm 1), TDF (arm 2), or LAM/TDF (arm 3) as HBV‐active drugs within HAART. At week 48, time‐weighted area under the curve analysis revealed that the median HBV DNA reduction from baseline was 4.07 log10 c/mL in arm 1, 4.57 log10 c/mL in arm 2, and 4.73 log10 c/mL in arm 3 (P = 0.70). HBV DNA suppressed to <3 log10 c/mL in 46% in arm 1, 92% in arm 2, and 91% in arm 3 (P = 0.013, intent‐to‐treat analysis). HBV‐resistant changes were detected in two subjects, both in arm 1. Hepatitis B e antigen (HBeAg) loss was observed in 33% of HBeAg‐positive subjects, and 8% experienced hepatitis B surface antigen loss. Hepatic flare was observed in 25% of subjects. Conclusion: LAM monotherapy resulted in a greater proportion of subjects with HBV DNA >3 log10 c/mL at week 48 and in early resistance development. This study confirms current treatment guidelines that recommend a TDF‐based regimen as the treatment of choice for HIV/HBV coinfection, but does not demonstrate any advantage of HBV combination therapy in this short‐term setting. (HEPATOLOGY 2008.)

96 weeks combination of adefovir dipivoxil plus emtricitabine vs. adefovir dipivoxil monotherapy in the treatment of chronic hepatitis B

BACKGROUND/AIMS In order to prevent the occurrence of drug-resistant mutants associated with treatment for chronic hepatitis B virus (HBV) infection, combination therapy is being developed. To determine the efficacy of adefovir dipivoxil (ADV) plus emtricitabine (FTC) combination therapy in chronic HBV infection. METHODS Thirty treatment-nai ve, HBeAg-positive patients were randomized to combination ADV plus FTC (n=14) or ADV plus placebo monotherapy (n=16) for 96 weeks. HBV DNA was measured by polymerase chain reaction. Treatment was stopped in those with HBeAg seroconversion. RESULTS The median decrease in HBV DNA at week 96 was higher in the combination group (-5.30 vs. -3.98 log(10)copies/ml, p=0.05). More patients in the combination group had normalization of alanine aminotransaminase and HBV DNA<300 copies/ml at week 96 when compared with the monotherapy group [11 of the 14 patients (78.6%) vs. 6 of the 16 patients (37.5%), p=0.03]. However, HBeAg seroconversion at week 96 was similar in the 2 groups [2/14 (14.3%) vs. 4/16 (25.0%), p=NS]. No ADV or FTC resistance was detected at week 96. In those with HBeAg seroconversion, 50.0% had post-treatment relapse. CONCLUSIONS Combination ADV plus FTC resulted in more potent suppression of HBV DNA over 96 weeks of therapy.

Hepatitis B virus and hepatitis C virus interaction in Huh-7 cells

BACKGROUND/AIMS Co-infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) increases the risk of development and the severity of chronic liver disease. Although dominant and suppressive effects of each virus over the other have been reported in vivo, in vitro studies of HBV/HCV co-infection have been limited to analysis of the effects of over-expression of HCV proteins on HBV replication. METHODS We have re-examined HBV/HCV interactions in Huh-7 cells following co-infection with cell culture-propagated HCV (HCVcc; genotype 2a) and a recombinant adenovirus vector capable of delivering a replication-competent HBV genome (AdHBV; genotype A). RESULTS While intracellular HCV RNA levels were significantly increased when cells were pre-infected with AdHBV, HCV replication and virion secretion were not altered by simultaneous infection with AdHBV or AdHBV superinfection of HCV-infected cells. Likewise intracellular and secreted HBV DNA levels and HBV promoter activities were either unchanged or modestly increased by HCVcc infection. Despite this, HCV E2 and HBsAg proteins colocalized extensively in co-infected cells suggesting shared stages in viral egress. CONCLUSIONS These studies indicate that there is little direct interaction of HBV and HCV in co-infected hepatocytes and imply that indirect effects of host-viral interactions dictate viral dominance in HBV/HCV co-infected individuals.

Combination antiviral therapy controls severe post‐liver transplant recurrence of hepatitis B virus infection

The authors have successfully used combination ganciclovir and foscarnet chemotherapy to control viral replication following liver transplantation in a patient with severe recurrence of hepatitis B virus (HBV) infection. The disease was characterized by extremely high viraemias, deteriorating liver function, and high levels of intra‐hepatic hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg). Treatment resulted in a greater than 30‐fold reduction in serum HBV DNA and HBsAg levels. Liver function tests returned to normal and the histological progression of the disease was arrested. Hepatic cytoplasmic HBsAg decreased substantially but there was little change in HBcAg, implicating HBsAg rather than HBcAg in the liver injury. Combination antiviral chemotherapy using agents such as ganciclovir and foscarnet may offer a new approach to the management of post‐transplant recurrence of HBV.

Cellular inhibitor of apoptosis proteins prevent clearance of hepatitis B virus

Significance Hepatitis B virus (HBV) causes substantial morbidity and mortality. A large proportion of infected individuals controls infection but does not completely eradicate HBV DNA from the liver, and flares in hepatitis can be precipitated by immunosuppression. A proportion of individuals never controls infection, and these people are at substantial risk of developing liver failure and liver cancer. Current therapies are not effective at eliminating virus, and there is a major interest in developing functional cures for HBV infection. We identified host cell signaling molecules that can restrict the ability to eradicate infected cells. These molecules can be therapeutically targeted, and drugs that interfere with the function of these host cell proteins may be useful therapies to promote clearance of HBV infection. Hepatitis B virus (HBV) infection can result in a spectrum of outcomes from immune-mediated control to disease progression, cirrhosis, and liver cancer. The host molecular pathways that influence and contribute to these outcomes need to be defined. Using an immunocompetent mouse model of chronic HBV infection, we identified some of the host cellular and molecular factors that impact on infection outcomes. Here, we show that cellular inhibitor of apoptosis proteins (cIAPs) attenuate TNF signaling during hepatitis B infection, and they restrict the death of infected hepatocytes, thus allowing viral persistence. Animals with a liver-specific cIAP1 and total cIAP2 deficiency efficiently control HBV infection compared with WT mice. This phenotype was partly recapitulated in mice that were deficient in cIAP2 alone. These results indicate that antagonizing the function of cIAPs may promote the clearance of HBV infection.

High Rates of Hepatitis C Virus Reinfection and Spontaneous Clearance of Reinfection in People Who Inject Drugs: A Prospective Cohort Study

Hepatitis C virus reinfection and spontaneous clearance of reinfection were examined in a highly characterised cohort of 188 people who inject drugs over a five-year period. Nine confirmed reinfections and 17 possible reinfections were identified (confirmed reinfections were those genetically distinct from the previous infection and possible reinfections were used to define instances where genetic differences between infections could not be assessed due to lack of availability of hepatitis C virus sequence data). The incidence of confirmed reinfection was 28.8 per 100 person-years (PY), 95%CI: 15.0-55.4; the combined incidence of confirmed and possible reinfection was 24.6 per 100 PY (95%CI: 16.8-36.1). The hazard of hepatitis C reinfection was approximately double that of primary hepatitis C infection; it did not reach statistical significance in confirmed reinfections alone (hazard ratio [HR]: 2.45, 95%CI: 0.87-6.86, p=0.089), but did in confirmed and possible hepatitis C reinfections combined (HR: 1.93, 95%CI: 1.01-3.69, p=0.047) and after adjustment for the number of recent injecting partners and duration of injecting. In multivariable analysis, shorter duration of injection (HR: 0.91; 95%CI: 0.83-0.98; p=0.019) and multiple recent injecting partners (HR: 3.12; 95%CI: 1.08-9.00, p=0.035) were independent predictors of possible and confirmed reinfection. Time to spontaneous clearance was shorter in confirmed reinfection (HR: 5.34, 95%CI: 1.67-17.03, p=0.005) and confirmed and possible reinfection (HR: 3.10, 95%CI: 1.10-8.76, p-value=0.033) than primary infection. Nonetheless, 50% of confirmed reinfections and 41% of confirmed or possible reinfections did not spontaneously clear. Conclusions: Hepatitis C reinfection and spontaneous clearance of hepatitis C reinfection were observed at high rates, suggesting partial acquired natural immunity to hepatitis C virus. Public health campaigns about the risks of hepatitis C reinfection are required.