Chronic carriers of hepatitis B virus who clear hepatitis B surface antigen: are they really "off the hook"?

Trends of acute hepatitis B notification rates in eastern China from 2005 to 2013

Zhejiang Province was a high endemicity for hepatitis B disease in the 1990's. A number of measures implemented since then have begun to control and prevent hepatitis B. In 1992, hepatitis B vaccine came on the market. In 2002, hepatitis B vaccine was included in the national Expanded Programme on Immunization (EPI). Between 2007 and 2010, catch-up vaccination was implemented for children under 15. Since 2010, vaccination guidelines for high-risk groups have also been adopted. This study evaluated the impact of these control and prevention strategies on acute hepatitis B notification rates from 2005 through 2013. Data from the National Notifiable Disease Reporting System (NNDRS) revealed a steady downward trend in notification rates of acute hepatitis B. The most dramatic decline occurred among pre-adults, highlighting the benefits of EPI's policy of universal vaccination for children. However, the highest notification rates occurred among young adults of lower socio-economic status. These findings indicate the strong need to vaccinate young adults at risk for HBV infection as well as to collect risk-factor information in the NNDRS for monitoring and following up persons with acute hepatitis B.

Association between SNPs in miRNA-machinery genes and chronic hepatitis B in the Chinese Han population

Single nucleotide polymorphisms (SNPs) in miRNA-machinery genes can influence their generation and maturation, then expression and structure. To explore the relationship between three SNPs (rs3757 in DGCR8, rs636832 in AGO1, rs7813 in GEMIN4) in miRNA-machinery genes and chronic hepatitis B, we genotyped the SNPs by high resolution melting method (HRM) in a case-control study of 332 unrelated chronic hepatitis B patients and 352 unrelated healthy controls in Western China. Interestingly, the rs636832 was significantly associated with the susceptibility of CHB (genotype: AA/GA/GG: p=0.010; allele: A/G: OR=0.727, 95% CI=0.575-0.920, p=0.008). The minor allele A of rs636832 was significantly associated with a decreased risk of CHB. Additionally, the dominant model AG+GG vs. AA showed a risk of 1.442-fold (p=0.018) with CHB. Further exploration for the association between rs636832 and HBV-DNA load in 329 cases showed no significant difference (genotype: p=0.321; allele: p=0.148). Neither did the association between rs636832 and the status of HBsAg and HbeAg (HBsAg: genotype p=0.337, allele p=0.436; HBeAg: genotype p=0.861, allele p=0.822). Our study first provided the evidence that rs636832 in AGO1 was associated with chronic HBV infection susceptibility in Chinese Han population. Further epidemiological and functional studies in larger populations are warranted to verify our results.

Clearance of hepatitis B surface antigen and risk of hepatocellular carcinoma in a cohort chronically infected with hepatitis B virus

Some individuals who are chronically infected with hepatitis B virus (HBV) eventually lose hepatitis B surface antigen (HBsAg). Hepatocellular carcinoma (HCC) has been demonstrated to occur in a few patients after loss of HBsAg. Neither factors associated with loss of HBsAg nor the incidence of HCC thereafter have been clearly elucidated. We performed a prospective population-based cohort study in 1,271 Alaska Native persons with chronic HBV infection followed for an average of 19.6 years to determine factors associated with loss of HBsAg and risk of developing HCC thereafter. HBsAg loss occurred in 158 persons for a rate of HBsAg clearance of 0.7%/year. Older age, but not sex, was associated with clearance of HBsAg, and loss of HBsAg was not associated with any particular HBV genotypes (A, B, C, D, and F) found in this population. Participants were followed for an average of 108.9 months after HBsAg loss. Six patients, two with cirrhosis and four without, developed HCC a mean of 7.3 years after HBsAg clearance (range, 2.0-15.5 years). The incidence of HCC after clearance of HBsAg was 36.8 per 100,000 per year (95% CI 13.5-80.0) which was significantly lower than the rate in those who remained HBsAg-positive (195.7 cases per 100,000 person-years of follow-up [95% CI 141.1-264.5; P < 0.001]). After loss of HBsAg, HBV DNA was detected in the sera of 28 (18%) of those who cleared a median of 3.6 years after clearance.

CONCLUSION

HCC can occur in persons with chronic hepatitis B who have lost HBsAg, even in the absence of cirrhosis. These persons should still be followed with periodic liver ultrasound to detect HCC early.

Surveillance for hepatocellular carcinoma in patients with chronic viral hepatitis in the United States of America

BACKGROUND

Measurement of serum alpha-fetoprotein (AFP) and abdominal ultrasound (US) examination are used for the early detection of hepatocellular carcinoma (HCC) in chronic liver disease patients. However, the accuracy and usefulness of these tests in a clinical setting in the United States of America have not been clarified.

METHODS

We conducted a 7-year prospective surveillance study by using both AFP and US to detect HCC in 602 patients with chronic viral hepatitis. Our main goal was to determine the optimal test for detection of early HCC. We also assessed the clinical outcome of HCC patients identified during this time period.

RESULTS

Thirty-one cases of HCC were detected. Serum AFP levels were elevated in 74% of HCC patients, but was also high in 10% of patients who did not develop HCC. The positive predictive value for AFP to detect HCC was only 12% or less for all AFP cut-off values, and the maximum joint sensitivity and specificity as determined by receiver operator characteristic analysis was approximately 65 and 90%, respectively. Abdominal US identified all 31 cases of HCC. The positive predictive value for US examinations to detect HCC was 78%, while the sensitivity and specificity was 100 and 98%, respectively. After detection of HCC, 24 (77%) patients died within a mean of 16.7 +/- 19.4 months.

CONCLUSIONS

Our study indicates that US examination was more accurate in detecting HCC. Because of its poor predictive value and low sensitivity, serum AFP should not be used as the only test for screening and surveillance for HCC.

Hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) appears to be declining in Taiwan and potentially in other high-prevalence areas as a consequence of vaccination for hepatitis B virus (HBV). However, there is evidence that the incidence of HCC is increasing in North America and Europe. This appears to be related to the increasing prevalence and duration of hepatitis C virus (HCV) infection in these countries. There is also growing evidence to support an increase in the risk of HCC in patients with HCV who are coinfected with occult HBV (patients who have lost HBV surface antigen but still have detectable HBV DNA either in blood or liver). Occult HBV infection in patients with HCV may be more common than previously thought, and HCC that occurs in this setting appears to have a worse prognosis. There is continuing interest in the effect of interferon therapy on the incidence of HCC in patients with HCV. Several studies from Japan have shown a benefit in patients without cirrhosis, although there are a number of potentially confounding variables that may partly explain these results. Prospective randomized studies are needed to investigate this important question. The molecular biology of HCC and the events of malignant transformation in the liver continue to be areas of intense study. Recently, there has been considerable interest in telomeres, the repeat units on the ends of chromosomes, and the enzyme that maintains these, telomerase. Telomeres shorten with each cell division and can be used to determine the number of divisions a cell has undergone. Eventually they reach a critical length, with further loss resulting in cellular senescence. Telomerase restores telomere length and may help malignant cells escape senescence. Nearly all HCCs have telomerase activity and assessments of telomeres and telomerase may be clinically useful.

Natural history of chronic hepatitis B virus infection

In chronic hepatitis B virus (HBV) infection acquired during adulthood, which is the type mostly seen in the Caucasian population, there is biochemical and histologic regression after HBeAg seroconversion, and the risk of death from hepatitis B-related causes is low. In chronic HBV infection acquired during birth or early childhood, which is the type most commonly seen in the Asian population, there is a prolonged phase of immunotolerance. The immune clearance phase is characterized by multiple acute exacerbations preceeded by elevations in serum HBV DNA levels, HBeAg concentration and HBeAg/anti-HBe immune complexes. Of these patients, 2.4% may develop hepatic decompensation during the stage of HBeAg seroconversion. The development of cirrhosis occurs more frequently in patients with episodes of decompensation and with repeated severe acute exacerbations. However progression to cirrhosis can be relatively silent and can occur even in children. After HBeAg seroconversion, precore and core promotor mutations occur frequently in the Asian population. However, there is little correlation between the occurrence of these mutations and alanine aminotransferase elevation in patients who are positive for anti-HBe. Although cirrhosis develops during the process of HBeAg seroconversion, 68% of the complications of cirrhosis and of hepatocellular carcinoma occur after HBeAg seroconversion. These complications may still occur even after HBsAg seroclearance.

Screening for hepatocellular carcinoma in patients with advanced cirrhosis

OBJECTIVE

Most available data on screening for hepatocellular carcinoma (HCC) in patients with cirrhosis originate from Asia and Europe. These data may not be applicable to patients from the United States because of geographic variation in the underlying etiology and other factors. Our aim was to assess the risk of HCC in U.S. patients with cirrhosis undergoing standardized screening.

METHODS

All cirrhotic patients evaluated for liver transplantation at our institution from January 1, 1994-December 31, 1997 were included in this study. The screening strategy included initial screening, which was offered to all patients and consisted of alpha-fetoprotein (AFP), abdominal ultrasound, and computed tomography (CT) scan, and extended screening, which was performed only on transplant-eligible patients and consisted of semiannual AFP and ultrasound.

RESULTS

During the study period, 285 patients with cirrhosis were evaluated for transplantation and underwent initial screening. Of these, 166 were eligible for transplantation and underwent extended screening during a median follow-up of 15 months (range 6-42 months). Twenty-seven HCC were found, 22 during initial screening and five during extended screening. The cancer-free proportions of the cohort who underwent extended screening at 1, 2, and 3.5 yr were 98.6% +/- 1.4%, 96.4 +/- 1.8%, and 77.1% +/- 1.7%, respectively (mean +/- SE). Hepatitis C, either alone or in part, was the etiology in 63% of patients with HCC. The sensitivity of CT scan (88%) was significantly higher than AFP >20 ng/ml (62%) and ultrasound (59%) for detecting HCC (p < 0.001).

CONCLUSIONS

In patients with established cirrhosis, the risk of detecting HCC is maximal at the baseline screening (7%). Hepatitis C was the most common etiology for cirrhosis in study. In U.S. patients with established cirrhosis, CT scan exhibited higher sensitivity for detecting HCC than ultrasound or AFP.