Strategy for vaccination against hepatitis B in areas with high endemicity: focus on Korea

Association between spleen volume and the post-hepatectomy liver failure and overall survival of patients with hepatocellular carcinoma after resection

OBJECTIVES

Post-hepatectomy liver failure (PHLF) can occur as a major complication after hepatic resection (HR) in patients with hepatocellular carcinoma (HCC) and negatively affects the prognosis. We aimed to retrospectively assess whether the spleen volume (SV) measured from preoperative CT images would be associated with the development of PHLF and overall survival (OS) after HR in patients with HCC.

METHODS

We enrolled 317 consecutive patients with very early/early stage HCC who underwent a preoperative CT and HR between January 2010 and December 2016. The SV was obtained from preoperative CT images using semi-automated volumetric software and was divided by body surface area to yield SV_BSA. Receiver operating characteristic (ROC) curves and logistic regression analyses were performed to identify factors affecting the development of PHLF. The Cox proportional hazard model was used to identify prognostic factors for OS.

RESULTS

PHLF was observed in 72 patients (22.7% [72/317]). SV_BSA was associated with the development of PHLF (odds ratio, 2.321; 95% CI, 1.347-4.001; p = 0.002) with the area under the ROC curve of 0.663 using the cutoff value of 107.5 cm³ (p < 0.001). SV_BSA was also an influencing factor for OS (hazard ratio, 3.935; 95% CI 1.520-10.184; p = 0.005), with the optimal cutoff of 146 cm³. The 5-year OS rate was higher in 245 patients with a SV_BSA ≤ 146 cm³ than in 72 patients with a SV_BSA > 146 cm³ (95.0% vs. 78.7%, p < 0.001).

CONCLUSIONS

In patients with HCC, a larger SV_BSA was associated with a higher rate of PHLF and worse OS after HR. The SV_BSA may be useful in selecting good surgical candidates.

KEY POINTS

• A significantly higher spleen volume divided by body surface area was observed in patients who experienced post-hepatectomy liver failure than in patients who did not (148 cm³ vs. 112 cm³, p < 0.001). • The area under the receiver operating characteristic curve of spleen volume divided by body surface area to predict the development of post-hepatectomy liver failure was 0.663 (p < 0.001). • Spleen volume divided by body surface area was a significant influencing factor for overall survival (hazard ratio, 3.935; 95% CI, 1.520-10.184; p < 0.001), with the optimal cutoff of 146 cm³.

Chronic hepatitis B infection and non-hepatocellular cancers: A hospital registry-based, case-control study

Background

Prior epidemiological evidences suggest that hepatitis B virus (HBV) infection is linked to cancers other than hepatocellular carcinoma. This prospective hospital registry-based case-control study aimed to investigate the sero-epidemiological association between chronic HBV infection and various types of cancer.

Methods

95,034 patients with first-diagnosed non-hepatocellular malignancy in a tertiary hospital between 2007 and 2014; and 118,891 non-cancer individuals as controls from a health promotion center were included. Cases and controls were compared for HBV surface antigen (HBsAg) positivity by conditional regression with adjustment for age, hypertension, diabetes, body mass index, alcohol consumption, smoking status and cholesterol level in both genders.

Results

An analysis of matched data indicated significant associations of HBV infection with lymphoma (adjusted odds ratio[AOR] 1.53 [95% CI 1.12–2.09] in men and 3.04 [1.92–4.82] in women) and biliary cancer (2.59[1.98–3.39] in men and 1.71[1.16–2.51] in women). Cervical (1.49[1.11–2.00]), uterine (1.69[1.09–2.61]), breast (1.16[1.02–1.32]), thyroid (1.49[1.28–1.74]), and lung cancers (1.79[1.32–2.44]) in women; and skin cancer (5.33[1.55–18.30]) in men were also significantly related to HBV infection.

Conclusions

Chronic HBV infection is associated with several malignant disorders including lymphoma, and biliary, cervical, uterine, breast, thyroid, lung, and skin cancers. Our findings may offer additional insights into the development of these neoplasms and may suggest the need to consider HBV screening in cancer patients and cancer surveillance in HBV-infected subjects.

Liver stiffness-based model for prediction of hepatocellular carcinoma in chronic hepatitis B virus infection: comparison with histological fibrosis

BACKGROUND & AIMS

Liver stiffness (LS) value using transient elastography is a reliable, non-invasive tool for assessing liver fibrosis. LS-based prediction model, LSPS (=LS value × spleen diameter/platelet count) is well correlated with the risk of developing portal hypertension-related cirrhotic complications. Here, we assessed the prognostic performance of LSPS in predicting the development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB).

METHODS

Between 2006 and 2010, we recruited 227 patients with CHB who underwent liver biopsy and LS measurement. The major end point was HCC development.

RESULTS

Median age was 45 years and 156 (68.7%) patients were male. During the follow-up period (median, 61 months), HCC developed in 18 patients. Patient with HCC had a higher LS value, a longer spleen, and lower platelet counts (all P < 0.05) than those without HCC. On multivariate analysis, LSPS was identified as an independent predictor of HCC development [hazard ratio (HR) 1.541, P < 0.001] after adjusting for age, serum albumin level and histological fibrosis stage. When patients were stratified into three groups (LSPS <1.1, 1.1-2.5 and >2.5), the 5-year cumulative risk of HCC increased significantly in association with a higher LSPS value (4.0, 13.8, 36.2%, respectively, P < 0.001). Patients with LSPS 1.1-2.5 (HR 2.0, P = 0.032) and LSPS > 2.5 (HR 8.7, P = 0.002) had a higher risk of developing HCC than those with LSPS < 1.1.

CONCLUSIONS

LS value-spleen diameter to platelet ratio score is useful for assessing the risk of HCC development and careful surveillance strategies are required in an individual manner.

Long-term outcomes of chronic hepatitis B virus infection in the era of antiviral therapy in Korea

BACKGROUND AND AIMS

Chronic hepatitis B (CHB) can progress to cirrhosis, hepatocellular carcinoma (HCC), and ultimately liver-related deaths. Recently, owing to potent antiviral therapy with minimal side-effects, sustained suppression of hepatitis B virus replication can be achieved, thereby preventing such complications. We aimed to reappraise clinical courses regarding disease progression in the era of antiviral therapy.

METHODS

Between 2001 and 2005, treatment-naïve Korean CHB patients without cirrhosis were enrolled and followed up for at least 5 years. During follow up, antiviral therapy was commenced according to Korean Association for the Study of the Liver guidelines, if eligible, and ultrasonography and laboratory and clinical assessment were performed regularly. Primary end-points were development of cirrhosis, hepatic decompensation, HCC, or liver-related deaths.

RESULTS

Of 360 patients, 323 (89.7%) received antiviral therapy such as lamivudine (70.6%), entecavir (8.7%), or telbivudine (6.5%). During follow up, cirrhosis developed in 29 (8.1%), hepatic decompensation in 4 (1.1%), and HCC in 15 (4.2%) patients. Annual incidences of cirrhosis, hepatic decompensation, and HCC were 1.05%, 0.14%, and 0.53% per person-year, respectively. Age was an independent predictor for developing cirrhosis (hazard ratio [HR] 1.075, 95% confidence interval [CI] 1.037-1.116; P < 0.001), whereas age (HR 1.060, 95% CI 1.012-1.111; P = 0.014) and cirrhosis (HR 17.470, 95% CI 5.081-60.063; P < 0.001) were those for developing HCC.

CONCLUSIONS

In the era of antiviral therapy, overall clinical courses have been much improved since introduction of lamivudine in 1999. However, patients with older age or cirrhosis are still subject to HCC development despite appropriate antiviral therapy, necessitating cautious surveillance.

Lack of association of RAD51 genetic variations with hepatitis B virus clearance and occurrence of hepatocellular carcinoma in a Korean population

The RecA homolog, E. coli (S. cerevisiae) (RAD51) may modulate hepatitis B virus (HBV) infection by maintaining genome integrity and mediating homologous DNA repairs. In this study, 16 sequence variations were detected by resequencing all exons, the exon-intron boundary, and promoter regions of the human RAD51 gene in DNA samples of 24 unrelated individuals. To investigate the association of common variations in the RAD51 locus with HBV infection and hepatocellular carcinoma (HCC) occurrence, six common polymorphisms were genotyped in a total of 1,103 Korean HBV cohort, composed of 433 spontaneously recovered patients as controls and 670 chronic carriers of HBV, who were stratified further into 327 cirrhosis/chronic hepatitis patients and 343 patients with HCC infected with HBV. Logistic analyses revealed no significant association of RAD51 polymorphisms and haplotypes with HBV clearance and HCC occurrence (P > 0.05). Furthermore, with age of infection as an important factor in disease progression to HCC, results from the Cox proportional hazards analysis showed no significant associations between any of the tested RAD51 variants and the age of onset of HCC (P > 0.05), suggesting that genetic polymorphisms of RAD51 may not play an important role in clearance of HBV and disease progression to HCC. Although studies in other populations are needed to confirm these findings, this preliminary data may contribute to the current knowledge on the pathogenesis of hepatitis.

Replicative activity of hepatitis B virus is negatively associated with methylation of covalently closed circular DNA in advanced hepatitis B virus infection

OBJECTIVES

The aim of this study was to examine the methylation status of intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and to elucidate the possible relationship between the cccDNA methylation and viral replicative activity in patients with HBV-related liver cirrhosis (HBV-LC).

METHODS

The methylation status of HBV cccDNA was investigated by bisulfite sequencing in nonneoplastic tissues from 12 patients with HBV-LC who underwent surgical resection for combined hepatocellular carcinoma. Clinical, biochemical and virologic factors were evaluated with respect to the degrees of cccDNA methylation. We also examined the effect of methylation of cccDNA on viral transcription by an in vitro transcription assay.

RESULTS

Variable degrees of CpG methylation were present in the HBV cccDNA from patients with HBV-LC. Old age, low serum HBV DNA levels and low virion productivity were significantly associated with elevated cccDNA methylation. Virion productivity of cccDNA was also lower in HepAD38 cells with a higher degree of cccDNA methylation. In vitro transcription assays showed that the transcriptional activity of HBV cccDNA was suppressed by increased methylation of cccDNA.

CONCLUSIONS

Increased CpG methylation of cccDNA is associated with old age, low serum HBV DNA levels and suppressed replicative activity in HBV-LC.

Hepatitis B virus infection and risk of non-Hodgkin lymphoma in South Korea: a cohort study

BACKGROUND

Hepatitis B virus (HBV) infection is common throughout Asia and Africa. Whether chronic HBV infection increases risk of non-Hodgkin lymphoma (NHL) is unclear. We aimed to assess the association between chronic HBV infection and subsequent development of NHL in a South Korean cohort.

METHODS

The Korean Cancer Prevention Study is a cohort study of South Korean workers and their dependants enrolled during 1992-95. From this cohort, we excluded individuals who died before Jan 1, 1993, who had cancer at or before the initial visit, who had missing information about weight, height, alanine aminotransferase or aspartate aminotransferase concentrations, or alcohol use, or who had evidence of HIV or HCV infection. Of 1,284,586 eligible participants, 603,585 had baseline data for serum hepatitis B surface antigen (HBsAg) status and were included in our study. We regarded HBsAg positivity at baseline as evidence of chronic HBV infection. Participants were followed up from baseline until Dec 31, 2006. We used national databases of inpatient and outpatient diagnoses and mortality records to ascertain occurrence of haematological malignancies. We assessed incidence of NHL overall and of NHL subtypes, malignant immunoproliferation, Hodgkin's lymphoma, multiple myeloma, and various leukaemias. We used Cox regression to evaluate associations with HBsAg status, adjusting for sex, age, and enrolment year.

FINDINGS

53,045 (9%) of 603,585 participants tested positive for HBsAg at baseline. Subsequently, 133 HBsAg-positive and 905 HBsAg-negative individuals developed NHL. HBsAg-positive participants had an increased risk of NHL overall compared with those who were HBsAg-negative (incidence 19.4 vs 12.3 per 100,000 person-years; hazard ratio [HR] 1.74, 95% CI 1.45-2.09, adjusted for sex, age at baseline, and enrolment year). Among NHL subtypes, HBsAg positivity was associated with increased risk of diffuse large B-cell lymphoma (n=325, incidence 6.86 vs 3.79 per 100,000 person-years; adjusted HR 2.01, 1.48-2.75) and other or unknown subtypes (n=591, incidence 10.5 vs 7.07 per 100,000 person-years; adjusted HR 1.65, 1.29-2.11), compared with HBsAg negativity. Increased risk was also recorded for malignant immunoproliferation (n=14, incidence 0.44 vs 0.15 per 100,000 person-years; adjusted HR 3.79, 1.05-13.7). Risk of these malignancies was consistently raised in HBsAg-positive participants throughout 14 years of follow-up. HBsAg positivity was not associated with follicular or T-cell NHL, Hodgkin's lymphoma, multiple myeloma, or various leukaemias.

INTERPRETATION

During extended follow-up, HBsAg-positive individuals had an increased risk of NHL, suggesting that chronic HBV infection promotes lymphomagenesis.

FUNDING

Korean Seoul City Research and the National Research and Development Program for Cancer Control, Ministry for Health, Welfare and Family Affairs, Republic of Korea; US National Cancer Institute.

Nonalcoholic fatty liver disease and hepatocellular carcinoma: a weighty connection

Hepatocellular carcinoma (HCC) is a common and deadly malignancy that is increasing in incidence in developed countries. The emergence of hepatitis C virus (HCV) accounts for about half of this increase in HCC, although the etiology of HCC in 15%-50% of new HCC cases remains unclear. The most common form of chronic liver disease in developed countries is nonalcoholic fatty liver disease (NAFLD), which encompasses a broad spectrum of histopathology. The prevalence of NAFLD, including the more aggressive nonalcoholic steatohepatitis (NASH), is increasing with the growing epidemics of diabetes and obesity. NASH can progress to cirrhosis and its related complications. Growing evidence suggests that NASH accounts for a large proportion of idiopathic or cryptogenic cirrhosis, which is associated with the typical risk factors for NASH. HCC is a rare, although important complication of NAFLD. Diabetes and obesity have been established as independent risk factors for the development of HCC. New evidence also suggests that hepatic iron deposition increases the risk of HCC in NASH-derived cirrhosis. Multiple case reports and case reviews of HCC in the setting of NASH support the associations of diabetes and obesity with the risk of HCC, as well as suggest age and advanced fibrosis as significant risks. Insulin resistance and its subsequent inflammatory cascade that is associated with the development of NASH appear to play a significant role in the carcinogenesis of HCC. The complications of NASH, including cirrhosis and HCC, are expected to increase with the growing epidemic of diabetes and obesity.

[Hepatitis B vaccination: a major player in the control of primary liver cancer]

In worst cases, chronic hepatitis B ultimately leads to primary liver cancer. Populations the more at risk to develop hepatocellular carcinoma (HCC), i.e. patients infected perinatally, reside essentially in Asia. A quarter of century after its introduction in medical practice, data coming from Eastern Asia demonstrate a strong impact of the vaccine on HCC incidence. Strikingly, universal immunization of Taiwanese newborns reduced fourfold pediatric HCC incidence. However, residual cases still appear though among children infected at birth by HBe antigen-carrying mothers. Epidemiologic models indicate that the continuation of universal vaccination policy will reduce chronic hepatitis B endemicity 50-fold in three generations. Recently, mutant forms of HBV potentially escaping to vaccine appeared as a potential consequence of large-scale vaccination. Finally, lack of early immunization of newborns in developing countries still represents a major limitation to the progresses against liver cancer.

Liver cancer in Korea

Hepatocellular carcinoma (HCC) is a highly malignant cancer and third major cause of death in Korean. It is more prevalent among men in the sixth to seventh decades. HCC is particularly prevalent in Korea where the age-standardized incidence rate is 45.0/100 000 population in males and 12.0/100 000 population in females. The death rate from HCC is 20.0/100 000 population. Approximately 65-75% of HCC patients were positive for hepatitis B surface antigen (HBsAg), where 10-20% of patients were anti-hepatitis C virus (HCV) positive. The high incidence rate of HCC in Korea is thought to be related to the high carrier rate of hepatitis B virus (HBV) in the general population. For primary prevention, a nationwide HBV vaccination program has been conducted since the late1980s in Korea. Although advances have been made in the various methods of management of HCC, there has been little overall survival improvement during the past 20 years. Only few patients are candidates for potentially curative forms of treatment. Therefore, the early detection of HCC is a key issue. When compared with clinical outcomes of HCC based on recent 10-year institutional data, our screening and surveillance programs might enable early detection and increased applicability of curative treatments.

Non-alcoholic steatohepatitis and cancer

Hepatocellular carcinoma (HCC) is part of the natural history of non-alcoholic steatohepatitis (NASH). A significant proportion of people who have cryptogenic cirrhosis develop HCC. NASH-related cirrhosis carries a substantial risk for early HCC development. Diagnosis of HCC often is made at first referral; the tumor usually is large with multiple localizations. Patients who have obesity or diabetes are at risk for HCC and a variety of cancers. Given the epidemic of obesity and diabetes, the incidence of NASH-related HCC is expected to increase. In addition to developing new diagnostic tools and pharmacologic therapies, efforts should be directed at preventing non-alcoholic fatty liver disease.

The Clinical Impact of Early Detection of the Ymdd Mutant on the Outcomes of Long-Term Lamivudine Therapy in Patients with Chronic Hepatitis B

The early emergence of lamivudine (3TC)-resistant tyro-sine–methionine–aspartate–aspartate (YMDD) mutants has been reported during 3TC therapy in patients with chronic hepatitis B (CHB) in hepatitis B virus (HBV)-endemic areas; however, its clinical impact during long-term 3TC therapy is unknown. This study was performed to investigate the impact of the early emergence of YMDD mutants 3 months after the initiation of treatment on the outcomes of long-term 3TC therapy in HBV e antigen (HBeAg)-positive CHB. We analysed YMDD genotypes in consecutive samples from 30 patients with HBeAg positive CHB throughout 3TC treatment using both restriction fragment length polymorphism and mass spectrometric assays. Long-term outcome was compared between patients who had YMDD mutations detected at 3 months and those who had no mutations. YMDD mutation was detected in 16 (53.3%) out of 30 patients at 3 months and only the rtM204I mutation was found. Cumulative HBeAg loss rates at 3 years was 12.5% and 57.4% in patients who had the rtM204I mutant and wild-type virus at 3 months, respectively ( P=0.010). Cumulative viral breakthrough rates at 3 years was 75.0% and 14.3% in patients who had the rtM204I mutant and wild-type virus at 3 months, respectively ( P=0.002). Logistic regression revealed that YMDD mutation at 3 months was significantly related to viral breakthrough within 24 months ( P=0.003). In conclusion, early detection for HBV YMDD mutation at 3 months may be useful to predict the long-term outcomes of 3TC therapy in patients with HBeAg-positive CHB in HBV-endemic areas.

Effects of excess weight on cancer incidences depending on cancer sites and histologic findings among men: Korea National Health Insurance Corporation Study

PURPOSE

The effects of excess weight on the development of cancers are controversial, and little is known for populations outside the United States and Europe. We conducted this study to assess the effects of excess weight with a large cohort of Koreans.

METHODS

We assessed the relationship between body mass index (BMI) and various cancers in a 10-year follow-up cohort of 781,283 Korean men who were free of prior cancer at baseline. Weight and height were measured, and questionnaires related to health behaviors and medical history were completed. Data on newly developed cancers were obtained from two organizations in Korea. A proportional hazards model was used to examine the relationship between BMI and cancer.

RESULTS

Adenocarcinoma in the colon and rectosigmoid, hepatocellular carcinoma, cholangiocarcinoma, adenocarcinoma in the prostate, renal cell carcinoma, papillary carcinoma in the thyroid, small-cell carcinoma in the lung, non-Hodgkin's lymphoma, and melanoma had positive dose-dependent relationships with BMI (all P < .05). Although no linear trend was found (P = .267), obese men who never smoked with a BMI of >or= 30 kg/m(2) had an increased risk of developing gastric adenocarcinoma (relative risk = 1.73). Other cancers, such as leukemia, multiple myeloma, and gallbladder and pancreatic cancer, did not show significant associations.

CONCLUSION

These findings show that, even in Koreans, obesity clearly increases the risk of many types of cancers and the strength of the associations varies with the organ and histologic type. Because these obesity-related cancers are reported to be rapidly increasing in Korea and many other Asian countries, controlling obesity epidemics could be an effective tool for preventing these cancers in these areas.

Global epidemiology of hepatitis B virus

The burden of hepatitis B virus (HBV) disease and efforts to control infection will determine the future size of the population requiring treatment of HBV infection. To quantify the current prevalence of HBV infection and to reexamine the epidemiology of HBV infection, a structured review was conducted that focused on available primary literature for over 30 countries worldwide. The prevalence of chronic HBV infection continues to be highly variable, ranging over 10% in some Asian and Western Pacific countries to under 0.5% in the United States and northern European countries. The current global estimate of the number of HBV infected individuals is 350 million. Routes of transmission include vertical (mother to child or generation to generation through close contact and sanitary habits), early life horizontal transmission (through bites, lesions, and sanitary habits), and adult horizontal transmission (through sexual contact, intravenous drug use, and medical procedure exposure) and are evident to varying degrees in every country. Younger age at acquisition of infection continues to be the most important predictor of chronic carriage. However, the choice of serologic markers, temporal influences, and representativeness of the study population limit comparability of HBV seroprevalence results. HBV vaccination programs will decrease the future global burden of HBV infection and evidence of reduced burden is mounting in country-specific populations, but vaccination programs have still not been implemented in all countries, thereby maintaining reservoirs of infection and continued HBV transmission. Regardless of vaccination, large numbers of persons are infected with HBV or will become infected. Preventing the most severe HBV disease consequences in infected individuals, such as cirrhosis and hepatocellular carcinoma, will require appropriate therapeutic agents.

Hepatitis B and C virus prevalence in a rural area of South Korea: the role of acupuncture

A cross-sectional study evaluated the prevalence of and the risk factors for hepatitis C and B viruses among 700 adults above the age of 40 years in a rural area of South Korea. Seropositivity for hepatitis C virus antibody (11.0%, 95% confidence interval: 8.7-13.6) was higher than that for hepatitis B surface antigen (4.4%, 95% confidence interval: 3.0-6.2). Anti-hepatitis C virus seropositivity was associated with a history of repeated acupuncture (odds ratio=2.1, 95% confidence interval: 1.1-4.0), and blood transfusion (odds ratio=5.5, 95% confidence interval: 1.6-19.3) before 1992 when hepatitis C virus screening in blood donors became mandatory. Hepatitis C virus 2a was the most prevalent genotype, followed by 1b. Hepatitis C virus risk attributable to acupuncture was 38% (9% for men and 55% for women). Safer acupuncture practice has become a priority for hepatitis C virus prevention in South Korea.

Comparison of hepatitis B vaccine coverage and effectiveness among urban and rural Mongolian 2-year-olds

BACKGROUND

The prevalence of hepatitis B (HBV) carriage in Mongolia is reported to be 14%. Universal HBV immunization of newborns has been shown to decrease carriage in Asian populations. Mongolia began universal newborn vaccination in 1991. This evaluation of vaccine coverage and effectiveness compares the success of the program between urban and nomadic rural populations.

METHODS

Using random cluster sampling, 148 Mongolian 2-year-olds from seminomadic rural families were compared with 127 2-year-olds from Ulaanbaatar, the capital city.

RESULTS

More than 95% of all subjects received hepatitis B vaccine although rural subjects were less likely to complete the series than were urban subjects. Adequate vaccine response differed significantly: 94.2% of urban subjects versus only 70.2% of rural subjects had protective anti-HBs levels (P < 0.001). Overall the proportion of hepatitis B infection in both samples was lower than the historical Mongolian prevalence. However, unexpectedly 40% of subjects in rural Bayanhongor Aimag (Province) were found to be HBsAg positive.

CONCLUSION

The Mongolian infant vaccination program for hepatitis B is successfully reducing the rate of chronic carriage in the immunized generation. However, vaccine response among rural subjects is less than that among urban. There appears to be a pocket of high disease prevalence in Bayanhongor that requires further study.

Seroepidemiology of HBV infection in South Korea, 1995 through 1999

BACKGROUND

We analyzed serologic data that were obtained from the Korea Association of Health from 1995 to 1999 to estimate the reliable prevalence of HBV in South Korea.

METHODS

603,375, 639,465, 621,476, 612,705 and 650,398 serum samples were annually tested for HBsAg. Of HBsAg positive persons whose serum samples were available, HBeAg positivity was checked.

RESULTS

HBsAg positivities among subjects between 6 and 19 years old were 8.2%, 3.9%, 2.1%, 2.6% and 1.3%. HBsAg positivities among subjects above 20 years old were 8.9%, 6.4%, 5.9%, 5.4% and 5.4%. The positive rates of HBeAg were 39.8 to 62.9% among subjects between 6 and 19 years old, and 18.3 to 37.9% among persons above 20 years old, in each year. In both subgroups, HBsAg positivity in the latter year was significantly lower than that in the former year (p < 0.001). It also showed that HBsAg positivities among subjects between 6 and 19 years old have been significantly lower than those among subjects above 20 years old, but those of HBeAg the exact reverse of HBsAg since 1996 (p < 0.001).

CONCLUSIONS

It was observed that prevalence of HBV infection in the late 1990s, especially in the group between 6 and 19 years old, was conspicuously lower than that in the past. The nationwide vaccination programme might be one of the most important contributors to this tendency in Korea.

Economic evaluation of the societal costs of hepatitis B in South Korea

BACKGROUND AND AIMS

Hepatitis B (HBV) infection remains a major public health problem in South Korea, and accounts for considerable morbidity and mortality. At present, very little is known about the cost of HBV to the South Korean health-care system and society. The present study was therefore conducted to estimate the total annual cost of HBV infection in South Korea for a given year (1997).

METHODS

The study was conducted from the South Korean societal perspective, taking into account the direct and indirect costs of HBV vaccination programs (prevention costs), and those related to the treatment of acute and chronic hepatitis, cirrhosis and liver cancer (disease costs). Several assumptions were made in arriving to actual cost estimates.

RESULTS

The total societal cost of HBV in 1997 was 1078.3 billion Won ($US 959.7 million), 142.3 billion Won or 13.2% being attributable to prevention costs and 225.4 billion Won or 20.9% being attributable to indirect costs of HBV-related diseases. The total cost (direct plus indirect) associated with HBV-related diseases to the South Korean society was 936.1 billion Won ($US 833.1 million), of which 45.3% was attributable to cirrhosis-related costs. In terms of disease-related direct costs alone (710.5 billion Won or $US 632.3 million), the estimated annual spending per patient was 1.37 million Won ($US 1219). The direct costs of the HBV disease (prevention and disease treatment, amounting to 782.2 billion Won or $US 696.2 million) is equivalent to 3.2% of the national health-care expenditure for 1997.

CONCLUSIONS

This study confirms that HBV is a significant cost burden to the South Korean society, and in the absence of an effective cure reinforces the importance of continued disease prevention via vaccination.

Association of chronic hepatitis C virus infection and diabetes mellitus in Korean patients

BACKGROUND

It has been suggested that chronic hepatitis C virus (HCV) infection is associated with diabetes. The aim of this study was to establish a potential relationship between chronic HCV infection and diabetes mellitus in Korean patients.

METHODS

We performed a prospective analysis of 404 patients with chronic viral hepatitis or liver cirrhosis who visited our hospital and analyzed whether age, sex, body mass index, alcohol consumption, hepatitis B virus (HBV) infection, HCV infection and cirrhosis were associated with diabetes. We also enrolled 627 diabetic patients and the seroprevalence of HBV surface antigen (HBsAg) and anti-HCV was determined.

RESULTS

Diabetes was observed more frequently in individuals with HCV infected chronic liver disease (24.0%) than in those with HBV infected (10.4%) (p < 0.05). Univariate analyses revealed that age, alcohol consumption and HCV infection were significant independent predictors for diabetes. The mean age of the patients with HCV infected chronic liver disease was higher than that of HBV infected (56 +/- 16 vs 44 +/- 13, p < 0.05). The prevalence of diabetes in HCV infected group was higher than that in HBV infected group in the age of 41-60 (p < 0.05). In diabetic group, the seroprevalence of HBsAg positivity was 4.5% and that of anti-HCV was 2.1%.

CONCLUSION

Our study demonstrates an association between diabetes and chronic HCV infection in Korean patients. The prevalence of diabetes in patients with HCV infected chronic liver disease is higher than that in those with HBV infected. Age and alcohol consumption are another risk factor for diabetes in patients with chronic viral liver disease.

TT virus infection among blood donors and patients with non-B, non-C liver diseases in Korea

BACKGROUND/AIMS

A novel virus, designated the TT virus (TTV), was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology, in Japan. Subsequently, TTV was suggested to be a causative agent in a proportion of cases with cryptogenic hepatitis in Japan. This study aimed to elucidate the significance of TTV infection in cases with cryptogenic liver disease in Korea, a neighbor of Japan.

METHODS

The prevalence of TTV infection was studied in 120 patients with liver diseases, including 85 patients diagnosed as having non-B, non-C liver diseases. As controls, 220 blood donors were also examined. TTV DNA was detected by polymerase chain reaction, and the sequence was analyzed by phylogenetic analysis.

RESULTS

Fourteen (14.0%) of 100 accepted blood donors, 23 (19.2%) of 120 rejected blood donors, and 15 (17.6%) of 85 patients with non-B, non-C liver diseases were positive for TTV DNA. The prevalences of TTV infection among these groups were not significantly different. Phylogenetic analysis suggested the existence of four major genotypes of TTV The proportions of each genotype among patients with non-B, non-C liver diseases were not different from those among accepted blood donors.

CONCLUSIONS

TTV exists in Korea, but the prevalence among patients with non-B, non-C liver diseases was almost the same as that among blood donors. TTV may not be the main causative agent of cryptogenic liver disease in Korea. The relationship between non-B, non-C liver diseases and TTV genotype remains unclear, although TTV can be classified into four genotypes.