Predominant etiologic association of hepatitis C virus with hepatocellular carcinoma compared with hepatitis B virus in elderly patients in a hepatitis B-endemic area

Understanding the complications of anti-tumor necrosis factor therapy in East Asian patients with inflammatory bowel disease

Remarkable advances have been made in the treatment of inflammatory bowel disease since the introduction of anti-tumor necrosis factor-α agents, especially for patients who are refractory to or cannot tolerate conventional therapies. Currently, infliximab, adalimumab, and golimumab are available in the East Asian medical market, and these agents have been shown to be effective for inducing and maintaining long-term remission of inflammatory bowel disease. Despite their clinical benefits, anti-tumor necrosis factor therapy can also lead to increased vulnerability to infections, development of autoimmune diseases and malignancy, and decreased immunogenicity of vaccinations. Because infectious diseases, such as tuberculosis, hepatitis, and influenza, remain major health problems in East Asia, more cautious use of biologics is needed. To further improve treatment efficacy and safety, close monitoring of inflammation, regular surveillance for malignancy, and regularly scheduled vaccinations are needed. Treatment strategies for biologics should be customized to meet the needs of different patients.

Association of HLA alleles with the responsiveness to hepatitis B virus vaccination in Korean infants

Hepatitis B virus (HBV) vaccination is the most effective means of countering HBV-related morbidity and mortality, and individuals who do not respond to vaccination (non-responders) are problematic. The aim of the present study was to investigate associations between HLA and responsiveness to HBV vaccine in Korean infants. A total of 944 healthy Korean infants 9-12 months old were enrolled, and HLA distribution was compared among subgroups in accordance with the response to HBV vaccination. The HLA distribution of the subjects was similar to known Korean population data and did not deviate from the HWE proportions. The alleles that showed positive associations with non-responsiveness (<10mIU/mL) or low antibody titer (<100mIU/mL) were HLA-A*33, B62, DRB1*04, and DRB1*07, while the alleles A*02 and DRB1*08 showed negative associations. Among these alleles, B62, DRB1*07 and DRB1*08(-) showed significant associations with a poor or decreased response to vaccination even after correction (OR=1.83, 1.99, 5.63; pc<0.05) and also showed dose effects. After stratification by other associated alleles at different loci, B62 and DRB1*07 were independently associated with non-responsiveness, but A*02(-) and DRB1*08(-) lost their individual associations. The combined association of A*02(-)-DRB1*08(-) and B62-DRB1*08(-) was significant (OR=25.2 and 24.5; pc<0.05). Although the hierarchy is not clear, we can assume the following: (i) B62 and DRB1*07 have independent effects, (ii) DRB1*08(-) has a very strong and synergic effect, and (iii) there is probability of a third factor controlling A*02(-) and DRB1*08(-) with an effect on non-responsiveness to HBV vaccination in Korean infants.

Status of primary liver cancer found through routine health check-up

This study aimed to investigate the status of primary liver cancers found through a routine health check-up. The data of subjects who were diagnosed with primary liver cancer for the first time through a routine health check-up during a period of 8-yr were analyzed. Primary liver cancers were detected for the first time in 34 subjects among 91,219 routine health check-up subjects. Only 11.8% of primary liver cancer subjects had been under previous surveillance. Of them, 55.8% were positive for HBsAg, 17.7% were positive for anti-HCV, and 8.8% were heavy alcohol comsumers. However, 17.7% of the subjects were neither heavy alcohol consumers nor positive for both HBsAg and anti-HCV. Of the subjects, 50.0% had a single nodular tumor, 23.5% had multi-nodular tumors, and 26.5% had an infiltrative tumor. A routine health check-up may provide beneficial opportunities to detect a liver cancer in a very early stage. It is beneficial to start surveillance in high-risk subjects for liver cancer or to detect any liver cancer in subjects without risk factors of chronic viral hepatitis or heavy alcohol consumption.

Prevalence and risk factors of hepatitis B and C virus infections among the general population and blood donors in Morocco

BACKGROUND

Viral hepatitis is a serious public health problem affecting billions of people globally. Limited information is available on this issue in Morocco. This cross-sectional study was undertaken with the aim of determining the seroprevalence and risk factors of hepatitis B virus (HBV) and hepatitis C virus (HCV) among the general population and among blood donors.

METHODS

Blood samples from volunteers, have been screened with ELISA tests for detecting the hepatitis-B surface antigen (HBsAg) and anti-HCV. Within the seroreactive patients for HCV in the general population, RT-PCR was performed by the Cobas Ampliprep/Cobas Amplicor.

RESULTS

HCV and HBV-seropositivity was documented in 1.58% and 1.81% out of 41269 and 23578 participants respectively from the general population. Two patients were found to be co-infected. HCV-RNA was detected by PCR in 70.9% of the 195 anti-HCV positive subjects. The anti-HCV prevalence was not different among males and females (P = 0.3). It increased with age; the highest prevalence was observed among subjects with >50 years old (3.12%). Various risk factors for acquiring HCV infection were identified; age, dental treatment, use of glass syringes and surgical history. In addition to these factors, gender and sexual risk behaviors were found to be associated with higher prevalence of hepatitis B. The HBV positivity was significantly higher among males than females participants in all age groups (P < 0.01). The peak was noticed among males aged 30-49 years (2.4%). None of the 152 persons younger than 20 years had HBsAg or anti-HCV. The prevalence of anti-HCV and HBsAg among 169605 blood donors was 0.62% and 0.96% respectively.

CONCLUSIONS

Our study provided much important information concerning hepatitis B and C prevalence and risk factors; it confirmed the intermediate endemicity for HCV infection and pointed to a decreasing trend of HBV incidence, which might reclassify Morocco in low HBV endemicity area. This could be attributed primarily to the universal HBV vaccination among infants and healthcare workers over the past 13 years. HCV and HBV infections in the present survey were mainly associated with nosocomial exposures. Prevention and control of HBV infection are needed to reduce HBV transmission between adults.

Behavioral and healthcare-associated risk factors for chronic hepatitis C virus infection in Korea

The risk factors related to hepatitis C virus (HCV) infection showed geographic and temporal differences. We investigated HCV-related risk factors in Korea where intravenous drug use (IVDU) is uncommon. The HCV-related risk factors were investigated in a prospective, multicenter chronic HCV cohort (n = 711) using a standardized questionnaire in four university hospitals. The results were compared with those of 206 patients with chronic liver diseases not related to either of HCV or hepatitis B virus infection (comparison group). The IVDU was found in 3.9% and remote blood transfusion (≥ 20 yr ago) in 18.3% in HCV cohort group, while that in comparison group was in none and 5.3%, respectively. In a multivariate logistic analysis, transfusion in the remote past (odds ratio [OR], 2.99), needle stick injury (OR, 4.72), surgery (OR, 1.89), dental procedures (OR, 2.96), tattooing (OR, 2.07), and multiple sexual partners (2-3 persons; OR, 2.14, ≥ 4 persons; OR, 3.19), were independent risk factors for HCV infection. In conclusion, the major risk factors for HCV infection in Korea are mostly related to conventional or alterative healthcare procedures such as blood transfusion in the remote past, needle stick injury, surgery, dental procedure, and tattooing although multiple sex partners or IVDU plays a minor role.

Hepatitis C virus (HCV) genotypes and the influence of HCV subtype 1b on the progression of chronic hepatitis C in Korea: a single center experience

Background/Aims

There is some controversy regarding whether or not hepatitis C virus (HCV) subtype 1b is more influential than non-1b subtypes on the progression of chronic hepatitis (CH) C to liver cirrhosis (LC) and hepatocellular carcinoma (HCC).

Methods

We retrospectively analyzed 823 patients with chronic HCV infection, including 443 CH patients, 264 LC patients, and 116 HCC patients, who were HCV RNA positive and HBsAg negative. These patients had not received any prior treatment with either interferon alone or a combination of interferon and ribavirin.

Results

HCV subtypes 1b (51.6%) and 2a/2c (39.5%) were the two most common genotypes. The proportions of genotypes 2 (2a/2c, 2b, and 2) and 3 were 45.8% and 1.1%, respectively. One case of genotype 4 was found. HCV subtype 1b (47.3%) was less common than the non-1b subtypes (52.7%) in non-LC patients, but its proportion (56.9%) was higher than that of non-1b subtypes (43.1%) in LC patients (P=0.006). The proportions of patients with HCV subtype 1b did not differ significantly between the LC (55.3%) and HCC (60.3%) groups. Older age, male gender, and the relative progression of liver damage (non-LC vs. compensated LC vs. decompensated LC) were significant risk factors for HCC, with odds ratios of 1.081 (95% confidence interval [CI], 1.056-1.106), 5.749 (95% CI, 3.329-9.930), and 2.895 (95% CI, 2.183-3.840), respectively. HCV subtype 1b was not a significant risk factor for HCC (odds ratio, 1.423; 95% CI, 0.895-2.262).

Conclusions

HCV subtypes 1b and 2a/2c were the two most common HCV genotypes. HCV subtype 1b seemed to be more influential than non-1b subtypes on the progression of CH to LC, but not on the development of HCC from LC.

Family history influences the early onset of hepatocellular carcinoma

AIM: To evaluate the relationship between a positive family history of primary liver cancer and hepatocellular carcinoma (HCC) development in Korean HCC patients.

METHODS: We studied a total of 2242 patients diagnosed with HCC between January 1990 and July 2008, whose family history of primary liver cancer was clearly described in the medical records.

RESULTS: Of the 2242 patients, 165 (7.4%) had a positive family history of HCC and 2077 (92.6%) did not. The male to female ratio was 3.6:1, and the major causes of HCC were chronic hepatitis B virus (HBV) infection in 75.1%, chronic hepatitis C virus infection in 13.2% and alcohol in 3.1%. The median ages at diagnosis in the positive- and negative-history groups were 52 years (range: 29-79 years) and 57 years (range: 18-89 years), respectively (P < 0.0001). Furthermore, among 1713 HCC patients with HBV infection, the number of patients under 45 years of age out of 136 patients with positive family history was 26 (19.1%), whereas those out of 1577 patients with negative family history was 197 (12.5%), suggesting that a positive family history may be associated with earlier development of HCC in the Korean population (P = 0.0028).

CONCLUSION: More intensive surveillance maybe recommended to those with a positive family history of HCC for earlier diagnosis and proper management especially when HBV infection is present.

[Shifting in seroprevalence of HBsAg and anti-HCV during recent 10 years in adults resident in Daegu and Gyeongbuk province]

BACKGROUND/AIMS

There have been only few studies on the population-adjusted seroprevalence of HBV and HCV and on the change of them for more than 10 years in Korea. Therefore, this study was performed to evaluate them at a single health center in Daegu and Gyeongbuk province considering the population composition ratio.

METHODS

We analyzed the seromarkers of HBV and HCV of 6,237 randomly sampled adults who had received health screening at the health promotion center in Dongsan hospital during the periods from year 1997 to 1999 (Period A) and from 2007 to 2009 (Period B).

RESULTS

The seroprevalences of HBsAg, anti-HBs, anti-HBc and anti-HCV were 4.8%, 70.2%, 47.4%, and 0.5%, respectively. There is no difference in the seroprevalence of HBsAg between period A and B. However, downward tendency of prevalence through A to B from 6.8% to 4.5% could be found in 40s, and upward tendency from 4.7% to 6.8% in 50s. As for the seroprevalence of anti-HCV, although there was no difference through A to B, for 50s, it decreasd from 2.0% to 0.3% (p=0.007). However, for 60s, it increased as much as decreasd for 50s.

CONCLUSIONS

The seroprevalence of HBsAg in Daegu/Gyeongbuk province was 4.8% and showed no difference through the time period of 10 years. The seroprevalence of anti-HCV was 0.5% and also showed no difference through the time periods.

Hepatocellular carcinoma during pregnancy: is hepatocellular carcinoma more aggressive in pregnant patients?

BACKGROUND/PURPOSE

Hepatocellular carcinoma (HCC) during pregnancy is a very rare condition and is believed to have a worse prognosis than HCC in non-pregnant women. We evaluated the prognosis and the diagnostic and therapeutic strategies for HCC in pregnant women.

METHODS

We retrospectively analyzed 4 cases in our hospital and 44 cases described in the medical literature since 1957; we also compared the cases reported before 1995 and those reported during/after 1995.

RESULTS

The overall 6-month and 1-, 2-, and 3-year survival rates in the patients reported in the literature were 50, 29.5, 18.2, and 13.6%, respectively (n = 44). The mean ages at diagnosis before and during/after 1995 were 31.4 ± 7.2 and 28.9 ± 4.4 years, respectively (P = 0.113). The following characteristics were significantly more common in the later group: fewer pregnancies; the absence of advanced signs or symptoms; receipt of therapy; tendency to undergo surgery; and higher 6-month and 1-, 2-, and 3-year survival rates. The median survivals of the groups before and during/after 1995 were 18 and 25.5 months, respectively (P < 0.001).

CONCLUSIONS

The morbidity and mortality of HCC during pregnancy has improved over time, as diagnoses have tended to be made earlier and patients have tended to receive surgical and other treatments.

Limited liver resection: a good indication for the treatment of hepatocellular carcinoma in elderly patients

OBJECTIVE

Hepatocellular carcinoma is often diagnosed in elderly people.

METHODS

One hundred and seventy-five patients older than 70 years were operated on for hepatocellular carcinoma (Group 1). The results were compared with 276 resected patients younger than 70 (Group 2) and to 108 aged patients with chronic liver disease without hepatocellular carcinoma (Group 3).

RESULTS

Hepatocellular carcinoma in the elderly is more frequently associated with hepatitis C virus, less frequently capsulated and less frequently diagnosed by screening programs than in young patients. After resection, no difference was noted in post-operative complications and in mortality rates (3.2%); major hepatic resection in cirrhosis carried a high risk of death (22%). Five years survival was 42%, comparable with the young surgical patients but significantly lower than the medical patients in Group 3. Recurrence of hepatocellular carcinoma was the main reason of death, but it was suitable for a radical treatment in 37.6% of cases, including surgery, with a mean survival of 31 months.

CONCLUSIONS

Liver resection is a valid option for the treatment of hepatocellular carcinoma in the elderly; major resections in cirrhotic old patients must be reserved for selected cases. Recurrence may be suitable of a radical approach, including surgery.

Current status of liver diseases in Korea: hepatocellular carcinoma

Primary liver cancer, most of which is hepatocellular carcinoma (HCC), is the third common leading cancer in Korea. During the last two decades, the incidence rate of primary liver cancer has shown a modest decrease, but its mortality rate has slightly increased. The incidence of HCC, according to age, peaks in the late sixth decade in men and in the early seventh decade in women. Hepatitis B virus (HBV) is the most important risk factor, which represents approximately 70% of all HCC, and hepatitis C virus (HCV) and alcohol are the next in order of major risk factors for the development of HCC in Korea. HBV-associated HCC occurs 10 years earlier than HCV-associated HCC due to a more prolonged exposure to HBV, which is vertically transmitted almost from HBsAg-positive mother in HBV-endemic area. National Cancer Control Institute, which was reorganized in 2005, is now working for several national projects such as National Cancer Registration Program, National R&D Program for Cancer Control and National Cancer Screening Program. International collaboration for the clinico-epidemiologic research would be needed to provide the specific measures for managing HCC in diverse etiologic situations. Finally, the mechanisms of hepatitis virus-associated hepatocellular carcinogenesis might be clarified to provide insights into the advanced therapeutic and preventive approaches for HCC in Korea, where the majority of HCC originate from chronic HBV and HCV infections.

Current status of liver disease in Korea: hepatitis C

Chronic hepatitis C (CHC) is the third most common cause of chronic liver disease and hepatocellular carcinoma (HCC) in Korea, following hepatitis B virus (HBV) infection and alcohol. HCV prevalence among Koreans older than 40 years of age has been estimated to be 1.29%. The prevalence of CHC increases with age, with the peak prevalence at the age of 60 or older. Blood transfusions have generated no risk of HCV infection since April 1991, when routine screening for anti-HCV in blood donors was adopted in Korea. Although injection drug use seems to be one of the most important risk factors of HCV infection among young adults in urban areas, the majority of CHC patients are not associated with injection drug use. Exposure to acupuncture was identified as a significant risk factor among older adults in rural areas. The mean age of patients with HCV-related cirrhosis and HCC was consistently about 10 years above that of patients associated with HBV. Genotypes 1b and 2a are the two most common types with almost equal proportions, and other genotypes are extremely rare. Korean patients with CHC have a high likelihood of responding to combination therapy with pegylated interferon and ribavirin, with a sustained virological response rate of 60-70% in patients with genotype 1 and 85-90% in those with genotype 2.

Current status of liver diseases in Korea: hepatitis B

Hepatitis B virus (HBV) infection is the one of the most common causes of the liver diseases in Korea. Since the discovery of Australia antigen (hepatitis associated antigen, or HBsAg later), hepatitis associated antigen was tested widely. HBsAg was detected in 6.6-8.6% in 1980's. Later, it decreased to 5.7% in 1990's. Remarkably, seropositivity of the children deceased to 0.2% after the nationwide vaccination program. Although hepatitis B vaccines are highly effective, the failure rate of perinatal prophylaxis in babies born to HBsAg positive mother was reported to be 4.25%. Treatment of chronic hepatitis B was initiated after the introduction of interferon alpha. Lamivudine opened a new era of oral antiviral agent, and it has been widely used in Korea since 1999. Adefovir was proven to have a good efficacy for lamivudine-resistant chronic hepatitis B. Newer potent antiviral agents such as entecavir, clevudine, and telbivudine are available currently. Further studies are warranted for understanding factors influencing natural history, improving treatment outcomes, and overcoming vaccine non-response.

Socio-economic status and the risk of liver cancer mortality: a prospective study in Korean men

OBJECTIVE

To examine the association between socio-economic status (SES) and liver cancer mortality among Korean men.

STUDY DESIGN

Prospective cohort study

METHODS

Data were acquired from a large, prospective cohort study that included 548,530 civil service workers aged 30-59 years who had undergone health examination in 1998 provided by the Korean National Health Insurance System. Information on lifestyle and demographic characteristics was acquired through self-administered questionnaires. The main outcome event was mortality from liver cancer. Cox proportional hazards model was used to estimate relative risks (RRs) and 95% confidence intervals (95% CIs) after adjusting for age, body mass index, fasting serum glucose, alcohol consumption, smoking and hepatitis B surface antigen (HBsAg) status.

RESULTS

Liver cancer mortality differentials relating to SES were statistically significant and consistent in the fully adjusted model. Compared with the highest SES category, excess risk associated with liver cancer mortality was observed with decreasing SES levels: the RRs in the upper middle, lower middle and low SES categories were 1.35 (95% CI 1.13-1.61), 1.54 (95% CI 1.28-1.86) and 1.72 (95% CI 1.45-2.04), respectively. There was no effect modification by HBsAg status on the association between SES and liver cancer mortality.

CONCLUSIONS

This study demonstrated an inverse association between SES and liver cancer mortality, suggesting that SES is an independent predictor of liver cancer mortality. The policies and interventions regarding prevention of liver cancer need to focus on disadvantaged groups in order to reduce health disparities related to liver cancer.

Do young hepatocellular carcinoma patients with relatively good liver function have poorer outcomes than elderly patients?

BACKGROUND AND AIM

The risk of hepatocellular carcinoma (HCC) is known to be age dependent; the influence of age on prognosis is, however, controversial. The aim of this study was to compare the tumor characteristics and survival rates of young and old HCC patients, with respect to tumor stage.

METHODS

We reviewed the clinical data and survival times of 71 young HCC patients from 1987 to 2003 and compared these with those of their older counterparts (n = 239). Patients were categorized into three age groups: group A, age <30 years (n = 71); group B, age >/=30 to <61 years (n = 168); and group C, age >/=61 years (n = 81). Kaplan-Meier methods and Cox proportional hazards regression were used to analyze survival.

RESULTS

The overall survival time of group A was shorter than groups B or C (P = 0.0071). Survival was not different in the three groups in subgroup analysis according to several tumor staging systems (e.g. Japan Integrated Staging score, Cancer of the Liver Italian Program scoring system and Barcelona Clinic Liver Cancer staging classification). The multivariate hazard ratio of group B was 0.840 (95% confidence interval [CI] 0.490-1.440) and that of group C was 0.770 (95% CI 0.410-1.446) in reference to group A.

CONCLUSIONS

Young HCC patients showed a poorer prognosis than older HCC patients because they have a more advanced tumor stage at diagnosis. However, age was not an independent prognostic factor when stages were matched. Therefore, we suggest that periodic surveillance in young chronic hepatitis B virus carriers would improve outcomes.

The prevalence of hepatitis C virus infection in Korea: pooled analysis

This study evaluated the prevalence of hepatitis C virus (HCV) infections in Korea. Pooled estimates of the anti-HCV positivity were calculated using the data published in 15 reports on the general population and health check-up examinees. The overall pooled estimate of the prevalence of HCV among middle-aged adults (40 yr old and above) was 1.68% (95% confidence interval: 1.51-1.86%) during the year of 1990-2000 among the general population. Most of the published data indicated that the prevalence of anti-HCV increased with age. The anti-HCV positivity was significantly higher in females than in males. Because the risk of HCV exposure in blood recipients has decreased remarkably, the spread of HCV through means other than a transfusion must be prevented.

Molecular genetic evidence supporting a novel human hepatocellular carcinoma tumor suppressor locus at 13q12.11

A novel 1-cM (1.8 Mb) homozygous deletion (HD) on 13q12.11 was identified in a human hepatocellular carcinoma (HCC) cell line, SK-Hep-1, after high-density genetic marker scan and Southern blotting analysis. A loss of heterozygosity (LOH) analysis indicated that LOH frequency of the HD region in 48 pairs of HCC tissues was 52%. Interestingly, the occurrence of LOH in the 13q12.11 HD region is significantly associated with early-onset HCC, inferred from Fisher's exact test (P = 0.0047) and Mann-Whitney test (P = 0.023). Since the novel 1-cM (1.8 Mb) HD region is gene-rich with more than 37 predicted transcripts, we used a candidate gene approach by examining down-regulation of known tumor suppressor genes (TSGs), including LATS2, TG737, CRYL1, and GJB2, in HCC tissues. We detected only 14% down-regulation of the LAST2 gene that flanks the outside of the HD, in HCC tissues, by quantitative RT-PCR assays. However, we observed significant down-regulation of the TG737, CRYL1, and GJB2 genes located within the HD in 59, 64, and 71% of HCC tissues, respectively. Together, our results indicated that the identified 13q12.11 HD region contained at least three significant down-regulated TSGs, and preferential LOH in early-onset HCC patients is a putative tumor suppressor locus in HCC.

Epidemiology of hepatitis C virus in Korea

Mortality due to liver cancer in Korea ranks as one of the highest in the world. Both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are high-risk factors for liver cancer. Although HBV is by far the more important risk factor for the development of hepatocellular carcinoma (HCC) in Korea, HCV infection is more closely associated with HCC in elderly patients. Therefore, the evaluation of risk factors for HCV infection, including blood transfusion, is important. This study reviews the literature on HCV prevalence and risk factors among the general population, as well as the distribution of HCV genotypes in Korea. An overall estimate of the prevalence of anti-HCV among Koreans older than 40 years was 1.29% (95% confidence interval 1.12-1.48) during 1995-2000. Blood transfusion was the strongest risk factor for transmission of HCV infection. Risk factors for HCV infection in Korea other than blood transfusion and history of acupuncture have not been proven. The most prevalent HCV genotype is 1b followed by 2a. Even though the prevalence of anti-HCV in Korea has been reduced and the risk of HCV transmission through blood transfusion has markedly decreased, public-health programs to prevent de novo infections should be developed. Moreover, most people infected with HCV in Korea are older than 40 years, and therefore, the surveillance of adults (> or =40 years) for HCV infection will be helpful in early detection of HCC developing in them.

Current status of hepatitis C virus infection in Korea

Chronic liver disease, including liver cirrhosis and hepatocellular carcinoma (HCC), has been a major cause of mortality in Korea. The prevalence rates of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections in the general population of Korea are approximately 1 and 5%, respectively. The most common genotypes of HCV in Korea are 1b and 2a. The sustained virological response rates after antiviral therapies, including combined interferon-alpha and ribavirin, have been reported to be 38-59%. The annual incidence of HCC among HCV-related liver cirrhosis has been estimated at 5%, and approximately 12% of HCC is attributable to HCV and 68% to HBV in Korea. The mean age of patients with HCV-related HCC at the time of diagnosis was consistently 10 years older than that of patients with HBV-related HCC. Moreover, HCV-related HCC was accompanied by more advanced liver cirrhosis than HBV-related HCC. Coinfection with HBV seemed to increase the risk of developing HCC in chronic HCV infection. After the successful program of hepatitis B vaccination, HCV infection is now emerging as an important etiology of chronic liver disease in Korea, which warrants more detailed and large-scale studies.

Hepatitis B and alcohol affect survival of hepatocellular carcinoma patients

AIM: In the USA, Hawaii has the highest incidence of hepatocellular carcinoma (HCC) and a diverse population. It is an ideal place to characterize HCC in the context of ethnicity/risk factors.

METHODS: A total of 262 cases of HCC (1992-2003) were retrospectively reviewed for demographics, ethnicity, birthplace, viral hepatitis, alcohol use, diabetes, smoking and risk factors for viral hepatitis such as intravenous drug abuse (IVDA), transfusions, tattoos and vertical transmission. Tumor stage, Child’s class, Cancer of the Liver Italian Program (CLIP) score, α-fetoprotein level, treatment and survival were recorded.

RESULTS: Gender, age, viral hepatitis, alcohol, IVDA, and diabetes differed significantly in Asians, non-Asians and Pacific Islanders. There were also specific differences within Asian subgroups. Alpha-fetoprotein, smoking, transfusions, stage and resectability did not differ between groups. Asians were more likely to have hepatitis B, while non-Asians were more likely to have hepatitis C. Factors that decreased survival included hepatitis B, alcohol, elevated alpha-fetoprotein, CLIP >2 and increased Child’s class. When Asians were combined with Pacific Islanders, median survival (1.52 years vs 3.54 years), 1- and 3-year survival was significantly worse than those for non-Asians. After Cox regression analysis for hepatitis B and alcohol, there was no difference in survival by ethnicity.

CONCLUSION: Various ethnicities have different risk factors for HCC. Hepatitis B, alcohol, and α-fetoprotein are more important factors for survival than ethnicity.

Epidemiology of hepatocellular carcinoma

Year 2000 estimates of the incidence of cancer indicate that primary liver cancer remains the fifth most common malignancy in men and the eighth in women. The number of new cases has been predicted as 564,000, corresponding to 398,000 in men and 166,000 in women. The geographic areas at highest risk are located in Eastern Asia, Middle Africa, and some countries of Western Africa. Changes in incidence among migrant populations underline the predominant role of environmental factors in the etiology of primary liver cancer. In high-risk countries, the early cases of primary liver cancer occur already at ages 20 and above, underlying the impact of viral exposures early in life. In countries at low risk, primary liver cancer is rare before the 50s, translating the impact of late exposures with moderate risks and long latency intervals. Sex ratios are typically between 2 and 4. The incidence of primary liver cancer is increasing in several developed countries including the United States, and the increase will likely continue for several decades. The trend has a dominant cohort effect related to exposures to hepatitis B and C viruses. The variability of primary liver cancer incidence is largely explained by the distribution and the natural history of the hepatitis B and C viruses. The attributable risk estimates for the combined effects of these infections account for well over 80% of liver cancer cases worldwide. Primary liver cancer is the first human cancer largely amenable to prevention using hepatitis B virus vaccines and screening of blood and blood products for hepatitis B and C viruses.

Primary liver cancer: worldwide incidence and trends

Estimates from the year 2000 indicate that liver cancer remains the fifth most common malignancy in men and the eighth in women worldwide. The number of new cases is estimated to be 564,000 per year, including 398,000 in men and 166,000 in women. In high-risk countries, liver cancer can arise before the age of 20 years, whereas, in countries at low risk, liver cancer is rare before the age of 50 years. Rates of liver cancer in men are typically 2 to 4 times higher than in women. The incidence of primary liver cancer is increasing in several developed countries, including the United States, and the increase will likely continue for some decades. The trend is a result of a cohort effect related to infection with hepatitis B and C viruses, the incidence of which peaked in the 1950s to 1980s. In selected areas of some developing countries, the incidence of primary liver cancer has decreased, possibly as a result of the introduction of hepatitis B virus vaccine. The geographic variability in incidence of primary liver cancer is largely explained by the distribution and the natural history of the hepatitis B and C viruses. The attributable risk estimates for the combined effects of these infections account for well over 80% of liver cancer cases worldwide. Primary liver cancer is the first human cancer largely amenable to prevention using hepatitis B virus vaccines and screening of blood and blood products for hepatitis B and C viruses.

Microvessel density and clinicopathological characteristics in hepatitis C virus and hepatitis B virus related hepatocellular carcinoma

AIMS

To compare intratumorous microvessel density (MVD) and clinicopathological features in two different groups of hepatocellular carcinoma (HCC), namely: hepatitis B virus (HBV) related HCC (B-HCC) and HCV related HCC (C-HCC).

METHODS

Fifty consecutive cases each of B-HCC and of C-HCC were studied. Microvessel numbers were assessed by staining for the antigen CD34; in each case, three areas with the highest numbers of microvessels were counted in both the intratumorous and the surrounding non-tumorous tissue; the mean value represented the final MVD.

RESULTS

Patients with B-HCC were significantly younger than those with C-HCC (mean age, 60.1 (SD, 4.1) v 66.4 (4.3) years); no significant differences were seen for sex or Child's class distribution. The tumour diameter was larger in B-HCCs than in C-HCCs (mean, 5.6 (SD, 1.8) v 3.8 (1.8) cm). Tumour microsatellite formation was significantly higher in C-HCCs (12 v 4 cases). No differences were found for histological subtype, degree of differentiation, tumour encapsulation, and vascular invasion. The mean MVD value was significantly higher in tumorous (mean, 54 (SD, 13.8) v 38 (8.9)) and in the surrounding non-tumorous liver tissue (mean, 15 (SD, 4.3) v 7 (3.1)) of C-HCCs.

CONCLUSIONS

C-HCCs present as smaller tumours in older patients, with a higher incidence of tumour microsatellite formation and higher MVD values both in the tumorous and the non-tumorous areas, suggesting a link between HCV infection, angiogenesis, and hepatocarcinogenesis.

TT virus and hepatitis G virus infections in Korean blood donors and patients with chronic liver disease

AIM: To determine the prevalences of TTV and HGV infections among blood donors and patients with chronic liver disease in Korea, to investigate the association of TTV and HGV infections with blood transfusion, and to assess the correlation between TTV and HGV viremia and hepatic damage.

METHODS: A total of 391 serum samples were examined in this study. Samples were obtained from healthy blood donors (n = 110), hepatitis B surface antigen (HBsAg)-positive donors (n = 112), anti-hepatitis C virus (anti-HCV)-positive donors (n = 69), patients with type B chronic liver disease (n = 81), and patients with type C chronic liver disease (n = 19). TTV DNA was detected using the hemi-nested PCR. HGV RNA was tested using RT-PCR. A history of blood transfusion and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were also determined.

RESULTS: TTV DNA was detected in 8.2% of healthy blood donors, 16.1% of HBsAg-positive donors, 20.3% of anti-HCV-positive donors, 21.0% of patients with type B chronic liver disease, and 21.1% of patients with type C chronic liver disease. HGV RNA was detected in 1.8% of healthy blood donors, 1.8% of HBsAg-positive donors, 17.4% of anti-HCV-positive donors, 13.6% of patients with type B chronic liver disease, and 10.5% of patients with type C chronic liver disease. The prevalence of TTV and HGV infections in HBV- or HCV-positive donors and patients was significantly higher than in healthy blood donors (P < 0.05), except for the detection rate of HGV in HBsAg-positive donors which was the same as for healthy donors. There was a history of transfusion in 66.7% of TTV DNA-positive patients and 76.9% of HGV RNA-positive patients (P < 0.05). No significant increase in serum ALT and AST was detected in the TTV- or HGV-positive donors and patients.

CONCLUSION: TTV and HGV infections are more frequently found in donors and patients infected with HBV or HCV than in healthy blood donors. However, there is no significant association between TTV or HGV infections and liver injury.

Therapeutic efficacy of transcatheter arterial chemoembolization as compared with hepatic resection in hepatocellular carcinoma patients with compensated liver function in a hepatitis B virus-endemic area: a prospective cohort study

PURPOSE

Identifying a special subgroup of hepatocellular carcinoma (HCC) patients who may benefit from transcatheter arterial chemoembolization (TACE) when compared with the standard treatment of hepatic resection (HR) warrants research in Asian countries.

PATIENTS AND METHODS

From January 1993 to December 1994, 182 patients with operable HCC (Child-Pugh class A and International Union Against Cancer [UICC] stage T1-3N0M0) were enrolled. After initial TACE and lipiodol computed tomography, 91 received HR and 91, who refused the operation, received repeated sessions of TACE. After stratification according to the tumor stage (UICC and Cancer of the Liver Italian Program [CLIP]) and lipiodol retention pattern, the survival rates of the two treatment groups were compared. The median follow-up period was 83 months.

RESULTS

As of December 31, 2000, 48 patients who underwent HR and 68 patients who underwent TACE had died. In a subgroup analysis according to tumor stage, the HR group survival rate was significantly higher than the TACE group in both UICC T1-2N0M0 (P =.0058) and CLIP 0 (P =.0027) subgroups. However, there was no significant difference in either UICC T3N0M0 (P =.7512) or CLIP 1-2 (P =.5366) subgroups. Even in patients with UICC T1-2N0M0 HCC, when lipiodol was compactly retained, the survival rate of the HR group was comparable to that of the TACE group (P =.0596).

CONCLUSION

TACE proved to be as effective as HR in the subpopulations with UICC T3N0M0 or CLIP 1-2 HCC and adequate liver function, and even with UICC T1-2N0M0 HCC when lipiodol was compactly retained in the tumor. In such cases, the choice of treatment modality between TACE and HR may be left to the patient's preference.

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.

Digital image analysis of the distribution of proliferating cell nuclear antigen in hepatitis C virus-related chronic hepatitis, cirrhosis, and hepatocellular carcinoma

Viral dynamic studies in chronic hepatitis C virus (HCV) infection indicate a significantly shortened survival of virus-infected cells. Since at the steady state of chronic viral infection, the rate of infected cell elimination equals new cell regeneration, this would imply a high rate of hepatocyte turnover in chronic HCV liver disease. We estimated the fraction of regenerating hepatocytes in liver biopsy sections in chronic HCV liver disease, cirrhosis, and hepatocellular carcinoma (HCC). We used antibodies to proliferating cell nuclear antigen (PCNA) to detect proliferating cell nuclei in liver biopsy specimen from controls and patients with chronic hepatitis, cirrhosis, and HCC. We also used bis-benzimide to label fluorescently all hepatocyte nuclei simultaneously. Using digital image analysis, we calculated the area occupied by PCNA-stained hepatocyte nuclei, as a fraction of the total area occupied by fluorescently labeled hepatocyte nuclei (labeling index; LI). Antibody staining was negligible in the control specimen. The mean +/- SE PCNA LI increased from 0.21 +/- 0.1 in chronic hepatitis to 0.63 +/- 0.15 in HCC. There was no significant difference between chronic hepatitis and cirrhosis. The fraction of cells undergoing regeneration is increased in chronic HCV liver disease, HCV-related cirrhosis, and HCC. Increased hepatocyte turnover could provide the link between chronic HCV liver disease and HCC.

Coexpression of neural cell adhesion molecules and bcl-2 in intrahepatic cholangiocarcinoma originated from viral hepatitis: relationship to atypical reactive bile ductule

It has been shown that atypical reactive bile ductules (ARBD) display positive immunoreactivity of neural cell adhesion molecules (NCAM) and bcl-2. We investigated the clinicopathological features of intrahepatic cholangiocarcinoma (CC) arising in cases of viral hepatitis B or C (VHBC) and examined their relation to ARBD by means of immunohistochemical analysis. Sixty-eight surgical cases with CC were included in this study. The cause of the background liver disease was hepatitis B surface antigen (HBsAg)(+) in eight cases, antihepatitis C virus antibody (HCVAb)(+) in 13 cases, both HBsAg(+) and HCVAb(+) in one case, and both HBsAg(-) and HCVAb(-) in 46 cases. The average age of patients with CC arising in the HBsAg(+) group was significantly less than that of patients with CC in the HCVAb(+) group (P = 0.0192). Immunohistochemically, CC arising in the HBsAg(+) and HCVAb(+) groups was correlated with coexpression of NCAM/bcl-2 in the tumor cells (P = 0.0068 and P = 0.0382, respectively). Among the 12 cases of CC coexpressing NCAM/bcl-2, 11 were of mass-forming and peripheral type (P = 0.0437), and lymph node metastasis was a rare finding compared with CC showing negative coexpression of NCAM/bcl-2 (P = 0.0213). The tumor cells of CCs arising in VHBC have some characteristics of ARBD. In such tumors, because lymph node metastases were rarely seen and lymph node dissection did not improve patient's survival, lymph node dissection can be limited.

Hepatitis C: an epidemiological review

The aim of the study was to analyse the current literature regarding the mode of transmission of HCV and its global prevalence in different groups of people. A systematic review of the literature on the epidemiology of hepatitis C from 1991 to 2000 using computerized bibliographic databases which include Medline, Current Content and Embase. The prevalence of hepatitis C virus (HCV) varies tremendously in different parts of the world, with the highest incidence in the Eastern parts of the globe compared with the Western parts. Furthermore, certain groups of individuals such as intravenous drug users are at increased risk of acquiring this disease irrespective of the geographical location. Although the main route of transmission is via contaminated blood, curiously enough in up to 50% of the cases no recognizable transmission factor/route could be identified. Therefore, a number of other routes of transmission such as sexual or household exposure to infected contacts have been investigated with conflicting results. Hepatitis C infection is an important public health issue globally. Better understanding of routes of transmission will help to combat the spread of disease. In order to prevent a world wide epidemic of this disease, urgent measures are required to (i) develop a strategy to inform and educate the public regarding this disease and (ii) expedite the efforts to develop a vaccine.

Liver disease in the elderly

Despite several morphologic and functional changes that have been described in the aging liver, most relevant studies fail to identify a significant age-related deficit in liver function in humans. One of the important age-related changes is a decrease in regenerative capacity, which may partly explain the impaired recovery after severe viral and toxic injury in the elderly. Nevertheless, livers from older subjects are used successfully for transplantation. Substantial morbidity and mortality in the elderly is attributable to liver diseases, and the number of patients older than 65 years of age with chronic liver disease is increasing rapidly. Although there are no liver diseases specific to advanced age, the presentation, clinical course and management of liver diseases in the elderly may differ in important respects from those of younger individuals.

[Predictive factors of the mortality of digestive hemorrhage caused by esophageal varices in elderly patients]

Complications of liver cirrhosis are increasingly frequent in elderly patients due to increased life expectancy and better management of cirrhotic patients. However, the influence of this condition on the evolution of variceal bleeding has not been well established. The aim of the present study was to determine the characteristics of esophagogastric variceal bleeding in elderly patients and the possible influence of advanced age on hemorrhage-related mortality. We analyzed 321 episodes of variceal bleeding in 227 cirrhotic patients. One hundred and thirteen (35.2%) episodes occurred in patients older than 65 years. No differences were found among patients older or younger than this age in terms of bleeding characteristics or Child-Pugh score. Patients older than 65 years more frequently presented serious associated diseases, hepatocellular carcinoma and hepatic encephalopathy during the episode (52.7% vs. 14%, p < 0.001; 19.7% vs. 8.7%, p = 0.01 and 17.4% vs. 10%, p = 0.09 respectively). Although hemorrhage-related mortality was higher in elderly patients (23.2% vs. 13.5%, p = 0.04), only the Child-Pugh score, definitive hemostasis, hepatocellular carcinoma and the development of encephalopathy or bacterial infection were independent predictive factors of mortality. A considerable proportion of the patients with esophagogastric variceal bleeding were older than 65 years. Advanced age does not independently influence mortality due to variceal bleeding.

Chronic liver disease in the extremely elderly of 80 years or more: clinical characteristics, prognosis and patient survival analysis

BACKGROUND/AIMS

This study aimed to elucidate the clinical characteristics of patients with chronic liver disease aged 80 years or more, especially the factors affecting prognosis and carcinogenesis.

METHODS

A total of 135 patients aged 80 years or above were divided into chronic liver disease without cirrhosis (non-LC) and cirrhosis (LC) groups according to the severity of fibrosis, and the clinical characteristics and prognoses were evaluated.

RESULTS

Seventy-three (54.1%) of 135 patients were in the LC group and 79 patients (58.5%) had hepatitis C virus. Various concomitant diseases were seen in 122 patients (90.4%). Liver-related deaths occurred in only 19 (36.5%) of 52 patients who died during observation, although 28 patients (53.8%) had liver cancer at the time of death. Cumulative survival rates in the non-LC and the LC groups were 85.7% and 58.8% at the 5th year, and 69.4% and 19.4% at the 9th year, respectively. Cumulative liver cancer appearance rates in the non-LC and the LC groups were 1.6% and 6.1% at the 1st year, 12.4% and 19.9% at the 5th year, and 12.4% and 32.0% at the 7th year, respectively. A multivariate Cox regression analysis revealed that the presence of liver cancer (p=0.0001), platelet count (p=0.0242), and fibrotic stage (p=0.0118) were independently associated with survival period, and alfa-fetoprotein (p=0.0194) and bilirubin (p=0.0282) were independently associated with carcinogenesis.

CONCLUSIONS

Cirrhosis is the major risk factor affecting the prognosis. On the other hand, we must pay more attention to concomitant diseases specific to advanced age.

Hepatitis C virus genotypes in a cohort of Middle Eastern patients

BACKGROUND

The epidemiology of hepatitis C virus infection has been well characterized in Western Europe, North America and Japan. Less is known about it in other regions of the world. In order to fully understand the relationship between host and virus, it is important to study the effect of virus infection in all regions of the world. In this report, we have analyzed patients from the United Arab Emirates, Egypt and Jordan.

DESIGN AND METHODS

Serum from 81 Middle Eastern HCV ELISA-2-positive patients was analyzed for the presence of HCV RNA by PCR. RNA-positive patients were genotyped by selective hybridization of amplicons to HCV genotype-specific oligonucleotides (InnoLipa2, Innogenetics, Belgium). Where possible, data was also obtained on racial origin, liver histology, serum ALT, prothrombin time, albumin, and risk factors for infection.

RESULTS

Sixty-five of 81 patients were HCV RNA-positive. A higher proportion of Middle Eastern patients were genotype 4 compared to equivalent studies from Western Europe, USA and Japan. However, the most common genotype was 1a. No significant difference in genotype was found between patients with chronic hepatitis and patients with cirrhosis.

CONCLUSIONS

Eight of 65 (12%) patients were genotype 4, but the most common genotype was 1a, a âWesternâ genotype (24/65, 37%). The mean age of cirrhotics was low compared to Western studies. This may be due to infection in early childhood or race-related host factors. Twelve of 65 patients (18%) were not classifiable for genotype using InnoLipa2. This may be due to multiple infecting genotypes in these patients, or unusual, non 13 HCV genotypes which cannot be classified by InnoLipa2.

Protection of 5alpha-dihydrotestosterone against TGF-beta-induced apoptosis in FaO cells and induction of mitosis in HepG2 cells

Administration of TGF-beta1 to both FaO and HepG2 cells significantly induced apoptosis, particularly in FaO cells. Degradation of genomic DNA in FaO cells was rapidly induced by treatment with TGF-beta1 (5 ng/ml) for only 4 hr. 5alpha-dihydrotestosterone (DHT, 25 nM) alone did not affect any significant changes in cell viability and in nuclei of FaO cells; however, pre-treatment with DHT protected genomic DNA degradation induced by TGF-beta1 for 14 hr. Simultaneous treatment with DHT plus TGF-beta1 (D + T) inhibited TGF-beta-induced apoptosis by approximately 50% in FaO cells. On the other hand, D + T treatment increased mitosis in actively growing HepG2 cells. Thus, it is reasonable to conclude that DHT gives growth advantage to hepatocellular-carcinoma cells by inhibiting TGF-beta-induced DNA fragmentation in FaO cells and by inducting mitosis in HepG2 cells.

Lack of association of cytochrome P450 2E1 genetic polymorphisms with the risk of human hepatocellular carcinoma

The iso-enzyme pattern of cytochrome P450 was shown to be related to the development of chemically induced hepatocellular carcinoma (HCC) in rats, which is accelerated by chronic alcohol ingestion. Our study was designed to investigate the association of cytochrome P450 2E1 (CYP2E1) genetic polymorphisms with the susceptibility to HCC in humans with and without chronic alcohol ingestion. We enrolled 171 male patients (108 Korean and 63 Japanese) with HCC and 31 age- and sex-matched healthy Korean subjects with no evidence of liver disease or cancer in any organ. Genotypes in the 5'-flanking region of the CYP2E1 gene were determined by restriction fragment length polymorphisms using 2 endonucleases: Pst I and Rsa I. Allelic frequencies in the CYP2E1 5'-flanking region in the Korean control population were 83.5% and 16.5% for allele c1 and c2, respectively. The frequencies of genotypes with the c2 allele (c1/c2 and c2/c2) were compared with those of genotypes without c2 (c1/c1) among HCC patients and controls, according to the pattern of alcohol consumption. There was no significant association between HCC risk and genotypes c1/c2 and c2/c2 either in all HCC patients or in HCC patients of different ethnic groups. Habitual drinkers with HCC, especially among Koreans, were more likely to carry genotype c1/c2 and c2/c2 (odds ratio = 3.0) than non-habitual drinkers (odds ratio = 1.2); however, the difference was not statistically significant. Even when patients were restricted to those without hepatitis B surface antigen and antibodies against hepatitis C virus but with a history of chronic alcohol ingestion, there was still no increased risk of HCC in those with genotypes c1/c2 and c2/c2. We conclude that there is a lack of association of the polymorphisms of CYP2E1 with the risk of HCC in humans.

Comparison of clinical features and survival in patients with hepatitis B and C virus-related hepatocellular carcinoma

We analyzed the clinical characteristics and survival of 185 patients with hepatitis B virus-related hepatocellular carcinoma (HBV group) and 1033 with hepatitis C virus-related hepatocellular carcinoma (HCV group) by multi center study. The patients in the HBV group (mean age 52.1 yr) were about 10 years younger than those in the HCV group (mean age 62.9 yr). Liver function, as measured by indocyanine green retention at 15 min, was better in the HBV group (17.5%) than in the HCV group (25.4%). A higher proportion of the HBV group (55%) than the HCV group (44%) had clinical stage I, T-factor differed significantly between the groups: 53% of the HBV group were T3-4 compared with 41% of the HCV group. Furthermore, a higher proportion of the HBV group were graded 2-3 for tumor thrombus in the portal vein (20.3%) and had poorly differentiated hepatocellular carcinoma (7%) compared with the HCV group (7.1% and 5% respectively). Univariate analysis identified poor prognostic factors for hepatocellular carcinoma as HBV, age < or = 50 yr, clinical stage II-III, a high AFP level, higher number of tumors, larger tumor size, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3. On multivariate analysis, poor prognostic factors were a high AFP level, higher number of tumors, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3, but not HBV, age, clinical stage or tumor size. These results suggest that HBV itself is not a stronger prognostic factor than HCV.

Hepatitis C virus genotypes in Korea and their relationship to clinical outcome in type C chronic liver diseases

OBJECTIVES

The relationship between HCV genotype and the development of more serious liver disease has not been clearly established. This study was to investigate the distribution pattern of HCV genotypes in Korea and their relationship to the viremic level and to progression of chronic liver disease.

METHODS

Study population was 217 patients with type C chronic liver disease. They were divided into 4 groups; 83 patients with near-normal ALT (group 1), 64 patients with elevated ALT (group 2), 20 patients with decompensated liver cirrhosis (group 3) and 50 patients with hepatocellular carcinoma (group 4). HCV genotypes were determined by reverse transcription polymerase chain reaction (RT-PCR) using mixed primer sets, and then the fidelity of genotyping was confirmed by cloning and sequencing. HCV RNA concentration was measured by quantitative competitive RT-PCR for 23 patients in group 2.

RESULTS

The genotypes could be determined in 166 (76%) out of 217 patients. Type 1b and type 2a were predominantly occurring over the other types in somewhat similar frequency (45% and 51%, respectively). The genotype distribution of type 1b and 2a among four different groups showed 42% and 54% in group 1, 49% and 45% in group 2, 53% and 47% in group 3 and 41% and 57% in group 4; thus there was no significant difference in genotype distribution among 4 different disease groups. However, the viremia levels in patients with genotype 1b infection were significantly higher than those with genotype 2a.

CONCLUSION

Genotype 2a infection is as prevalent as genotype 1b in Korea, and genotype 2a infection may pose no less risk for progression of disease despite lower replication level than genotype lb infection.

Hepatitis C: progress and problems

The hepatitis C virus (HCV), a single-stranded RNA virus, is the major cause of posttransfusion hepatitis. HCV isolates differ in nucleotide and amino acid sequences. Nucleotide changes are concentrated in hypervariable regions and may be related to immune selection. In most immunocompetent persons, HCV infection is diagnosed serologically, using antigens from conserved regions. Amplification of RNA may be necessary to detect infection in immunosuppressed patients. Transmission by known parenteral routes is frequent; other means of spread are less common and may represent inapparent, percutaneous dissemination. Infection can lead to classical acute hepatitis, but most infected persons have no history of acute disease. Once infected, most individuals apparently remain carriers of the virus, with varying degrees of hepatocyte damage and fibrosis ensuing. Chronic hepatitis may lead to cirrhosis and hepatocellular carcinoma. However, disease progression varies widely, from less than 2 years to cirrhosis in some patients to more than 30 years with only chronic hepatitis in others. Determinants important in deciding outcome are unknown. Alpha interferon, which results in sustained remission in selected patients, is the only available therapy. Long-term benefits from such therapy have not been demonstrated. Prevention of HCV infection by vaccination is likely to be challenging if ongoing viral mutation results in escape from neutralization and clearance.