Maternal transmission of hepatitis B surface antigen in patients with hepatocellular carcinoma in Taiwan

To determine the source of the highly prevalent hepatitis B virus (HBV) infection in our patients with hepatocellular carcinoma (HCC), we examined hepatitis B surface antigen (HBsAg) and its subtypes and antibody in 11 patients with HCC and their parents. All the patients were positive for HBsAg. Eight (73%) of the mothers were also HBsAg-positive, whereas only one of the seven fathers was an HBsAg carrier (P = 0.025). The observation is compatible with maternal transmission as a source of HBV infection in most of our patients with HCC. The subtype was identifiable in 10 patients, 9 with HBsAg/adw and one with adr. The subtype was identical in the patient--mother carrier pairs, suggesting that HBV infection in the patient and the mother is intimately related. This is further evidenced by the observation of a relatively uncommon adr subtype in one patient--mother pair. These observations suggest that the HBV infection in our patients results from vertical transmission from their carrier mothers probably long before the development of HCC.     

Significance of the minor i and t determinants of hepatitis B virus in hepatocellular carcinoma

Stored sera from asymptomatic hepatitis B virus (HBV) carriers and hepatitis B virus surface antigen-positive hepatocellular carcinoma (HCC) patients were tested for HBV subtypes, such as subtype determinants d, y, w, r and also antigenic determinants isoleucine (i) and threonine (t) by direct S gene nucleotide sequencing. Significant changes in minor i and t determinants in hepatocellular carcinoma patients with adr hepatitis B carriers were seen. The adr subtype with t determinant was present in 14/25 (56%) of HCC patients compared with only two of 28 (7%) in asymptomatic hepatitis B carriers ( P < 0.001). However, the adr subtype with i determinant was present in nine of 25 (36%) of the HCC patients and also present in 24/28 (86%) of asymptomatic carriers ( P < 0.001). No significant changes were seen with the adw subtypes. These results show that i and t minor determinant changes are more common with adr subtypes associated with HCC than with the adw subtype. Whether these subtle changes are pathologically relevant or only a polymorphism of hepatitis B genotypes will depend on subsequent follow-up studies.     

Geographical distribution of the subtype of hepatitis B surface antigen in Chinese.

Using the much more sensitive hemagglutination inhibition assay for subtyping of hepatitis B surface antigen (HBsAg), we examined the determinants a, d, w and r in 192 from 228 HBsAg positive adults who had been found after screening with reversed passive hemagglutination method. Sixty-four subtypable cases were asymptomatic carriers and the remaining 128 were liver disease patients. Among them there was no significant difference of the subtypes, invariably with adw as the main subtype. Geographical difference was evident: adr was the main subtype (78 per cent) among the northern Chinese; while adw was dominant (76 per cent) among the southern Chinese with the Yangtze River as a boundary. Eight of the 18 adr-subtyped northern Chinese were born and live in Taiwan where 91 per cent of HBsAg positive Taiwanese were adw-subtyped. This was an indirect evidence that intra-familial spreading from parents played an important role in hepatitis B virus infection.     

Hepatitis B surface antigen disappearance and hepatitis B surface antigen subtype: a prospective, long-term, follow-up study of Japanese residents of Okinawa, Japan with chronic hepatitis B virus infection.

To determine the natural course of hepatitis B surface antigen (HBsAg) disappearance in chronic hepatitis B virus (HBV) infection and the factors related to its disappearance, 946 HBsAg carriers in Okinawa, Japan were prospectively followed for up to 19 years (mean = 9.2 years). The disappearance of HBsAg, as determined by radioimmunoassay (RIA), was observed in 62 (6.6%) and the overall annual disappearance rate was 0.79%/year. Its disappearance was more frequent in 60 (7.4%) of 815 serum samples negative for hepatitis B e antigen (HBeAg) by RIA at entry compared with only two (1.5%) of 131 serum samples that were HBeAg positive by RIA at entry (P < 0.05). Stepwise logistic regression analysis showed that age and HBsAg subtype were significantly associated with HBsAg disappearance (both P < 0.05), and that carriers with subtype adr (odds ratio = 2.87) had an increased probability of clearing HBsAg compared with carriers with subtype adw. Conversely, HBeAg disappearance was earlier in those with the adw subtype than in those with adr. Hepatitis B virus DNA was not detected by the polymerase chain reaction after HBsAg disappearance in any of the 62 from whom it had disappeared. The HBsAg titer, as measured by reverse passive hemagglutination, was related to the time to its disappearance; the higher the titer, the longer the time to disappearance. These findings suggest that HBeAg negativity, a more advanced age, and low titers of HBsAg are favorable factors for HBsAg disappearance in the natural course of chronic HBV infection. Moreover, HBsAg subtype adr was a predictive factor for HBsAg disappearance, whereas subtype adw was predictive of early HBeAg disappearance.     

Seroepidemiological study on the horizontal infection of HBV in healthy students

In a seroepidemiological study of hepatitis B virus (HBV) over 7 years from 1982 to 1988, in a fixed population of 633 healthy students (15-20 years old), it was found that one HBV carrier who had adw subtype of HBV had also become sero-positive to r subtype, suggesting the superinfection with r subtype of HBV to the carrier. Then, some serological markers of HBV were further examined in the other 10 HBsAg positive carriers in the same population, and discussed the possibility of horizontal transmission of r subtype of HBV in the population. Of the 10 HBsAg positive carriers, 5 possessed adr subtype, 2 adwr, 2 adw, respectively, and the remaining one was not tested. Four of seven r subtype of HBsAg positive carriers exhibited pre-S2Ag and HBeAg activities which were considered as infectious markers. Epidemiological survey was carried on the four carriers with special reference to the possibility of the superinfection. As a result, it is still unclear the source of the superinfection, but at least, iatrogenically accidental transmission at the time of vaccination and contact infection in everyday life in school may be unlikely to attribute to the horizontal transmission.     

A comparative study of hepatitis B viral markers in the family members of Asian and non-Asian patients with hepatitis B surface antigen-positive hepatocellular carcinoma and with chronic hepatitis B infection.

Serologic tests for evidence of hepatitis B virus (HBV) infection were performed on family members of Asian and non-Asian patients with either hepatitis B surface antigen (HBsAg)-positive hepatocellular carcinoma or chronic HBV infection. Asian family members had a significant increase of HBsAg (34% higher) and of antibody to HBsAg or of antibody to hepatitis B core antigen (50% higher) when they were compared with non-Asian family members. In the Asian group, viral markers were detected more frequently in blood relatives than in nonblood relatives of the index cases. Within this group, birthplace did not influence the frequency of antigenemia, since HBsAg was positive in 55 (44%) of 125 Asians born in Asia and in 36 (38%) of the 94 Asians who were born in the United States. Also, HBsAg positivity frequently was seen in offspring from HBsAg-positive carrier mothers as well as from HBsAg-positive carrier fathers whose spouses were either HBsAg-negative or who had antibody. The e antigen was found more often in individuals 30 years of age or younger than in older individuals. This study indicates that intrafamilial spread of HBsAg in Asian families plays an important role in the perpetuation of HBV infection and in the eventual development of chronic liver disease in this ethnic group.     

Frequency of concurrence of hepatitis B surface antigen and antibody in a large number of carriers in Okinawa,Japan

A large number of chronic hepatitis B surface antigen (HBsAg) carriers in Okinawa, Japan were tested for antibody to HBsAg (anti-HBs), by both radioimmunoassay and enzyme immunoassay methods. Concurrence of HBsAg and anti-HBs was found in 166 (26.1% ). We found no clear predominance of either liver damage or hepatitis B e antigen (HBeAg) in the concurrent carriers studied. Antibody to pre-82 antigen (anti-pre-S2) was detected in 16 (9.6%) of 166 subjects with concurrent markers, 15 of these 16 carriers were positive for antibody to HBeAg (anti-HBe). Anti-pre-S2 was correlated wit anti-HBe rather than with anti-HBs. The distribution of HBsAg subtypes among carriers determined to have subtypes was 76.7% adw, 22.0% adr, 0.2% ayr, 0.9% adwr, and 0.2% adyr. The distribution of anti-HBs subtypes among concurrent carriers was 51.5% anti-r, 21.4% anti-w, 15.5% anti-d, and 10.7% anti-y. Concurrent carriers had HBsAg of one subtype and heterotypic anti-HBs. Because the HBsAg subtype ay is rare in this area, it is hard to believe that the concurrent carriers with anti-y were infected with hepatitis B virus of which the HBsAg subtype was ay. A dual infection was highly unlikely. It seems that some of the concurrent carriers correlate with compound subtypes adwr and adyr.     

Frequency of concurrence of hepatitis B surface antigen and antibody in a large number of carriers in Okinawa, Japan

A large number of chronic hepatitis B surface antigen (HBsAg) carriers in Okinawa, Japan were tested for antibody to HBsAg (anti-HBs), by both radioimmunoassay and enzyme immunoassay methods. Concurrence of HBsAg and anti-HBs was found in 166 (26.1%). We found no clear predominance of either liver damage or hepatitis B e antigen (HBeAg) in the concurrent carriers studied. Antibody to pre-S2 antigen (anti-pre-S2) was detected in 16 (9.6%) of 166 subjects with concurrent markers, 15 of these 16 carriers were positive for antibody to HBeAg (anti-HBe). Anti-pre-S2 was correlated with anti-HBe rather than with anti-HBs. The distribution of HBsAg subtypes among carriers determined to have subtypes was 76.7% adw, 22.0% adr, 0.2% ayr, 0.9% adwr, and 0.2% adyr. The distribution of anti-HBs subtypes among concurrent carriers was 51.5% anti-r, 21.4% anti-w, 15.5% anti-d, and 10.7% anti-y. Concurrent carriers had HBsAg of one subtype and heterotypic anti-HBs. Because the HBsAg subtype ay is rare in this area, it is hard to believe that the concurrent carriers with anti-y were infected with hepatitis B virus of which the HBsAg subtype was ay. A dual infection was highly unlikely. It seems that some of the concurrent carriers correlate with compound subtypes adwr and adyr.     

Hepatitis B virus infections in families in which the mothers are negative but the fathers are positive for HBsAg.

We studied a total of 37 families, in which HBsAg was positive in either or both of father and mother, to assess intra-familial transmission of hepatitis B virus (HBV). The HBsAg positive rate for children with HBsAg-negative mothers was significantly lower than that with positive mothers (4 of 31, 12.9% versus 18 of 32, 56.3%, p<0.01) of course. However, there were three families in which the infection source for children was thought to be fathers, not mothers, i.e., of eight children in these three families with HBsAg +/- father/mother pairs, 4 (50%) were positive for both HBsAg and HBV DNA of genotypes identical to those of their fathers, and another child was positive for HBcAb despite being negative for HBsAg. Interestingly, moreover, all the mothers in these three families were HBcAb-positive even though HBsAg-negative, suggesting that not only father-to-child but also inter-spouse HBV transmission might have occurred. With these findings we would suggest that all the family members with HBsAg-positive fathers should receive HBV vaccine, let alone for those with HBsAg-positive mothers.     

Source of transmission in children with chronic hepatitis B infection after the implementation of a strategy for prevention in those at high risk

Aim: In order to clarify the sources of chronic HBV (hepatitis B virus) infection in children after the implementation of an “at‐risk” strategy in Japan, chronically infected children were assessed. In addition, chronically infected children born to HBsAg‐negative mothers and their family members were assessed to identify the sources of HBV transmission. Methods: Fifty‐seven children who tested HBsAg‐positive after the initiation of a mother‐to‐child transmission prevention program were enrolled in this study. The full‐genome HBV DNA sequence was analyzed to confirm the transmission sources. Results: Of the 57 patients, 37 (65%) were born to HBV carrier mothers. The remaining 20 (35%) patients were born to HBsAg‐negative mothers. Fourteen of these patients had HBV carrier fathers, and 2 patients, who were siblings, did not have an HBV carrier father. The remaining 4 patients had no family members with HBV infection. Phylogenetic tree analysis confirmed that father‐to‐child transmission and sibling‐to‐sibling transmission occurred in 3 families and 1 family, respectively. Conclusion: Although vaccine failure of mother‐to‐child transmission was the major cause of chronic HBV infection in children, father‐to‐child transmission was the second most common mode of transmission. In addition, sibling‐to‐sibling transmission was found. Unless at‐risk individuals and groups can be accurately identified to prevent horizontal transmission, the introduction of universal vaccination is essential for achieving the elimination of HBV infection in Japan.     

Hepatitis B virus infection in 6,130 unvaccinated Korean-Americans surveyed between 1988 and 1990

OBJECTIVES: During the past decades, the influx of immigrants from hepatitis B virus (HBV) endemic regions has brought significant changes in the prevalence of HBV-associated liver diseases and hepatocellular carcinoma (HCC) in the United States. Our program, which was intended to identify those in need of hepatitis B vaccination, helped us to learn of the natural history of HBV infection in Korean Americans. METHODS: Between November of 1988 and May 1990, we screened 6,130 Korean Americans in the eastern United States for HBV infection. RESULTS: The overall hepatitis B surface antigen (HBsAg) (+) rate was 6.1%, with 8.0% for males and 4.4% for females. The carrier rate peaked in subjects between the ages of 21 and 40 yr. The HBsAg (+) rate for 452 U.S.-born children was lower (2.7%) than that of 623 Korean-born (5.5%). None received hepatitis B immune-globulin or HBV vaccination. The vertical transmission rate was 30.3% in children born to HBsAg (+) mothers and 100% in those born to hepatitis B e antigen (HBeAg) positive mothers. In contrast, the paternal transmission rate was low; 10.3% in children with HBsAg (+) fathers and 19.2% in those with HBeAg (+) fathers. Another significant observation was the unexpected finding of ongoing liver diseases in incidentally identified carriers. Evaluation of 139 asymptomatic adult carriers revealed that 42% had elevated liver enzymes and 11% had already developed liver cirrhosis. CONCLUSION: These findings strongly suggest the need for active HBV screening of immigrants from endemic regions and, most importantly, the need for careful monitoring of the carriers.     

Global control of hepatitis B virus infection

Worldwide about 350 million people are chronic carriers of the hepatitis B virus (HBV). The infection can cause acute and chronic liver disease including cirrhosis and hepatocellular carcinoma (HCC). Hepatocellular injuries of HBV infection are predominantly immune-mediated, and the natural history of chronic infection can be divided into three phases based on virus-host interactions-namely, immune tolerance, immune clearance, and viral integration phases. Four serotypes (adw, ayw, adr, and ayr) and seven genotypes (A to G) of HBV have been identified, and they show some distinct geographic distributions. The HBV genotypes may have clinical relevance and are currently under investigation. On the basis of disease burden and the availability of safe and effective vaccines, the WHO recommended that by the end of the 20th century hepatitis B vaccine be incorporated into routine infant and childhood immunisation programmes for all countries. The efficacy of universal immunisation has been shown in different countries, with striking reductions of the prevalence of HBV carriage in children. Most important, hepatitis B vaccination can protect children against HCC and fulminant hepatitis, as has been shown in Taiwan. Nevertheless, the implementation of worldwide vaccination against HBV requires greater effort to overcome the social and economic hurdles. Safe and effective antiviral treatments are available but are still far from ideal, a situation that, hopefully, will be improved soon. With hepatitis B immunisation, the global control of HBV infection is possible by the end of the first half of 21st century.     

Relationship of HBsAg Subtypes with HBeAg/anti-HBe Status and Chronic Liver Disease. Part I: Analysis of 1744 HBsAg Carriers

A total of 1744 HBsAg carriers were investigated to determine whether there are clinical differences among HBsAg subtypes or not. Although adr was more predominant than adw in 1078 asymptomatic carriers as well as in 666 carriers with liver dysfunction, the adr carriers had liver dysfunction more frequently than the adw carriers (p = 0.005). In addition, the adr carriers were more often positive for HBeAg and less often positive for anti-HBe than the adw carriers (p less than 0.001). Multivariate analyses indicated that the HBsAg subtypes were associated with liver dysfunction not directly but through the relationship between the HBsAg subtypes and HBeAg/anti-HBe status. HBeAg/anti-HBe status of each age bracket in the adr carriers and in the adw carriers suggested that adr carriers are seroconverted later than adw carriers. In conclusion, HBsAg subtypes may affect the development of chronic liver disease, through their association with HBeAg/anti-HBe status.     

Distribution of hepatitis B virus genotypes among patients with chronic infection.

Hepatitis B virus (HBV) can be classified into at least eight genotypes, A-H. We evaluated the distribution HBV genotypes among patients with chronic infection. METHODS: We consecutively evaluated adult patients with chronic HBV infection from Salvador, Brazil. Patients were classified according to HBV infection chronic phases based on HBV-DNA levels and presence of serum HBV markers. HBV-DNA was qualitatively and quantitatively detected in serum by polymerised chain reaction (PCR). Isolates were genotyped by comparison of amino acid mutations and phylogenetic analysis. RESULTS: One-hundred and fourteen patients were evaluated. HBV-DNA was positive in 96 samples. HBV genotype was done in 76. Mean age was 36 +/- 11.3. In 61 of 76 cases subjects were classified as inactive HBsAg carriers. Their mean HBV serum level was 1760 copies/ml and 53 of 61 were infected with HBV genotype A, seven with HBV genotype F and one with genotype B. Twelve of the 76 patients had detectable hepatitis B e-antigen (HBeAg) in serum. Ten were infected with HBV genotype A and two with genotype F; most had increased alanine aminotransferase and high HBV-DNA levels. Three patients were in the immunotolerant phase, two were infected with HBV genotype A and one with genotype F. HBV subtyping showed subtypes adw2 and adw4. CONCLUSIONS: HBV genotype A adw2 and genotype F adw4 were the most prevalent isolates found. We could not find differences in genotype distribution according to HBV clinical phases and DNA levels. We did not detect HBV genotype D in contrast to a previous study in our center with acute hepatitis B. All inactive HBsAg carriers had low HBV-DNA levels.     

Molecular epidemiological study of hepatitis B virus in Thailand based on the analysis of pre-S and S genes.

Aims: This study was undertaken to determine the prevalence and characteristics of hepatitis B virus (HBV) genotypes, antigen subtypes, "a" determinant variants and pre-S gene mutations circulating on a large scale in Thailand. Methods: The sequences of the Pre-S1, Pre-S2 and S regions were determined in serum samples of 147 HBsAg and HBV DNA-positive subjects who had been enrolled from the nationwide seroepidemiological survey conducted on 6213 individuals in 2004. Results: The results showed that genotypes C, B and A accounted for 87.1%, 11.6% and 1.3%, respectively. The distribution of the HBV antigen subtypes was: adr (84.4%), adw (14.2%) and ayw (1.4%). Regarding the "a" determinant, 2/43 (4.65%) and 2/104 (1.92%) samples of vaccinated and non-vaccinated subjects, respectively, displayed mutations, all ofwhich were Thr126Asn. Sequencing analysis showed the pre-S mutations in 14 (9.5%) samples, with pre-S2 deletion as the most common mutant (4.1%) followed by pre-S2 start codon mutation (2.9%), both pre-S2 deletion and start codon mutation (2.0%), and pre-S1 deletion (0.7%). The pre-S mutations were associated with older age and higher mean serum HBsAg level. Conclusion: This study demonstrated that HBV genotype/subtype C/adr and B/adw were the predominant strains circulating in Thailand. The "a" determinant variants seemed to be uncommon, and might not be attributed to vaccine-induced mutation.     

慢性乙型肝炎病毒感染者家族隐匿性乙型肝炎病毒感染的调查

目的 了解慢性HBV感染者家族隐匿性HBV感染的发生率及其与HBV标志物、年龄和性别等的关系.方法 ELISA方法检测慢性HBV感染者家族成员的HBV血清学标志物,套式PCR法检测136例HBsAg阴性家族成员的血清HBV DNA,并将隐匿性HBV感染者和HBsAg、HBV DNA均阴性者分别作为试验组和对照组进行HBV标志物、年龄、性别和生物化学检测结果的比较.两组均数比较采用t检验.率的比较采用χ~2检验或Fisher确切概率法检验.结果 在52个慢性HBV感染者家族中共检测到92例HBsAg阳性者和136例HBsAg阴性者,其中15例为隐匿性HBV感染者,慢性HBV感染者家族HBsAg阳性率和隐匿性HBV感染的发生率分别为40.4%和11.0%,15例隐匿性HBV感染者中有7例抗-HBc阳性(χ~2=5.341,P=0.02),但隐匿性HBV感染的存在与年龄、性别等无关.结论 HBV感染存在家庭聚集现象,且在其家族中存在隐匿性HBV感染,并在抗-HBc阳性者中发生率较高.     

门诊慢性HBV感染者初次就诊的临床诊断亚类构成比分析

目的:了解门诊就诊的慢性乙型肝炎不同临床诊断亚类患者的构成比及其变化趋势.方法:通过门诊电子病历获取肝病门诊2007～2009年3年期间初次就诊慢性HBV感染者的临床信息,统计分析9类慢性HBV感染者临床诊断亚类的构成比及其3年的变化趋势.结果:3年期间共有2 677例门诊初次就诊的慢性HBV感染者,其诊断分类构成比依次为:HBeAg阳性慢性乙型肝炎32％；非活动HBsAg携带者24.1％；HBeAg阴性慢性乙型肝炎23.9％；慢性HBV携带者12.1％；HBeAg阴性代偿性肝硬化4 4％；乙肝相关性原发性肝癌1.4％；HBeAg阳性代偿性肝硬化0.9％；乙肝合并其他疾病0.6％；失代偿性乙肝后性肝硬化0.4％.3年期间各亚类患者构成比及排序保持相对稳定,其中HBeAg阳性慢性乙型肝炎患者构成比有逐年下降趋势,HBeAg阴性慢性乙型肝炎构成比有逐年上升趋势；各诊断类型患者的平均年龄与HBV自然史保持一致；男/女患者比例约2.55.结论:慢性乙型肝炎和携带者是肝病门诊慢性HBV感染者的就诊主体,HBeAg阳性慢性乙型肝炎患者构成比有逐年下降趋势,可能是受我国乙肝疫苗接种计划的影响.     

Hepatitis B virus markers in Japanese immigrants and their descendants in Bolivia and native Bolivians

A survey of hepatitis B virus (HBV) markers of Japanese immigrants, their descendants and native Bolivians was performed in two agricultural settlements in Bolivia. The prevalence of HBV markers in sera, either hepatitis B surface antigen (HBsAg) or its antibody (HBsAb), was higher in the Japanese (46.4%) than in the native Bolivian (12.9%) adult generations of both colonies. There was no significant difference between Japanese (4.3%) and Bolivian (0.9%) school children in one colony, but a high percentage (32.6%) was recognized among Japanese children in the other colony. The numbers of adw subtypes were unexpectedly high among these HBsAg positive Japanese children, compared to those in Japan. Antibody to hepatitis delta virus (HDV) was detected in one case. These data suggested that although horizontal transmission of adw HBV had occurred within the Japanese population, HBV and HDV were not endemic to this geographic area.     

Hepatitis B viral genotypes: clinical relevance and molecular characteristics

Hepatitis B virus (HBV) infection is a global health problem and the clinical outcome of chronic HBV infection depends on the frequency and severity of hepatitis flares in the immune clearance phase. Currently, four subtypes and seven genotypes of HBV are identified and most have specific geographic distributions. The impact of HBV genotypes on the clinical outcome of chronic HBV infection has been partially clarified. In Taiwan, genotype C is associated with more severe liver disease and genotype B is associated with the development of hepatocellular carcinoma (HCC) in young non-cirrhotic patients. In contrast, genotype B has a relatively good prognosis in Japan and China and is rarely associated with the development of HCC. Similarly, genotype D is associated with more severe liver disease than genotype A in India and may predict occurrence of HCC in young patients. Although superinfection of HBV on top of hepatitis B carriers occurs in Taiwan, it is rarely associated with acute exacerbations. As to the response to antiviral treatment, genotypes C and D are associated with a lower response rate to interferon therapy compared with genotypes B and A. In addition, the subtype adw is reported to be associated with a higher risk of lamivudine resistance than ayw. In HBV subtype adw-infected HCC patients, genotype B responds better to embolization therapy and has a lower rate of HCC recurrence than genotype C. In summary, pathogenic and therapeutic differences do exist among HBV genotypes and determining the genotype in patients with chronic HBV infection would help gain further information for etiologic, clinical, virologic and anthropologic investigations. Further studies to clarify the molecular virological factors that contribute to these differences are awaited.