Hepatitis B virus DNA in anti-HBe-positive asymptomatic carriers

OBJECTIVES: We examined the level of hepatitis B virus (HBV) DNA and the mutations in the precore, core and polymerase regions of HBV in sera from anti-HBe-positive asymptomatic carriers (ASC). METHODS: The amount of HBV DNA was determined semiquantitatively by mutation site-specific assay in sera from 19 anti-HBe-positive ASC and 31 HBeAg-positive patients with chronic liver disease (CLD). The mutations in the precore, core and polymerase (terminal protein) regions, spanning 1,037 nucleotides, of HBV in sera from three cases each of anti-HBe-positive ASC, HBeAg-positive ASC and HBeAg-positive CLD were examined by directly sequencing the amplified HBV DNA. RESULTS: The level of HBV viremia in anti-HBe-positive ASC was significantly lower than that in HBeAg-positive CLD patients (p < 0.01). By sequence analysis, there were a few missense mutations detected in HBeAg-positive ASC and HBeAg-positive CLD patients. In contrast, many mutations, especially in the central or N-terminal half of the core region and N-terminal part of the polymerase region, were detected in anti-HBe-positive ASC. CONCLUSION: Mutations not only in the precore/core region, but also in the polymerase region of HBV might cause damage to some important functions for efficient replication of HBV and be involved in the reduced amount of HBV in anti-HBe-positive ASC.     

Difference of subtypes of hepatitis B surface antigen between asymptomatic carriers and patients with chronic liver diseases

Subtypes of hepatitis B surface antigen (HBsAg) were studied in 20 asymptomatic HBsAg carriers and 18 HBsAg-seropositive patients with chronic hepatitis or live cirrhosis. Among them 25 were university students. In the male university students, subtypes adw was found to be significantly higher in asymptomatic HBsAg carriers than in patients with chronic hepatitis (p=0.04). The difference in subtypes of HBsAg between male asymptomatic carriers and male patients with liver disease was further confirmed by the combined results of university students and other subjects (p=0.007).     

Phytohemagglutinin-induced lymphocyte transformation in liver diseases and in asymptomatic HBsAg carriers.

Phytohemagglutin (PHA)-induced lymphocyte transformation was impaired in acute viral hepatitis. It was significantly correlated with grades of liver cell damage as shown by prothrombin time, GOT, or GPT. It was also lower in drug-induced hepatitis and in prolonged hepatitis than in controls. Of asymptomatic HBsAg carriers, only those with minimal hepatic change showed lower values in stimulation index as well as incorporated radioactivity.     

Hepatitis B virus genotype distribution among chronic hepatitis B virus carriers in Shanghai, China

OBJECTIVE: Hepatitis B virus (HBV) genotype distribution is still unclear in China, where a high prevalence of HBV infection exists, although it is well known that HBV can be classified into six genotypes based on intergroup divergence. The aim of this study was to investigate the epidemiological distribution of HBV genotypes and to clarify further the genotype-related differences in the pathogenicity of HBV. METHODS: Seminested PCR and restriction fragment length polymorphism analysis were conducted in 97 asymptomatic HBV carriers (ASC) and 46 chronic hepatitis (CH), 37 liver cirrhosis (LC) and 44 hepatocellular carcinoma (HCC) patients in Shanghai, China. RESULTS: Two hundred and twenty samples (98.2%) were positive for HBV DNA, and of these, 3 (1.4%), 38 (17.2%) and 179 (81.4%) were classified as genotype A, B and C, respectively. There was a statistically significant difference in the distribution of genotypes B and C among various categories of liver diseases (p < 0.01). The distribution of genotype C showed an increasing trend from ASC, CH and LC to the HCC group; in contrast, the distribution of genotype B showed a decreasing trend in the same order. HBeAg positivity was higher in genotype C than in genotype B in all the subjects or in the ASC group alone (p < 0.05, p < 0.01, respectively). More severe liver damage and a higher mean age were observed in genotype C than in genotype B (p < 0.01, p < 0.05, respectively). CONCLUSIONS: These results indicate the following: (1) genotypes A, B and C of HBV exist in Shanghai, China; (2) genotype C is the major genotype in this area; (3) genotype C is associated with the development of severe liver diseases, and (4) genotype B has a relatively good prognosis.     

Hepatitis B surface antigen in saliva of HB-SAg carriers.

Two hundred and twelve saliva specimens of HB-SAg carriers were tested for HB-SAg by crossover immunoelectrophoresis (CIEP) and radioimmunoassay (RIA) after concentration, between April 1971 and September 1973. They were divided into 3 groups (A, B, and C). CIEP detected HG-SAg in 6 per cent in Group A (66 specimens) and in 12 percent in Group B (87 specimens), and in 78 per cent in Group C. Different methods of preparation and concentration of saliva specimens were discussed. The positive results by RIA were confirmed by a blocking test with rabbit HB-SAg antiserum. Intermittent presence of HB-SAg in repeated saliva specimens from individual carriers was found. Infected saliva of HB-SAg carriers may be of importance in transmission of hepatitis B infection.     

Serum hyaluronan as a marker of liver fibrosis in asymptomatic chronic viral hepatitis B.

Increased concentrations of serum hyaluronan, a polysaccharide widely distributed in the extracellular space, have been demonstrated in liver disease of various aetiologies and proposed as a useful marker of liver fibrosis. The aim of the present study was to evaluate the association of serum hyaluronan with the extent of hepatic fibrosis in asymptomatic cases of chronic hepatitis B viral infection. The study was conducted in a consecutive sample of 111 asymptomatic chronic carriers of hepatitis B surface antigen. Liver function tests, alcohol consumption and cigarette smoking were determined and, for 84 subjects, liver biopsy was performed and degrees of inflammation and fibrosis were scored. Hyaluronan was measured using a radiometric assay. Mean serum hyaluronan increased with increasing fibrosis score (from 22.2 +/- 4.8 to 50.6 +/- 12.7 microg/l, p = 0.058) or pathological severity (from 18.8 +/- 5.9 to 50.6 +/- 12.5 microg/l, p = 0.048), even after adjusting for the effect of age. No such correlation was found with portal inflammation. The study showed that, in asymptomatic chronic carriers of hepatitis B, serum hyaluronan concentration correlates with hepatic fibrosis, a known marker of disease prognosis. This finding supports the hypothesis that hyaluronan might be of use in assessing and monitoring time trends in liver disease, substituting for repeated biopsies.     

Cellular and humoral immunity in asymptomatic carriers of the hepatitis B virus

Eighty-eight asymptomatic HBsAg carriers were examined for cellular and humoral immunity and markers of virus B hepatitis in liver tissue and blood serum. The following results were obtained: HBsAg and HBcAg in liver tissue were found in 10 and 19 out of the 24 examinees, respectively, HBeAg and anti-Hbe in blood serum in 2 and 20 out of the 25 examinees, respectively. No alterations were recorded on the part of humoral immunity. Changes in cellular immunity manifested themselves by reduction in the number of T lymphocytes, and decreased response to PHA. Sensitization to HBsAg led to the purification of hepatitis B virus whereas the presence of simultaneous sensitization to liver-specific lipoprotein contributed to development of graver patterns of liver injury. The role of the immune system and hepatitis B virus itself in the pathogenesis of liver injury in asymptomatic HBsAg carriers is discussed.     

Antibody pattern to hepatitis C virus antigens in patients with acute and chronic liver diseases

The present paper describes the antibody pattern in the early stages of hepatitis C virus (HCV) infection and compares it with that obtained in chronic carriers. Samples were tested for anti-HCV from 470 consecutive patients admitted to gastroenterology services at three Havana hospitals, with serological and biochemical signs of non-A, non-B hepatitis, including those referred from three Havana blood banks because of a positive result in anti-HCV in pre-donation screening. Four anti-HCV enzyme immunoassay (EIA) systems and two supplementary assays were used for antibody detection. These results show that antibodies to viral core antigens are the first and commonest among Cuban patients infected with HCV, and generally, they can reveal the infection before the supplementary tests do. LiaTek HCV has proved to be a good tool for the confirmation of enzyme-linked immunosorbent assay (ELISA) positive samples.     

Synthesis of antibodies to hepatitis B virus by cultured lymphocytes from chronic hepatitis B surface antigen carriers

It has been postulated that host immune defects are responsible for the development and persistence of the hepatitis B surface antigen (HBsAg) carrier state. The nature of these defects is unknown, but the absence of a readily detectable antibody response to HBsAg (anti-HBs) may be important. The synthesis of both anti-HBs and antibody to hepatitis B core antigen (anti-HBc) in cultures containing peripheral blood mononuclear cells from chronic HBsAg carriers and from control (antibody-positive) patients was measured in the presence of pokeweed mitogen. Similar amounts of polyclonal IgG and IgM were synthesized by cultures containing lymphocytes from chronic carriers and controls. Anti-HBc was detectable in lymphocyte supernatants from 2 of 20 controls and from 21 of 29 carriers. The presence of anti-HBc synthesis in vitro correlated with high serum titers of anti-HBc. In contrast, anti-HBs was detected in lymphocyte supernatants from 6 of 20 controls (predominantly in those who had high serum titers of anti-HBs) but in none of the supernatants from 29 HBsAg carriers. In order to identify the mechanisms for the lack of detectable anti-HBs synthesis by chronic HBsAg carrier lymphocytes, co-culture experiments were performed using T and B lymphocyte fractions that had been purified by affinity chromatography. B lymphocytes from carriers co-cultured with allogeneic irradiated ("helper") T lymphocytes from controls synthesized normal amounts of IgG, IgM, and anti-HBc but still did not synthesize detectable amounts of anti-HBs. In the converse experiments, B lymphocytes from controls were co-cultured with irradiated T lymphocytes from carriers. The T lymphocytes from 16 of 24 carriers augmented anti-HBs production by control B cells normally, the remaining eight did not. Finally, mixtures of control B cells and control irradiated T lymphocytes were co-cultured with T lymphocytes from chronic HBsAg carriers. 5 of 12 carriers demonstrated active suppression of anti-HBs production, and in three this suppression was specific, as IgG and IgM production remained normal. We conclude that chronic HBsAg carriers have a specific B lymphocyte defect in anti-HBs production. In addition, defects in the function of regulatory T lymphocytes may contribute to the absence of anti-HBs synthesis in some HBsAg carriers.     

The clinical significance of hepatitis B virus antigens and antibodies.

There are two well-characterized antigen-antibody systems which relate specificially to viral hepatitis B. Tests for HBsAg and anti-HBs are readily available and of great benefit to the diagnosis, prevention and understanding of hepatitis B. Tests for HBcAg and anti-HBc are still research techniques which requires further development before they can be used at the level of everyday medical practice. HBsAg in an individual indicates that he harbors the virus of hepatitis B; it may be present in the absence of liver disease or be found in association with both acute and chronic type B hepatitis. The presence of HBsAg also suggests that HBV may be causally related to some cases of periarteritis nodosa, chronic glomerulonephritis, and hepatoma. Although HBV is readily transmitted in blood, the major portion of post-transfusion hepatitis now appears to be serologically unrelated to either the hepatitis B virus ("serum") or the hepatitis A virus ("infectious"); the etiology of these cases is currently undetermined. There is increasing evidence that HBV may be transmitted by modes other than blood, but the exact mechanisms of such transmission is not established. The combined transmission of HBV by blood and other routes has resulted in a large number of persistent carriers of HBsAg in the world. There is no current method to alter this carrier state. The hepatitis risk of such persistent carriers to their personal and professional contacts is under investigation.