Serum HBsAg Levels Research Articles

Effects of testosterone suppression on serum levels of hepatitis B surface antigen and HBV-DNA in men.

There is epidemiological evidence that progression of hepatitis B virus (HBV)-induced liver disease is adversely influenced by male gender. Furthermore, in male transgenic mice, HBsAg levels increase after puberty, resulting in 4- to 10-fold higher HBsAg levels than in female transgenic mice. Castration reduces HBsAg levels by 90-95%, while substitution of testosterone to castrated animals rapidly increases HBsAg concentrations. We hypothesized that suppression of endogenous testosterone levels may have similar effects on HBsAg serum levels in men, as observed in male mice. To test our hypothesis, we studied the influence of reversible testosterone suppression by the LHRH-analog triptorelin on serum concentrations of HBsAg and HBV-DNA. Eight male patients, who were chronically infected with HBV, were studied in a prospective interventional study. Triptorelin decreased serum testosterone levels to castration levels for several weeks. However, this reversible testosterone suppression had no effect on HBsAg or HBV-DNA serum concentrations (p > 0.05). Suppression of endogenous testosterone levels had no effect on HBsAg levels in men, which points to a different regulation of HBsAg expression in men compared with transgenic mice.

Genetic alterations in the gene encoding the major HBsAg: DNA and immunological analysis of recurrent HBsAg derived from monoclonal antibody-treated liver transplant patients.

A gene region encoding a segment of the major surface protein, HBsAg, of hepatitis B virus was analyzed from serum samples after orthotopic liver transplantation of three hepatitis B virus chronic carrier patients treated with a human anti-hepatitis B virus monoclonal antibody (SDZ OST 577). Each of these three patients became HBsAg negative after transplantation and therapy with the human anti-hepatitis B virus monoclonal antibody but returned to HBsAg positivity (first detected 143,251 and 252 days after the transplantation). Polymerase chain reaction DNA amplification was performed on DNA from serum samples showing low levels of recurrent HBsAg and reduced antigen reactivity with SDZ OST 577 antibody. Polymerase chain reaction DNA included a 230-bp highly conserved, major S gene region that was cloned into M13 bacteriophage; analysis of this DNA segment provided a consensus of DNA sequences for the serum samples exhibiting altered reactivity with the therapeutic monoclonal. Analysis of independent DNA clones from serum samples of patients exhibiting low but detectable recurrent serum levels of posttherapy HBsAg revealed the presence of S protein variant sequences when compared with polymerase chain reaction DNA derived from the original infected liver or pretherapy serum HBsAg. Genetic variation was predominant in a highly conserved peptide domain that has previously been implicated in antibody binding and neutralizing antibody epitopes. In independent patients infected with either adw or ayw hepatitis B virus subtypes, single nucleotide changes resulted in one to two amino acid differences for each variant allele (residues 124, 129, 131, 137, 140 and/or 145) when compared with pretherapy viral DNA. Administration of serum containing one of these variant viruses to a single hepatitis B-naive chimpanzee resulted in subclinical hepatitis and detectable levels of circulating anti-HBs and anti-HBc antibodies 49 and 70 days after virus administration, respectively. Hepatitis B virus DNA was recovered on liver biopsy between 6 and 8 wk after inoculation, although the animal remained persistently seronegative for HBsAg. DNA sequence analysis of both primate and patient liver hepatitis B virus confirmed the presence of the DNA encoding the S protein variant and associates this DNA with the predominant hepatotropic virus in liver infection.

Export of intracellular HBsAg in chronic hepatitis B virus infection is related to viral replication†

Serum and liver HBsAg bear an inverse relation to each other during the evolution of chronic hepatitis B virus infection and the quantity of HBsAg in tissue rises gradually with time. In this study, intracellular and extracellular levels of HBsAg were measured by radioimmunoassay in primary culture of hepatocytes from 30 patients with chronic hepatitis B virus infection to determine a possible relationship with hepatitis B virus replication. Serum levels of HBsAg correlated with markers of active viral replication (serum hepatitis B virus DNA, p less than 0.005, and tissue HBcAg, p less than 0.02) but inversely with tissue HBsAg (p less than 0.05). In similar fashion, in vitro export of HBsAg was also related to the presence of active viral replication markers (serum hepatitis B virus DNA, p less than 0.02, and tissue HBcAg, p less than 0.05) and negatively with tissue HBsAg (p less than 0.001). Export of HBeAg also correlated positively with markers of active viral replication (serum hepatitis B virus DNA, p less than 0.05 and tissue HBcAg, p less than 0.05). Further experiments indicated that intrahepatic pre-S1 and pre-S2 correlated closely with intrahepatic HBsAg, indicating that a failure to export HBsAg was unlikely to be attributable to deficient intracellular expression of pre-S1 or pre-S2. These data indicate that in vitro primary hepatocyte culture of hepatitis B virus-infected cells provides an accurate reflection of in vivo export of HBsAg and that this is closely related to the presence of active viral replication.

Export of intracellular HBsAg in chronic hepatitis B virus infection is related to viral replication

Serum and liver HBsAg bear an inverse relation to each other during the evolution of chronic hepatitis B virus infection and the quantity of HBsAg in tissue rises gradually with time. In this study, intracellular and extracellular levels of HBsAg were measured by radioimmunoassay in primary culture of hepatocytes from 30 patients with chronic hepatitis B virus infection to determine a possible relationship with hepatitis B virus replication. Serum levels of HBsAg correlated with markers of active viral replication (serum hepatitis B virus DNA, p < 0.005, and tissue HBcAg, p < 0.02) but inversely with tissue HBsAg (p < 0.05). In similar fashion, in vitro export of HBsAg was also related to the presence of active viral replication markers (serum hepatitis B virus DNA, p < 0.02, and tissue HBcAg, p < 0.05) and negatively with tissue HBsAg (p < 0.001). Export of HBeAg also correlated positively with markers of active viral replication (serum hepatitis B virus DNA, p < 0.05 and tissue HBcAg, p < 0.05). Further experiments indicated that intrahepatic pre-S1 and pre-S2 correlated closely with intrahepatic HBsAg, indicating that a failure to export HBsAg was unlikely to be attributable to deficient intracellular expression of pre-S1 or pre-S2. These data indicate that in vitro primary hepatocyte culture of hepatitis B virus—infected cells provides an accurate reflection of in vivo export of HBsAg and that this is closely related to the presence of active viral replication.

Identification of HBsAg determinants in immune complexes from hepatitis B virus-associated vasculitis.

Circulating immune complexes were characterized from 25 sera obtained from five patients with polyarteritis nodosa and three with cutaneous venulitis associated with hepatitis B virus infection. Complexes were isolated by polyethylene glycol and conglutinin-anticonglutinin precipitation methods and were analyzed for HBsAg and anti-HBsAg. Low pH was used to dissociate the complexes, and components were separated into antigen and antibody fractions by using immobilized protein A. In this study, three observations were significant: 1) complexes were frequent and quantitatively more in cutaneous venulitis than in polyarteritis; 2) the levels of HBsAg in the antigen fractions of polyarteritis were greater and correlated with the clinical improvement of the disease; the serum levels of HbsAg remained the same throughout the course of the disease; and 3) complexes from polyarteritis were not completely dissociable at pH 2.6 compared with those from patients with cutaneous venulitis and chronic active hepatitis. The antigen fractions electrophoresed in polyacrylamide gel with SDS demonstrated 6 to 10 protein bands with m.w. ranging between 17,000 and 120,000 daltons. To precisely define the polypeptide antigen moiety involved in the immune complex formation, a transfer blotting technique was used employing human anti-HBsAg globulin as probe. Polypeptides with m.w. 97,000, 49,000, and 23,000 were found to form complexes in both groups of patients.

Receptors for polymerized human serum albumin on hepatitis B virus particles detected by radioimmunoassay: Changes in receptor activity in serum during acute and chronic infection

Receptor sites that bind polymerized human serum albumin on hepatitis B virus (HBV) particles were evaluated in purified virus particle preparations and in HBsAg positive sera, by using solid phase radioimmunoassay. The receptor, found in previous reports to be species-specific, was inhibited neither by native human serum albumin, nor by anti-human immunoglobulins or anti-C1q sera, indicating that these host components are not involved in the reaction. Differential receptor expression on various HBsAg particles was evaluated by relating levels of HBsAg to those of polyalbumin binding activity. This ratio was lower in HBsAg particles purified from hepatitis Be antigen (HBeAg) positive serum (mean ratio: 3.5) than in those obtained from anti-HBe positive serum (mean ratio: 20.1), suggesting that HBeAg/anti-HBe status influences the expression of the receptor on virus particles. Accordingly, during acute hepatitis type B receptor activity was high in sera obtained at the onset, but rapidly decreased afterwards, particularly at the time of anti-HBe seroconversion. A similar behavior of the receptor was observed in cases of chronic HBV infection, where mean receptor counts by radioimmunoassay were 3825±4422 (mean cpm ±SD) in HBeAg positive cases and 868±1196 cpm in anti-HBe positive cases ( P<0.01). Seven HBsAg chronic carriers, all initially HBeAg positive, were followed up over a period of 1 to 4 yr and in all of them a progressive decrease in receptor activity was noted, independently of HBeAg persistence. These results indicate that the expression of the receptor for polymerized human albumin on HBV particles is an early event in the natural course of acute and chronic HBV infection, being followed by a progressive reduction in receptor activity, that parallels the reduction in virus replication, often independently of HBsAg serum levels.

Levamisole therapy for HBsAg-positive chronic liver disease.

Eight subjects with HBsAg-positive chronic liver disease received levamisole therapy continuously for 6 to 8 weeks. Depressed T-lymphocyte concentrations, found in all patients before therapy, transiently returned towards normal. All of the three patients who had normal delayed hypersensitivity responses before treatment showed an acute hepatitic reaction manifested by elevation of serum aspartate transaminase (AsT) and HBsAg levels, with transient cell-mediated immunity to HBsAg. This was interpreted as indicating increased lysis of infected hepatocytes. All of the five anergic patients showed no change in AsT or HBsAg levels. The clinical features and hepatic histology were unchanged. In patients with the capacity to mount normal delayed hypersensitivity responses, levamisole enhanced the cell-mediated response to HBsAg, and there was increased lysis of infected cells. Nevertheless, this treatment failed to eradicate the virus, as all patients remained HBsAg-positive.