No abstract

Three assays, one based on monoclonal antibodies and the others on polyclonal antibodies, were employed to detect hepatitis B surface antigen (HBsAg)-reactive samples in both vaccinated and unvaccinated populations in areas of the world where hepatitis B virus (HBV) is endemic. Any discordant sera were tested by polymerase chain reaction (PCR) to confirm current infection, and sequence data were obtained from the DNA coding for the major hydrophilic region (MHR) of HBsAg of those samples positive for PCR. In all countries studied, samples that reacted in one HBsAg assay but not another were found. In the most extreme case, about 5% of viremic sera in Papua New Guinea were nonreactive in the monoclonal HBsAg assay; 9 of the 13 PCR-positive samples had novel or once-described variants, or a variant out of its usual genotype context. In South Africa, samples with sequences of subtype ayw2 reacted poorly, particularly in the polyclonal assay. Two had novel variants. In Sardinia, antibody to hepatitis B core antigen (anti-HBc) was analyzed as a marker of infection. A significant proportion of anti-HBc-positive, but monoclonal HBsAg-negative, vaccinees and unvaccinated persons were found to be PCR positive, as were some individuals without any markers of hepatitis B virus infection. Five more novel variants were found in these groups. There are implications for the design of HBsAg assays, which may have to be modified according to local sequence variability. Not all discordant samples were explained by variants, indicating that assay sensitivity is fundamental to diagnostic efficacy. Overall, this study defined 16 novel variants and 2 new potential epitope clusters.

No abstract

Antibodies to asialoglycoprotein receptor have diagnostic specificity for autoimmune hepatitis, but it is uncertain if they are complementary or redundant markers of the disease. Our aims were to assess their frequency and significance in type 1 autoimmune hepatitis and determine their contribution to the evaluation of these patients. Sera from 54 well-characterized patients were evaluated for antibodies to asialoglycoprotein receptor by a radioimmunofiltration assay based on rabbit-derived protein. Forty-four patients (82%) were seropositive. Seropositive patients were distinguished from seronegative counterparts by having higher serum gamma globulin (3.7 +/- 0.2 g/dl vs 2.3 +/- 0.3 g/dl, P = 0.0007) and immunoglobulin G levels (3707 +/- 179 mg/dl vs 2203 +/- 263 mg/dl, P = 0.0005) at presentation and a greater frequency of relapse after drug withdrawal (88% vs 33%, P = 0.01). Seropositivity for smooth muscle and/or antinuclear antibodies did not define treatment outcomes and antinuclear antibodies occurred less frequently than the other markers. Concurrent testing for antibodies to asialoglycoprotein receptor and smooth muscle identified all patients. We conclude that antibodies to asialoglycoprotein receptor are common in type 1 autoimmune hepatitis and they identify patients with a high frequency of relapse after corticosteroid withdrawal. Concurrent testing for these antibodies and smooth muscle antibodies has the same diagnostic sensitivity as testing for antinuclear and smooth muscle antibodies but a greater prognostic implication.

A three-step solid-phase radioimmunoassay, HAVAB-M, was developed for use in clinical labs as an aid to diagnosing hepatitis A. Polystyrene beads were coated with anti-human IgM (mu-chain specific) and were incubated successively with serum specimen, HAV, and anti-HAV 125I. HAVAB-M was used to assay sera from patients with hepatitis A and was found to have high sensitivity for the IgM antibody to HAV. The antibody was detectable within a few days of onset of symptoms of hepatitis, and it reached maximum concentrations within one to three weeks. The test was designed so that most patients' sera would become negative approximately three months after onset. HAVAB-M was shown to be specific for IgM antibody, with virtually no detection of IgG anti-HAV. The test showed no interference fro rheumatoid factor and no cross-reactivity with sera from patients with hepatitis B or other infectious diseases.

Over a period of 30 months, 64 patients with concurrently positive hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) were identified at two institutions. When all assays were considered, 23.9% of HBsAg-positive individuals exhibited anti-HBs. Both persistent HBsAg/anti-HBs positivity and variable changes in antigen or antibody status were observed among the 36 patients with follow-up beyond six months. When compared to a control group, these patients did not exhibit differences in risk factors for acquiring hepatitis B or in clinical and histological diagnoses. Concurrent HBsAg and anti-HBs was present at detection in 25 patients, while antibody appeared in the remaining 11 subjects. Subsequently, it was undetectable in seven of these 36 patients; no clinical changes occurred at the time of acquisition or loss of the antibody. The titer of the antibody was below 10 mIU/ml in 75% of these individuals. In 10 patients, the subtype of HBsAg was ad, while the anti-HBs was anti-y. Concurrent HBsAg and anti-HBs is a pattern frequently observed throughout the spectrum of hepatitis B-related events. The heterotypic antibody in these patients is of a low titer, and its appearance or disappearance is not associated with changes in the clinical course; simultaneous HBsAg/anti-HBs positivity does not appear to reflect a distinct clinical entity.

No abstract

Serial serum specimens from 149 patients with clinically diagnosed hepatitis were tested for five hepatitis B serological markers: hepatitis B surface antigen and its antibody (anti-HBs); hepatitis B e-antigen and its antibody (anti-HBe); and antibody to hepatitis B core antigen (anti-HBc). The times of appearance, disappearance, and persistence of these markers were used to differentiate various serological profiles obtained from the study. Four distinctive profiles were found to be associated with acute hepatitis B followed by recovery, and three with chronic hepatitis. These serologic profiles were assessed as diagnostic and prognostic guides for clinical management of the disease.