False positive hepatitis B surface antigen after recent vaccination in pregnancy: a diagnostic pitfall

A new role for an old marker, HBsAg

Serum HBV DNA level is crucial in the management of chronic hepatitis B (CHB); however, the assay is expensive and cannot be used widely. Therefore, we explored the possibility of hepatitis B surface antigen (HBsAg) quantification as a surrogate marker for HBV DNA level in CHB patients. A total of 289 CHB patients were enrolled, 251 were evaluated at baseline and 75 of them were also evaluated during anti-HBV treatment. Another 38 on-treatment patients were used for validation. Serum HBsAg titre was quantified by an immunoassay and HBV DNA level by a PCR-based method. Baseline and on-treatment data were analysed. In parallel to log(10) HBV DNA, the log(10) HBsAg was high in both immune tolerance and immune clearance phases, and significantly decreased in the inactive carrier state and was again increased in the reactivation phase of the CHB infection. There was a positive correlation between log(10) HBsAg and log(10) HBV DNA, which was greater in patients with chronic hepatitis, hepatitis B e antigen-positivity, greater alanine aminotransferase or HBsAg levels at baseline and during pegylated interferon treatment. Log(10) HBsAg could predict log(10) HBV DNA independently. An HBsAg titre of >900 IU/ml at baseline or >1,500 IU/ml within the first year of treatment could predict an HBV DNA level of >20,000 IU/ml, especially in subgroups of chronic hepatitis with alanine aminotransferase levels >40 IU/l. The dynamics of HBsAg might also predict serial HBV DNA changes. In the validation group, 64% of patients with on-treatment HBV DNA levels >20,000 IU/ml could be correctly predicted. Serum HBsAg concentration might serve as a surrogate marker of HBV DNA level in CHB patients.

To evaluate whether hepatitis B virus (HBV) preS/S gene variability has any impact on serum hepatitis B surface antigen (HBsAg) levels and to analyze the replication capacity of naturally occurring preS/S variants, sera from 40 untreated patients with HBV-related chronic liver disease (hepatitis B e antigen [HBeAg]-positive, n = 11; HBeAg-negative, n = 29) were virologically characterized. Additionally, phenotypic analysis of three different preS/S variant isolates (carrying a 183-nucleotide deletion within the preS1 region, the deletion of preS2 start codon, and a stop signal at codon 182 within the S gene, respectively) was performed. HBV infecting 14 (35%) patients had single or multiple preS/S genomic mutations (i.e., preS1 and/or preS2 deletions, preS2 start codon mutations, C-terminally truncated and/or "a" determinant mutated S protein). Presence of preS/S variants negatively correlated with HBsAg titers (r = -0.431; P = 0.005) and its prevalence did not significantly differ between HBeAg-positive and HBeAg-negative patients. No correlation was found between HBsAg and HBV DNA levels in patients infected with preS/S mutants, whereas a significant correlation was found between HBsAg and viremia levels (r = 0.607; P = 0.001) in patients infected with wild-type HBV strains. HepG2 cells replicating the above-mentioned three preS/S variants showed significant reduction of HBsAg secretion, retention of envelope proteins in the endoplasmic reticulum, less efficient virion secretion and nuclear accumulation of significantly higher amounts of covalently closed circular DNA compared with wild-type HBV replicating cells. In patients infected with preS/S variants, HBV DNA replication and HBsAg synthesis/secretion appear to be dissociated. Therefore, the use of HBsAg titer as diagnostic/prognostic tool has to take into account the frequent emergence of preS/S variants in chronic HBV infection.

Although the North West Thames Region collects over 200,000 blood donations each year, less than four cases of post­ transfusion hepatitis B are reported to us annually (Barbara and Briggs 1981) presumably reflecting the exclusion of approximately 40 donors per annum found to be Hepatitis B surface antigen (HBsAg) positive. This study is the first step in the analysis of some of the unique data accumulated on these HBsAg-positive donations over an eighteen year period. Routine HBsAg screening of all blood donations became mandatory in the U.K. by 1971. Since then, we at the North London Blood Transfusion Centre (NLBTC) have monitored as many HBsAg-positive donors as possible to obtain epidemiological data on HBsAg carriage and the prevalence of other hepatitis B virus (HBV) markers, and to examine ways of predicting the course of HBV infection, so that we can advise carriers concerning their level of infectivity and management of their infection in everyday life. The first section examines the role of HBV in the context of blood transfusion. The serological markers of HBV infection are described in detail, including viral subtypes and a description of mutant and defective strains. The HBV carrier state is then briefly described. The second section describes current microbiological practices in blood transfusion including the present trend towards laboratory automation. The third section details the serological assays available for the laboratory detection of HBV infection and an experimental evaluation defines the confidence we can place upon assay results. Section four is a preliminary analysis of some of the epidemiological data accumulated at the NLBTC over 18 years. 286 HBsAg carriers have been followed up; with particular attention to their HBe antigen and antibody status as the markers most relevant to defining infectivity levels. Of the 35 carriers who were HBeAg-positive at the time of detection, 8 seroconverted from HBe antigen to anti-HBe during the follow-up period. HBeAg positivity was shown to be associated with raised liver function test (LFT) values. Those who seroconverted from HBe antigen to anti-HBe eventually developed normal LFT levels. My preliminary observations on the duration of HBsAg positivity and also on temporal changes in HBsAg titre will form the basis of further work. Although complete in itself, this study also serves as a pilot for a more comprehensive analysis of the wealth of material still to be examined.

Hepatitis B virus (HBV) is endemic in the Kingdom of Saudi Arabia. To prevent the chronic carriage of HBV in Saudi children, hepatitis B vaccine was added as the seventh immunogen in the expanded program on immunization (EPI). In the first year, the coverage of the first dose and third dose of HB vaccine was 90% and 73%, respectively. In a survey of 637 children, 603 (95%) were positive for antibody to hepatitis surface antigen (anti-HBs) without concomintant antibody to hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (HBsAg). A total of 592 (93%) with anti-HBs titer of > 10 IU/L were considered as responders to the vaccine. The majority (60%) of these responders had titers > 100 IU/L. Only one (0.3%) non-responder was positive for anti-HBc alone. Using historical control, the protective efficacy was estimated as 99%. Neither the gender of the recipient, schedule of the vaccination, nor the sourve of vaccine influenced the response to the vaccine. The successful integration of the HB vaccine into the EPI was due to the effectiveness of the EPI and the efficient primary health care system in Saudi Arabia.

Despite the existence of a safe and effective vaccine, Nigeria has remained a hyper-endemic area for hepatitis B virus infection, with estimated 12% of the total population being chronic carriers. Vertical transmission is an important route of transmission for hepatitis B virus infection. Neonates who contact hepatitis B virus infection will have an almost 90% risk of developing chronic hepatitis B surface antigen (HBsAg) carrier state and chronic liver disease. The objectives of this study was to determine the sero-prevalence of hepatitis B Virus among pregnant women, rate of vertical transmission and identifying potential risk factors associated with the infection. This study was an observational cross-sectional study of 250 pregnant women who presented to the labour ward of the University of Port-Harcourt Teaching Hospital (UPTH). Blood samples from all consenting pregnant women and corresponding umbilical cord blood were collected at delivery. A structured proforma designed for this purpose was used to obtain socio-demographic information and the presence of risk factors. Data collated was analysed using Statistical Package for Social Sciences (SPSS) 17.0 for windows® statistical software with P<0.05 at 95% confidence interval.The mean age of the pregnant women studied was 33.5±0.8 years, while the mean parity was 1.58 ± 0.5. HBsAg was detected in 15 women, giving a seroprevalence rate of 6% and a neonatal seroprevalence rate of 3.2%. All HBsAg-positive babies were born to HBsAg-positive mothers with a vertical transmission rate of 53.3%. Hepatitis B virus infection amongst parturients was more in patients with history of termination of pregnancy and multiple sexual partners (P<0.05). An intermediate prevalence of hepatitis B virus infection was identified which justifies the need for routine screening in pregnancy in order to identify and treat the infection, thus reducing the risk of vertical transmission of the virus. Contraceptive options aimed at prevention of pregnancy and sexually transmitted infection (STI) should be encouraged. Key words: Hepatitis B surface antigen (HBsAg), seroprevalence, University of Port-Harcourt Teaching Hospital (UPTH), Nigeria.

To assess the infectivity of hepatitis B surface antigen (HBsAg)-containing body fluids other than blood, chimpanzees were inoculated intravenously with saliva and semen obtained from HBsAg-positive individuals implicated in non-percutaneous transmission of hepatitis B. Saliva and semen samples were negative for occult blood. The titer of HBsAg in saliva was on the average only 1/3,000 that of the corresponding serum. One chimpanzee, inoculated sequentially with saliva from three individuals, developed HBsAg at 9 weeks and serum glutamic pyruvic transaminase elevation at 13 weeks after injection. HBsAg persisted for 15 weeks. This animal also developed e antigen, anti-core antibody, and anti-surface antibody. Liver biopsies showed acute hepatitis that subsequently resolved. A second chimpanzee, inoculated with HBsAg-positive semen, developed HBsAg and elevated serum glutamic pyruvic transaminase 4 weeks after inoculation and then died suddenly without explanation. HBsAg was positive in two consecutive samples and was confirmed by specific neutralization. Autopsy did not reveal evidence of hepatitis. This study demonstrates that HBsAg-positive saliva and, probably, semen contain infectious virus and suggests that saliva and/or semen may serve as important mechanisms in the transmission of type B hepatitis.

BACKGROUNDIn recent decades, artificial neural network (ANN) has been shown to be a robust and promising tool in monitoring and controlling bioprocess systems. In a previous study, the authors designed a highly accurate and precise recurrent neural network (RNN) for predicting the biomass amount of recombinant Pichia pastoris Mut+ producing intracellular hepatitis B surface antigen (HBsAg) during fed‐batch methanol fermentation. In the current work, the aim was to compare the production efficiency of HBsAg between conventional predefined μ‐stat methanol feeding control (open‐loop control) – already established in large‐scale production – and methanol feeding based on a μ‐stat feedback control system using RNN. For this purpose, for each methanol feeding strategy, bench‐scale, fed‐batch fermentation processes were carried out twice.RESULTSAccording to the results, in contrast to the established μ‐stat predefined feeding strategy (open‐loop), the deviation of specific growth rate and biomass in μ‐stat feedback control based on RNN was negligible. Also, in the suggested methanol feeding control strategy, the HBsAg titer, specific productivity and yield between the performed fed‐batch fermentations – unlike the conventional method – were approximately identical, with average values of 110.8 μg mL−1, 1.52 μg g−1 dry biomass and 0.34 μg g−1 MeOH respectively.CONCLUSIONComparing the biomass growth pattern and HBsAg production efficiency with the conventional μ‐stat predefined feeding in open‐loop control, the new proposed feeding control system illustrated significantly high process efficiency. This reliable control system based on ANN can have many applications in the biopharmaceutical industry for the control of process key parameters as well as for enhancing process efficiency. © 2019 Society of Chemical Industry

Bringing to an end mother-to-child transmission of hepatitis B: A role for quantitative hepatitis B surface antigen?

The aim of the present study was to observe the efficacy and safety of nucleoside analogs in inhibiting father-to-infant vertical transmission of hepatitis B virus (HBV). Nucleoside analogs compete with HBV DNA polymerase substrate to inhibit DNA polymerase, thus preventing the replication of HBV DNA. A case group and control group were recruited for the study. Between March 2006 and March 2012 at the Liver Disease Center of Qinhuangdao Third Hospital, a total of 201 couples were recruited for the case group. In each case, the father tested positive the following HBV markers: Hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), antibodies against the hepatitis B core antigen (anti-HBc) and HBV DNA. In total, 189 male patients presented with abnormal liver function (94.0%; 189/201). Prior to pregnancy, all the males in the case group were required to test negative for HBV DNA and exhibit normal liver function, while the females were required to test positive for antibodies against HBsAg (anti-HBs). In total, 188 couples comprised the control group. The couples were recruited between March 2006 and March 2012 in the Prenatal Clinic of Qinhuangdao Women's and Children's Hospital. The fathers tested positive for HBsAg, HBeAg, anti-HBc and HBV DNA. With regard to the females, HBsAg tests were all negative and anti-HBs tests were positive. In the case group, there were no HBsAg-positive or HBV DNA-positive newborns, while anti-HBs tests were all positive; thus, the father-to-infant HBV vertical transmission was successfully inhibited. In the control group, 147/188 newborns tested positive for anti-HBs at birth, accounting for 78.2%. In addition, 28 newborns were positive for HBV DNA (14.9%), and 19 newborns tested positive for HBsAg (10.1%). Statistically significant differences were observed between the two groups with regard to these parameters. However, no statistically significant differences in gestational age, birth weight, birth height, 1- and 8-min Apgar scores, presence of jaundice, other internal and surgical diseases, delivery mode and other birth information were observed when comparing the case group with the control group. Furthermore, there were no fetal malformations or stillbirths in the two groups. In the HBV DNA-positive fathers prior to pregnancy, antiretroviral therapy resulted in a reduced virus load. Therefore, blocking father-to-infant HBV vertical transmission maximally was important. The use of antiviral nucleoside analogs prior to pregnancy was shown to be safe. When the benefits outweighed the risks, the fathers who wanted to have a child continued to use antiviral therapy. However, the sample size of the present study was small, and an increased number of cases and longer follow-up times are required. In addition, the use of nucleoside analogs requires further in-depth assessment from the point of view of prenatal and postnatal care.

Hepatitis B virus (HBV) is the most common significant chronic viral infection world-wide. Approximately 350–400 million people have active HBV infections, and as many as one third of the world’s population has evidence of exposure to HBV. Spread of the virus occurs primarily through contact with infected serum, sexual contact with infected individuals, and vertical transmission from mother to infant. Since shortly after its discovery as the “Australia antigen” (1), hepatitis B surface antigen (HBsAg) has been the principal target for laboratory testing to identify active infection by HBV. Accumulating evidence, including the article by Chen and Kaplan (2) in this issue of Clinical Chemistry , calls into question the degree to which HBsAg assays can be used as the “gold standard” for detecting HBV infection. The increasing availability of automated assays for viral markers on instruments traditionally found in immunochemistry laboratories makes it imperative for those working in such laboratories to be familiar with issues in HBsAg testing. Exposure to HBV has a variable outcome that is largely determined by the age and immune status of an infected individual. In healthy adolescents and adults, the most common population exposed to HBV in northern Europe and most of North America, exposure to HBV typically leads to acute hepatitis, followed by loss of detectable HBsAg and loss of circulating HBV DNA (as measured by most assays). Chronic infection, identified by persistence of HBsAg, may follow infections in infants, persons with immunosupression, and a small number of otherwise healthy individuals. Such chronic infection may be associated with active viral replication (detected by circulating HBV DNA), or with “nonreplicating” infection, in which HBsAg continues to be produced but HBV DNA is undetectable (by most assays) in the circulation. Replicating forms of infection can convert to nonreplicating forms, either spontaneously (5%–10%/year) or after treatment …

In an attempt to interrupt perinatal and postnatal transmission of hepatitis B virus (HBV) infection, hepatitis B vaccine trials were initiated in October 1981 in Taiwan, starting in neonates of hepatitis B e antigen (HBeAg)‐positive hepatitis B surface antigen (HBsAg) carrier mothers and extending to neonates of non‐carrier mothers. All neonates had received a four‐dose schedule of Pasteur plasma‐derived hepatitis B vaccine. Among neonates of HBeAg‐positive HBsAg carrier mothers, the protective efficacy rate of vaccination was 75% in those who received vaccine alone and 90% in those who received vaccine plus hepatitis B immunoglobulin (HBIG) at birth. Among neonates of HBeAg‐negative HBsAg carrier mothers, the protective efficacy rate was 100% whether they had received vaccine alone or vaccine plus HBIG at birth. The protective efficacy rate was also 100% in neonates of non‐carrier mothers. During 6–9 years of long‐term follow‐up, 12 (6%) responsive vaccinees of HBeAg‐positive carrier mothers, one (2%) child of HBeAg‐negative carrier mothers and one child (0.4%) of non‐carrier mothers had seroconverted to antibody to hepatitis B core antigen (anti‐HBc) positivity. ‘Natural booster’ phenomenon, defined as a spontaneous sharp rise in serum antibody to HBsAg (anti‐HBs) titres in the absence of anti‐HBc and HBsAg, was observed in 7% of vaccinees whose mothers were HBeAg‐positive, 6% of vaccinees whose mothers were HBeAg‐negative HBV carriers, and 8% in vaccinees of non‐HBV carrier mothers. None of the responsive vaccinees had seroconverted to HBsAg. Thus, in the first decade of life, the protective efficacy in neonates who responded to plasma‐derived hepatitis B vaccine was 100%.

The roles of single-nucleotide polymorphisms (SNPs) at HLA-DP and IL28B loci on hepatitis B surface antigen (HBsAg) seroclearance in chronic hepatitis B (CHB) infection are unknown. We compared the HLA-DP (rs3077, rs9277378, rs3128917) and IL28B (rs12979860, rs8099917) polymorphisms of 203 CHB patients achieving spontaneous HBsAg seroclearance with 203 age- and sex-matched CHB patients without HBsAg seroclearance (controls). The distribution of all 5 polymorphisms was in Hardy-Weinberg equilibrium. HLA-DP rs3077 was associated with HBsAg seroclearance in terms of allelic frequency (minor allele A vs major allele G, P = .035; odds ratio [OR], 0.699; 95% confidence interval [CI], .501-.976) and genotypic frequency (AA vs GG/GA, P = .014; OR, 0.295; 95% CI, .106-.822). Haplotype analysis of HLA-DP polymorphisms showed haplotype block GAT (rs3077/rs9277378/rs3128917) to be associated with HBsAg seroclearance (OR, 2.17; 95% CI, 1.06-4.45, P = .034). Influence of HLA-DP polymorphisms on HBsAg seroclearance was more pronounced in younger patients, with the OR for rs3077 minor allele A and haplotype block GAT being 0.560 and 2.68, respectively, among patients aged <50 years (P = .027 and P = .047, respectively). IL28B haplotype block CG (rs12979860/rs8099917) was associated with HBsAg seroclearance (OR, 10.5, P = .026). None of the 5 polymorphisms influenced anti-HBs positivity among patients achieving HBsAg seroclearance, or serum HBV DNA and HBsAg titers among controls (P > .05). Specific SNPs in HLA-DP and IL28B locus, through individual and haplotype analysis, were associated with a higher chance of HBsAg seroclearance in CHB infection. The associations were more prominent in patients with HBsAg seroclearance at a younger age.

IntroductionIt remains unclear whether kidney transplantation (KT) from hepatitis B surface antigen (HBsAg) +donors to HBsAg− recipients (D(HBsAg+)/R(HBsAg−)) provides comparable transplant outcomes without hepatitis B virus (HBV) transmission compared with...

The aim of this study was to determine the effects of hepatitis B surface antigen (HBsAg) positivity of the donors on graft survival and liver complications in HBsAg(+) renal transplant recipients. A group of 55 patients who underwent renal transplantation (RTx) in our hospital between 2001 and 2012 were included in the study. Patients were divided into 2 groups. Group 1 (n = 50) consisted of HBsAg(+) renal transplant recipients (RTR) whose donors were HBsAg(-). In Group 2 (n = 5), RTR and donors were both HBsAg(+). Lymphocyte cross matches, number of mismatches, donor types, renal replacement treatment modalities, drugs of induction treatment, and preoperative hepatitis B virus DNA titers of the groups were similar. In Group 1, 42 patients were taking lamivudine, 3 patients were taking entecavir, and 5 patients were taking tenofovir. All of the patients in Group 2 were taking lamivudine. Patient and graft survival rates, graft functions, acute hepatitis rates, acute rejection rates, and other clinical outcomes of the groups were compared. Demographic data of the groups were similar. Acute rejection rates (P = 0.458), graft survival rates (P = 0.515), and patient survival rates (P = 0.803) were also similar. No significant difference was found between the groups in terms of acute hepatitis rate (P = 0.511), glomerular filtration rate (calculated by Modification of Diet in Renal Disease formula) in the last follow-up (P = 0.988), alanine aminotransferase levels (P = 0.069), or delayed graft function rate (P = 0.973). Rates of chronic allograft dysfunction and new onset diabetes mellitus after transplantation were similar. Our study revealed that, RTx from HBsAg(+) donors to HBsAg(+) recipients is safe with antiviral treatment.