Quantitative detection of hepatitis B surface antigen by chemiluminescent microparticle immunoassay during lamivudine treatment of chronic hepatitis B virus carriers

Lateral Flow Assay for Hepatitis B Detection: A Review of Current and New Assays

From acute to chronic hepatitis, cirrhosis, and hepatocellular cancer, hepatitis B infection causes a broad spectrum of liver diseases. Molecular and serological tests have been used to diagnose hepatitis B-related illnesses. Due to technology limitations, it is challenging to identify hepatitis B infection cases at an early stage, particularly in a low- and middle-income country with constrained resources. Generally, the gold-standard methods to detect hepatitis B virus (HBV) infection requires dedicated personnel, bulky, expensive equipment and reagents, and long processing times which delay the diagnosis of HBV. Thus, lateral flow assay (LFA), which is inexpensive, straightforward, portable, and operates reliably, has dominated point-of-care diagnostics. LFA consists of four parts: a sample pad where samples are dropped; a conjugate pad where labeled tags and biomarker components are combined; a nitrocellulose membrane with test and control lines for target DNA-probe DNA hybridization or antigen-antibody interaction; and a wicking pad where waste is stored. By modifying the pre-treatment during the sample preparation process or enhancing the signal of the biomarker probes on the membrane pad, the accuracy of the LFA for qualitative and quantitative analysis can be improved. In this review, we assembled the most recent developments in LFA technologies for the progress of hepatitis B infection detection. Prospects for ongoing development in this area are also covered.

What does quantitative HBsAg level mean in chronic hepatitis D infection?

OBJECTIVE

In hepatitis delta virus (HDV) infection, which is an important etiological cause of chronic liver disease, the relationship between serum quantitative HBsAg level and fibrosis and histological activity was investigated.

METHODS

Between 2014 and 2020, 98 patients with chronic HDV infection (53 noncirrhotic, 45 cirrhotic) participated in this prospectively designed study. Quantitative HBsAg levels of the patients were measured and their relationship with the stage of chronic liver disease was compared with histological activity index (HAI), fibrosis score and HDV RNA, model for end-stage liver disease score and other biochemical parameters.

RESULTS

All patients were infected with genotype 1 (100%). HBeAg was positive in 8 (8.1%) of the patients. A correlation was found between quantitative HBsAg level and HDV RNA level in patients with both cirrhotic (r = 0.568; P < 0.001) and noncirrhotic (r = 0.644; P < 0.001) HDV infection. Alanine transaminase (P = 0.001; r = 0.495) and aspartate transaminase (P = 0.001; r = 0.511) levels correlated with quantitative HBsAg levels, more prominently in noncirrhotic patients. There was a correlation between quantitative HBsAg level and histological activity index (HAI) in patients with noncirrhotic HDV infection (P < 0.001; r = 0.664). In receiver operating characteristic analysis, both quantitative HBsAg (for cutoff: 1000; sensitivity 76%; specificity 17%; P = 0.335) and HDV RNA (for cutoff: 100000; sensitivity 2%; specificity 98%; P = 0.096) were not predictive markers for cirrhosis.

CONCLUSION

Quantitative HBsAg level can be evaluated as an indicator of viral replication and histological activity in patients with chronic delta hepatitis without cirrhosis. We think that quantitative HBsAg level will be useful in the management of chronic HDV infection, especially in noncirrhotic patients.

Switching to tenofovir disoproxil fumarate vs continuing treatment in patients with chronic hepatitis B who maintain long-term virological response to entecavir therapy: A randomized trial

No controlled trial in patients with chronic hepatitis B virus (HBV) infection on long-term entecavir (ETV) treatment, comparing switching to tenofovir disoproxil fumarate (TDF) with continuing the therapy, has been reported. Twenty-seven nucleos(t)ide-naïve patients with chronic HBV who underwent ETV therapy for ≥5 years and maintained virological response were included and randomized into two groups: one group continued ETV, and the other switched to TDF, in a 1:2 ratio. The primary endpoint was changed from baseline in serum hepatitis B surface antigen (HBsAg) level at week 48. The baseline characteristics were not different between nineteen patients in the TDF group and eight patients in the ETV group. Mean decreases in HBsAg level at week 48 were 0.023 and 0.042 log₁₀  IU/mL in the TDF and ETV groups, respectively (P = 0.94). The mean drops in hepatitis B core-related antigens were also not different between the TDF and ETV groups at week 48 (P = 0.80). HBV DNA was sustainedly <2.1 log ₁₀  copies/mL in all patients throughout the study period. In contrast, the mean aminotransferase levels were significantly higher in the TDF group than in the ETV group at weeks 12, 24, and 36, although being within the reference range. Estimated glomerular filtration rate was lower in the TDF group than in the ETV group at weeks 24 (P = 0.016) and 48 (P = 0.003). In conclusion, we could not find the effect on reducing HBsAg level by switching to TDF in chronic hepatitis B patients with maintained virological response to ETV for ≥5 years.

Progression and status of antiviral monitoring in patients with chronic hepatitis B: From HBsAg to HBV RNA

As alternative indexes of hepatitis B virus (HBV), covalently closed circular DNA (cccDNA) transcriptional activity, hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg), and peripheral blood RNA known as pgRNA, have been advocated as novel serum markers for prediction of prognosis and treatment response in chronic hepatitis B (CHB). Since the availability of commercial quantitative assays of HBsAg in 2011, HBsAg has been widely used for predicting treatment response of patients with CHB. Patients who received interferon therapy have shown a sharper reduction of HBsAg level than those who received nucleoside drug (NAs) therapy. Upon peginterferon treatment, sustained responders have presented a larger reduction of HBsAg level than the non-responders. An absence of HBsAg decline, together with < 2log reduction in HBV DNA at week 12, can serve as a stopping rule in HBsAg-negative patients infected with genotype D HBV. A sharp reduction of HBsAg titer in the NAs therapy is a predictor of HBsAg clearance in long-term treatment. HBcrAg, which consists of three species of related proteins sharing an identical 149 amino acid sequence, including HbcAg, hepatitis B e antigen (HBeAg), and a truncated 22-kDa precore protein, is still detectable in situations where serum HBV DNA levels become undetectable or HBsAg loss is achieved. Therefore, HBcrAg remains a measurable serum marker to correlate with cccDNA in this situation. The decline in HBcrAg has been observed with NAs therapy and the pattern of decline might provide prognostic information on the risk of HBV post-treatment reactivation. Peripheral blood RNA, which is known as pgRNA, directly derives from cccDNA and reflects intrahepatic cccDNA level. Quantitative pgRNA has been suggested to be helpful in CHB management. However, commercial quantitative assays are lacking. Additionally, the use of simultaneous and continuous clearance of HBV RNA and HBV DNA in serum has been suggested to be a safe stopping rule of NAs therapy for patients with CHB. However, clinical studies of large sample sizes are needed to prove the feasibility and significance of using serum HBV RNA as the assessment standard of antiviral therapy in CHB and the safety of the stopping rule in clinics.

Sequential therapy involving an early switch from entecavir to pegylated interferon-α in Japanese patients with chronic hepatitis B

AIM

The optimal combination of two currently available agents with different mechanisms of action, a nucleos(t)ide analog and pegylated interferon-α (PegIFNα), must be determined to improve treatment of chronic hepatitis B (CHB).

METHODS

In this study, 24 patients with CHB (14 hepatitis B envelope antigen [HBeAg]-positive patients and 10 HBeAg-negative patients) received entecavir for 36-52 weeks, followed by entecavir plus Peg-IFNα2a for 4 weeks, and finally by PegIFNα-2a alone for 44 weeks.

RESULTS

A sustained biochemical, virologic, and serologic response was obtained in 7/24 (29%) patients at 48 weeks post-treatment (2/14 [14%] in HBeAg-positive vs 5/10 [50%] in HBeAg-negative patients, P = 0.085). At baseline, patients with a sustained response had a significantly lower γ-glutamyl transferase level (P = 0.0023), a lower aspartate aminotransferase-to-platelet ratio index (P = 0.049), and a lower α-fetoprotein level (P = 0.042) than those without a sustained response. The decline in hepatitis B surface antigen (HBsAg) levels during the first 24 weeks of PegIFNα-2a treatment in patients with a sustained response was greater than that in patients without (P = 0.017). Additionally, HBsAg seroclearance was achieved in two patients (8.3%): one HBeAg-positive and one HBeAg-negative patient.

CONCLUSION

The outcomes of sequential therapy involving an early switch from entecavir to PegIFNα-2a were unsatisfactory in Japanese patients with CHB. In addition to viral factors, host metabolic characteristics and liver fibrosis/tumor markers can be used for prediction of a sustained response to therapy, but accurate prediction of the therapeutic response is difficult.

Dual-Labeled Time-Resolved Immunofluorometric Assay for the Simultaneous Quantitative Detection of Hepatitis B Virus Antigens in Human Serum

In this paper, a novel time-resolved fluorescence immunoassay (TRFIA) is described that allows the simultaneous quantitative detection of hepatitis B virus surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in human serum to aid the diagnosis and monitoring of hepatitis B virus infection. The proposed method was developed based on a two-step sandwich immunoassay protocol in which monoclonal antibodies against HBsAg and HBeAg were co-coated in 96 microtitration wells, then tracer polyclonal antibodies against HBsAg labeled with samarium and tracer monoclonal antibodies against HBeAg labeled with europium chelates were used for detection. The detection range was 0.1-150 IU/mL for HBsAg and 0.5-160 PEIU/mL for HBeAg, and the detection limits were 0.03 IU/L and 0.09 PEIU/ml, respectively. The intra- and inter-assay coefficients of variation were below 8 % for both virus antigens. The dilution linearity and accuracy of the assay were satisfactory. No statistically significant differences were observed in sensitivity or specificity for the serum samples between the dual-label TRFIA and a commercial single-label TRFIA. These results demonstrate that an effective, reliable and convenient HBsAg/HBeAg dual-label TRFIA was successfully developed that may be clinically applicable for blood screening to monitor the course of hepatitis B virus infection and predict treatment responses.

Correlation between two chemiluminescence based assays for quantification of hepatitis B surface antigen in patients with chronic hepatitis B infection

PURPOSE

Hepatitis B surface Antigen (HBsAg) is the hallmark in diagnosing hepatitis B virus (HBV) infection. In India many commercial assays are available for detection of HBsAg but very few can measure it quantitatively. The present study presents the comparative evaluation of two methods and their correlation with serum HBsAg in chronic hepatitis B (CHB) patients.

MATERIALS AND METHODS

Consecutive patients of CHB were included and there HBsAg levels were measured by two methods: (i) Elecsys, Roche Diagnostics, a qualitative assay and (ii) Architect, Abbott Diagnostics, a quantitative assay. The HBV DNA was measured by real-time polymerase chain reaction (qPCR).

RESULTS

Total of 136 patients were included in the study and there was a significant overall correlation between both the assays (correlation coefficient [r] = 0.83; P < 0.001). Assays correlated well with each other across all subgroups of CHB: treatment naοve (r = 0.73; P < 0.001, n = 32), on treatment (r = 0.56; P < 0.05, n = 104), hepatitis Be (HBe) antigen positive (r = 0.67; P < 0.001, n = 62) and anti-HBe positive (r = 0.61; P < 0.05, n = 74) group. On correlation with serum HBV DNA, Architect assay demonstrated good correlation (r = 0.73; P < 0.001, n = 136) as compared to the Elecsys assay (r = 0.27; P = 0.068, n = 136). Architect HBsAg QT assay (A1) also correlated well with HBV DNA in the treatment naοve group (r = 0.69; P < 0.001, n = 32).

CONCLUSIONS

Our study hence proved that both the assays are comparable and a simple qualitative assay with in-house modification can be used easily for quatitation of HBsAg in clinical samples.

High treatment modification rates with lamivudine therapy in HBV-infected patients with low baseline viremia and early virological response: A multicenter study

OBJECTIVE

Low baseline viremia and an early treatment response predict the best outcomes in hepatitis B virus (HBV)-infected patients treated with nucleoside analogues with low barriers to resistance. The aim of this study was to assess the long-term results and effectiveness of lamivudine in patients with low baseline viremia and early virological treatment response.

METHODS

In this multicenter, real-life setting study, 111 antiviral-naive patients with low baseline viremia (HBV DNA <10(7) copies/mL) plus an early virological response (HBV DNA <300 copies/mL at week 24) treated with lamivudine were enrolled. The primary end-point was treatment failure, defined as the re-emergence of detectable viremia or at least a 1 log increase in HBV DNA, resulting in a titer of ≥ 300 copies/mL with lamivudine treatment after week 24, which required treatment modification.

RESULTS

Altogether 111 patients, including 78 non-cirrhotic and 33 cirrhotic patients, were included in the study. Treatment failure occurred in 30.8% of the non-cirrhotic patients over a median follow-up period of 32.5 months, and the 1-, 2-, 3-, 4- and 5-year treatment failure rates were 6.5%, 14.0%, 31.4%, 39.6% and 43.1%, respectively. Treatment failure occurred in 28.8% of the whole group. There were no differences between the cirrhotic and non-cirrhotic patients.

CONCLUSIONS

Lamivudine treatment had a high treatment modification rate in patients with low baseline viremia and early virological response over a long-term follow-up in a real-life setting. The pretreatment and on-treatment favorable characteristics found in the studies with telbivudine appeared to be inapplicable to lamivudine.

Long-Term Outcome of Sequential Therapy with Lamivudine Followed by Interferon-β in Nucleoside-Naive, Hepatitis B e-Antigen-Positive Patients with Chronic Hepatitis B Virus Genotype C Infection

It is unclear whether the combination of a nucleos(t)ide analog and interferon (IFN) is superior to monotherapy for treating chronic hepatitis B. In this study, we report the long-term outcomes of sequential therapy using lamivudine followed by IFN-β. This study included 24 hepatitis B e-antigen (HBeAg)-positive patients with chronic hepatitis B virus (HBV) genotype C infection who were treated with lamivudine alone for 16-32 weeks, then with both IFN-β and lamivudine for 4 weeks, and finally with IFN-β alone for 20 weeks. All patients were followed up for 7.1±2.8 years post-treatment. The rate of response, defined as transaminase normalization, HBeAg loss, and HBV DNA <10(4) copies/mL, was 5/24 (21%) at 24 weeks post-treatment. The patients with short-term responses were younger than those with no response (P=0.039). More short-term responders had undetectable HBV DNA at the start of IFN-β compared with the nonresponders (P=0.0059). Subsequently, 4 of the 5 short-term responders remained free of the need for further drug treatment for 4.2±3.5 years post-treatment; more short-term responders remained drug free than did nonresponders (P=0.035). In conclusion, the rate of response to sequential therapy was limited in HBeAg-positive patients with chronic HBV genotype C infection at 24 weeks post-treatment. In the majority of the short-term responders, however, the response was sustainable in the long term.

Serum hepatitis B surface antigen levels predict treatment response to nucleos(t)ide analogues

Quantification of hepatitis B surface antigen (HBsAg) has been suggested to be helpful in the management of chronic hepatitis B (CHB) patients. Nucleos(t)ide analogs (NAs) are the therapy of choice for CHB and are used in the majority of CHB patients. NAs are able to induce hepatitis B virus (HBV) viral suppression, normalization of alanine aminotransferase (ALT) levels, and improvement in liver histology. Automated quantitative assays for serum HBsAg have recently become available, facilitating standardized quantification of serum HBsAg. This has led to increased interest in the clinical application of quantitative serum HBsAg for predicting therapeutic response to NAs. Recent studies have shown that a decline in serum HBsAg levels in patients receiving peginterferon may signal successful induction of immune control over HBV, and can therefore be used to predict therapeutic response. NA treatment typically induces a less rapid decline in HBsAg than interferon treatment; it has been estimated that full HBsAg clearance can require decades of NA treatment. However, a rapid HBsAg decline during NA therapy may identify patients who will show clearance of HBsAg. Currently, there is no consensus on the clinical utility of serum HBsAg monitoring for evaluating patient responses to NA therapy. This review focuses on recent findings regarding the potential application of HBsAg quantification in the management of CHB patients receiving NA therapy.

Correlation of hepatitis B surface antigen level with response to telbivudine in naive patients with chronic hepatitis B

AIM

Hepatitis B surface antigen (HBsAg) has become a marker to judge immunological response to hepatitis B therapy. Quantified serum HBsAg levels can predict the response to pegylated interferon and entecavir. In this study, we aimed to explore the correlation of serum HBsAg levels with response to telbivudine (LdT) treatment in patients with chronic hepatitis B (CHB).

METHODS

Seventy-three treatment-naive CHB patients were recruited and received LdT monotherapy for 52 weeks and serial HBsAg levels were measured at five protocol time points. According to therapeutic efficacy at week 52, three subgroups of patients were identified, including complete responders (CR), partial responders (PR) and non-responders (NR).

RESULTS

After 52 weeks of treatment, CR, PR and NR represented 19 (26%), 33 (45%) and 21 (29%) patients in the sample of 73, respectively. The median values of baseline HBsAg (log10 IU/mL) were 4.05, 4.50 and 5.03 for CR, PR and NR, respectively. There was a distinct decline of HBsAg at week 52; median log10 HBsAg levels (IU/mL) were 3.61 (CR), 3.86 (PR) and 4.31 (NR). Positive correlation between HBsAg levels and HBV DNA loads was observed in the group of NR and early antiviral treatment of PR, but not in CR.

CONCLUSION

Initial HBsAg level was closely correlated with the efficacy of LdT. Patients with low HBsAg levels presented satisfactory responses. Therefore, initial level and correlation with HBV DNA of the serum HBsAg levels could predict responsiveness in CHB patients receiving LdT.

Hepatitis B surface antigen quantification in chronic hepatitis B and its clinical utility

Serum HBsAg levels have been quantified extensively in recent years with simple completely automated assays in the various phases of the natural course of chronic HBV infection, have been compared with cccDNA in the liver, with various markers of HBV replication and have been correlated with several viral, host and environmental variables. Low HBsAg levels in inactive carriers predict a spontaneous HbsAg loss. Quantification of HBsAg in serum at baseline and its decline under interferon-alfa based regimens, both in HBeAg-positive and HBeAg-negative CHB, provides important information on the prediction of sustained post-treatment outcomes and on subsequent HBsAg clearance. The value of HBsAg quantification in the monitoring of long term nucleos(t)ide analogue treatment of CHB and in the prediction of sustained response remains unclear. In this review, the most recent data regarding the overall clinical utility of HBsAg measurement in HBeAg-positive and -negative CHB and in their treatment, is critically presented.

Development of an amplified luminescent proximity homogeneous assay for quantitative determination of hepatitis B surface antigen in human serum

BACKGROUND

Hepatitis B virus (HBV) poses a serious risk to human health and the hepatitis B surface antigen (HBsAg) is a popular biomarker in the diagnosis of HBV infection. A quantitative method with a high degree of accuracy, sensitivity and throughput is needed.

METHODS

A novel amplified luminescent proximity homogeneous assay (AlphaLISA) was developed for HBsAg determination. A set of monoclonal antibodies was screened against the main subtypes of HBsAg (adr, ay) to confirm the assay's sensitivity to mutants. Technological processes and reaction conditions were optimized and the assay performance was evaluated.

RESULTS

HBsAg concentrations were determined within a linear range of 0.04 to 100 IU ml(-1). The detection sensitivity was established as 0.01 IU ml(-1). Assay sensitivity to mutant HBsAg was achieved through antibody screening. The results demonstrate that the reproducibility, recovery, and specificity of this assay for HBsAg were better than acceptable. Compared with the commercial light-initiated chemiluminescence assay, the correlation coefficient of the novel assay was established as 0.921.

CONCLUSIONS

The novel AlphaLISA developed in this study has shorter incubation time and easier protocol than the ones of conventional ELISA. It could be used for the clinical determination of HBsAg in human serum. We established a platform for further development of other biomarkers.

Application of a newly developed high-sensitivity HBsAg chemiluminescent enzyme immunoassay for hepatitis B patients with HBsAg seroclearance

We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique. Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abbott Architect assay. The Lumipulse HBsAg-HQ assay was used to recheck those 26 patients who demonstrated seroclearance by the Abbott Architect assay. The performance of the Lumipulse HBsAg-HQ assay was compared with that of a quantitative HBsAg detection system (Abbott Architect) and the Roche Cobas TaqMan HBV DNA assay (CTM) (lower limit of detection, 2.1 log copies/ml) using blood serum samples from patients who were determined to be HBsAg seronegative by the Abbott Architect assay. Ten patients had spontaneous HBsAg loss. Of 8 patients treated with nucleotide analogues (NAs), two were HBsAg seronegative after stopping lamivudine therapy and 6 were HBsAg seronegative during entecavir therapy. Eight acute hepatitis B (AH) patients became HBsAg seronegative. Of the 26 patients, 16 were HBsAg positive by the Lumipulse HBsAg-HQ assay but negative by the Abbott Architect assay. The differences between the two assays in terms of detectable HBsAg persisted over the long term in the spontaneous loss group (median, 10 months), the NA-treated group (2.5 months), and the AH group (0.5 months). In 9 patients, the Lumipulse HBsAg-HQ assay detected HBsAg when HBV DNA was negative by the CTM assay. HBsAg was also detected by the Lumipulse HBsAg-HQ assay in 4 patients with an anti-HBs concentration of >10 mIU/ml, 3 of whom had no HBsAg escape mutations. The automatic, highly sensitive HBsAg CLEIA Lumipulse HBsAg-HQ is a convenient and precise assay for HBV monitoring.

Association of on-treatment serum hepatitis B surface antigen level with sustained virological response to nucleos(t)ide analog in patients with hepatitis B e-antigen positive chronic hepatitis B

AIM

  This study evaluated the on-treatment serum hepatitis B surface antigen (HBsAg) level during nucleos(t)ide analog (NUC) therapy and the correlation with off-treatment sustained virological response (SVR).

METHODS

  Fifty-one consecutive patients with hepatitis B e-antigen (HBeAg) positive chronic hepatitis B who achieved HBeAg loss/seroconversion after NUC therapy and completed 12 months or more of additional therapy were included. Serum HBsAg and hepatitis B virus (HBV) DNA levels were determined at baseline, 3, 6, 9 and 12 months, and at the end of treatment. SVR was defined as HBV DNA levels of less than 10 000 copies/mL until 6 or 12 months off-treatment without reappearance of HBeAg.

RESULTS

  Twenty-two (43.1%) and 13 (25.5%) patients maintained SVR at 6 and 12 months off-treatment, respectively. In univariate analyses, a decline of HBsAg of 0.5 log(10)  IU/mL or less at 6 months (P = 0.006) and 12 months (P = 0.013), the mean change in HBsAg level at 6 months (P = 0.024), and lamivudine or entecavir treatment (P = 0.019) were significant predictive factors for SVR at 6 months off-treatment. A decline of HBsAg of 0.5 log(10)  IU/mL or less at 6 months and lamivudine or entecavir treatment were independent factors on multivariate analyses (odds ratio [OR], 16.67; 95% confidence interval [CI], 1.86-142.86 [P = 0.012]; and OR, 14.83; 95% CI, 1.18-185.73 [P = 0.036]; respectively).

CONCLUSION

  On-treatment serum HBsAg level predicted early off-treatment SVR to NUC therapy in patients infected with genotype C.

Entecavir and interferon-α sequential therapy in Japanese patients with hepatitis B e antigen-positive chronic hepatitis B

BACKGROUND

The outcomes of sequential therapy with lamivudine followed by interferon have been unsatisfactory in Japanese patients with hepatitis B envelope antigen (HBeAg)-positive chronic hepatitis B. However, the efficacy of sequential therapy with entecavir and interferon remains unclear.

METHODS

Twenty-four HBeAg-positive patients (23 men and 1 woman; mean age 39 ± 7 years) received entecavir 0.5 mg alone for 36-52 weeks, followed by entecavir plus interferon-α for 4 weeks, and lastly by interferon-α alone for 20 weeks. Twenty-three patients had genotype C infection, and one had genotype A infection.

RESULTS

No entecavir-resistant mutant variants emerged in any patient. Hepatitis flare occurred in three patients during interferon-α treatment after the withdrawal of entecavir, but none had hepatic decompensation. Serum hepatitis B surface antigen levels did not change during or after therapy. Serum hepatitis B core-related antigen levels were significantly decreased at the start (P < 0.0001) and at the end of interferon-α treatment (P < 0.0001), but returned to baseline levels after treatment. Twenty-four weeks after the completion of the sequential therapy, a sustained biochemical, virological, and serological response was achieved in 5 (21 %) patients. The proportion of patients in whom HBeAg was lost during entecavir treatment was significantly higher among those with a sustained response than among those with no response (P = 0.015).

CONCLUSIONS

The rate of response to sequential therapy with entecavir and interferon-α in Japanese patients with HBeAg-positive chronic hepatitis B was not higher than the rate in previous studies of lamivudine followed by interferon.

Serum hepatitis B surface antigen levels correlate with high serum HBV DNA levels in patients with chronic hepatitis B: a cross-sectional study

PURPOSE

The hallmark of chronic hepatitis B (CHB) infection is the presence of hepatitis B surface antigen (HBsAg) positivity for at least 6 months. Recently, serum levels of HBsAg have been compared with serum HBV DNA as a surrogate marker to monitor CHB patients. However, data correlating these two markers are scarce. Hence, the present study was done to correlate HBV DNA with HBsAg in CHB patients.

MATERIALS AND METHODS

Consecutive patients of CHB were included. HBV DNA was measured by real-time polymerase chain reaction (PCR). Serum HBsAg was measured by Architect HBsAg.

RESULTS

Of the 198 patients enrolled, 166 fulfilled the inclusion criteria (mean age 43 ± 14 years, 87% males) and the median HBV DNA was 1.7 × 10 3 (range 6.0-1.1 × 10 8 ) IU/ml. Median HBsAg was 8.7 × 10 3 (range 5.0-3.2 × 10 5) IU/ml. Overall correlation between HBV DNA and HBsAg was weak but significant (Spearman ρ = 0.443, P < 0.01). Correlation in HBe antigen-positive group was better (ρ = 0.402, P < 0.01) in comparison to HBe antigen-negative group (ρ = 0.193 P = 0.05). Good correlation existed in treatment-naïve group (ρ = 0.538, P < 0.01) .Correlation was regardless of normal or raised alanine transaminase (ALT). Eighty (48%) patients had high HBV DNA (≥ 2000 IU/ml). Correlation in high DNA group was significant (P < 0.01). The best cut-off of HBsAg for diagnosing high DNA is 3.36 ×10 3 IU/ml.

CONCLUSIONS

Serum HBsAg correlates with HBV DNA in CHB patients, especially in high serum HBV DNA, HBe antigen-positive and treatment-naïve group. HBsAg levels can be used for predicting high serum HBV DNA levels.

Kinetics of hepatitis B surface and envelope antigen and prediction of treatment response to tenofovir in antiretroviral-experienced HIV-hepatitis B virus-infected patients

OBJECTIVE

Hepatitis B surface (HBsAg) and envelope (HBeAg) antigen loss are the primary goals of treating chronic hepatitis B virus (HBV). Although their quantification is useful for other antivirals, such has not been the case with tenofovir disoproxil fumarate (TDF), particularly in HIV infection.

DESIGN

Prospective, multicenter, cohort study in 143 antiretroviral-experienced HIV-HBV-co-infected patients initiating TDF.

METHODS

HBsAg (IU/ml) and HBeAg levels (S/CO) were measured every 6 months. HBsAg and HBeAg decline (Δ) were assessed by mixed-effect linear models. Quantification criteria were used to assess predictability of antigen loss with time-dependent receiver operating characteristic curves.

RESULTS

After a median follow-up of 30.3 months, cumulative incidence rate of HBsAg loss was 4.0% (n = 4) in the entire study population and HBeAg loss was 21.0% (n = 17) in the 96 HBeAg-positive patients. ΔHBsAg was steady during follow-up (HBeAg-positive: -0.027; HBeAg-negative: -0.017 log(10) IU/ml per month), whereas ΔHBeAg ratio was strongly biphasic (-27.1 S/CO per month before and -6.5 S/CO per month after 18 months). Baseline HBeAg and ΔHBeAg were significantly different in patients harboring precore mutations (P < 0.01), whereas both ΔHBsAg and ΔHBeAg were significantly slower among HBeAg-positive patients with CD4(+) T-cell count less than 350 cells/μl (P < 0.05). HBeAg-ratio of 10 S/CO or less at 12 months of therapy was the optimal marker of HBeAg loss, with high sensitivity (0.82) and specificity (0.84) at 36 months. In patients with HBsAg loss, three of four (75.0%) patients had a baseline level of HBsAg of 400 IU/ml or less.

CONCLUSION

During TDF treatment, HIV-induced immunosuppression and HBV genetic variability are associated with differences in HBsAg and HBeAg decline among antiretroviral-experienced, co-infected patients. Considering the decline of HBsAg level is slow, further evaluation is needed to determine its role as a marker of therapeutic efficacy.

Quantification of hepatitis B surface antigen can help predict spontaneous hepatitis B surface antigen seroclearance

BACKGROUND AND AIM

The clinical outcomes of hepatitis B virus (HBV) carriers are favorable following hepatitis B surface antigen (HBsAg) seroclearance. The aim of this study was to investigate the clinical course of spontaneous HBsAg seroclearance and the factors predicting it.

METHODS

A total of 423 patients who tested positive for HBsAg and were referred to Chiba University Hospital between January 1985 and April 2008 were included in the study and the following characteristics were analyzed: age, sex, status of hepatitis B e antigen, alanine aminotransferase level, HBV DNA level, number of platelets, HBV genotype, past treatment with interferon, and HBsAg level. When a nucleotide analog was used for treatment, we stopped follow-up. Measurement of HBsAg was performed using the chemiluminescent enzyme immunoassay method and less than 0.03 IU/ml of HBsAg was designated as HBsAg seroclearance.

RESULTS

The study group included 239 men and 184 women and their average age was 40.5 ± 13.8 years. Twenty-five patients achieved HBsAg seroclearance during the follow-up period with an incidence rate of 0.97% per year. Multivariate analysis revealed that HBsAg titer (compared with patients with a low HBsAg level: odds ratio=0.45, 95% confidence interval: 0.29-0.70) at baseline was the only predictive factor for HBsAg seroclearance.

CONCLUSION

HBsAg seroclearance occurred at a frequency of 0.97% per year without the use of a nucleotide analog. HBsAg titer at baseline was the only predictive factor for HBsAg seroclearance.

Clinical implications of HBsAg quantification in patients with chronic hepatitis B

Quantification of serum hepatitis B surface antigen (HBsAg) helps the management of patients with chronic hepatitis B virus (HBV) infection. Median HBsAg levels differ significantly during the natural history of HBV infection, progressively declining from immune tolerance to inactive phase. The combination of an HBsAg <1000 IU/mL and HBV DNA <2000 IU/mL at a single time point accurately identifies true inactive carriers. During antiviral treatment, HBsAg levels decline more rapidly in patients under peg-interferon (Peg-IFN) than in those under nucleos(t)ide analogues (NUC), and in responders to peg-IFN compared to non responders suggesting that a response-guided therapy in both HBeAg-positive and -negative patients treated with Peg-IFN could improve to cost-effectiveness of this therapeutic approach. Given the low rates of HBsAg clearance on NUC therapy, new studies to test whether Peg-IFN and NUC combination fosters HBsAg decline in long-term responders to NUC, are being explored.

Hepatitis B surface antigen quantification: why and how to use it in 2011 - a core group report

Quantitative HBsAg had been suggested to be helpful in management of HBV, but assays were cumbersome. The recent availability of commercial quantitative assays has restarted the interest in quantitative serum hepatitis B surface antigen (HBsAg) as a biomarker for prognosis and treatment response in chronic hepatitis B. HBsAg level reflects the transcriptional activity of cccDNA rather than the absolute amount of cccDNA copies. Serum HBsAg level tends to be higher in hepatitis B e antigen (HBeAg)-positive than HBeAg-negative patients. Among patients with a low HBV DNA (<2000IU/ml), HBsAg <1000IU/ml in genotype D HBV infection and HBsAg <100IU/ml in genotype B/C HBV infection is associated with inactive carrier state in HBeAg-negative patients. The HBsAg reduction by nucleos(t)ide analogues (NA) is not as pronounced as by interferon treatment. On peginterferon treatment, sustained responders tend to show greater HBsAg decline than the non-responders. The optimal on-treatment HBsAg cutoff to predict response needs further evaluation in HBeAg-positive patients, but an absence of HBsAg decline together with a <2 log reduction in HBV DNA at week 12 can serve as stopping rule in HBeAg-negative patients with genotype D HBV infection. A rapid serum HBsAg decline during NA therapy may identify patients who will clear HBsAg in the long-term. There are early reports among Asian patients that an HBsAg level of <100IU/ml might predict lower risk of relapse after stopping NA treatment. In clinical practice, serum HBsAg level should be used together with, but not as a substitute for, HBV DNA.

Clinical importance of serum hepatitis B surface antigen levels in chronic hepatitis B

Quantitative serology for hepatitis B surface antigen (HBsAg) is a new candidate marker for prediction of clinical outcome. The aim of this study was to investigate the clinical significance of quantifying HBsAg in patients with hepatitis B virus (HBV) infection. A total of 424 patients who tested positive for HBsAg and were referred to Chiba University Hospital between January 1985 and April 2008 were included in the study, and the following characteristics were analyzed: age, gender, status of hepatitis B e antigen (HBeAg), alanine aminotransferase level (ALT), HBV DNA level, number of platelets and development of hepatocellular carcinoma. Measurement of HBsAg was performed using the chemiluminescent enzyme immunoassay method. The study group consisted of 239 men and 185 women, and their average age was 40.6 ± 14.0 years. HBsAg showed a positive correlation with HBV DNA level (Pearson's product moment correlation, r = 0.586, P < 0.001) and a weak inverse correlation with age (r = 0.3325, P < 0.001). A control study, matched with age and sex, was performed between two groups with and without HBeAg seroconversion during follow-up period. Compared with the age and sex-matched controls, the change in HBsAg levels per year showed a significant decrease 2 years before seroconversion (paired t-test, P < 0.05). The serial measurement of quantitative HBsAg level has the possibility of predicting the occurrence of HBeAg seroconversion.

Serum hepatitis B surface antigen monitoring in long-term lamivudine-treated hepatitis B virus patients

Serum hepatitis B virus surface antigen (HBsAg) levels have been suggested to predict interferon response in chronic hepatitis B. A few data are available on the role of HBsAg measurement in nucleos(t)ide analogues (NA) treatment. We retrospectively investigated the relation between HBsAg changes and main treatment outcomes during long-term lamivudine treatment in hepatitis e antigen (HBeAg)-negative chronic hepatitis B. A total of 42 HBeAg-negative patients were consecutively enrolled in an open-label study on long-term lamivudine monotherapy (150 mg/die). Serum HBsAg levels were quantified every 6 months by Architect assay (Abbott Diagnostics). HBV-DNA was quantified quarterly by real-time PCR (Roche Diagnostics). The median duration of lamivudine treatment was 66 months (20-153). One patient (2%) was a primary nonresponder, 35 (83%) developed virological breakthrough (VB) and the remaining six patients (14%) were classified as long-term on-treatment responders. During treatment, HBsAg levels decreased only in long-term on-treatment responders, while no changes were observed in resistant patients. Failure to achieve a decrease of 0.7 log(10) IU/mL in serum HBsAg at month six of lamivudine had a positive predictive value of developing VB of 90% and a negative predictive value of 100%. These high predictive values were also maintained in the subgroup of patients negative for HBV-DNA at month six. The results of this study with a small sample size suggest a role of on-treatment HBsAg quantification in the management of lamivudine-treated patients. If validated prospectively in a larger patient cohort, HBsAg measurements would be a useful adjunct to optimize antiviral therapy.

The change of the quantitative HBsAg level during the natural course of chronic hepatitis B

BACKGROUND

There is insufficient information about HBsAg levels and their correlation with serum hepatitis B virus (HBV) DNA in chronic hepatitis B (CHB).

AIMS

We aimed to describe HBsAg levels during various phases of CHB and to investigate the correlation with serum HBV DNA levels.

METHODS

A total of 645 treatment-naïve Korean CHB patients were included in this retrospective cross-sectional study. They were categorized into immune tolerance (IT, n=56), HBeAg-positive hepatitis (EPH, n=150), inactive carrier (IC, n=274) and HBeAg-negative hepatitis (ENH, n=165). The baseline HBsAg and HBV DNA levels were measured.

RESULTS

The mean HBsAg titres (log IU/ml) differed (P<0.001): IT 4.29, EPH 3.64, IC 2.05 and ENH 3.23. In 645 patients, HBsAg and HBV DNA showed a significant correlation (r=0.693, P<0.001), and this was also observed in the IT, EPH and IC groups (r=0.664, r=0.541, r=0.505, respectively, all P<0.001), but not in the ENH group (r=0.093, P=0.321). Age had a negative correlation with HBsAg (r=-0.451, P<0.001). The cirrhotic patients had a significantly lower HBsAg level than the non-cirrhotic patients (2.41 ± 1.36 vs. 3.02 ± 1.21 log IU/ml, P<0.001).

CONCLUSIONS

The HBsAg level varied significantly in different phases of CHB and was correlated with HBV DNA during the IT, EPH and IC phases. These findings can provide additional information to understand the natural course and pathogenesis of CHB.

HBsAg blood screening and diagnosis: performance evaluation of the ARCHITECT HBsAg qualitative and ARCHITECT HBsAg qualitative confirmatory assays

A low initial reactive rate for screening assays is important for time- and cost-effective infectious disease testing. Therefore, the new ARCHITECT HBsAg Qualitative screening assay, in conjunction with the new ARCHITECT HBsAg Qualitative Confirmatory assay, was introduced. As the role of hepatitis B surface antigen (HBsAg) as surrogate marker for HBV resolution and the monitoring of drug effectiveness are becoming increasingly important, the established ARCHITECT HBsAg Quantitative assay remains available on the market. Precision, sensitivity, and specificity of the newly developed screening assay were in the range of established HBsAg assays. Seroconversion sensitivity was slightly superior compared to other commercially available assays. An initial reactive rate of 0.2% (without HBsAg-confirmed positive samples of 0.17%) for the ARCHITECT HBsAg Qualitative assay was observed. As the new screening assay is a 1-step assay format, the "high-dose hook effect" was investigated to assess the risk of false-negative results, but even very high positive HBsAg samples obtained signals clearly above the cutoff.

Update of chronic hepatitis B

PURPOSE OF REVIEW

We review here new developments in chronic hepatitis B (CHB) treatment, based on review of published articles between December 2009 and November 2010.

RECENT FINDINGS

It is estimated that two-thirds of US CHB patients have not been identified, evaluated and appropriately treated, largely due to lack of knowledge and awareness of CHB among medical professionals and at-risk populations. Seven medications have been approved to treat CHB in adults, but only four medications have been approved to treat CHB in children.Hepatitis B e antigen (HBeAg) seroconversion is still an important treatment endpoint in HBeAg-positive patients. Durability of nucleoside analogue treatment-related HBeAg seroconversion is still questionable. Hepatitis B surface antigen (HBsAg) seroclearance has been achieved in some patients with antiviral therapy. HBsAg quantitation and kinetics is now being studied to determine its role in the natural history of CHB and whether these measures may predict future response to current antiviral therapy.

SUMMARY

Great advances have been made in understanding the HBeAg seroconversion durability. The clinical significance of serum HBsAg kinetics has been recognized in naive CHB patients and patients with antiviral therapy. More education programs are needed to improve the public awareness of the importance of CHB to the health of whole population.

Quantitative hepatitis B surface antigen and hepatitis B e antigen titers in prediction of treatment response to entecavir

Quantitative hepatitis B surface antigen (qHBsAg) and quantitative hepatitis B e antigen (qHBeAg) titers are emerging as useful tools for measuring viral loads and for predicting the virological response (VR) and serological response (SR) to pegylated interferon therapy. However, the clinical utility of these assays in patients taking entecavir (ETV) is largely unknown. Treatment-naive patients with chronic hepatitis B (CHB) who were taking ETV for 2 years were enrolled. The qHBsAg and qHBeAg levels were serially measured with the Architect assay. From 95 patients, 60.0% of whom were hepatitis B e antigen-positive [HBeAg(+)], 475 samples were analyzed. The median baseline log hepatitis B virus (HBV) DNA, log qHBsAg, and log qHBeAg values were 6.73 copies/mL (4.04-9.11 copies/mL), 3.58 IU/mL (1.17-5.10 IU/mL), and 1.71 Paul Ehrlich (PE) IU/mL (-0.64 to 2.63 PE IU/mL), respectively. For the prediction of VR (HBV DNA < 60 copies/mL at 24 months) in HBeAg(+) patients, baseline alanine aminotransferase (P = 0.013), HBV DNA (P = 0.040), and qHBsAg levels (P = 0.033) were significant. For the prediction of VR, the area under the curve for the baseline log qHBsAg level was 0.823 (P < 0.001); a cutoff level of 3.98 IU/mL (9550 IU/mL on a nonlogarithmic scale) yielded the highest predictive value with a sensitivity of 86.8% and a specificity of 78.9%. As for SR (HBeAg loss at 24 months), the reduction of qHBeAg was significantly greater in the SR(+) group versus the SR(-) group. The sensitivity and specificity were 75.0% and 89.8%, respectively, with a decline of 1.00 PE IU/mL at 6 months. With ETV therapy, the correlation between HBV DNA and qHBsAg peaked at 6 months in HBeAg(+) patients.

CONCLUSION

Both qHBsAg and qHBeAg decreased significantly with ETV therapy. The baseline qHBsAg levels and the on-treatment decline of qHBeAg in HBeAg(+) patients were proven to be highly useful in predicting VR and SR, respectively. The determination of qHBsAg and qHBeAg can help us to select the appropriate strategy for the management of patients with CHB. However, the dynamic interplay between qHBsAg, qHBeAg, and HBV DNA during antiviral therapy remains to be elucidated.

Serum hepatitis B surface antigen concentration correlates with HBV DNA level in patients with chronic hepatitis B

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Serum HBsAg concentration might serve as a surrogate marker of HBV DNA level in CHB patients.

[HBsAg quantification: virological significance]

HBsAg is a classic marker of hepatitis B virus infection. Since the levels of serum HBsAg are correlated to those of intrahepatic cccDNA, HBsAg quantification indirectly reflects the number of infected hepatocytes. The kinetics of serum HBsAg decline seems to be a predictive marker for sustained virological response, and clearance of HBsAg. This new tool may be clinically relevant for the monitoring and optimization of hepatitis B treatments. To fulfill this objective, prospective studies are still warranted for the the spread of sensitive and standardized techniques standardization of the quantification assays and to define cut off values with clinical predictive values.

Kinetics of hepatitis B surface antigen differ between treatment with peginterferon and entecavir

BACKGROUND & AIMS

We aimed to investigate serum hepatitis B surface antigen (HBsAg) levels in patients with chronic hepatitis B virus (HBV) infection during peginterferon (PEG-IFN) and entecavir (ETV) monotherapy.

METHODS

HBsAg was quantified (Abbott ARCHITECT) at baseline and during antiviral therapy (weeks 12, 24, 36, 48) in hepatitis B e antigen (HBeAg-) positive patients treated with ETV (n=33) or PEG-IFN (n=61) and in HBeAg-negative patients treated with ETV (n=37) or PEG-IFN (n=69).

RESULTS

Within the HBeAg-positive population, patients treated with PEG-IFN tended to have a steeper HBsAg decline than ETV-treated patients (mean decline 0.94 versus 0.38 log IU/ml at week 48, p=0.07 for comparison of the slope of HBsAg decline). The HBsAg decline was larger in those patients who became HBeAg negative, irrespective of the treatment regimen. A decline in HBsAg was confined to ETV-treated patients with elevated baseline alanine aminotransferase (ALT) levels, whereas HBsAg decline was not associated with baseline ALT in patients treated with PEG-IFN. Within the HBeAg-negative population, PEG-IFN induced a significant HBsAg decline, while HBsAg did not decrease in ETV-treated patients (0.56 versus -0.10 log IU/ml, p<0.001). Both in HBeAg-positive and HBeAg-negative patients, the decline in serum HBV DNA was larger in patients who received ETV as compared to patients treated with PEG-IFN.

CONCLUSIONS

In HBeAg-positive patients, the decline in serum HBsAg is mainly confined to patients who clear HBeAg, by either PEG-IFN or ETV treatment. In HBeAg-negative patients, PEG-IFN therapy resulted in a significant reduction in HBsAg levels, whereas HBsAg did not decrease in ETV-treated patients.

Quantification of HBsAg: Basic virology for clinical practice

Hepatitis B surface antigen (HBsAg) is produced and secreted through a complex mechanism that is still not fully understood. In clinical fields, HBsAg has long served as a qualitative diagnostic marker for hepatitis B virus infection. Notably, advances have been made in the development of quantitative HBsAg assays, which have allowed viral replication monitoring, and there is an opportunity to make maximal use of quantitative HBsAg to elucidate its role in clinical fields. Yet, it needs to be underscored that a further understanding of HBsAg, not only from clinical point of view but also from a virologic point of view, would enable us to deepen our insights, so that we could more widely expand and apply its utility. It is also important to be familiar with HBsAg variants and their clinical consequences in terms of immune escape mutants, issues resulting from overlap with corresponding mutation in the P gene, and detection problems for the HBsAg variants. In this article, we review current concepts and issues on the quantification of HBsAg titers with respect to their biologic nature, method principles, and clinically relevant topics.

Change in serum hepatitis B surface antigen level and its clinical significance in treatment-naïve, hepatitis B e antigen-positive patients receiving entecavir

BACKGROUND/AIM

We investigated changes in hepatitis B surface antigen (HBsAg) level and its correlation with clinical outcomes in treatment-naive chronic hepatitis B (CHB) patients undergoing entecavir therapy.

PATIENTS AND METHODS

Among 51 hepatitis B e antigen (HBeAg)-positive treatment-naive CHB patients receiving entecavir for more than 1 year, 28 were enrolled. HBsAg levels were measured at baseline, 6 months, and 12 months after treatment using the Architect HBsAg QT assay (Abbott, dynamic; range: 0.05 to 125,000 IU/mL). Serum alanine aminotransferase, HBeAg, anti-HBe, and hepatitis B virus (HBV) DNA (Cobas Taqman: low detection limit 1.84 log10 copies/mL) were measured at baseline and every 3 months. The HBsAg response was defined as an HBsAg level that decreased more than 1 log10 IU/mL from baseline level at 12 months after entecavir treatment.

RESULTS

Twenty-eight patients were treated for a median period of 21 months (range: 18 to 24 mo). Serum HBsAg level showed a mean of 4.0, 3.7, and 3.6 log10 IU/mL at pretreatment, 6, and 12 months, respectively, and declined significantly (P<0.001). Serum HBV DNA level showed a mean of 8.1, 3.1, and 2.4 log10 copies/mL at pretreatment, 6, and 12 months, respectively, and declined significantly (P<0.001). The decline in HBsAg level was significantly correlated with that of the HBV DNA level at 12 months from baseline (γ=0.391, P=0.044). Five patients showed an HBsAg response, and cumulative incidence of HBeAg loss at 1 year after entecavir treatment was 80% versus 30% in patients with an HBsAg response and those without, respectively (P=0.034).

CONCLUSIONS

Monitoring changes in quantitative HBsAg level could be a useful parameter for assessing the response to entecavir therapy in HBeAg-positive treatment-naive CHB patients.

[Comparison of nine different qualitative HBsAg assay kits]

BACKGROUND

Qualitative hepatitis B surface antigen (HBsAg) assay kits are still commonly used in Korea where hepatitis B virus (HBV) infection is endemic. The accurate determination of HBsAg plays a crucial role in the diagnosis and prevention of HBV infection, especially in endemic areas. The aim of this study was to compare the detection sensitivities of 9 qualitative HBsAg assay kits.

METHODS

Seven pooled sera with HBsAg concentration ranging from 0.14 IU/mL to 29.96 IU/mL were prepared. The HBsAg concentration of each pooled serum was determined by a quantitative HBsAg assay, Architect HBsAg (Abbott Laboratories, Ireland). The fully automated immunoassay kits included Elecsys HBsAg (Roche Diagnostics, Germany) and Immulite 2000 HBsAg (DPC, USA) and the rapid tests included 5 immunochromatographic assay (ICA) kits and 2 reverse passive hemagglutination assay (RPHA) kits.

RESULTS

Elecsys HBsAg (Roche Diagnostics) showed positive result in pooled serum with HBsAg concentration of 0.14 IU/mL, but Immulite 2000 HBsAg (DPC) showed negative result in the same concentration. Although ICA kits showed variable results among different assay kits, all of them showed negative results in pooled sera with HBsAg concentration of < or = 1.89 IU/mL. Two RPHA kits showed negative results in pooled sera with HBsAg concentration of < or = 7.98 IU/mL.

CONCLUSIONS

Although ICAs were more sensitive than RPHAs, they had variable sensitivities for HBsAg and were less sensitive than the automated immunoassay kits. Therefore, ICAs and RPHAs should be used with caution in the screening tests for HBsAg and their sensitivities need to be improved.

The role of quantitative hepatitis B serology in the natural history and management of chronic hepatitis B

Chronic hepatitis B (CHB) remains a serious clinical problem worldwide. Advances in molecular technology have enabled the development of sensitive assays for the detection and quantification of hepatitis B virus (HBV) nucleic acid and demonstrated a positive correlation between serum HBV DNA levels and disease progression. Assessment of specific serologic and virologic factors also plays a pivotal role in the diagnosis and effective management of individuals with CHB. Recent development of quantitative assays for intrahepatic HBV replicative intermediates, as well as hepatitis B e antigen and hepatitis B surface antigen, has spurred investigation into the relationship between these factors and response to antiviral therapy and disease progression. Recent findings from preclinical and clinical investigations indicate that these factors may have promise in identifying patients likely to respond to treatment. Additional work is needed to standardize and validate these assays before they can be considered to be of true diagnostic value. Further evaluation is needed to decide which will have the greatest clinical applicability.

Clearance of serum HBsAg and anti-HBs seroconversion following antiviral therapy for chronic hepatitis B

In this study, we have analyzed the evolution of serum HBsAg levels in 16 patients with chronic hepatitis B who showed an HBsAg seroconversion following antiviral therapy. The data showed that the clearance of serum HBsAg is slower than that of serum HBV DNA, which may reflect a slow kinetics of clearance of infected hepatocytes. Interestingly, HBsAg was detectable for a longer time using the Architect assay than with the Bio-Rad assay. As viremia suppression is achieved in most patients under therapy with the new generation of nucleoside analogs, these data suggest that the quantitative monitoring of serum HBsAg may represent a novel tool for the assessment of antiviral therapy efficacy.

Correlation of quantitative assay of HBsAg and HBV DNA levels during chronic HBV treatment

BACKGROUND AND AIM

Viral load is used for the diagnosis and monitoring the treatment of chronic hepatitis B (CHB). These methods are molecular-based and are expensive. Previous studies suggest that quantitative hepatitis B surface antigen (HBsAg) studied by automated chemiluminescent microparticle immunoassay can be a surrogate marker. In this study, we aimed to investigate whether quantitative HBsAg correlates hepatitis B virus (HBV) DNA levels during CHB treatment.

METHODS

The study included 18 patients (13 male, 5 female, mean age: 33 +/- 9 years) with CHB. They were given pegylated interferon +/- lamivudine for 52 months and serum samples were obtained in weeks 0, 4, 8, 24, 48, 52, and 76. HBV DNA was measured by TaqMan polymerase chain reaction (PCR; Erasmus MC, University Medical Center, Rotterdam, The Netherlands). Quantitative HBsAg was studied by automated chemiluminescent microparticle immunoassay (Architect HBsAg, Abbott, IL). Results HBV DNA levels were measured as follows: 9.66, 7.69, 7.06, 5.93, 5.89, 5.88, and 7.27 logarithmic genome equivalent/ml, respectively. The corresponding HBsAg quantitation results were 42,888, 31,176, 37,882, 27,277, 28,279, 29,471, and 31,535 IU/ml, respectively. They showed a significant correlation (canonical correlation = 0.85).

CONCLUSIONS

HBsAg studied by automated chemiluminescent microparticle immunoassay correlates with HBV DNA and can be a surrogate marker during the monitoring of the efficacy of HBV treatment.

Diagnosis of human hepatitis B virus in non-treated blood by the bovine IgG DNA-linked carbon nanotube biosensor

OBJECTIVES

To identify an effective bioassay for human hepatitis B virus (HBV) using voltammetric sensor.

STUDY DESIGN

Electrode was prepared with bovine IgG immobilized onto a DNA-linked carbon nanotube electrode (BIDCE). Analytical BIDCE conditions were optimized through square wave (SW) stripping and cyclic voltammetry (CV).

RESULTS

Optimum parameters of 75 Hz SW frequency, 0.1 V SW amplitude, -1.3 V SW accumulation potential, 100 s accumulation time, and 3.0 mV SW increment potential were obtained. Within working ranges of 0.035-0.242 mg/mL anti-bovine IgG, the relative standard deviation of 0.2 mL HBV was observed to be 0.04 (n=4).

CONCLUSIONS

Diagnostic application was performed through direct assay of HBV in non-treated human blood.

Serum HBsAg changes in HBeAg positive chronic hepatitis B patients with continuous viral load reductions during treatment with adefovir or peg-interferon-alpha-2a

Hepatitis B surface antigen (HBsAg) loss under antiviral therapy is rare in chronic hepatitis B patients and the dynamics of serum HBsAg in these patients are not available. The changes in serum HBsAg following treatment with adefovir (n=31) or peg-interferon-alpha-2a (n=23) were studied in hepatitis B e-antigen (HBeAg) positive chronic hepatitis B patients. Abbott Architect HBsAg assay was used to quantify serum HBsAg. HBsAg levels were significantly decreased during the first 12 weeks of treatment with median change of -397.0 IU/ml and -555.4 IU/ml, respectively for adefovir and peg-interferon-alpha-2a (p=0.005 and 0.001, respectively). Beyond 12 weeks, no further significant HBsAg reductions were found even in patients with sustained viral replication inhibition in either group. Three distinct patterns of HBsAg changes were observed in most patients in both treatment groups: biphasic pattern (rapid HBsAg reduction from baseline to week 12); assurgent pattern (higher HBsAg level at week 12 than at baseline); and wavy pattern (HBsAg reduction from baseline to week 12, followed by relapse at week 24 or week 28). These results might offer insights into the possible mechanism(s) underlying the unusual occurrences of HBsAg loss under antiviral therapy.

What is the role of serology for the study of chronic hepatitis B virus infection in the age of molecular biology?

To assess quantitative serology in chronic hepatitis B virus (HBV) infection, testing by novel immunoassays has been carried out on 202 specimens from untreated patients and in 83 samples from 10 patients with chronic hepatitis B treated with lamivudine. Serum samples were assayed for quantitative HBsAg, in comparison with quantitative HBV-DNA, and for anti-HBc IgM and the avidity index (AI) of total anti-HBc antibodies. The AI was high (mean: 0.93 +/- 0.19) in all groups, confirming the consistency of this procedure in chronic HBV infections. A low-level positivity (2-28 Paul-Ehrlich units/ml) for IgM anti-HBc was detectable both in HBeAg-positive and in HBeAg-negative untreated chronic hepatitis cases (mean S/CO values by the Abbott Architect assay: 0.51 +/- 0.12 and 0.48 +/- 0.10, respectively; correlation between assays: r = 0.685), while treated patients (mean: 0.20 +/- 0.15) and inactive carriers (mean: 0.17 +/- 0.21), were generally negative for IgM. The levels of HBsAg (IU/ml) showed a weak correlation with HBV-DNA (IU/ml). A difference in HBsAg levels was found between inactive carriers (1,935 +/- 2,887 IU/ml) and chronic hepatitis B cases, either treated (5,199 +/- 9,259 IU/ml) or untreated (14,596 +/- 15,227 IU/ml). Pre-treatment levels of HBsAg in patients undergoing lamivudine treatment were correlated with a sustained response to therapy over 13-33 months (mean: 27.3) of follow-up: mean HBsAg values were 1,576 + 1,487 IU/ml in five responders and 6,063 + 5,142 in five nonresponders or breakthrough responders (P < 0.05). The availability of standardized quantitative immunoassays for HBsAg and anti-HBc IgM may be considered in addition to quantitative HBV-DNA in the staging and monitoring of chronic HBV infection.

A Decline in Hepatitis B virus Surface Antigen (HBsAg) Predicts Clearance, but does not Correlate with Quantitative HBeAg or HBV DNA Levels

Background

The elimination of hepatitis B virus surface antigen (HBsAg) is the final goal of hepatitis B treatment, but is rarely achieved. As quantitative assays for HBsAg recently became available, we have investigated whether quantitative HBsAg measurements can substitute for hepatitis B virus (HBV) DNA quantification in treatment monitoring.

Methods

Within this study, 23 liver transplant patients and 18 heart transplant recipients were retrospectively analysed. Patients had been treated with famciclovir and/or lamivudine, in addition some had also received adefovir in cases of lamivudine resistance. Quantitative HBsAg and hepatitis B virus e antigen (HBeAg) levels were determined with the ArchitectTM assay. HBV DNA levels were determined with different assays available at given time points.

Results

We did not find a significant correlation between either HBsAg or HBeAg and HBV DNA levels – both in treated and untreated patients. More importantly, there was no significant concordance between an increase or decrease of HBsAg or HBeAg with HBV DNA. However, the curve and decline of quantitative HBsAg enabled prediction of eventual viral clearance. Eight patients showed a 2 log10 drop of HBsAg levels and eight patients demonstrated a reduction of HBsAg levels below 100 IU/ml; five patients fulfilled both criteria. Three of those five cleared HBsAg and became positive for antibodies against HBsAg.

Conclusions

Quantitative HBsAg and HBeAg cannot substitute for HBV DNA quantification during the assessment of antiviral therapy; however, the decline of HBsAg does predict eventual HBsAg clearance. A 2 log10 drop to below 100 IU/ml is associated with a high likelihood of HBsAg clearance.

Quantitative Analysis of Hepatitis D Virus RNA and Hepatitis B Surface Antigen Serum Levels in Chronic Delta Hepatitis Improves Treatment Monitoring

Background/aims

Treatment of chronic delta hepatitis is long and difficult and better monitoring is needed.

Methods

In this study, hepatitis delta virus (HDV) RNA, hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) DNA were retrospectively quantified in 53 patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis delta. Twenty-one had received 28 courses of 3–5 MU interferon-α2b (IFN-α2b) thrice weekly for a median of 12.6 months (interquartile range [IQR]: 7.3–31.6), five had received eight courses of 100 mg lamivudine (LAM) daily for 23.6 months (IQR: 8.4–61.5) and 27 were untreated. The controls were 54 untreated, randomly selected, HBeAg-negative chronic hepatitis B patients without delta infection. Quantification of serum HDV RNA, HBsAg and HBV DNA were performed at baseline, during and at the end of treatment and end of follow up.

Results

Untreated patients had significantly higher median HBsAg levels than controls (5,872 vs 3,501 IU/ml; P=0.046), but lower median HBV DNA levels (2.933 vs 6.459 log10 copies/ml; P<0.001). Median baseline HDV RNA (6.374 log10 copies/ml) was similar in IFN-α2b-treated, LAM-treated and untreated patients. At the end of treatment, IFN-α2b significantly suppressed in paired measurements HDV RNA ( P=0.012) and HBsAg ( P=0.043), but LAM was inefficient. In IFN-α2b-treated patients, HDV RNA became undetectable in five patients within a median of 30 months (IQR: 8–90), followed by a slower decrease in HBsAg.

Conclusions

In untreated chronic delta hepatitis, suppressed HBV replication is associated with significantly increased HBsAg serum levels. IFN-α2b significantly suppresses both HDV RNA and HBsAg, but LAM has no effect. Long-term IFN-α2b treatment (IQR: 1.5–5.0 years) appears necessary for undetectable serum HDV RNA and further treatment is required for HBsAg loss. Monitoring of HDV RNA and HBsAg serum levels in patients with chronic delta hepatitis provides insight during treatment.