Measuring HBsAg and HBV DNA Levels in Cilegon

Background: Implication of measuring HBsAg level is still not recognized well. The aim of this study to recognize the correlation of serum HBsAg level and serum HBV DNA level between in HBeAg positive patients and HBeAg negative patients. Method: Quantitative serum HBV DNA were collected retrospectively between January 2006 and May 2009. We stratified the patients into four groups, that were; HBeAg positive and (a) ALT > 2 x upper limited normal (UNL) (group A),( b) ALT < 2 x UNL (group B), HBeAg negative and:( a) ALT > 2 x UNL (group C) (b) ALT < 2 x UNL (group D). We studied the correlation of serum HBsAg and HBV DNA level in each group. In addition, we also studied the accuracy of HBsAg titers to predict serum HBV DNA levels in each group by using receiver operating characteristic (ROC) curve analysis. Results: Eighty nine patients were recruited in this study. Most of them 63 (70%) were male; the mean age of the patients was 38.49 ± 11.21 years. The number of patients with HBeAg positive and negative were 28 and 61 respectively. Based on the group stratification, the A, B, C and D groups we found 16, 12, 11, 50 respectively. There was a positive correlation between HBsAg titers and HBV DNA level in HBeAg positive patients but it was statistically not significant. Similar result was also found in HBeAg negative patients. There were positive correlation in group A, C, and D but they were not statistically significant. In group B the correlation was negative (r = -0.40). We found 100% sensitivity and 100% specificity of predicting serum HBV DNA levels in group A with HBsAg cut-off level of 7.91 IU/mL and baseline serum HBV DNA cut-off level > 20,000 IU/mL. In group B, C and D the accuracy to predict serum HBV DNA level were not so good . Conclusion: There were positive correlation between HBsAg titers and HBV DNA levels in HBeAg positive and HBeAg negative patients as demonstrated in the three group stratification; however, the correlation was negative in group HBeAg positive and ALT < 2 x UNL. We found excellent (100%) specificity and sensitivity for predicting serum HBV DNA level in group HBeAg positive and ALT > 2 x UNL with HBsAg cut-off level 7.91 IU/mL and baseline serum HBV DNA cut-off level > 20,000 IU/mL; while in other groups, the correlation were not so good

Prediction of conformational changes by single mutation in the hepatitis B virus surface antigen (HBsAg) identified in HBsAg-negative blood donors

<p>Abstract</p> <p>Background</p> <p>Selection of hepatitis B virus (HBV) by host immunity has been suggested to give rise to variants with amino acid substitutions at or around the <it>'a' </it>determinant of the surface antigen (HBsAg), the main target of antibody neutralization and diagnostic assays. However, there have never been successful attempts to provide evidence for this hypothesis, partly because the 3 D structure of HBsAg molecules has not been determined. Tertiary structure prediction of HBsAg solely from its primary amino acid sequence may reveal the molecular energetic of the mutated proteins. We carried out this preliminary study to analyze the predicted HBsAg conformation changes of HBV variants isolated from Indonesian blood donors undetectable by HBsAg assays and its significance, compared to other previously-reported variants that were associated with diagnostic failure.</p> <p>Results</p> <p>Three HBV variants (T123A, M133L and T143M) and a wild type sequence were analyzed together with frequently emerged variants T123N, M133I, M133T, M133V, and T143L. Based on the Jameson-Wolf algorithm for calculating antigenic index, the first two amino acid substitutions resulted in slight changes in the antigenicity of the <it>'a' </it>determinant, while all four of the comparative variants showed relatively more significant changes. In the pattern T143M, changes in antigenic index were more significant, both in its coverage and magnitude, even when compared to variant T143L. These data were also partially supported by the tertiary structure prediction, in which the pattern T143M showed larger shift in the HBsAg second loop structure compared to the others.</p> <p>Conclusions</p> <p>Single amino acid substitutions within or near the <it>'a' </it>determinant of HBsAg may alter antigenicity properties of variant HBsAg, which can be shown by both its antigenic index and predicted 3 D conformation. Findings in this study emphasize the significance of variant T143M, the prevalent isolate with highest degree of antigenicity changes found in Indonesian blood donors. This highlights the importance of evaluating the effects of protein structure alterations on the sensitivity of screening methods being used in detection of ongoing HBV infection, as well as the use of vaccines and immunoglobulin therapy in contributing to the selection of HBV variants.</p

Chronic hepatitis B in pregnant women: is hepatitis B surface antigen quantification useful for viral load prediction?

SummaryBackgroundNew cases of hepatitis B virus (HBV) infection continue to occur worldwide. Most of these are due to mother-to-child transmission (MTCT), with maternal viraemia as the most important contributing factor. The hepatitis B surface antigen (HBsAg) level, which correlates positively with viral load, has been used for treatment monitoring in chronic hepatitis B. This study evaluated the usefulness of quantitative HBsAg for viral load prediction in HBsAg-positive pregnant women.MethodsA total of 943 pregnant women in Makassar, Indonesia, were screened for HBsAg. Sixty-four women were HBsAg-positive and investigated. HBsAg level and hepatitis B e antigen (HBeAg)/hepatitis B e antibody (anti-HBe) status were determined serologically. Viral load was measured by real-time PCR. HBV DNA was sequenced and analysed for identification of genotype and basal core promoter (BCP)/precore (PC) mutations.ResultsOf 64 subjects, 12 (18.8%) were HBeAg-positive and 52 (81.3%) were HBeAg-negative. HBsAg and HBV DNA levels were significantly higher in the HBeAg-positive group (p<0.001). HBsAg and HBV DNA levels were positively correlated in the HBeAg-positive group (r = 0.659; p=0.02), but not in the HBeAg-negative group (r=0.194; p=0.168). Low HBsAg levels (<3.0 log10 IU/ml) corresponded with HBV DNA levels<6.0 log10 IU/ml (r=0.404; p=0.001), a recognized threshold for MTCT. Genotype C was more prevalent than genotype B, but not associated with HBsAg level, viral load, or HBeAg status. Two-thirds of HBeAg-negative subjects with high HBV DNA levels harboured BCP (A1762T/G1764A) and/or PC (G1896A) variants.ConclusionsHBsAg levels provide a good viral load predictor in HBeAg-positive but not HBeAg-negative pregnant women. The HBeAg-negative group had a frequent occurrence of BCP/PC variants, which may have contributed to the lack of correlation observed. Samples with a low HBsAg level, which is associated with a low risk of MTCT, do not require HBV DNA measurement