复合金标法同步检测HBsAg 、抗-HBc的研究

目的：建立一种快速，简便，敏感的检测乙型肝炎患者血清指标的方法。方法：以胶体金标记的HBsAb,HBcAb为指示物，应用ELISA夹心法和竞争法，建立同步检测乙型肝炎患者血清中HBsAg，抗－HBc两项指标的胶体金免疫渗滤法。结果：检测了150例乙型肝炎患者阳性血清，与ELISA法总符合率为92．0％，检测了66例阴性血清，与ELISA的总符合率为98．48％。结论：滴金免疫法同步检测乙型肝炎2项指标是快速，简便的诊断方法。     

Development of a respiratory syncytial virus vaccine using human hepatitis B core-based virus-like particles to induce mucosal immunity

BackgroundRespiratory syncytial virus (RSV) is an important viral pathogen responsible for severe infection of the lower respiratory tract in children under the age of 5 years. No vaccines against RSV are currently in clinical use. Vaccine-associated enhanced respiratory disease (ERD) caused by excess Th2 type responses was observed in a clinical trial of formalin-inactivated RSV (FI-RSV) in antigen-naïve infants. Thus, inducing a balanced immune response is a crucial issue in the development of an RSV vaccine.MethodsIn this study, we constructed, expressed, and purified a recombinant RSV vaccine candidate (i.e., HRØ24) containing the two heptad repeat regions and the antigenic sites Ø, II, and IV of the RSV F protein. The RSV vaccine candidate was intranasally administrated to BALB/c and C57BL/6 mice in combination with virus-like particles (VLPs) derived from the core protein of the hepatitis B virus (HBc). Mucosal immunity to HRØ24 was then assessed.ResultsIntranasal administration of HBc VLPs in combination with HRØ24 induced serum IgGs against HRØ24 as well as lung HRØ24-specific sIgAs in both C57BL/6 and BALB/c mouse models. The secretion of IFN-γ from splenocyte re-stimulation and an elevated ratio of serum IgG2a to IgG1 indicated that the immune response induced by the HBc VLPs/HRØ24 mixture was Th1-biased. Weight loss of <5% and no to low eosinophil infiltration was observed in histological analysis of the lung following a challenge with the RSV A2 strain. These results suggest that the HBc VLPs/HRØ24 combination conferred substantial partial protection against RSV-induced illness in mice.ConclusionsLong-term immunity to RSV-induced illness was achieved via intranasal vaccination using a mixture of HBc VLPs and HRØ24 in mouse models.     

Role of quantitative hepatitis B core antibody levels in predicting significant liver inflammation in chronic hepatitis B patients with normal or near‐normal alanine aminotransferase levels

Aim

Chronic hepatitis B (CHB) patients with normal alanine aminotransferase (ALT) levels are not free from significant hepatic lesions. Recently, there has been an improved understanding of the clinical significance of quantitative hepatitis B core antibody levels (qAnti‐HBc) during CHB management. In this cross‐sectional study, we evaluated the utility of qAnti‐HBc in identifying significant liver inflammation in CHB patients.

Methods

A total of 469 patients (training set, n = 363; validation set, n = 106) who underwent liver biopsy (LB) were included. The qAnti‐HBc levels were quantified and the relationship between histology and serum markers was systematically analyzed.

Results

In the training set, qAnti‐HBc levels were found to have significant diagnostic value for moderate to severe liver inflammation (≥G2) in all patients (area under the receiver operating characteristic curve [AUROC] = 0.768; 95% confidence interval [CI], 0.721–0.810; P < 0.001) and in patients with normal or near‐normal ALT levels (AUROC = 0.767; 95% CI, 0.697–0.828; P < 0.001). Our novel index (AC index) for the identification of ≥G2 inflammation, which combined the qAnti‐HBc and ALT levels, significantly improved diagnostic performance (AUROC = 0.813; 95% CI, 0.768–0.852) compared to the use of ALT alone (AUROC = 0.779; 95% CI, 0.732–0.821) in all patients. In the validation set, the AC index showed an improved AUROC of 0.890 (95% CI, 0.814–0.942) and 0.867 (95% CI, 0.749–0.943) in all patients and patients with normal ALT levels, respectively.

Conclusions

The qAnti‐HBc level predicts significant liver inflammation well, even in patients with normal or near‐normal ALT levels. Compared with the conventional ALT level, the AC index is a more reliable non‐invasive biomarker for significant liver inflammation in CHB patients.     

Acquirement and disappearance of HBsAg and anti‐HCV in an aged population: a follow‐up study in an endemic township

Background: HBsAg and anti‐hepatitis C virus (anti‐HCV) are stable markers and widely used. The seroconversion and seroclearance of HBsAg and anti‐HCV are important for disease control and prognosis of diseases. Aims: To investigate acquirement and disappearance of HBsAg and anti‐HCV in an endemic area. Methods: Seven years after a community screening, 1002 of 2909 residents of Tzukuan Township were recruited. HBsAg, anti‐HCV and alanine transaminase (ALT) were checked in all who participated and hepatitis B virus (HBV) DNA, anti‐HBs, anti‐HBc, HCV RNA, anti‐HDV and upper abdominal ultrasonography were studied in different groups. Results: There were 461 male and 541 female residents with a mean age of 66.7±8.6 years. No new HBsAg carrier was noted and the HBsAg clearance rate was 1.58% per year. One of the 17 cases with HBsAg clearance had positive HBV DNA, three had ALT elevation, two had cirrhosis and seven had anti‐HBs seroconversion. Quantitative of HBsAg and HBV DNA were concordant and 78.1% subjects had low levels of titration. Anti‐HBc alone contributed to 32.1% and was prominent in old age and the anti‐HCV‐positive group. The anti‐HCV seroconversion rate was only 0.74% per year and household transmission was the only risk factor. Only 37.5% of cases with anti‐HCV seroconversion had HCV viraemia and the anti‐HCV seroreversion rate was 0.63% per year. The anti‐HDV seroconversion rate was 0.72% per year and no subject showed anti‐HDV clearance. Conclusions: Much higher rates of HBsAg seroclearance, anti‐HCV seroreversion and anti‐HBc alone were noted in this endemic area and no subject showed anti‐HDV clearance.     

Significance of detecting anti‐HBc among Egyptian male blood donors negative for HBsAg*

Background: Screening for hepatitis B virus surface antigen (HBsAg) reduces the risk of transfusion‐transmitted hepatitis B viral (HBV) infection. However, the absence of HBsAg in the blood of apparently healthy individuals may not be sufficient to ensure the lack of circulating HBV. Blood containing anti‐hepatitis B core antibody (anti‐HBc) without detectable presence of HBsAg might be infectious; therefore, screening for anti‐HBc has been implemented in some countries resulting in a decrease in the risk of post‐transfusion HBV infection. Aim: To study the seroprevalence of anti‐HBc. The relationship between anti‐HBc positivity and the presence of circulating HBV among healthy blood donors negative for HBsAg will be helpful to decide whether supplemental testing may bring additional safety to blood products. Material and methods: A total of 1026 serum samples collected from HBsAg‐negative Egyptian healthy male donors were tested for the presence of anti‐HBc (both IgM and IgG types) using the competitive enzyme‐linked immunosorbent assay technique. Anti‐HBc‐positive samples were subjected to real‐time polymerase chain reaction to confirm the presence of HBV DNA. Results: Of the 1026 samples tested, 80 (7·8%) blood samples were found to be reactive to anti‐HBc. Of those, HBV DNA was detected in five of the samples (6·25%). The levels of detected viraemia were variable among the five donors. Conclusion: This study shows the insufficient effectiveness of HBsAg screening in protecting blood recipients from HBV infection. Inclusion of anti‐HBc testing should be considered in the screening of blood donors.     

HBsAg阴性血液传播乙型肝炎危险性的探讨

559名HBsAg阴性的健康人抗-HBc和抗-HBs均阳性者检出率为31.31%(175/559),单项抗-HBc阳性检出率为26.83%(150/559)。随机抽取单项抗-HBc阳性,以及抗-HBs和抗-HBc均阳性血标本各150份,应用斑点分子杂交技术,HBVDNA的检出率分别为5.33%和2.0%;高滴度单项抗-HBc阳性血HBVDNA检出率(12.0%)高于低滴度单项抗-HBc阳性血的HBVDNA检出率(4.0%)。结果表明,HBsAg阴性血液仍具有传播HBV的危险性;抗-HBs和抗-HBc均阳性的血液并非绝对安全;高滴度单项抗-HBc阳性血液传播HBV的危险性更大。建议对献血者加测抗-HBc。     

T‐ and B‐cell responses and previous exposure to hepatitis B virus in ‘anti‐HBc alone’ patients

A serologic response to hepatitis B virus (HBV) defined as ‘anti‐HBc alone’ is commonly observed, but its significance remains unclear. This study aimed to define the relationship between ‘anti‐HBc alone’ serostatus and HBV infection, including HBV‐specific T‐ and B‐cell memory responses. We enrolled 31 ‘anti‐HBc alone’ patients. Total HBV DNA and cccDNA were tested by nested polymerase chain reaction (PCR) analysis in liver samples from 22 ‘anti‐HBc alone’ patients vs controls (chronic or resolved HBV infection), followed by HBsAg/HBcAg immunohistochemical (IHC) staining. IFN‐γ secretion by HBV‐specific T cells was compared in individuals who were ‘anti‐HBc alone’ (n = 27), resolved HBV (n = 21), chronic HBV (n = 24) and 12 healthy controls using enzyme‐linked immunospot (ELISpot) assays. An HBsAg‐IgG B‐cell ELISpot assay was performed in ‘anti‐HBc alone’ patients before and after one dose of recombinant HBsAg vaccine. The majority (23/31, 74.2%) of the ‘anti‐HBc alone’ individuals were co‐infected with HCV. Infrequent intrahepatic total HBV DNA (2/22, 9.1%) and cccDNA (1/22, 4.5%) were detected in biopsies; HBsAg and HBcAg IHC staining was negative. HBV‐specific T‐cell responses were similar between ‘anti‐HBc alone’ individuals and HBV resolvers. Circulating HBV‐memory B‐cell responses were detected in all ‘anti‐HBc alone’ individuals, consistent with an HBsAg‐specific memory pool. After one HBV vaccine dose, increased anti‐HBs antibody levels were observed, accompanied by an expansion of HBsAg‐specific memory B cells (P = 0.0226). ‘Anti‐HBc alone’ individuals showed HBV‐specific T‐cell and memory B‐cell responses typical of previous viral exposure and protective memory, suggesting a resolved infection.     

Hepatitis B vaccination after living donor liver transplantation.

BACKGROUND: The efficacy of hepatitis B vaccination after living donor liver transplantation (LDLT) in patients transplanted anti-HBc-positive grafts or in patients who underwent LDLT for fulminant hepatitis B remains unknown. METHOD: A total of 11 recipients who underwent LDLT between October 1996 and October 2002 prospectively received hepatitis B vaccination three times within 6 months, starting a few weeks after the cessation of hepatitis B immunoglobulin (HBIG) prophylaxis. Serial quantification of the hepatitis B surface antibody (HBsAb) was performed. RESULTS: At the last follow-up, six out of 11 patients (54.5%) had seroconversion and were free from HBIG thereafter. Four out of those six responders had a peak HBsAb level of more than 1000 IU/L, while the other two patients had peak HbsAb levels below 1000 IU/L. Five patients never responded to the treatment and were back to HBIG prophylaxis. The average age of the six responders was 25.5 years, which was significantly younger than that of non-responders (44.4 years, P<0.05). None had side effects or hepatitis B infection during the study period. CONCLUSIONS: In conclusion, the use of this treatment modality could be used to reduce the cost of HBIG.