Is there a need for universal double reflex testing of HBsAg-positive individuals for hepatitis D infection?

Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.

不同HDV诊断试剂对HBsAg阳性样品的检测分析

目的比较HDV抗原,-抗HDV IgM和抗-HDV总抗体诊断试剂在我国HBsAg阳性样品中的检出情况。方法利用7个来自不同厂家的HDV抗原、抗-HDV IgM和抗-HDV总抗体诊断试剂对收集自我国各地的HBsAg阳性样品进行检测,比较分析各血清学试剂的检出差异。对以上血清学指标阳性的样品利用Rt-PCR方法进行HDV RNA核酸检测,PCR产物直接测序,与HDVⅠ、Ⅱ和Ⅲ基因型的序列进行比较,构建进化树划分基因型。结果 687份HBsAg阳性样品中HDV抗原,抗-HDV IgM和抗-HDV总抗体的阳性率范围为0%-5.17%,各试剂间阴性符合率均大于95%,阳性符合率小于50%。34份HDV血清学指标阳性的样品中2份HDV RNA阳性,均为Ⅰa基因型。仅抗-HDV总抗体试剂C1和IgM试剂C2可全部检出该HDV RNA阳性的2份样品。结论本研究发现的HDV均为Ⅰa基因型,我国HDV诊断试剂的质量需要进一步提高。

我国河南株丁型肝炎病毒抗原在原核细胞中的高效表达及分泌

将我国河南株丁型肝炎（丁肝）病毒抗原的编码基因，克隆到分泌性原核表达载体ｐＥＴ－１２ａ的Ｔ７启动子下游，构建了保留和去除终止子（Ｔｅｒｍｉｎａｔｏｒ）的两个表达载体ｐＥＴＤＡｇ和ｐＥＴＤＡｇ－１。将重组的表达质粒转化宿主菌ＢＬ２１，经ＩＰＴＧ诱导，成功地高效表达了丁肝病毒抗原（ＨＤＡｇ）。ＳＤＳ－ＰＡＧＥ及ｗｅｓｔｅｍｂｌｏｔ表明，分泌到细胞周间质和包涵体中的ＨＤＡｇ的分子量约为２７ｋＤ和２８ｋＤ。ＥＬＩＳＡ分析表明，分泌性ＨＤＡｇ的活性优于包涵体中的ＨＤＡｇ，分泌性ＨＤＡｇ的ＥＬＩＳＡ滴度高于１：３２０００比活性为１００００ＥＬＩＳＡ滴度／ｍｇ蛋白；包涵体ＨＤＡｇ的ＥＬＩＳＡ滴度可达１：２５６００，比活性为４５００ＥＬＩＳＡ滴度／ｍｇ蛋白。另外，利用本室建立的６株抗美国株ＨＤＡｇ单克隆抗体对该河南株重组丁肝病毒抗原（ｒＨＤＡｇ）进行了鉴定分析，表明它可与其中５株ＭｃＡｂ起特异性结合反应，而与另一株ＭｃＡｂ反应不好，推测可能与其ＨＤＡｇ的不同空间结构有关。

Prevalence of hepatitis C infection among intravenous drug users in Shanghai

AIM:To characterize the prevalence of hepatitis C virus(HCV)infection among Chinese intravenous drug users(IDUs).METHODS:A total of 432 adult IDUs(95 women and337 men)in Shanghai were included in the study.The third-generation Elecsys Anti-HCV assay(Roche Diagnostics GmbH,Sandhofer Strasse 116,D-68305,Mannheim,Germany)was used to screen for antibodies against HCV.The RIBA strip,a supplemental antiHCV test with high specificity,was performed on all of the samples that tested positive during the initial screening.All of the anti-HCV positive samples were analyzed with a Cobas TaqMan 48 Analyzer(Roche Diagnostics)for direct detection of HCV RNA.All of the HCV RNA-positive samples were sequenced for genotype determination.RESULTS:The preliminary screening identified 262(60.6%)subjects who were seropositive for HCV.Of the 62 females and 200 males seropositive subjects,16(16.7%)and 65(19.3%),respectively,were confirmed by RIBA,yielding an overall HCV seropositive rate of18.8%.Four female(6.5%)and 14 male(7.0%)subjects tested positive for HCV RNA,indicating an active infection rate of 4.2%for the entire study population.The 18 HCV RNA-positive serum samples were genotyped.Seven individuals were genotype 1b,and four were genotype 1a.One individual each was infected with genotypes 2a,2b and 3a.Four subjects were coinfected with multiple strains:two with genotypes 1a and 2a,and two with genotypes 1b and 2a.The active infection rate among HCV-seropositive individuals was22.2%,which was significantly lower than most estimates.CONCLUSION:The prevalence of HCV is relatively low among IDUs in Shanghai,with a spontaneous recovery rate much higher than previous estimates.

Acute hepatitis B or exacerbation of chronic hepatitis B-that is the question

Hepatitis B virus (HBV) infection constitutes a serious global health problem. In countries with intermediate or high endemicity for HBV, exacerbations of chronic hepatitis B may be the first presentation of HBV infection. Some of these patients may be diagnosed mistakenly as having acute hepatitis B. Accurate diagnosis in these cases is very important for deciding whether to start treatment or not, because acute hepatitis B does not require therapy, while exacerbation of chronic hepatitis may benefit from it. Clinical and routine laboratory findings cannot help distinguishing between these two conditions. Therefore, several assays have been proposed for this purpose during the last few years. The presence of high levels of anti-HBe antibodies, HBsAg and HBV DNA are typical of chronic disease, whereas high titers of IgM anti-HBc, together with their high avidity index, characterize acute HBV infection. Starting from the description of a patient with acute hepatitis B-who recently came to our observation-we critically review the currently available assays that may help distinguishing between the different conditions and lead to the optimal management of each patient.

丁型肝炎抗体检测方法比较分析

丁型肝炎是由丁型肝炎病毒(HDV)与乙型肝炎病毒(HBV)合并感染或者HDV重叠感染HBV携带者引起的一种严重病毒性肝炎。由于长期重视不足,丁型肝炎的诊断目前还存在巨大空白。近年来,随着相关研究的不断深入,科研和医疗行业逐渐意识到丁型肝炎的危害。同时相关药物研发的重大进展也为丁型肝炎的治疗甚至治愈带来了新的机遇。而这些进展将大大增加对丁型肝炎诊断的需求。抗-HD抗体是丁型肝炎诊断的关键指标。本文就目前丁型肝炎抗体包括抗-HD总抗体、IgG和IgM的检测方法进行了总结和比较分析,并对相关的重要问题进行了讨论,以期加深对丁型肝炎抗体检测现状的了解,并为开发更好的丁型肝炎诊断工具提供参考。

Community-based cross-sectional seroprevalence study of hepatitis A in Bangladesh

AIM： TO elucidate the age-distribution of anti-hepatitis A virus （HAY） seroprevalence across different socioeconomic status （SES） categories in Bangladesh which, despite scarce data, is generally deemed to have high endemicity. METHODS： Blood samples of 818 subjects from a stratified samp#e of schools and hospitals, comprising different age categories and SES were collected. They were assayed for total anti-HAV antibodies. Social and medical history data were obtained using a questionnaire. RESULTS： Overall anti-HAV seroprevalence was 69.6%, increasing with age from 1-5 years （40.4%） to 〉 30 years （98.4%）. Seroprevalence was lowest （49.8%） in the high SES group and highest （96.5%） in the rural lower-middle SES group. Among subjects aged 6-20 years, anti-HAV seroprevalence was lowest in urban private school children （43.0%）, followed by urban government school children （76.2%） and rural school children （96.5%） （P 〈 0.01）. Within the high SESgroup, anti-HAV seroprevalence was 32.3% in subjects 〈 10 years and 51.7% in those aged 11-20 years. Until now Bangladesh has been deemed to have high endemicity for HAV. CONCLUSION： The transition from high to intermediate HAV endemicity may be underway; high SES adolescents and adults remain particularly at risk of symptomatic illness. Preventive measures need consideration.

各种HBsAg阳性人群中抗D型肝炎病毒抗体的研究

采用Abbott EIA法对各种HBsAg阳性人群血清抗HDV抗体进行了调查,结果在1004份血清标本中检出有18份标本抗HDV抗体阳性,阳性率为1.8%。抗HDV抗体检出率与年龄、性别无关。但在无症状HBsAg携带者、急性乙型肝炎、慢性乙型肝炎(包括慢性活动性肝炎、慢性迁延性肝炎、肝硬化)、肝癌患者血清中,抗HDV抗体检出率有显著性差别,分别为0.6%、0%、1.7%、和12.1%。这些阳性血清中抗HDV抗体滴度<1:10,间隔2～6个月后对部份患者重新采血复查时,抗HDV抗体转为阴性。研究结果提示了低感染率的D型肝炎在我国的存在。