化学发光法和酶联免疫法作为筛选试验测定丙肝抗体的评价

目的比较化学发光法(CLIA)和酶联免疫法(EIA)测抗-HCV对诊断HCV感染的检出率,分析CLIA测定抗-HCV作为HCV感染初筛试验的重要临床意义。方法分别用CLIA、EIA方法检测所有临床标本中的抗-HCV,选取抗-HCV初筛阳性样本进行HCV RNA确认试验。结果 6461例样本中,EIA和CLIA测抗-HCV阳性率分别为2.86%和3.17%;确认试验中,CLIA法抗-HCV阳性与HCV RNA的符合率为97.1%,显著高于EIA组(91.9%)。EIA法测抗-HCV,S:CO>5.0以上,与HCV RNA检测符合率可达100%;弱阳性样本,与HCV RNA符合率为69.7%;CLIA法测抗-HCV,S:CO>2.0以上,与HCV RNA检测符合率可达100%;弱阳性样本,与HCV RNA符合率为92.9%。有31例样本CLIA法抗-HCV和HCV RNA阳性,而EIA法抗-HCV阴性;有4例样本EIA法检测为阳性,而CLIA法和PCR确认试验均为阴性。结论CLIA法测抗-HCV作为HCV感染初筛实验,与传统EIA相比,特异性和阳性预测值更高,有效降低了假阳性率,有利于临床医生对HCV感染患者的早期诊断和治疗。     

乙肝病毒表面抗体TRFIA方法的建立及其应用

建立乙型肝炎病毒表面抗体(抗-HBs)的时间分辨荧光免疫分析法(TRFIA).检测体系由纯化的HBsAg包被的微孔板、Eu3 标记的HBsAg、抗-HBs系列标准品和增强液组成,采用双抗原夹心法定量检测人血清或血浆抗HBs.测定药检所2、5、10 mIU/mL SAb血清盘均可准确检出,阴性血清(20/20)符合率为100%,CV为2.5%.测定范围为5～2000 mIU/mL,正常参考值小于10 mIU/mL.用本法与固相RIA、ELISA和ECLIA对1189份临床血样进行考核,并与参比试剂盒临床符合率一致,具有同等的临床诊断价值.     

Molecular Epidemiology of Hepatitis C Virus Infection in an Area of Hyperendemicity in Southern Italy: a Population-Based Study

In a cohort of subjects from Italy, anti-hepatitis C virus (HCV) and HCV RNA [HCV(+) subgroup] prevalences were 24.6 and 79.6%, respectively. HCV types 1b and 2a/c accounted for 95% of infections. Adjusted alanine aminotransferase levels were higher in males than in females and in RNA-positive subjects than in RNA-negative subjects regardless of HCV type. Genotype distribution was unrelated to demographic variables.     

Long-term follow-up of Hepatitis B Surface antibody levels in subjects receiving universal Hepatitis B vaccination in infancy in an area of hyperendemicity: correlation between radioimmunoassay and enzyme immunoassay

The aims of the present study were to determine (i) the long-term immunogenicity and the decay rate of hepatitis B virus (HBV) surface antibody (anti-HBs) from universal hepatitis B vaccination at infancy for a healthy population in an area of hyperendemicity and (ii) whether the anti-HBs levels measured by enzyme immunoassay (EIA) were closely correlated with those assayed by radioimmunoassay (RIA) methods during long-term monitoring. A total of 1,337 apparently healthy children (696 boys and 641 girls) who were vaccinated against HBV at infancy and monitored for anti-HBs annually from 7 to 16 years of age entered the study. Serum samples were analyzed for anti-HBs by RIA at 7 to 15 years of age and were also analyzed by EIA at 13 to 16 years of age. Antibody titers were quantified in mIU/ml by EIA as well as by the ratio of the count in the sample to the count for a negative control (S/N) by RIA. In non-boosted children, the average decay of anti-HBs from 7 to 16 years of ages indicated that approximately 20% of the geometric mean titer decays per year. There was a good correlation between serum anti-HBs levels measured by the RIA and the EIA methods (r=0.91; P<0.0001). An equation for RIA to EIA level conversion was established: log EIA titer=-0.12+ (1.31 . log RIA S/N). The anti-HBs titers measured by EIA correlate well with the S/N assayed by RIA. The annual decay rate of the log anti-HBs level may help in planning booster immunizations for hypo-responders or individuals at risk in adolescence.     

乙型肝炎病毒临床感染形式与乙型肝炎病毒基因型之间的关系

目的 分析浙江省乙型肝炎病毒(HBV)的基因型分布,并了解基因型与临床表现形式之间的关系.方法 采用实时荧光定量PCR技术分别检测HBV基因型和HBV-DNA含量,采用化学发光技术检测乙肝免疫标志物,并对三种检测结果进行分析.结果 425份标本检出基因B型138例(32.47％),基因C型272例(64.00％),B\C混合型15例(3.50％),未发现其他基因型;发现C型基因HBV-DNA含量与HBeAg阳性率均高于B型基因,具有统计学差异P＜0.05;以临床诊断分析无症状的病毒携带者(ASC)以B型基因为主,而慢性乙型肝炎(CHB)、肝硬化(LC)以C型感染为主.结论 浙江地区HBV感染者基因型以B、C为主,未检出其他基因型,不同基因型中基因C型较基因B型更易转为慢性化,基因C型HBV感染者所致病更为严重.     

Long-Term Follow-Up of Antibody Titers Against Measles,Mumps, and Rubella in Recipients of Allogenic Hematopoietic Cell Transplantation

Outbreaks of viral infections, such as measles, are regularly observed and pose a serious threat to recipients of allogeneic hematopoietic cell transplantation (HCT). The questions of how long cellular and humoral protective host immunity persists, and whether donor immunity can be transferred has not been clarified. Here we present a retrospective analysis of humoral immunity—serial antibody titers against measles, mumps, and rubella—in 331 patients who underwent allogeneic HCT at our single center between 2002 and 2015. Associations between the loss of protective antibody levels and clinical patient characteristics and transplantation parameters were examined. In general, antibody protection against measles persisted longer, with 72% of patients maintaining sufficient titers at 5 years post-HCT even without revaccination, while at that time only 65% and 50% of patients had protective immunity against rubella and mumps, respectively. The great majority of donors were seropositive for all 3 viruses; however, it appeared that donor humoral immunity could not be transferred and had no impact on post-HCT serostatus. Rather, the most relevant factor for persistent protective antibody titers against measles and rubella was whether patients were born before the introduction of the respective vaccine and thus were immunized by the wild-type disease-inducing virus instead of the vaccine. Moreover, the presence of moderate and severe chronic graft-versus-host disease (GVHD) was associated with more rapid loss of immune protection. In contrast, underlying disease, intensity of the conditioning regimen, use of antithymocyte globulin, age, and graft source had no influence on antibody titers. Overall, our findings suggest that the majority of antibodies against measles, mumps, and rubella originate from residual host cells, whereas donor immune status appears to have no influence on antibody protection post-HCT.     

Antibody Assays for Varicella-Zoster Virus: Comparison of Enzyme Immunoassay with Neutralization, Immune Adherence Hemagglutination, and Complement Fixation

An enzyme immunossay (EIA) was adapted for detection of antibody to varicella-zoster virus, and its sensitivity and specificity were compared with those of neutralization, immune adherence hemagglutination (IAHA), and complement fixation tests. Test sera showed little nonspecific reactivity in the EIA system, and valid results could usually be obtained at serum dilutions as low as 1:8. Demonstration of the presence or absence of varicella-zoster viral antibody by EIA showed 94% correlation with results obtained in neutralization tests, but EIA titers were 2- to 16-fold higher than neutralizing antibody titers. Results by IAHA showed 87% correlation with those obtained by neutralization. No false positive IAHA results were seen, but a number of false negative IAHA results were seen at the 1:8 serum dilution, particularly in older individuals. With increasing age (>40 years), and presumably increased time from varicella infection, neutralizing antibody levels generally declined to 1:8 or 1:16, EIA levels fell to 1:128 or 1:256, and IAHA and complement fixation antibody titers were usually <1:8 or 1:8. EIA and IAHA were as reliable as the neutralization and complement fixation tests for serodiagnosis of varicella and zoster infections. All tests demonstrated heterotypic varicella-zoster antibody titer rises in selected patients with initial herpes simplex virus infections, but fewer heterotypic responses were seen by EIA than by the other methods. EIA offers a rapid, sensitive, and specific method for varicella-zoster antibody assay that is applicable to use in a clinical setting.     

362例乙肝患者HBV-DNA含量与免疫学标志物、肝功能关系分析

目的探讨乙型肝炎患者HBV—DNA含量与血清免疫学标志物、肝功能的关系。方法将362例乙肝患者按血清免疫学标志物不同模式分成两组：HBeAg阳性组,82例;HBeAg阴性组,280例。HBV-DNA、免疫学标志物和肝功能检测分别采用荧光定量PCR法、酶联免疫吸附法和生化分析法,数据分析采用SPSS11．0统计学软件。结果HBeAg阳性组HBV—DNA含量≥10^3IU／mL者为97．56％,高于HBeAg阴性组的43．57％,二者间差异有统计学意义（X^2=74．96,P〈0．01）。HBV-DNA含量10^3～10^4IU／mL者,HBeAg阳性组为2．44％,低于HBeAg阴性组的35．00％。二者间差异有统计学意义（X^2=33．63,P〈0．01）。HBV-DNA含量为10^5—10^6IU／mL者,肝功能异常者的比例为64．70％。结论HBeAg阳性者乙肝病毒复制水平较高,HBeAg阴性者病毒复制水平相对较低,但病毒并非停止复制,HBeAg阴性者也存在高水平病毒复制。判断乙型肝炎患者是否存在病毒复制,是否具有传染性,最直接、最可靠的指标是HBV—DNA定量检测。     

Enzyme-Linked Immunosorbent Assay for Detection of Hepatitis A Antigen in Stool and Antibody to Hepatitis A Antigen in Sera: Comparison with Solid-Phase Radioimmunoassay, Immune Electron Microscopy, and Immune Adherence Hemagglutination Assay

Previously described techniques for detection of hepatitis A antigen (HA Ag) and antibody (anti-HA) have required purified HA Ag and expensive equipment. Herein is described an enzyme-linked immunosorbent assay (ELISA) for specific detection of HA Ag in human stool filtrates and of anti-HA in sera by using selected HA Ag-containing human stool filtrates as the antigen source. Because human stools often react nonspecifically in serological tests for HA Ag, blocking with preexposure and hyperimmune anti-HA sera from a chimpanzee inoculated with hepatitis A virus was used to confirm specific detection of HA Ag. The sensitivity of ELISA was found to be comparable to that of solid-phase radioimmunoassay (SPRIA) and immune electron microscopy (IEM). Of 37 acute-phase stools collected from nine patients, 16 were positive for HA Ag by ELISA. In 13 of these, HA Ag particles were found by IEM, and an additional 3 stools negative by ELISA contained HA Ag particles by IEM. Eight control stools were negative by both ELISA and IEM. Anti-HA was measured in sera by demonstrating its ability to block binding of the enzyme conjugate to HA Ag in a stool without detectable nonspecificity. This test (blocking ELISA) was as sensitive and specific as blocking SPIRA, IEM, and immune adherence hemagglutination and, like SPRIA and IEM, detected early-developing antibody. The ELISA is simple to perform and requires only a minimum of equipment. It is useful for screening stools for HA Ag and for monitoring HA Ag during purification, as well as for detecting early and late anti-HA in sera.     

Significance and Management of Isolated Hepatitis B Core Antibody (Anti-HBc) in HIV and HCV: Strategies in the DAA Era

Purpose of Review

The purpose of this review is to summarize the prevalence and clinical implications of the isolated anti-HBc serologic profile in HIV-infected individuals. We highlight the rare but important issue of HBV reactivation in the setting of HCV therapy and describe an approach to management.

Recent Findings

The isolated anti-HBc pattern, a profile that most often indicates past exposure to HBV with waning anti-HBs immunity, is found commonly in HIV-infected individuals, particularly those with HCV. Some large cohort studies demonstrate an association with advanced liver disease, while others do not. Conversely, meta-analyses have found an association between occult HBV infection (a component of the isolated anti-HBc pattern) and advanced liver disease and hepatocellular carcinoma in HIV-uninfected individuals. In HIV-uninfected individuals with anti-HBc positivity, HBV reactivation has been reported in patients receiving HCV therapy. This phenomenon is likely the result of disinhibition of HBV with HCV eradication.

Summary

In HIV-infected patients, the long-term liver outcomes associated with the isolated anti-HBc pattern remain to be fully elucidated, supporting the need for large cohort studies with longitudinal follow-up. HBV reactivation during HCV DAA therapy has been well-described in HIV-uninfected cohorts and can inform algorithms for the screening and management of the isolated anti-HBc pattern in this population.

     

Detection of the 70-Kilodalton Histoplasma capsulatum Antigen in Serum of Histoplasmosis Patients: Correlation between Antigenemia and Therapy during Follow-Up

Histoplasmosis is an important systemic fungal infection, particularly among immunocompromised individuals, who may develop a progressive disseminated form which is often fatal if it is untreated. In such patients, the detection of antibody responses for both diagnosis and follow-up may be of limited use, whereas the detection of Histoplasma capsulatum var. capsulatum antigens may provide a more practical approach. We have recently described an inhibition enzyme-linked immunosorbent assay (ELISA) for the detection in patients’ sera of a 69- to 70-kDa H. capsulatum var. capsulatum-specific antigen which appears to be useful in diagnosis. To investigate its potential for the follow-up of histoplasmosis patients during treatment, antigen titers in the sera of 16 patients presenting with different clinical forms of histoplasmosis were monitored at regular intervals for up to 80 weeks. Sera from four of five patients with the acute form of the disease showed rapid falls in antigenemia, becoming antigen negative by week 14 (range, weeks 10 to 16). Sera from four patients with disseminated histoplasmosis showed falls in antigen levels; three of them became antigen negative by week 32; the fourth patient became negative by week 48. In contrast, antigen titers in four of six AIDS patients with the disseminated form of the disease remained positive throughout follow-up. Sera from only one patient who presented with the chronic form of the disease were analyzed, and this individual’s serum became antigen negative by week 9. The inhibition ELISA is shown to be of particular use in the monitoring of non-AIDS patients with the acute and disseminated forms of the disease and may complement existing means of follow-up.     

慢乙肝中度患者的甲状腺指标变化及其相关性分析

目的 探讨慢乙肝中度患者的甲状腺指标(TSH、FT3、TT3、FT4、TT4)水平变化及其相互关系.方法 收集在本院2014年下半年住院的慢乙肝中度患者34例、慢乙肝轻度患者30例及30例正常体检者,检测血清的TSH、FT3、TT3、FT4、TT4,并进行统计分析.结果 (1)3组间的甲状腺指标相互比较,差异有统计学意义(P＜0.05).(2)组间两两比较,FT3和FT4差异有统计学意义(P＜0.05).(3)TSH与FT3呈直线负相关(r=-0.370,P=0.031),与TT4呈直线正相关(r=4.735,P=0.000).FT3与TT3呈直线正相关(r=0.613,P=0.000).FT4与TT4呈直线正相关(r=0.499,P=0.003).结论 甲状腺激素指标在评价慢乙肝中度患者的肝功能损害有重要的临床意义.     

Long-Term Outcomes of an Australian Universal Prevention Trial of Anxiety and Depression Symptoms in Children and Youth: An Evaluation of the Friends Program

This study evaluated the long-term effectiveness of the FRIENDS Program in reducing anxiety and depression in a sample of children from Grade 6 and Grade 9 in comparison to a control condition. Longitudinal data for Lock and Barrett's (2003) universal prevention trial is presented, along with data from 12-month follow-up to 24- and 36-month follow-up. Results of this study indicate that intervention reductions in anxiety reported in Lock and Barrett were maintained for students in Grade 6, with the intervention group reporting significantly lower ratings of anxiety at long-term follow-up. A significant Time × Intervention Group × Gender Effect on Anxiety was found, with girls in the intervention group reporting significantly lower anxiety at 12-month and 24-month follow-up but not at 36-month follow-up in comparison to the control condition. Results demonstrated a prevention effect with significantly fewer high-risk students at 36-month follow-up in the intervention condition than in the control condition. Results are discussed within the context of prevention research.     

Low-Level Viremia and Intracellular Expression of Hepatitis B Surface Antigen (HBsAg) in HBsAg Carriers with Concurrent Hepatitis C Virus Infection

Assays of hepatitis B virus (HBV) replication and antigen expression in HBV surface antigen (HBsAg) carriers with concurrent hepatitis C or D virus (HCV or HDV) infection revealed that HCV and HDV can suppress HBV replication but that HCV also substantially suppresses HBV surface protein expression. HBsAg carriers with concurrent HCV infection thus have low-level viremia and intracellular HBsAg.     

Precore Stop Mutant in HBeAg-Positive Patients with Chronic Hepatitis B: Clinical Characteristics and Correlation with the Course of HBeAg-to-Anti-HBe Seroconversion

This study aimed to investigate the ratios of precore stop mutant (codon 28; TGG to TAG) to total viremia in 53 HBeAg-positive patients with chronic hepatitis B by amplification-created restriction site assays along the course of HBeAg-to-anti-HBe seroconversion. At baseline, 11% had exclusive wild-type hepatitis B virus (HBV), 15% had exclusively precore mutant, and 74% had mixed viral strains. Precore mutant ratios correlated little with age, sex, or HBV DNA levels (all P > 0.1), but correlated modestly with alanine aminotransferase (ALT) levels (P = 0.05). The intervals from presentation to anti-HBe seroconversion correlated significantly with ALT and precore mutant ratios in univariate analysis but with only precore mutant ratios in multivariate analysis (P = 0.003). Precore mutant ratios at baseline were significantly higher (P < 0.001) in six patients with persistent high viremia and ALT elevation after anti-HBe seroconversion (group 1) than in 47 with remission (group 2). All group 1 patients had exclusive precore mutant after anti-HBe seroconversion, as did only 14 (30%) of the group 2 patients (P = 0.003). Among group 2 patients, precore mutant ratios at baseline or after anti-HBe seroconversion showed no significant difference between 34 patients with sustained remission and 13 with relapse. Cirrhosis developed in 50% (5 of 10) of patients with precore mutant ratios >50% at baseline but only in 12% (5 of 43) of those with precore mutant ratios of <50% at baseline (P < 0.05). In conclusion, precore mutant of variable ratios was frequently detected in HBeAg-positive patients with chronic hepatitis B. Precore mutant ratios tended to correlate with ALT levels and anti-HBe seroconversion, but high precore mutant ratios were associated with persistent hepatitis after anti-HBe seroconversion and increased risk of cirrhosis.     

Relationship between Plasma Interleukin-12 (IL-12) and IL-18 Levels and Severe Malarial Anemia in an Area of Holoendemicity in Western Kenya

In this study, we investigated whether levels of interleukin-12 (IL-12) and IL-18 in plasma are associated with severe malarial anemia outcomes in an area of holoendemicity in western Kenya. We compared plasma IL-12 and IL-18 levels in six groups of children grouped into the categories aparasitemic, asymptomatic, mild malaria, high-density uncomplicated malaria (UC), moderate malarial anemia (MMA), or severe malarial anemia (SMA). IL-12 levels were significantly reduced in children with SMA (P < 0.05) but not in other groups compared to children in the aparasitemic control group. IL-18, a cytokine known to be critical for the induction of gamma interferon along with IL-12, was produced more frequently (70%) in children with UC (P = 0.06) than in children in the aparasitemic control group (32%). However, in the SMA group the IL-18 response rate declined to 30%, which was similar to that in the aparasitemic control group, which showed a 32% response rate. This finding suggests that the IL-18 response may be impaired in children with SMA. In summary, the results from this study support the hypothesis that impairment of IL-12 and/or IL-18 response may contribute to the development of severe malarial anemia in areas of holoendemicity for malaria.     

Humoral and Cellular Responses to a Single Dose of Fendrix in Renal Transplant Recipients with Non‐response to Previous Hepatitis B Vaccination

Approximately 70% of kidney transplant recipients are non‐responders to conventional hepatitis B virus (HBV) vaccines. We examined whether Fendrix™, an HBV vaccine containing 3‐O‐desacyl‐4′‐monophosphoryl lipid A (MPL) as adjuvant, could induce HBV immunity in these patients and compared their vaccination efficacy with healthy controls tested previously by the same assays. We selected 35 kidney transplant recipients who had been vaccinated at least thrice against HBV but had never displayed anti‐HBs antibodies. We re‐assessed their anti‐HBs antibody titres and further determined cellular HBV immunity by proliferation assay and interferon (IFN)‐γ ELISpot. Seventeen recipients did neither display humoral nor cellular immunity and could be tested prior to and at month 1 after vaccination. Of note, HLA antigens associated with non‐response to HBV vaccination (HLA‐DRB1*03 and HLA‐DQB1*02) were over‐represented in these 17 recipients. At month 1 after a single vaccination with Fendrix™, we observed a significant increase in anti‐HBs antibodies (P = 0.02). In seven of 17 recipients, we detected anti‐HBs antibodies ≥10 IU/l (10–264), in four HBV‐specific lymphocyte proliferation (stimulation index of 2.6–8.7) and in one specific IFN‐γ responses (12 spots increment). The vaccination response to Fendrix™ was significantly higher (P = 0.035) than the response to HBVaxPro™ in young healthy controls. In summary, the results show that a single vaccination with Fendrix^™ could already induce HBV‐specific humoral and/or cellular responses in ten of 17 kidney transplant patients. Thus, Fendrix™ appears as an efficient vaccine in this patient cohort.     

Correlation between activity in neuron B52 and two features of fictive feeding in Aplysia

Intracerebroventricular administration of N-acetyl-L-aspartyl-L-glutamate (NAAG), an agonist at group II metabotropic and NR1/NR2D-containing N-methyl-D-aspartate (NMDA) ionotropic glutamate receptors, increased the permeability of the blood-brain barrier (BBB) to serum albumin in the striatum, but produced no similar effects in the entorhinal cortex or in the hippocampal formation. Electron microscopy showed that NAAG, but not its hydrolytic products L-glutamate and N-acetyl-L-aspartate, increased the number of transport vesicles in the hippocampal endothelial cells. Furthermore, immunocytochemistry detected NR2D subunits on hippocampal capillaries. Consequently, NAAG may have influenced the vesicular transport via NMDA receptors. There was, however, no correlation with the regional pattern of BBB changes (increased permeability in the striatum) that, in turn, could not be directly related to the NAAG-induced neurodegeneration described previously in the hippocampus where no significant changes in BBB permeability were detected.