树状DNA杂交技术在HCV检测中的应用

目的：建立一种敏感性,特异性,重复性较好的,适同原体群体筛查的检验方法。方法：通过RT－PCR－DDH,RT－nested-PCR和HCV RNA－DDH3种方法检测HCV核酸,推断RT－PCR－DDH技术检测病毒核酸的特异性,敏感性和稳定性。结果：47份ELISA检测HCV抗体阳性血清标本,RT－nested-PCR检出阳性标本33例（70．21％）,RT－PCR－DDH检出阳性标本39例（82．98％）,结论：RT－PCR－DDH技术在逆转录病毒核酸检测的应用中具有较好的特异性,敏感性和稳定性,而且成本较低,操作安全简便,适于中小实验室和基层医院病原微生物的检测。     

Direct detection of circulating hepatitis C virus RNA using probes from the 5'' untranslated region.

Diagnostic testing for hepatitis C virus (HCV) infection currently is based on the presence of anti-HCV antibodies or a positive HCV RNA polymerase chain reaction (PCR) test. Although HCV RNA PCR is a sensitive and specific technique, widespread application is limited. Moreover, HCV RNA PCR is subject to false-positive reactions through contamination and is inherently difficult to standardize and quantitate. To overcome limitations of HCV RNA PCR, we produced both cDNA and riboprobes from a 241 nucleotide sequence of the 5' untranslated region of the HCV genome for slot hybridization. Hybridization was absent using normal human serum, horse serum, or hepatic cellular RNA from noninfected liver. Hybridization occurred predominantly with positive-stranded HCV RNA and was abolished by pretreatment with RNase A. Slot hybridization was performed on serum samples from 60 patients with chronic HCV infection and a positive HCV RNA PCR and 20 patients with liver diseases unrelated to HCV who had a negative HCV RNA PCR. Slot hybridization with cDNA and riboprobes showed concordance with HCV RNA PCR of 95 and 98.3%, respectively. There were no false-positive reactions in controls. The sensitivity of riboprobe hybridization was comparable to that of one stage HCV RNA PCR using 5' untranslated region primers. Riboprobe hybridization with the HCV H strain standard was positive in the dilution corresponding to 10(-6) chimpanzee infectious doses50/ml. The density of the hybridization signals correlated significantly with the mass of an RNA standard extracted from the liver of a patient with HCV infection. The relative quantities of HCV RNA in the sera of selected patients varied and were not correlated with the duration of disease or the histopathological stage. The highest relative quantities were associated with concurrent immunosuppression. We conclude that slot hybridization is a sensitive, specific alternative to HCV RNA PCR that can be directly quantitated using appropriate HCV RNA standards.     

New approaches to in vitro diagnosis of hepatitis C infection a reason for post transfusion hepatitis: Diagnostic value of determination of hepatitis C virus core antigen

In between the dates of February 2008–March 2009, by applying to Istanbul University CTF Microbiology and Clinical Microbiology Basic Sciences Branch and Duzen laboratories, 123 cases, where HCV RNA and anti-HCV positivity are identified with molecular (real-time PCR) and serologic (ELISA) methods as a positive control group, and 48 cases where HCV RNA and anti-HCV negativity are identified as a negative control group are established. The values of sensitivity, specificity, positive and negative approximation of recently developed HCV Core Ag (Abbott Diagnostics, Germany) kit are determined successively as 94.3%, 97.9%, 99.1%, 87%, 95.3% and 88%. Although the new HCV Ag assay is clearly not sensitive enough to replace HCV NAT it may serve as a valuable tool in the HCV diagnostic algorithm as it is able to pick up a great majority of anti-HCV and HCV RNA positive samples, thus allowing a timely and less expensive serological diagnosis of an active HCV infection. This may be an advantage for labs that do not have access to PCR easily.     

丙型病毒性肝炎与性传播关系的临床研究

目的　研究丙型病毒性肝炎与性传播的关系。方法　应用逆转录巢式聚合酶链反应 (RT PCR)检测丙型病毒性肝炎患者、性病患者精液以及阴道分泌物中HCVRNA。应用ELISA法检测其配偶的抗 HCV ,并与正常健康夫妇 18对作对照观察。结果　① 3 3例男性丙型病毒性肝炎患者精液中HCVRNA阳性 6例 (18 18% ) ,2 5例女性丙型病毒性肝炎患者阴道分泌物中HCVRNA阳性 9例 (3 6 0 % )。② 6例男性丙型病毒性肝炎患者精液HCVRNA阳性者配偶抗 HCV阳性1例 (16 67% ) ,9例女性丙型病毒性肝炎患者阴道分泌物HCVRNA阳性者配偶抗 HCV阳性 7例 (77 78% )。③ 72例性病患者生殖道分泌物HCVRNA阳性 4例 (5 5 % )。④对照组配偶抗 HCV均为阴性。结论　①丙型病毒性肝炎患者精液、阴道分泌物中可检出HCVRNA ,丙型病毒性肝炎病毒存在性传播的可能性。②女性丙型病毒性肝炎患者性传播丙型病毒性肝炎病毒可能性比男性丙型病毒性肝炎患者要大。③性乱人群通过性接触感染丙型病毒性肝炎病毒的可能性高于正常人群     

铕标记基因探针半定量检测丙型肝炎病毒RNA

目的 利用自行设计的引物、探针和新型铕螯合物BHHCT,建立一种半定量丙型肝炎病毒(HCV)RNA的检测方法。方法 收集44份丙型肝炎病人血清,20份正常人血清。利用中山大学达安基因有限公司RNA提取试剂提取HCV RNA,用自行设计的引物进行逆转录聚合酶链反应(RT-PCR)。扩增产物cDNA与微孔板上的捕捉探针杂交后,借助于其上游引物5′端带有的生物素,与标记有铕的链霉亲合素特异性结合,将铕连接到微孔板上,在特定波长激发光激发下,发出荧光,进行检测。结果 铕标记HCV RNA检测法的线性范围为102-106cDNA拷贝,敏感性、特异性均为100％。结论 铕标记RT-PCR检测HCV RNA法的线性范围宽,敏感性、特异性好,检测时间短,无放射性污染,有推广应用的价值。     

Clinical performance of the new rRoche COBAS TaqMan HCV Test and High Pure System for extraction, detection and quantitation of HCV RNA in plasma and serum

We evaluated the Roche COBAS TaqMan HCV Test For Use With The High Pure System (TaqMan HPS; Roche Diagnostics), for the extraction, detection and quantitation of hepatitis C virus (HCV) RNA in serum or plasma of HCV-infected individuals. The TaqMan HPS is a real-time PCR assay with a reported linear dynamic range of 3.0x10(1) to 2.0x10(8) HCV RNA IU/ml, and a reported lower limit of detection (LLD) of 10 IU/ml. Calculation of the HCV RNA titre is based upon an external standard curve in the presence of an internal control. Intra-assay and inter-assay variation were small in reference panel members with HCV RNA > or =100 IU/ml. Genotype performance and quantitative correlation between the TaqMan HPS and the bDNA (VERSANT HCV 3.0 assay; Bayer Diagnostics), assessed in 59 patient samples, were good for HCV genotype 1 but poor for genotypes 2, 3 and 4. For genotypes 2, 3 and 4, values obtained from the TaqMan HPS were in general 0.5 log lower than those from the bDNA. Sensitivity was poor in low viral titre samples of genotypes 1, 2, 3 and 4. The LLD (95%) was estimated at 41 HCV RNA IU/ml for genotype 4. The TaqMan HPS underestimates HCV RNA at all levels in plasma and serum from HCV-infected individuals, and the LLD should be reconsidered. This is clinically relevant because underestimation of HCV RNA levels during therapy may lead physicians into making incorrect treatment decisions.     

HCV-RNA与HCV-cAg检测的相关性分析

目的探讨丙型肝炎病毒核心抗原(HCV-cAg)与HCV-RNA检测的相关性及其在丙型肝炎病毒感染诊断中的价值。方法采用双抗体夹心酶联免疫分析法(ELISA)检测HCV-cAg;采用实时荧光定量PCR法检测HCV-RNA,以了解两者检测方法的相关性。结果在160例HCV-RNA阳性血清中,HCV-cAg阳性148例,阳性符合率92.5%;在60例HCV-cAg阳性血清中,HCV-RNA阳性59例,阳性符合率98.3%。结论通过对HCV-RNA与HCV-cAg检测,说明HCV核心抗原与HCV-RNA检测可作为反映HCV复制的间接指标,预防窗口期感染。由于HCV-cAg在方法学上与HCV-RNA相比,具有方法简便、快速、价廉,所需设备简单,易于普及应用等优点,特别是在不具备HCV-RNA检测条件的基层医疗单位作为HCV感染检测的直接证据具有重要的意义。     

High-throughput HBV DNA and HCV RNA detection system using a nucleic acid purification robot and real-time detection PCR: its application to analysis of posttransfusion hepatitis

BACKGROUND: A high-throughput detection system was developed for HBV DNA and HCV RNA. METHODS: A combination of real-time detection PCR using an automated system (PRISM 7700, PE Biosystems, Foster City, CA) and automatic viral nucleic acid extraction (BioRobot 9604, Qiagen, Hilden, Germany) was used as the high-throughput detection system. An internal control for HBV DNA detection was also developed. RESULTS: Testing of 96 samples for HBV and HCV was completed within 5 hours. The sensitivity of this system almost equals that of the manual method using nested PCR. The addition of an internal control for HBV detection did not affect the sensitivity of the method and confirmed the accuracy of results. It was possible to quantify HBV in HBV+ samples that contain more than 500 genome equivalents per mL. We started using this system from June 1999 for testing stored donor and patient samples to analyze cases of posttransfusion hepatitis and identified three HBV+ donations that were implicated in posttransfusion hepatitis B. CONCLUSION: The high-throughput detection system is a useful tool for HBV DNA and HCV RNA detection because it enables rapid and reliable testing of a large number of samples.     

Incidence of hepatitis C virus RNA in anti-HCV negative plasma pools in Croatia.

The risks of transmitting viral infection by blood and products derived from plasma have long been known and still remain an area of concern. Blood banks and transfusion centres are faced with the imminent introduction of nucleic acid amplification testing (NAT) of plasma pools as used by the plasma industry. In this paper, we show a part of our results of a validation study of an in-house method for routine polymerase chain reaction (PCR) screening for hepatitis C virus (HCV) RNA in plasma pools and the results of testing 2,718 anti-HCV negative plasma pools for the presence of HCV RNA. The European Committee for Proprietary Medical Products (CPMP) recommended that from 1 July 1999, only batches derived from plasma pools tested and found non-reactive for HCV RNA, using validated test methods of suitable sensitivity and specificity, should be batch released by authorities. The quality and efficiency of NAT detection of HCV RNA is among others influenced by the efficacy of RNA isolation, the primer selection and the use of control samples. Using modern molecular biology techniques (sensitive and specific in-house amplification methods for detection of HCV RNA and automated sequencing), we analysed samples of plasma pools from different Croatian transfusion centres. By detection of HCV RNA in an NIBSC working reagent (genotype 3) and a Pelispy HCV RNA run control (genotype 1) we determined a high reproducibility and sensitivity (below 100 International Units (IU)/ml) for our in-house method. By direct sequencing PCR cDNAs we proved the specificity of the test system and the possibility of determining the HCV genotype when the method was used for PCR screening of HCV RNA in single donations. Of 2,718 anti-HCV negative plasma pools we have found that 2.1$ were HCV RNA positive. Results of our investigation confirm the necessity of testing HCV RNA in plasma pools to further increase the safety of human plasma-derived drugs.     

High frequency of HCV infection in individuals with isolated antibody to hepatitis B core antigen

Although isolated antibody to hepatitis B core antigen (anti-HBc) is frequently nonspecific or may be the only serological marker of past self-limiting hepatitis B, where antibodies against the surface antigen have disappeared, isolated anti-HBc seropositivity is frequently associated with chronic hepatitis B in HIV- and HCV-infected individuals. Of 5,520 samples that tested positive for anti-HBc (IMx and AxSYM CORE, Abbott, Delkenheim, Germany) at the Institute of Virology, University Clinic Frankfurt during the time interval from January 1994 to February 1996, 643 (11.6%) were isolated anti-HBc-reactive in the IMx and AxSYM CORE assays (inhibition values >90%). There was a statistically significant association between isolated anti-HBc seropositivity and HCV and HIV/HCV coinfection (p < 0.05). A total of 190 samples were available for further testing. Six (3.2%) of 190 isolated anti-HBc-positive samples were considered false-positive since they were only positive in the AxSYM or IMx CORE assay and a linear decrease of the measured signal could not be observed in dilution series. Of 184 serum samples tested with nested PCR using primers of the S genome region, only 6 (3.3%) were HBV DNA-positive. Anti-HBc-IgM antibody could be detected in 3 (1.6 %) of the tested samples using the IMx CORE-M. With the more sensitive VIDAS HBc IgM specific IgM antibody was detected in 15 (8.5%) of 177 samples at concentrations ranging from 10 to >200 Paul Ehrlich Institute U/ml. HIV or HCV coinfection was present in 28.1% and 37.5% of isolated anti-HBc-positive individuals, respectively. We conclude from our observations that only a limited proportion of anti-HBc-isolated individuals are potentially infectious, however anti-HBc-IgM which is detectable in any form of liver disease associated with HBV infection was present in more than 8% of the individuals. Of isolated anti-HBc-positive sera 37% were positive for anti-HCV, suggesting that anti-HCV antibody testing should be performed in isolated anti-HBc-positive individuals.     

Polymerase chain reaction detection of Pneumocystis jiroveci: evaluation of 9 assays

Various polymerase chain reaction (PCR) amplification strategies have been described for detecting Pneumocystis jiroveci in clinical specimens. Different combinations of primer/target and platforms have been reported to yield varying PCR detection rates. PCR was evaluated on clinical specimens using internal transcribed spacer regions of the rRNA nested, dihydropteroate synthase single and nested, dihydrofolate reductase nested, major surface glycoprotein heminested, mitochondrial large subunit rRNA (mtLSUrRNA) single and nested, 18S rRNA 1-tube nested, and real-time 5S rRNA PCR. The most sensitive PCR was subsequently compared with routine diagnostic immunofluorescence (IF) microscopy. Discrepant PCR and IF results were resolved after review of clinical and histology/cytology records. Major discrepancies were observed among the methods investigated. mtLSUrRNA nested PCR was the most sensitive, produced less false-negative results, and displayed the highest degree of concordance with histology. Direct comparison of mtLSUrRNA nested PCR versus IF yielded low sensitivity and specificity, which were improved for PCR and lowered for IF on review of clinical and laboratory records.     

Routine HCV PCR screening of blood donations to identify early HCV infection in blood donors lacking antibodies to HCV

BACKGROUND: Detection of early hepatitis C infection of blood donors is still a major problem for blood transfusion. Common anti-HCV screening assays show differences in sensitivity and specificity. The often mild symptoms of acute hepatitis C also cause difficulties in the identification of early HCV infection. The feasibility and efficacy of routine screening of blood donations for HCV RNA were investigated. STUDY DESIGN AND METHODS: Blood donations (n = 251,737) were screened for HCV RNA over 4 years. RNA extraction, amplification, and detection were done by two commercial HCV PCR kits (HCV Cobas Amplicor and HCV Cobas Amplicor 2.0, Roche Diagnostics). Screening was done by pool testing with a maximum pool size of 40 serum samples. RESULTS: Three donations out of 251,737 were HCV RNA positive and anti-HCV negative. ALT levels of these donations were 271, 32, and 10 U per L. The HCV infection of a fourth HCV RNA-positive donor could not be identified by routine, second-generation HCV EIA (Abbott Diagnostika). In this case, two previous donations were also HCV RNA positive, and three second-generation test systems (Abbott) could not detect anti-HCV, whereas third-generation anti-HCV screening assays detected antibody with different sensitivity. The first HCV RNA-positive donation was identified only by the HCV ELISA 3.0 (Ortho Diagnostic Systems). The results of confirmatory assays like RIBA HCV 3.0 (Ortho) and Matrix (Abbott) indicate a restricted immune response to NS3 only. CONCLUSION: HCV RNA detection by PCR can be carried out routinely in blood donor screening without significant delay of release of the components. The residual risk of transmission can be reduced by identification of early infection, which can lead to an improved safety of blood components. RNA screening can also be advantageous in cases of incomplete or lack of antibody response to HCV.     

逆转录套式聚合酶链反应检测庚型肝炎病毒

目的建立敏感、特异的逆转录套式聚合酶链反应（ＲＴ－ｎｅｓｔｅｄ－ＰＣＲ）方法，以检测中国人庚型肝炎病毒（ＨＧＶ）感染。方法根据中国人感染ＨＧＶ者ＮＳ５区部分核苷酸序列分析结果，设计套式ＰＣＲ引物，用于ＨＧＶＲＮＡ的检测，并与用国外报道引物所作的一次ＰＣＲ和套式ＰＣＲ检测结果进行比较。结果共检测标本１３３份。以国外报道引物作一次ＰＣＲ和套式ＰＣＲ检出率分别为８．３％和１１．３％，作者建立的套式ＰＣＲ检出率为１８．０％，对部分ＰＣＲ产物进行序列分析证实为ＨＧＶ特异性基因。结论建立的方法可在中国人群中显著提高ＨＧＶＲＮＡ检出率。     

Hepatitis C virus RNA testing by nested PCR in blood preparations in Yugoslavia

Patients receiving any kind of human blood preparations are in permanent danger of any infection including hepatitis C (HCV) infection. Testing for the presence of HCV in blood preparations is one of the steps towards safe medical treatment. One of the approaches for this testing is a detection of HCV nucleic acid. In this paper we describe a simple method for isolation of HCV RNA from blood preparations and control of HCV RNA presence in 19 intravenous and intramuscular products, manufactured in the National Blood Transfusion Institute in Belgrade. RT-PCR was performed according the rules saving RNA. Primers were located in 5' conserved region. Seven out of 19 batches of gamma-globulin, albumin, anti-tetanus and anti-rabies immunoglobulin preparations were found to be HCV RNA positive. For the time being, the PCR method is too expensive for routine HCV RNA testing of hundreds of blood donors per day. Serological screening test of blood donors and nested PCR testing for HCV RNA in blood preparations could be an efficient combination of tests in prevention of posttransfusion hepatitis C.     

Multicenter evaluation of PCR methods for detecting CMV DNA in blood donors

BACKGROUND: CMV DNA screening may be a useful adjunct to serologic tests in distinguishing potentially infectious blood donations from those that are "CMV-safe." However, there is currently no consensus on the optimal assay method for accurate detection of CMV DNA in donors. STUDY DESIGN AND METHODS: A blinded multicenter evaluation of seven CMV PCR assays was performed by five laboratories by using coded sets of analytical controls and donor blood samples. RESULTS: Five assays displayed sufficient sensitivity for donor screening, as judged by consistent detection of a minimum of 25 CMV genome equivalents (geq) in analytical controls constructed to contain from 1 to 100 CMV geq in background DNA from 250,000 cells, while the other two assays displayed inadequate sensitivity. Three sensitive assays, two based on nested PCR directed at the UL93 and UL32 regions of the CMV genome and another test (Monitor Assay, Roche), did not detect CMV DNA in samples from any of 20 pedigreed CMV-seronegative, Western blot-negative (S-/WB-) donors. Two other assays based on nested PCR occasionally detected CMV DNA in S-WB- samples, and one sensitive nested PCR assay directed at UL123 detected CMV DNA in a large proportion (85%) of S-WB- samples. CONCLUSION: Seven CMV PCR assays currently used for research and/or diagnostic applications displayed marked variations in sensitivity, specificity, and reproducibility when applied to coded analytical and clinical control samples containing cellular DNA from the equivalent of 250,000 WBCs. These results will be useful in the selection of assays with performance characteristics appropriate to donor screening objectives. They may also help explain discrepant findings from previous studies that used PCR to determine CMV DNA prevalence in seronegative and seropositive blood donors.     

丙型肝炎患者血清和外周血单个核细胞中HCV RNA检测及意义

目的 了解丙肝患者血清和外周血单个核细胞(PBMC)中HCV RNA存在情况及其临床意义。方法 应用套式PCR检测46例急性丙型肝炎(丙型肝炎以下简称丙肝)和42例慢性丙肝患者血清和PBMC中HCV RNA.结果 慢性丙肝患者PBMC中HCV RNA检出率显著高于急性丙肝患者(P<0.001);急、慢性丙肝患者血清和慢性丙肝患者PBMC中HCV RNA检出率显著高于ALT正常的抗-HCV阳性者(P<0.001);2例患者血清中HCV RNA阴性,PBMC中可测及,12例患者血清抗-HCV阴性,而血清HCV RNA阳性。结论 血清HCV RNA检测有助于抗-HCV阴性丙肝的诊断和早期诊断;丙肝的肝损害可能与HCV RNA血症有关;PBMC中HCV感染在丙肝的慢性化和慢性肝损害中可能起一定作用,PBMC中可贮存HCV RNA。