[Show abstract][Hide abstract] ABSTRACT: The participation of laboratories in external quality assessment (EQA) programs is required for the quality assurance of nucleic acid amplification of Chlamydia trachomatis. This study aimed to construct a new quality control (QC) material applicated in EQA of C. trachomatis PCR.
Annals of Laboratory Medicine 09/2014; 34(5):360-6. · 1.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
This study aimed at analyzing the prevalence of hepatitis B virus (HBV) DNA among hepatitis B surface antigen (HBsAg)–negative donations by cobas TaqScreen MPX test (Roche Molecular Systems) and discussing the meaning of a reactive minipool (MP) that does not resolve to an individual donation (ID)–reactive result.Study Design and Methods
Nucleic acid amplification testing (NAT) was performed in 12 Chinese blood centers on 826,044 serologic negative donations in MPs of six. MP-reactive pools that were resolved to ID-reactive donations were confirmed by Roche TaqMan viral load assays. Antibody to hepatitis B surface antigen and antibody to hepatitis B core antigen (anti-HBc) results were also analyzed. Cycle threshold (Ct) values of reactive MPs were analyzed in relation to the probability of pool resolution.ResultsA total of 1267 of 137,674 pools were reactive, of which 839 donations were reactive by ID-NAT. The MP6 HBV NAT–yield rate lay between 1 in 1600 and 1 in 1000. At MP Ct values equal or below 37, the probability of pool resolution was approximately 80%. The prevalence of anti-HBc in ID-reactive donations was 81%. The proportion of reactive pools that could not be resolved was 36%. The prevalence of anti-HBc in donations implicated in nonresolved MPs was significantly higher than those in nonreactive MPs (48% vs. 37%, p = 0.016).Conclusion
The anti-HBc data suggest that approximately 10% of nonresolved MPs contain HBV DNA from a low-viral-load occult carrier. We consider ID-NAT resolution testing in duplicate to minimize HBV transmission risk associated with transfusing nonreactive donations implicated in reactive MPs.
[Show abstract][Hide abstract] ABSTRACT: Abstract Background: Laboratory testing for KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) mutations in metastatic colorectal cancer (mCRC) is performed by various methods in China, but there is no standardized system for proficiency testing or assay performance evaluations. The aim of this study was to evaluate assay and laboratory performance with artificial samples derived from formalin-fixed, paraffin-embedded (FFPE) cell lines. Methods: Artificial FFPE samples were prepared from cultured cell lines to construct a proficiency panel of 10 samples covering eight KRAS mutations and two wild-type samples. The samples were validated by Sanger sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The panel was distributed to participating laboratories and their reported results were compared to the reference sequences. Results: The percentages of mutant KRAS alleles in each mutant sample were more than 50% by MALDI-TOF-MS. Sixty-three laboratories reported results, including 41 hospital laboratories and 22 commercial laboratories and reagent manufacturers. Only 55.6% (35/63) of the laboratories correctly identified the mutations in all samples and 33.3% (21/63) reported at least one false-positive result. The false-positive ratio was 7.1% (45/630) and the false-negative ratio was 3.0% (15/504). Conclusions: KRAS mutations can be missed even by the most sensitive methods if the procedures are not performed correctly. False-positive results are a substantial problem in KRAS testing; laboratories must use sufficient negative controls to identify cross-contamination from PCR-amplified products or between samples during handling and DNA extraction.
Clinical chemistry and laboratory medicine : CCLM / FESCC. 06/2014;
[Show abstract][Hide abstract] ABSTRACT: Context: As a new antibody concept, natural bispecific antibodies (nBsAbs) have been detected in long-term passive immunization and some diseases, but their potential immunomodulatory role remains unclear. Hashimoto thyroiditis (HT) appears to fulfill the condition for nBsAb production but has not yet been characterized. Objective: To identify a new nBsAb against thyroid peroxidase (TPO) and thyroglobulin (Tg) in HT patients and to preliminarily explore its immunomodulatory role. Design, Setting, Patients: Serum samples were obtained from 136 HT patients, 92 diseased controls and 99 healthy controls for anti-TPO/Tg nBsAb detection. The relationship between anti-TPO/Tg nBsAb and other clinical parameters was also analyzed. Main Outcome Measures: The anti-TPO/Tg nBsAb was detected using a double-antigen sandwich enzyme-linked immunosorbent assay. Higher nBsAb levels were found to be associated with decreased inflammation in HT patients. Results: The prevalence of anti-TPO/Tg nBsAb in HT was 44.9% (61/136), significantly higher than that of diseased controls (2.2%, 2/92) (p < 0.0001) and healthy controls (0%, 0/99) (p < 0.0001). HT patients who were nBsAb-positive were prone to have significantly lower levels of serum C-reactive protein and tumor necrosis factor alpha compared to the nBsAb-negative individuals (p < 0.05). The serum amyloid A and interferon gamma levels also showed a similar trend in the two groups. The IgG subclass of anti-TPO/Tg nBsAb was IgG4. Further analysis showed a negative correlation between anti-TPO/Tg nBsAb and serum total IgG4 (r = -0.697, p = 0.025) in IgG4 thyroiditis patients. Conclusions: A new type of nBsAb against TPO and Tg in HT patients is identified. Our data also indicate a protective effect of anti-TPO/Tg nBsAb in the pathogenesis of HT and extend prior knowledge about nBsAb in diseases.
The Journal of clinical endocrinology and metabolism. 06/2014;
[Show abstract][Hide abstract] ABSTRACT: An external quality assessment (EQA) program for molecular detection of avian influenza A (H7N9) virus was implemented by National Center for Clinical Laboratory (NCCL) of China during June 2013. Virus-like particles (VLPs) that containing full length RNA sequences of hemagglutinin (HA), neuraminidase (NA), matrix protein (MP) and nucleoprotein (NP) genes from the H7N9 virus (armored RNAs) were constructed. The EQA panel comprising 6 samples with different concentrations of armored RNAs positive for H7N9 viruses and four H7N9-negative samples (including one sample positive only for MP gene of the H7N9 virus) was distributed to 79 laboratories in China that carry out molecular diagnosis of H7N9 viruses. The overall performances of data sets were classified according to the results of both H7 and N9. Consequently, 80 data sets were received (one participant provided two sets of results), which were generated using commercial (n = 60) or in-house (n = 17) real-time RT-PCR (qRT-PCR) kits and commercial assay employed isothermal amplification method (n =3). The results revealed that the majority (82.5%) of data sets correctly identified "H7N9 virus" while 17.5% of the data sets need to improve their diagnostic capability. The "improvable" data sets were derived mostly from false-negative results of N9 at relatively low concentrations. The false-negative rate was 5.6% and the false-positive rate was 0.6%. In addition, we observed varied diagnostic capabilities between different commercially available kits and in-house developed assays, with assay manufactured by BioPerfectus Technologies (Jiangsu, China) performing better than others did. Overall, the majority of laboratories have reliable diagnostic capacity.
Journal of clinical microbiology 10/2013; · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Prostate cancer (PCa) is the most diagnosed cancer in the western male population with high mortality. Recently, alternative approaches based on immunotherapy including mRNA vaccines for PCa have shown therapeutic promise. However, for mRNA vaccine, several disadvantages such as the instability of mRNA, the high cost of gold particles, the limited production scale for mRNA-transfected dendritic cells in vitro, limit their development. Herein, recombinant bacteriophage MS2 virus-like particles (VLPs), which based on the interaction of a 19-nucleotide RNA aptamer and the coat protein of bacteriophage MS2, successfully addressed these questions, in which target mRNA was packaged by MS2 capsid. MS2 VLP-based mRNA vaccines were easily prepared by recombinant protein technology, nontoxic and RNase-resistant. We show the packaged mRNA was translated into protein as early as 12 hr after phagocytosed by macrophages. Moreover, MS2 VLP-based mRNA vaccines induced strong humoral and cellular immune responses, especially antigen-specific cytotoxic T-lymphocyte (CTL) and balanced Th1/Th2 responses without upregulation of CD4(+) regulatory T cells, and protected C57BL/6 mice against PCa completely. As a therapeutic vaccine, MS2 VLP-based mRNA vaccines delayed tumor growth. Our results provide proof of concept on the efficacy and safety of MS2 VLP-based mRNA vaccine, which provides a new delivery approach for mRNA vaccine and implies important clinical value for the prevention and therapy of PCa.
International Journal of Cancer 09/2013; · 6.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Remarkable progress has been made in the quality assurance of Hepatitis B virus (HBV) DNA nucleic amplification techniques (NAT) during the past decade. And this report presents a 10-y external quality assessment (EQA) program performed by National Center for Clinical Laboratories in China since 2003.
EQA panels were produced using freeze-dried HBV plasma or negative controls and then calibrated against the first International Standard for HBV DNA.
By 2012, total 35,570 qualitative EQA reports and 56,826 quantitative reports have been collected. The overall correct recognition rate in qualitative test increased from 95.15% in 2003 to 97.99% in 2012. The proportion of participants with acceptable quantitative results also rose to 87.99% in 2012 compared with that of 27.53% in 2003. Besides, we observed a satisfactory reproducibility of <5% in all parallel samples. However, some laboratories still had difficulties in exact quantification of some low viral loads, which near to the limits of the dynamic range of the assays.
Taking together, current EQA program showed an encouraging improvement of HBV DNA NAT in China. Distributing more challenging samples and increasing the subtypes are still needed in the future.
Clinica chimica acta; international journal of clinical chemistry 08/2013; · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Local overexpression of tumor necrosis factors alpha (TNF-α) is critically involved in the inflammatory response and tissue destruction of rheumatoid arthritis (RA). Currently, the blockade of TNF-α by passive immunotherapy is indeed efficacious in the treatment of RA, but it still present some disadvantages. Induction of high level of anti-TNF-α neutralizing autoantibodies by TNF-α autovaccine has been developed to avoid these shortcomings. This review is to briefly introduce several vaccination approaches that have been used to induce a B cell response, including coupled TNF-α (entire/peptide) with a carrier protein, modified TNF-α with foreign Th cell epitopes, and engineered DNA vaccine. These methods showed remarkable therapeutic efficiency in experimental animals which indicated that active TNF-α immunization would be a promising and cost-effective new treatment option for RA.
[Show abstract][Hide abstract] ABSTRACT: Background: In China, various assays for human papillomavirus (HPV) genotyping are currently used for cervical cancer screening. However, a proficiency test system is not available for standardizing and evaluating assay performance. The aim of this study was to evaluate the performance of clinical laboratories for their ability to discriminate 9 HPV types with the proficiency panel. Methods: The panel of 24 samples included cloned genomic DNAs for HPV types 6, 11, 16, 18, 31, 33, 39, 51 and 52 at different concentrations, which were distributed to 76 clinical laboratories. Results reported by participants were compared with the reference results. Results: The samples containing 10(6) IU HPV-16/ml and 10(6) IU HPV-18/ml were (98.7 and 96.0%, respectively) identified correctly most often. For other high-risk HPV types, about 90% of data sets correctly identified samples containing 10(6) GE/ml of HPV-6, HPV-31, HPV-33 and HPV-52, while HPV-51, HPV-11 and HPV-39 in 10(6) GE/ml were correctly identified by only 42.7, 55.6 and 21.3% of laboratories, respectively. Conclusion: Our proficiency test system provided a traceable panel and showed that the differences in performance between laboratories were high, indicating that it is necessary for the laboratories to improve their operation and standardization of HPV genotyping.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Food allergy has been reported increasingly around the world during the past several decades. Epstein-Barr virus (EBV), a common herpesvirus with high infection rate, is now suspected to be a risk or protective factor in food allergy. The aim of the study was to investigate the possible role of EBV infection in IgE-mediated food allergy. METHODS: 34 patients with an egg allergy and 34 healthy controls participated in this study. Egg allergy was confirmed by open-food challenge. Serum anti-viral capsid antigen (VCA), anti-Epstein-Barr nuclear antigen 1 (EBNA-1) IgG and egg specific (yolk and white)-IgE levels were evaluated by enzyme linked immunosorbent assay (ELISA). At the same time, EBV DNA as well as viral miRNAs in these samples was quantified by real-time PCR. RESULTS: The results showed that serum anti EBNA-1 IgG and two viral miRNAs (miR-BART1-5p and miR-BART7) were highly expressed in patients with egg allergy compared with healthy controls (p < 0.05, < 0.001 and < 0.01, respectively). Moreover, the expressions of anti EBNA-1 specific IgG, miR-BART1-5p and miR-BART7 positively correlated with the level of egg-specific IgE (p < 0.05, < 0.01 and < 0.01, respectively). The differences in anti VCA IgG concentration and EBV DNA copy number between the allergy patients and control individuals were not statistically significant. CONCLUSIONS: The high expression of EBV-specific antibody and miRNAs indicated that EBV infection might play a promoting role in IgE-mediated egg food allergy, and viral miRNAs-related immunomodulatory pathway was likely involved in this allergy process.
[Show abstract][Hide abstract] ABSTRACT: Abstract During the past few years there has been great interest in the development of circulating microRNAs (miRNAs) as stable blood-based biomarkers for cancer detection. Deregulation of miRNAs in blood samples has shown considerable clinical utilities in cancers. Due to poorly characterized preanalytical and analytical variables and the lack of a standardized measurement protocol, the application of these miRNA fingerprints is hindered by conflicting results. In this review, we outline our current understanding of preanalytically and analytically confounding factors. We believe that great consideration should be taken in the development of circulating miRNA as tumor biomarkers.
Clinical Chemistry and Laboratory Medicine 09/2012; · 3.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Since the discovery of xenotropic murine leukemia virus-related virus (XMRV) in 2006, one of the most controversial topics is whether it contributes to the pathogenesis of prostate cancer (PCa) and/or chronic fatigue syndrome (CFS). The debate began with the failure to detect XMRV in clinical PCa samples. Concerns about the potential health risk of XMRV exposure were reinforced by a study demonstrating the presence of XMRV in patients with CFS. However, serious concerns on whether XMRV plays a role in the development of PCa and/or CFS have been raised. However, inconsistent reports linking XMRV with PCa and/or CFS have led to conflicting views about the potential of XMRV as a human pathogen. Several recent studies suggest that contamination could account for the positive correlations between XMRV and PCa and/or CFS to date. At present, evidence does not indicate that XMRV plays any role in the pathogenesis of PCa or CFS.
Virus Research 04/2012; 167(1):1-7. · 2.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recently, microRNA (miRNA)-mediated RNA interference has been developed as a useful tool in gene function analysis and gene therapy. A major obstacle in miRNA-mediated RNAi is cellular delivery, which requires an efficient and flexible delivery system. The self-assembly of the MS2 bacteriophage capsids has been used to develop virus-like particles (VLPs) for RNA and drug delivery. However, MS2 VLP-mediated miRNA delivery has not yet been reported. We therefore used an Escherichia coli expression system to produce the pre-miR 146a contained MS2 VLPs, and then conjugated these particles with HIV-1 Tat(47-57) peptide. The conjugated MS2 VLPs effectively transferred the packaged pre-miR146a RNA into various cells and tissues, with 0.92-14.76-fold higher expression of miR-146a in vitro and about two-fold higher expression in vivo, and subsequently suppressed its targeting gene. These findings suggest that MS2 VLPs can be used as a novel vehicle in miRNA delivery systems, and may have applications in gene therapy.
[Show abstract][Hide abstract] ABSTRACT: One major impediment to improving the management of breast cancer is the current lack of tumor marker with sufficient sensitivity and specificity. A growing body of evidence implicates the diagnostic potential of circulating miRNAs in cancer detection. MiR-155 plays an important role in the pathogenesis of breast cancer. However, the level of circulating miR-155 and its clinical relevance are not well established. The objective of the current study was to learn more about serum miR-155 in patients with breast cancer.
Using quantitative reverse transcription polymerase chain reaction (RT-qPCR), we demonstrated that serum miR-155 had significant increased levels in breast cancer patients (n = 103) compared with healthy subjects (n = 55) (p<0.001), which had a mean fold change of 2.94. Receiver operating characteristic (ROC) analysis revealed that miR-155 had considerable diagnostic accuracy, yielding an ROC-AUC (the areas under the ROC curve) of 0.801 (sensitivity 65.0%, specificity 81.8%). In addition, sera from a subset of breast cancer patients (n = 29) were collected after surgery and after four cycles of chemotherapy to evaluate the effects of clinical treatment on serum levels of candidate miRNAs. Surprisingly, a decreased level of serum miR-155 was found; whereas the concentrations of carbohydrate antigen 15-3 (CA15-3), carcinoembryonic antigen (CEA) and tissue polypeptide specific antigen (TPS) did not show this trend. Our results revealed that 79% patients showed response or stable disease after therapy had declined levels of serum miR-155.
Our results suggest that serum miR-155 is a potential biomarker to discriminate breast cancer patients from healthy subjects. For the first time, we demonstrated a declined trend of miR-155 after surgery and chemotherapy, which raises the possibility to use it as an indicator for treatment response.
PLoS ONE 01/2012; 7(10):e47003. · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aptamers are artificial oligonucleotides (DNA or RNA) selected in vitro that bind a broad range of targets with high affinity and specificity; a sensitive yet simple method to utilize aptamers as recognition elements for the development of biosensors (aptasensors) is to transduce the signal electrochemically. So far, aptasensors have been applied to clinical diagnostics and several technologies are in development. Aptasensors will extend the limits of current clinical diagnostics. Although the potential diagnostic applications are unlimited, the most current applications are foreseen in the areas of biomarker detection, cancer clinical testing, detection of infectious microorganisms and viruses. This review attempts to list examples of the research progresses of aptamers in biosensor platforms that have been published in recent years; in particular, we display cases of aptasensors that are already incorporated in clinical diagnostics or have potential applications in clinical diagnostics.
[Show abstract][Hide abstract] ABSTRACT: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the presence of pathogenic autoantibodies. Recent studies suggest that microRNAs (miRNAs) play an essential role in immunoregulation and may be involved in the pathogenesis of SLE. Therefore, it was of interest to investigate the potential therapeutic application of miRNAs in SLE, a concept that has not been thoroughly investigated thus far. Virus-like particles (VLPs) are a type of recombinant nanoparticle enveloped by certain proteins derived from the outer coat of a virus. Herein, we describe a novel miRNA-delivery approach via bacteriophage MS2 VLPs and investigate the therapeutic effects of miR-146a, a well-studied and SLE-related miRNA, in BXSB lupus-prone mice.
VLPs containing miR-146a, and the control VLPs, were prepared using an Escherichia coli expression system and then administered to lupus-prone mice over a 12-day period. We performed an enzyme-linked immunosorbent assay to evaluate the anti-dsDNA antibody, autoantibody to nuclear antigen (ANA), total IgG and total IgM levels in serum. The expression of miR-146a was analyzed by qRT-PCR. SLE-related cytokines as well as some toll-like receptor signaling pathway molecules were also measured.
Treatment with MS2-miR146a VLP showed profound effects on lupus-prone BXSB mice, including an increased level of mature miR-146a, which led to a significant reduction in the expression of autoantibodies and total IgG. Remarkably, these mice also exhibited reduced levels of proinflammatorycytokines, including IFN-Interferon-α (IFN-α), Interleukin-1β (Il-1β) and Interleukin-6 (Il-6). Moreover, we showed that the toll-like receptor pathway was involved in this regulation.
Restoring the loss of miR-146a was effective in eliminating the production of autoantibodies and ameliorating SLE progression in lupus-prone mice. Thus, the induction of dysregulated miRNAs by an MS2 VLP-based delivery system may lead to novel therapies.
International Journal of Nanomedicine 01/2012; 7:5957-67. · 4.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The scope of our understanding of the evolutionary history between viruses and animals is limited. The fact that the recent availability of many complete insect virus genomes and vertebrate genomes as well as the ability to screen these sequences makes it possible to gain a new perspective insight into the evolutionary interaction between insect viruses and vertebrates. This study is to determine the possibility of existence of sequence identity between the genomes of insect viruses and vertebrates, attempt to explain this phenomenon in term of genetic mobile element, and try to investigate the evolutionary relationship between these short regions of identity among these species.
Some of studied insect viruses contain variable numbers of short regions of sequence identity to the genomes of vertebrate with nucleotide sequence length from 28 bp to 124 bp. They are found to locate in multiple sites of the vertebrate genomes. The ontology of animal genes with identical regions involves in several processes including chromatin remodeling, regulation of apoptosis, signaling pathway, nerve system development and some enzyme-like catalysis. Phylogenetic analysis reveals that at least some short regions of sequence identity in the genomes of vertebrate are derived the ancestral of insect viruses.
Short regions of sequence identity were found in the vertebrates and insect viruses. These sequences played an important role not only in the long-term evolution of vertebrates, but also in promotion of insect virus. This typical win-win strategy may come from natural selection.