scholarly journals External Quality Assessment for Detection of Fetal Trisomy 21, 18, and 13 by Massively Parallel Sequencing in Clinical Laboratories

2016 ◽  
Vol 18 (2) ◽  
pp. 244-252 ◽  
Author(s):  
Rui Zhang ◽  
Hongyun Zhang ◽  
Yulong Li ◽  
Yanxi Han ◽  
Jiehong Xie ◽  
...  
Author(s):  
Jin-Sook Wang ◽  
Mee-Kyung Kee ◽  
Byeong-Sun Choi ◽  
Chan-Wha Kim ◽  
Hyon-Suk Kim ◽  
...  

AbstractThe external quality assessment schemes (EQAS) organizer provides a suitable program to monitor and improve the quality of human immunodeficiency virus (HIV) testing laboratories with EQAS panels prepared under various conditions. The aim of the current study was to investigate the effects of human plasma samples on the EQAS results of HIV obtained from hospital-based clinical laboratories.From 2007 to 2009, HIV EQAS panels consisted of four to six samples that consisted of undiluted positive and negative samples and were provided to laboratories twice per year. Up until the first half EQAS in 2008, EQAS panel materials were obtained by converting acid citrate dextrose treated plasma to serum via chemical treatment with CaClApproximately 300 HIV clinical laboratories participated in this program. The overall performance of clinical laboratories was shown to be improved when using unrecalcified plasma panels compared with recalcified panels. Significant differences were observed in EIA analyses of plasma for both positive (p<0.001) and negative (p<0.001) samples between the recalcified and unrecalcified groups.Our finding suggested that defibrination status of EQAS panels might affect the results of anti-HIV EQAS of Korean HIV testing laboratories.


2010 ◽  
Vol 56 (3) ◽  
pp. 459-463 ◽  
Author(s):  
Rossa WK Chiu ◽  
Hao Sun ◽  
Ranjit Akolekar ◽  
Christopher Clouser ◽  
Clarence Lee ◽  
...  

Abstract Background: Noninvasive prenatal diagnosis of trisomy 21 (T21) has recently been shown to be achievable by massively parallel sequencing of maternal plasma on a sequencing-by-synthesis platform. The quantification of several other human chromosomes, including chromosomes 18 and 13, has been shown to be less precise, however, with quantitative biases related to the chromosomal GC content. Methods: Maternal plasma DNA from 10 euploid and 5 T21 pregnancies was sequenced with a sequencing-by-ligation approach. We calculated the genomic representations (GRs) of sequenced reads from each chromosome and their associated measurement CVs and compared the GRs of chromosome 21 (chr21) for the euploid and T21 pregnancies. Results: We obtained a median of 12 × 106 unique reads (21% of the total reads) per sample. The GRs deviated from those expected for some chromosomes but in a manner different from that previously reported for the sequencing-by-synthesis approach. Measurements of the GRs for chromosomes 18 and 13 were less precise than for chr21. z Scores of the GR of chr21 were increased in the T21 pregnancies, compared with the euploid pregnancies. Conclusions: Massively parallel sequencing-by-ligation of maternal plasma DNA was effective in identifying T21 fetuses noninvasively. The quantitative biases observed among the GRs of certain chromosomes were more likely based on analytical factors than biological factors. Further research is needed to enhance the precision for measuring for the representations of chromosomes 18 and 13.


2019 ◽  
Vol 57 (6) ◽  
pp. 812-821 ◽  
Author(s):  
Min Duan ◽  
Fengfeng Kang ◽  
Haijian Zhao ◽  
Wei Wang ◽  
Yuxuan Du ◽  
...  

Abstract Background This study aimed to comprehensively evaluate laboratory quality in China and explore factors affecting laboratory errors through analyzing the external quality assessment (EQA) results of quality indicators (QIs). Methods According to model 3 (interpretive) of the proficiency testing scheme, the National Center for Clinical Laboratories of China (CNCCL) developed a questionnaire for 15 QIs. Clinical laboratories from different provinces of China participated in the EQA program of QIs annually and submitted data via an online reporting system named Clinet-EQA. The results of QIs were expressed in percentage and sigma value or minute. Three levels of quality specifications (QSs) were defined based on percentile values. Furthermore, the QIs were analyzed by disciplines, hospital scales and information construction levels of participant laboratories. Results A total of 3450 laboratories nationwide continuously attended the EQA program and submitted complete data from 2015 to 2018. The performance of most QIs has improved year by year. QIs in post-analytical gained the best performance with sigma values that varied from 5.3σ to 6.0σ. The comparison of results among different disciplines showed significant differences for five QIs. More than half of QIs had statistical differences among different hospital scales measured by hospital grades and number of hospital beds. The performance of nine QIs were influenced by information construction levels of participant laboratories. Conclusions The overall laboratory quality in China has improved since the initiation of EQA program for QIs, but the performance of some QIs was still unsatisfactory. Therefore, laboratories should make efforts for continuous quality improvement based on information provided by QSs.


2017 ◽  
Vol 63 (4) ◽  
pp. 861-869 ◽  
Author(s):  
Chenming Xu ◽  
Ting Wang ◽  
Chao Liu ◽  
Hong Li ◽  
Xiaoyan Chen ◽  
...  

Abstract BACKGROUND Noninvasive prenatal screening (NIPS) using plasma cell-free DNA has gained tremendous popularity in the clinical assessment of fetal aneuploidy. Most, if not all, of these tests rely on complex and expensive massively parallel sequencing (MPS) techniques, hindering the use of NIPS as a common screening procedure. METHODS We have developed and optimized an MPS-independent noninvasive genetic test that can rapidly detect fetal aneuploidy at considerably lower costs. We used the high-throughput ligation-dependent probe amplification (HLPA) assay with standard z score statistics to identify the minute copy number change of targeted chromosomal regions. HLPA was modified from multiplex ligation-dependent probe amplification to allow quantification of up to 200 genomic loci in a single multiplex PCR. As a proof of principle, we conducted Down syndrome screening in 1182 women with singleton pregnancies [maternal age (SD): 32.7 (4.6)] using whole-genome sequencing-based NIPS and our method. RESULTS Nineteen fetuses with trisomy 21 were detected by both methods and confirmed by karyotyping of amniotic fluid. Overall, our method showed 100.0% sensitivity (19/19) and 99.7% specificity (1076/1079) in trisomy 21 screening, generating a positive predictive value of 86.4% (19/22) and a 7.1% (84/1182) no-call rate. CONCLUSIONS Our technique potentially opens new avenues for the development of inexpensive, yet effective, prenatal aneuploidy tests. The simplicity and accuracy of this method make it a good candidate for clinical implementation as a standard screening procedure.


2018 ◽  
Vol 56 (10) ◽  
pp. 1644-1654 ◽  
Author(s):  
Laura Sciacovelli ◽  
Sandra Secchiero ◽  
Andrea Padoan ◽  
Mario Plebani

Abstract Effective management of clinical laboratories participating in external quality assessment schemes (EQAS) is of fundamental importance in ensuring reliable analytical results. The International Standard ISO 15189:2012 requires participation in interlaboratory comparison [e.g. external quality assessment (EQA)] for all tests provided by an individual laboratory. If EQAS is not commercially available, alternative approaches should be identified, although clinical laboratories may find it challenging to choose the EQAS that comply with the international standards and approved guidelines. Great competence is therefore required, as well as knowledge of the characteristics and key elements affecting the reliability of an EQAS, and the analytical quality specifications stated in approved documents. Another skill of fundamental importance is the ability to identify an alternative approach when the available EQAS are inadequate or missing. Yet the choice of the right EQA program alone does not guarantee its effectiveness. In fact, the fundamental steps of analysis of the information provided in EQA reports and the ability to identify improvement actions to be undertaken call for the involvement of all laboratory staff playing a role in the specific activity. The aim of this paper was to describe the critical aspects that EQA providers and laboratory professionals should control in order to guarantee effective EQAS management and compliance with ISO 15189 accreditation requirements.


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