BACKGROUND: Serological prenatal screening tests are widely used to detect fetal chromosomal abnormalities such as Down and Edward syndromes. After determining the presence of fetal cell-free DNA in maternal blood, the non-invasive prenatal test (NIPT) coupled with next-generation sequencing has been performed in other countries, therefore, we developed a domestic NIPT technology. METHODS: The results of genomics-based NIPT performed between April and May, 2015 were analyzed. Maternal blood samples were collected in a specific Cell-Free DNA BCT tube. The samples were then massively sequenced using MiSeq and NextSeq 500 (Illumina Inc., USA) using LabGenomics laboratory-developed libraries. Chromosomal abnormalities were analyzed using a bioinfomatics algorithm. RESULTS: A total of 464 cases were analyzed. The samples of 12 subjects had to be collected again because of a low fetal DNA fraction in the initially obtained samples. Among the 456 cases for which fetal genome results were obtained, 436 had a low risk of trisomy, 12 had a high risk for Down syndrome, two had a high risk for Edward syndrome, and four had sex chromosomal aneuploidy, showing that the positive percentage of chromosomal abnormalities was 4.4%. All 12 cases with high risk for Down syndrome were confirmed as having trisomy 21 by amniocentesis. CONCLUSIONS: Our laboratory-developed genomics-based NIPT showed high positive predictive value, therefore, NIPT may be replaced by our own developed method.
Amniocentesis ; Aneuploidy ; Chromosome Aberrations ; DNA ; Down Syndrome ; Genome ; Prenatal Diagnosis ; Trisomy

BACKGROUND: Acinetobacter baumannii causes various hospital-acquired infections, its multidrug resistance is rapidly increasing worldwide. Although colistin is used in treatments against multidrug-resistant A. baumannii, resistance to colistin has also been reported recently. Few studies have reported colistin susceptibility testing using MicroScan. In this study, we compared colistin susceptibility tests for resistant A. baumannii by MicroScan (Siemens, USA) and Etest (BioMerieux, France). METHODS: We collected 115 A. baumannii clinical isolates, showing colistin resistance (minimum inhibitory concentration [MIC] > or =4 microg/mL) by MicroScan, from July 2014 to March 2015 at Kangdong Sacred Heart Hospital. Species identification and antimicrobial susceptibility tests were performed using the MicroScan Neg Combo Panel Type 72. Additionally, Etest was also performed for comparison. RESULTS: Of the 115 isolates, Etest revealed that 103 (89.6%) were colistin-susceptible (MIC < or =I microg/mL). Moreover, 52 isolates, showing a MIC of 4 microg/mL by MicroScan, were all susceptible to colistin. Only 12 (19.0%) of 63 isolates, showing a MIC of >4 microg/mL by MicroScan were resistant to colistin according to the Etest. CONCLUSIONS: The MicroScan automated system, using the commercial broth microdilution method, exhibited some discrepancies with the Etest for colistin susceptibility in A. baumannii. Therefore, more practical and reliable susceptibility tests for colistin are required in clinical laboratories using MicroScan.
Acinetobacter baumannii* ; Acinetobacter* ; Colistin* ; Drug Resistance, Multiple ; Heart ; Microbial Sensitivity Tests

In 2014, two external quality assessment trials were performed on 13 test items grouped in four categories. The laboratories procured the materials for the first and second trials on 13 May 2014 and 11 November 2014, respectively. The trials were performed on 13 test items, including tumour markers, thyroid hormones, cardiac marker troponin (troponin T or troponin I), and procalcitonin as a new biomarker for immunoassay methods. The bone marker carboxy-terminal collagen crosslinks (CTX) has been replaced by procalcitonin this year because only a limited number of institutions used it. External quality surveys of the 13 immunoassay test items with 8 control materials were performed as scheduled. The 13 control materials included six tumour markers, alpha-fetoprotein, carcinoembryonic antigen, carcinoma antigen 125, carbohydrate antigen 19-9, human chorionic gonadotrophin, and prostate specific antigen, as well as five thyroid markers, thyroid hormone 3 (T3), T4, thyroid stimulating hormone, free T4, and thyroglobulin. This year, procalcitonin has been introduced as a new biomarker in addition to troponin, which was introduced last year. Five homemade pooled sera and three commercial control sera were used as survey materials. The MAS Tri-point Liquimmune level 3 (Medical Analysis Systems Inc., USA) was used for controls of thyroid hormones, while Elecsys PreciControl Varia and Elecsys PreciControl Troponin (Roche, Germany) were used for controls of the new biomarkers procalcitonin and troponin, respectively. In the external quality assessment by the Immunoassay Subcommittee, 712 institutions participated in the first trial survey (response rate 97.9%), while 715 participated in the second survey (response rate 97.9%). The quality of the participating laboratories seems to be continuously improving compared to the results of their peers. Additionally, this year procalcitonin has been introduced as a new biomarker instead of the CTX, which was used in 2013, while thyroglobulin and troponin-T/troponin-I, which were used for the 2013 samples, continue to be used in surveys by the Immunoassay Subcommittee.
alpha-Fetoproteins ; Biomarkers ; Carcinoembryonic Antigen ; Chorion ; Collagen ; Humans ; Immunoassay* ; Korea* ; Prostate-Specific Antigen ; Thyroglobulin ; Thyroid Gland ; Thyroid Hormones ; Thyrotropin ; Troponin

In 2014, external quality assessment trials for urinalysis and faecal occult blood (FOB) were performed of 1,270 participants. Urine chemistry and FOB tests were evaluated three times, while urine sediment examination by photography was evaluated one time. Urine chemistry tests consisted of pH, protein, glucose, ketone, bilirubin, blood, urobilinogen, nitrite, leukocyte, and specific gravity (SG). The urine chemistry test results showed accuracy rates >95%, while those of the SG test by using a refractometer had accuracy rates <95%. In the FOB quality test, the Bio Focus reagent (BIO FOCUS Co., Korea) disclosed low positive rates (87%). The result of the FOB quantity test showed different values according to the instruments used, and the Kyowa instrument (Kyowa Chemical Industry Co., Japan) revealed the lowest values. In a urinary sediment examination, it is necessary to increase the frequency of the quality assessment trials due to low accuracy rates.
Bilirubin ; Chemical Industry ; Chemistry ; Glucose ; Hydrogen-Ion Concentration ; Korea* ; Leukocytes ; Occult Blood* ; Photography ; Specific Gravity ; Urinalysis* ; Urobilinogen

Annual proficiency surveys were performed in March, June and September 2014 by clinical microbiology division of The Korean Association of Quality Assurance for Clinical Laboratory. Parasitology part has been newly incorporated in this survey. For each trial, three sets which were composed of different combinations of five bacteria and yeast were distributed for gram stain, culture, identification, and antimicrobial susceptibility tests of general bacteriology and five fixed sputum smear on slides were distributed for acid fast bacilli stain. Two advanced bacteriology survey materials for culture and identification of anaerobic bacteria and mold were distributed to the voluntary participants in every trial and five mycobacterial culture and identification specimens, five anti-tuberculosis susceptibility testing specimens, and two Mycobacterium tuberculosis strains for rapid detection of rifampin and isoniazid resistance were distributed to the voluntary participants in March and June trials. Five virtual microscopic slides for stool parasite examination were open for the registered participants in June trial. A total of 340 laboratories were enrolled and 330 (97.0%), 331 (97.4%), and 331 (97.4%) returned the results on trial I, II, and III, respectively. For bacterial identification, the percent acceptable identification of Burkholderia cepacia, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae, Streptococcus agalactiae, Plesiomonas shigelloides, and Enterococcus faecalis were greater than 95%. Group C and group D Salmonella species challenged as the different sets of M1422 resulted in the acceptable rate lower than 95% because nine participants reported the identification of different sets. Surveillance cultures for methicillin-resistant S. aureus and vancomycin-resistant enterococci were correctly determined by 89.6% and 69.0% of the respondents, respectively. Correct identification to species level of Candida albicans, Candida auris, Candida glabrata, and Candida parapsilosis were 86.1%, 1.6%, 48.1%, and 83.8%. Vancomycin disk diffusion test in S. aureus, missing oxacillin screen or penicillin susceptibility test in S. pneumoniae and lack of reliable methods of quinolone resistance detection in Salmonella species caused unacceptable results in antimicrobial susceptibility testing. Advanced bacteriology trials revealed low performance in species identification of mold. Mycobacterial culture, identification and susceptibility test performance was kept in excellence. The performance of identification of stool parasites was acceptable >90% for detection of helminth eggs and amebic cysts but 28.6% false positive responses resulted from negative specimens. In conclusion, species-level identification of fungi of both candida species and mold were challenging to clinical microbiology laboratories. Vancomycin disk diffusion method for S. aureus and lack of proper penicillin susceptibility test for S. pneumoniae were still common cause of inaccurate results. Virtual microscopic survey has been successfully introduced in parasitology.
Bacteria ; Bacteria, Anaerobic ; Bacteriology ; Burkholderia cepacia ; Candida ; Candida albicans ; Candida glabrata ; Surveys and Questionnaires ; Diffusion ; Eggs ; Enterococcus faecalis ; Fungi ; Helminths ; Isoniazid ; Klebsiella pneumoniae ; Korea* ; Methicillin Resistance ; Mycobacterium tuberculosis ; Ovum ; Oxacillin ; Parasites ; Parasitology ; Penicillins ; Plesiomonas ; Pneumonia ; Pseudomonas aeruginosa ; Rifampin ; Salmonella ; Sputum ; Staphylococcus aureus ; Streptococcus agalactiae ; Streptococcus pneumoniae ; Streptococcus pyogenes ; Vancomycin ; Yeasts

BACKGROUND: The aim of the study was to develop an accurate, convenient, and easy microplate system for the identification of enterococcal species from clinical specimens. METHODS: The microplate identification method was composed of twelve biochemical tests and identification programs. The tests comprised in microplate were initially screened by a two-tube method, NaCl-esculin hydrolysis and pyrrolidonyl-beta-naphthylamide test; arginine dihydrolase, acid production from mannitol, sorbitol, sucrose, arabinose, raffinose, methyl-alpha-D-glucopyranoside, and ribose in the microplate; and pigment production and hemolytic pattern in blood agar plate. The performance of the microplate for identifying enterococci to the species level was evaluated in comparison with conventional reference tests and commercial kits. RESULTS: Among the 111 clinical isolates of Enterococcus species, the microplate system correctly identified 100% to genus level, and 91.0% to species level. All of E. casseliflavus, E. durans, and E. hirae were correctly identified by the microplate. The diagnostic sensitivity and specificity for identification of Enterococcus species were as follows: 100% and 96.7% in E. faecium, 93.5% and 100% in E. faecalis, 100% and 97.2% in E. raffinosus, and 33.3% and 98.1% in both E. avium and E. gallinarum. CONCLUSIONS: It is concluded that the microplate method offers a simple, cost-effective, rapid, and accurate identification system for the identification of most clinical isolates of Enterococcus species.
Agar ; Arabinose ; Arginine ; Enterococcus* ; Hydrolysis ; Mannitol ; Raffinose ; Ribose ; Sensitivity and Specificity ; Sorbitol ; Sucrose

BACKGROUND: Enterococcus faecium (E. faecium) is potential pathogens of mixed infections for which a broad-spectrum antimicrobial agents such as imipenem has a therapeutic role. But controversy continues concerning testing imipenem versus enterococci. The purpose of this study were 1) to investigate the ability of penicillin and ampicillin minimum inhibitory concentration (MIC) to predict in vitro susceptibility of E. faecium versus imipenem. and 2) to compare MICs of ampicillin, penicillin and imipenem by the Vitek system with those by agar dilution method. METHODS: Fifty-two isolates of E. faecium between April 2002 and May 2002 were tested. Each isolate was tested versus penicillin, ampicillin and imipenem. MICs were determined by Vitek system and agar dilution method according to NCCLS guidelines. Imipenem MIC determinations were repeated by E-test. RESULTS: MIC of Vitek system tends to be lower than that of agar dilution method, but there was good concordance between MICs of penicillin and ampicillin by Vitek system and agar dilution method. But for imipenem, the MICs by the agar dilution method did not correspond with the Vitek results. Of the 52 E. faecium isolates tested, in vitro activity of penicillin and ampicillin accurately predicts that of imipenem. CONCLUSIONS: MICs of ampicillin and penicillin are reliable, but imipenem MIC is not reliable for E. faecium by Vitek system. In vitro activity of penicillin and ampicillin versus E. faecium accurately predicts that of imipenem.
Agar ; Ampicillin ; Anti-Infective Agents ; Coinfection ; Enterococcus faecium* ; Enterococcus* ; Imipenem* ; Microbial Sensitivity Tests ; Penicillins

Chronic myelogenous leukaemia (CML) is a myeloproliferative neoplasm that is almost always characterised by the presence of t(9;22)(q34;q11.2). Approximately 5% to 10% of CML patients lack cytogenetic evidence of t(9;22)(q34;q11.2) but have the breakpoint cluster region (BCR)/ABL1 fusion, as revealed by fl uorescence in situ hybridisation (FISH) or the reverse transcription-polymerase chain reaction (RT-PCR). We present a case of Philadelphia-negative CML with a cryptic insertion of BCR at 9q34. A 22-year-old woman incidentally presented with marked leucocytosis and anaemia. Her complete blood count results were as follows: white blood cells, 238.61x10(9)/L; haemoglobin, 9.6 g/dL; platelets, 395x10(9)/L. A peripheral blood smear showed leucocytosis with neutrophilia, basophilia, left-shifted neutrophils, and circulating blasts comprising 2% of the total leucocytes. The bone marrow showed a striking increase in megakaryocytes and granulocytic precursors. The myeloid/erythroid ratio was 7.4:1, and blasts comprised up to 1.8% of all nucleated cells. Bone marrow sections revealed active megakaryopoiesis and granulopoiesis with 100% cellularity. Chromosomal analysis revealed a normal karyotype. However, interphase FISH using a dual-colour BCR/ABL1 fusion probe showed an atypical pattern consisting of one red, two green, and one fusion (1R2G1F) signal in 97.5% of the 200 analysed cells. Metaphase FISH revealed a single BCR/ABL1 fusion signal on chromosome 9. RT-PCR was positive for BCR/ABL1 (b3a2). Quantitative PCR revealed a normalised copy number of 15.32. The patient started her treatment with imatinib, reached a complete molecular response eight months afterwards, and has been coping well without any adverse events.
Blood Cell Count ; Bone Marrow ; Chromosomes, Human, Pair 9 ; Cytogenetics ; Female ; Humans ; Interphase ; Karyotype ; Leukocytes ; Megakaryocytes ; Metaphase ; Neutrophils ; Polymerase Chain Reaction ; Strikes, Employee ; Young Adult ; Imatinib Mesylate

BACKGROUND: The e602, a module of the recently released cobas 8000 modular analyzer series, is an automated system for immunoassays. In this study, we evaluated its analytical performance using 17 immunoassay analytes. METHODS: The Clinical Laboratory Standards Institute guidelines were used to determine the efficiency of the cobas 8000 e602 based on its precision, linearity, assay comparison, and reference range validation. Performance analyses were completed using two levels of quality control materials and pooled sera from our institution. The performance of the cobas 8000 e602 was compared to that of the modular analytics E170. Statistical analyses were performed using Excel 2010 (Microsoft Co., USA) and EP Evaluator Release 10 (Data Innovations, USA). RESULTS: For all analytes, except level 1 total vitamin D, the coefficients of variation were <5%. The linearity results were within the allowable systemic error limits. The performance comparison revealed that the two systems are comparable, with correlation coefficients (r) >0.975 for all analytes. The reference range validation was also within the allowable criteria. CONCLUSIONS: Taken together, these findings demonstrate that the cobas 8000 e602 analyzer has good precision, linearity, performance comparison, and reference range validation. Thus, e602 is a useful module of the cobas 8000 modular analyzer series.
Immunoassay ; Quality Control ; Reference Values ; Vitamin D

BACKGROUND: The proficiency testing (PT) program for HbA1c, performed by the Korean Association of External Quality Assessment Service (KAEQAS), first started in 2007. From 2007 to 2008, the results were assessed using means as the standard within a peer group (identical method group). However, the assessment method changed to accuracy-based PT in 2009. This study aimed to analyse the results of an external quality assessment of HbA1c from 2009 to 2014. METHODS: Based on the data obtained from the external quality assessment of HbA1c from 2009 to 2014, we analysed the number of participating institutions, response rate, 'unacceptable' result rate, bias from the target value, and CVs according to each instrument code. RESULTS: The number of participating institutions was only 180 in 2009. However, it increased over the next 5 years, and as of 2014, 345 institutions were enrolled. The response rates were 93.8% to 99.1%. Since 2009, the measurement method changed and most of the participating institutions now use the high-performance liquid chromatography (HPLC) method. As of 2014, the HPLC method showed small bias from the target value and inter-laboratory CVs (<3.5%), demonstrating satisfactory performance. Immunoassays and point-of-care testing (POCT) demonstrated relatively unsatisfactory performance, showing larger inter-laboratory CVs compared to those obtained with the HPLC method, with some of them exceeding the acceptance limit of +/-8% of the target value. CONCLUSIONS: As of 2014, relatively large-scale laboratories are participating in the accuracy-based PT for HbA1c. According to the accuracy-based PT for HbA1c, POCT showed the highest 'unacceptable' rate and imprecision. Therefore, small-scale laboratories mostly using POCT for HbA1c measurement should be encouraged to participate in the accuracy-based PT program for HbA1c, and the external quality assessment program undertaken by KAEQAS should be expanded.
Bias (Epidemiology) ; Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Hemoglobin A, Glycosylated ; Immunoassay ; Korea ; Laboratory Proficiency Testing ; Peer Group