Assessment of Bone Marrow Involvement in B-Cell non-Hodgkin Lymphoma Using Immunoglobulin Gene Rearrangement Analysis with Next-Generation Sequencing.

BACKGROUND: Assessment of bone marrow involvement (BMI) in non-Hodgkin lymphoma (NHL) is crucial for determining patient prognosis and treatment strategy. We assessed the prognostic value of next-generation sequencing (NGS)-based immunoglobulin (Ig) gene clonality analysis as an ancillary test for BMI evaluation in NHL. METHODS: A retrospective cohort of 124 patients newly diagnosed with B-cell NHL between 2019 and 2022 was included. NGS-based Ig clonality analysis was conducted using LymphoTrak IGH FR1 Assay and IGK Assay (Invivoscribe Technologies, San Diego, CA, USA) on BM aspirate samples, and the results were compared with those of histopathological BMI (hBMI). RESULTS: Among the 124 patients, hBMI was detected in 16.9% (n = 21). The overall agreement of BMI between Ig clonality analyses and histopathological analysis for IGH, IGK, and either IGH or IGK was 86.3%, 92.7%, and 90.3%. The highest positive percent agreement was observed with clonal rearrangements of either IGH or IGK gene (90.5%), while the highest negative percent agreement was observed with clonal rearrangement of IGK gene (96.1%). For the prediction of hBMI, positive prediction value ranged between 59.1% and 80.0% and the negative prediction value ranged between 91.3% and 97.9%. CONCLUSION: NGS-based clonality analysis is an analytic platform with a substantial overall agreement with histopathological analysis. Assessment of both IGH and IGK genes for the clonal rearrangement analysis could be considered for the optimal diagnostic performance of BMI detection in B-cell NHL.

Comparison of three molecular diagnostic assays for SARS-CoV-2 detection: Evaluation of analytical sensitivity and clinical performance.

BACKGROUND: Currently, SARS-CoV-2 RNA detection using real-time reverse-transcription PCR (rRT-PCR) is the standard diagnostic test for COVID-19 infection. Various rRT-PCR assays are currently used worldwide, targeting different genes of the SARS-CoV-2. Here, we compared the analytical sensitivity and clinical performance (sensitivity and specificity) of Allplex SARS-CoV-2/FluA/FluB/RSV assay (Seegene), Standard M nCoV real-time detection kit (SD Biosensor), and U-TOP COVID-19 detection kit (Seasun Biomaterials) for SARS-CoV-2 detection. METHODS: Two hundred and forty-nine nasopharyngeal swab samples were evaluated to compare the clinical performance of the rRT-PCR assays. For the analytical performance evaluation, two RNA controls with known viral loads-SARS-CoV-2 RNA control and SARS-COV-2 B.1.351 RNA control-were used to investigate the potential impact of SARS-CoV-2 variants, particularly the B.1.351 lineage. RESULTS: Limits of detection ranged from 650 to 1300 copies/ml for rRT-PCR assays, and the mean differences in cycle threshold (Ct ) values of the two RNA controls were within 1.0 for each target in the rRT-PCR assays (0.05-0.73), without any prominent Ct value shift or dropouts in the SARS-COV-2 B.1.351 RNA control. Using the consensus criterion as the reference standard, 89 samples were positive, whereas 160 were negative. The overall clinical performance of rRT-PCR assays was comparable (sensitivity 98.88%-100%; specificity 99.38%-100%), whereas the sensitivities of each target gene were more variable. CONCLUSIONS: The three rRT-PCR assays showed comparable analytical sensitivity and clinical performance. The analytical and clinical sensitivities of each target gene were influenced more by the primer and probe design than the target gene itself.

Comparative study of i-SENS glucometers in neonates using capillary blood samples.

OBJECTIVES: The accuracy of point-of-care blood glucometers in the detection and evaluation of neonatal hypoglycemia is a concern. This study compared the performance of three i-SENS glucometers with that of the YSI 2300 STAT Plus Analyzer, which was used as a reference. METHODS: The leftover neonatal capillary blood samples of 319 patients were used in this study. The evaluation process and accuracy performance criteria were based on the International Organization for Standardization 15197:2013 guidelines. The evaluation involved three i-SENS glucometers (BAROzen H Expert plus, CareSens PRO, and CareSens H Beat) and the ACCU-CHEK® Inform II glucometer. RESULTS: The accuracy evaluation yielded acceptable results as follows: a) 100 and 100% for BAROzen H Expert plus; 99.8 and 100% for CareSens PRO; 98.7%, and 97.2% for CareSens H Beat glucometers were within the range of ±0.8 mmol/L (15 mg/dL) and ±15% of the average reference values at glucose concentrations <5.55 mmol/L (100 mg/dL) and ≥5.55 mmol/L (100 mg/dL), respectively, and b) all estimated glucose values (100%) were within the zones A and B of Consensus Error Grid for all three i-SENS glucometers. There was good correlation between the glucose values estimated by the glucometers and the reference values (R>0.990). CONCLUSIONS: This study demonstrated that i-SENS glucometers exhibit acceptable performance and can be used as effective point-of-care devices in neonates.

Comparison of a new enzymatic assay for serum homocysteine on Toshiba TBA-c16000 against an immunoassay on Abbott Architect.

Homocysteine, a risk factor for cardiovascular disease, is commonly analyzed using enzymatic measurements and immunoassays. We compared the results of a new enzymatic assay with those of an immunoassay, using new reagents for homocysteine. The 87 serum samples were analyzed using the Abbott Architect i2000sr (immunoassay) and Toshiba TBA-c16000 (enzymatic assay), and the results obtained from the two assays were compared for precision, correlation, linearity, sample carryover, and reference range verification according to the Clinical and Laboratory Standards Institute guidelines. Repeatability and total imprecision were within the desirable range (Westgard QC, 4.15%). Correlation analysis revealed a strong correlation with a slope ranging from 0.9887 to 1.052, a correlation coefficient (R 2) of 0.9886 [95% confidence interval (CI) of 0.9899-0.9968], and a y-intercept from -0.5741 to 0.6252. Linearity was acceptable (R 2 = 0.9993), and the recovery rate was within ±10% of the expected value. The enzymatic assay showed an acceptable carryover rate (-0.15%) and a shorter turnaround time (10-12 min) compared with that of the immunoassay (30 min). Our new enzymatic assay for the measurement of homocysteine showed an acceptable performance in terms of precision, correlation, linearity, carryover test, cost-effectiveness, and speed.

Performance of ivisen IA-1400, a new point-of-care device with an internal centrifuge system, for the measurement of cardiac troponin I levels.

BACKGROUND: We present the analytical performance of the ivisen IA-1400, a new point-of-care device that features a characteristic built-in centrifuge system, to measure blood cardiac troponin I (cTnI) levels. METHODS: Whole blood and plasma samples obtained from patients who visited Korea University Guro Hospital were used to analyze measurement range, cross-reactivity, interference, and sensitivity and specificity. We performed a correlation analysis of the ivisen IA-1400 versus the Access AccuTnI+3 immunoassay using the UniCel™ DxI 800 platform and the PATHFAST™ hs-cTnI assay. RESULTS: Within-run precisions were classified as low, 9.8%; middle, 10.2%; and high, 8.5%. The limit of blank was 3.1 ng/L for plasma samples and 4.3 ng/L for whole blood samples. The limit of detection was 8.4 ng/L for plasma samples and 10.0 ng/L for whole blood samples, respectively. The limit of quantitation at a coefficient of variation of 20% and 10% was 19.5 ng/L and 45.5 ng/L for plasma samples, respectively. The comparative evaluation between the two other assays and ivisen IA-1400 showed excellent correlation, with Spearman's correlation coefficients (R) of 0.992 and 0.985. The sensitivity and specificity of ivisen IA-1400 using the optimum cut-off value of 235 ug/L were 94.6% and 98.2%, respectively. CONCLUSION: The ivisen IA-1400 showed acceptable and promising performance in cTnI measurements using whole blood and plasma samples, with limited information in the clinical performance. The flexibility for sample selection using the internal centrifugation system is the main advantage of this point-of-care device.

Simultaneous point-of-care testing of blood lipid profile and glucose: Performance evaluation of the GCare Lipid Analyzer.

BACKGROUND: Point-of-care (POC) testing provides quick results and includes tests for blood glucose and lipid profiles. We evaluated the newly developed POC device, the GCare Lipid Analyzer, which is used to measure glucose, total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) levels. METHODS: Venous and capillary blood samples were collected from patients who visited Korea University Guro Hospital. The results obtained using the GCare Lipid Analyzer were compared with those obtained using the TBA 2000FR chemistry analyzer and YSI 2300 STAT Plus analyzer. The glucose system evaluation process was based on the International Organization for Standardization 15197:2013 guidelines. RESULTS: The correlation coefficients (R) for TC, TG, and HDL-C were 0.965, 0.969, and 0.943 in capillary blood and 0.969, 0.990, and 0.956 in venous blood, respectively. The total errors for TC, TG, and HDL-C of the lipid profile using venous blood were all acceptable at 6.6%, 9.3%, and 11.6%, respectively. For glucose concentrations <100 mg/dl, 96.1% of the measured glucose levels were within ±15 mg/dl in venous samples and 100% were within ±15 mg/dl in capillary samples. For glucose concentrations ≥100 mg/dl, 100% and 99.5% of the measured glucose levels were within 15% for venous and capillary blood, respectively. CONCLUSION: The performance of the GCare Lipid Analyzer is acceptable for both blood glucose and lipid profile testing, indicating that it is reliable for use in patients with diabetic dyslipidemia.

Performance of Norudia Glycated Albumin Assay on Multiple Analytical Platforms and Comparison to Lucica Assay.

BACKGROUND: The Norudia glycated albumin (GA) assay was evaluated for analytical performance and assay applicability on multiple analytical platforms. METHODS: The evaluation included precision, linearity, reference interval, and comparison with Lucica GA assay. A multicenter study was conducted to compare the results of Norudia GA assay on five kinds of widely used automated clinical chemistry analyzers. RESULTS: Within-laboratory imprecisions for GA% presented 1.3 - 3.3% and 0.8 - 2.6% for low- and high-level control materials, respectively, on different analyzers. GA assay was linear from 20.0 to 680.0 µmol/L of GA. The claimed reference range (12 - 16 GA%) was verified. Norudia GA showed a good GA% correlation with Lucica GA (correlation coefficient 0.999). GA% from each analyzer showed good correlation with the consensus mean of the results of five analyzers (correlation coefficient 0.997 - 0.999). CONCLUSIONS: The Norudia GA assay can successfully be implemented in all the tested platforms, with good GA% correlation.

Performance evaluation of three i-SENS glucometers using arterial blood samples compared with the YSI 2300 Glucose Analyzer.

BACKGROUND: Capillary blood is the most commonly used sample for point-of-care (POC) glucometers. However, in critically ill patients, the glucose levels measured from capillary blood may not be reliable. Thus, we aimed to evaluate and compare the accuracy of glucose levels measured with POC glucometers and the YSI 2300 glucose analyzer using leftover arterial blood samples. METHODS: In total, 100 leftover heparinized arterial blood samples were used to evaluate the performance of three i-SENS glucometers (BAROzen H Expert plus, CareSens PRO, and CareSens H Beat) and the ACCU-CHEK® Inform II glucometer. The reference value was obtained using the YSI 2300 glucose analyzer. The results were analyzed based on International Organization for Standardization 15197:2013 guidelines. RESULTS: More than 95% of results obtained using POC glucometers were within ±15 mg/dL of the reference value for glucose concentrations <100 mg/dL and within ±15% of the reference value for glucose concentrations ≥100 mg/dL. In the consensus error grid analysis, more than 99% of results were found to be within zones A and B. An excellent correlation was found between the values obtained using POC glucometers and the YSI 2300 glucose analyzer (R2  > .99). CONCLUSION: The i-SENS glucometers showed stable and accurate results when leftover arterial blood samples were used. Therefore, POC glucometers could be useful in critical care settings, such as intensive care units, where arterial samples are routinely used.

Performance Evaluation of RapiSure (EDGC) COVID-19 S1 RBD IgG/Neutralizing Ab Test for the Rapid Detection of SARS-CoV-2 Antibodies.

The accurate detection of anti-neutralizing SARS-CoV-2 antibodies can aid in the understanding of the development of protective immunity against COVID-19. This study evaluated the diagnostic performance of the RapiSure (EDGC) COVID-19 S1 RBD IgG/Neutralizing Ab Test. Using the 90% plaque reduction neutralization test (PRNT90) as a reference, 200 serum samples collected from 78 COVID-19-positive and 122 COVID-19-negative patients were divided into 76 PRNT90-positive and 124 PRNT90-negative groups. The ability of the RapiSure test to detect antibodies was compared to that of the STANDARD Q COVID-19 IgM/IgG Plus test and that of PRNT90. The positive, negative, and overall percent agreement between the RapiSure and STANDARD Q test was 95.7%, 89.3%, and 91.5%, respectively, with a Cohen's kappa of 0.82. The RapiSure neutralizing antibody test results revealed a sensitivity of 93.4% and a specificity of 100% compared to the PRNT results, with an overall percent agreement of 97.5% and Cohen's kappa of 0.95. The diagnostic performance of the RapiSure test was in good agreement with the STANDARD Q COVID-19 IgM/IgG Plus test and comparable to that of the PRNT. The RapiSure S1 RBD IgG/Neutralizing Ab Test was found to be convenient and reliable and, thus, can provide valuable information for rapid clinical decisions during the COVID-19 pandemic.

Rapid Detection of Mycobacterium Tuberculosis Using a Novel Point-of-Care BZ TB/NTM NALF Assay: Integrating LAMP and LFIA Technologies.

Tuberculosis (TB) is one of the leading causes of infectious mortality from a single infectious agent, Mycobacterium tuberculosis (MTB). This study evaluated the performance of the newly developed BZ TB/NTM NALF assay, which integrated loop-mediated isothermal amplification and lateral flow immunochromatographic assay technologies, for the detection of MTB. A total of 80 MTB-positive samples and 115 MTB-negative samples were collected, all of which were confirmed by TB real-time PCR (RT-PCR) using either AdvanSureTM TB/NTM RT-PCR Kit or Xpert® MTB/RIF Assay. The performance of the BZ TB/NTM NALF assay was evaluated by calculating its sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in comparison to those of the RT-PCR methods. Compared to the RT-PCR, the sensitivity, specificity, PPV, and NPV of BZ TB/NTM NALF assay were 98.7%, 99.1%, 98.7%, and 99.1%, respectively. The concordance rate between BZ TB/NTM NALF and RT-PCR was 99.0%. Rapid and simple detection of MTB is essential for global case detection and further elimination of TB. The performance of the BZ TB/NTM NALF Assay is acceptable with a high concordance with RT-PCR, indicating that it is reliable for use in a low-resource environment.

Molecular characterization of human respiratory syncytial virus in Seoul, South Korea, during 10 consecutive years, 2010-2019.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections and hospitalization in infants and young children. Here, we analyzed the genetic diversity of RSV using partial G gene sequences in 84 RSV-A and 78 RSV- B positive samples collected in Seoul, South Korea, for 10 consecutive years, from 2010 to 2019. Our phylogenetic analysis revealed that RSV-A strains were classified into either the ON1 (80.9%) or NA1 (19.0%) genotypes. On the other hand, RSV-B strains demonstrated diversified clusters within the BA genotype. Notably, some sequences designated as BA-SE, BA-SE1, and BA-DIS did not cluster with previously identified BA genotypes in the phylogenetic trees. Despite this, they did not meet the criteria for the assignment of a new genotype based on recent classification methods. Selection pressure analysis identified three positive selection sites (amino acid positions 273, 274, and 298) in RSV-A, and one possible positive selection site (amino acid position 296) in RSV-B, respectively. The mean evolutionary rates of Korean RSV-A from 1999 to 2019 and RSV-B strains from 1991 and 2019 were estimated at 3.51 × 10-3 nucleotides (nt) substitutions/site/year and 3.32 × 10-3 nt substitutions/site/year, respectively. The population dynamics in the Bayesian skyline plot revealed fluctuations corresponding to the emergence of dominant strains, including a switch of the dominant genotype from NA1 to ON1. Our study on time-scaled cumulative evolutionary analysis contributes to a better understanding of RSV epidemiology at the local level in South Korea.

Identification of a Complex Karyotype Signature with Clinical Implications in AML and MDS-EB Using Gene Expression Profiling.

Complex karyotype (CK) is associated with a poor prognosis in both acute myeloid leukemia (AML) and myelodysplastic syndrome with excess blasts (MDS-EB). Transcriptomic analyses have improved our understanding of the disease and risk stratification of myeloid neoplasms; however, CK-specific gene expression signatures have been rarely investigated. In this study, we developed and validated a CK-specific gene expression signature. Differential gene expression analysis between the CK and non-CK groups using data from 348 patients with AML and MDS-EB from four cohorts revealed enrichment of the downregulated genes localized on chromosome 5q or 7q, suggesting that haploinsufficiency due to the deletion of these chromosomes possibly underlies CK pathogenesis. We built a robust transcriptional model for CK prediction using LASSO regression for gene subset selection and validated it using the leave-one-out cross-validation method for fitting the logistic regression model. We established a 10-gene CK signature (CKS) predictive of CK with high predictive accuracy (accuracy 94.22%; AUC 0.977). CKS was significantly associated with shorter overall survival in three independent cohorts, and was comparable to that of previously established risk stratification models for AML. Furthermore, we explored of therapeutic targets among the genes comprising CKS and identified the dysregulated expression of superoxide dismutase 1 (SOD1) gene, which is potentially amenable to SOD1 inhibitors.

Performance evaluation and clinical impact of the Oncomine Myeloid Research Assay for gene expression analysis in myeloid haematologic malignancies.

AIM: Gene expression analysis facilitates the detection of diagnostic and prognostic biomarkers for myeloid haematological malignancies. The Oncomine Myeloid Research Assay (OMA; Thermo Fisher Scientific, Massachusetts, USA) provides a comprehensive analysis of gene expression of five target genes, along with gene alteration and fusion. Here, we present the performance of the OMA for gene expression analysis. METHODS: In total, 53 RNA samples from patients diagnosed with acute myeloid leukaemia (AML) or myelodysplastic syndrome were included. Of these 53 samples, 3 were evaluated for reproducibility and 50 were evaluated for comparison with RNA-sequencing (RNA-seq). The prognostic impact of the gene expression profile produced by both OMA and RNA-seq in AML was investigated using follow-up data from 33 patients with AML. RESULTS: The OMA showed good intrarun and interrun reproducibility. Compared with the RNA-seq results, high correlations were found in BAALC, MECOM and WT1 (all r>0.9), with moderate correlations in MYC (r=0.75, p<0.001) and SMC1A (r=0.42, p=0.002). The agreement between OMA and RNA-seq in classifying the dysregulated expression group was almost perfect, except for SMC1A (κ=0.175). Among these five genes, only BAALC showed a significant clinical impact in patients with AML. Patients with high BAALC expression showed significantly shorter overall survival based on both OMA (p=0.037) and RNA-seq (p=0.003). CONCLUSIONS: OMA gene expression analysis offers reproducible and accurate gene expression data for most targeted genes and demonstrates the utility of BAALC expression as a prognostic marker in AML.

Implications of the 5th Edition of the World Health Organization Classification and International Consensus Classification of Myeloid Neoplasm in Myelodysplastic Syndrome With Excess Blasts and Acute Myeloid Leukemia.

The fifth edition of the WHO classification (2022 WHO) and the International Consensus Classification (2022 ICC) of myeloid neoplasms have been recently published. We reviewed the changes in the diagnosis distribution in patients with MDS with excess blasts (MDS-EB) or AML using both classifications. Forty-seven patients previously diagnosed as having AML or MDS-EB with available mutation analysis data, including targeted next-generation and RNA-sequencing data, were included. We reclassified 15 (31.9%) and 27 (57.4%) patients based on the 2022 WHO and 2022 ICC, respectively. One patient was reclassified as having a translocation categorized as a rare recurring translocation in both classifications. Reclassification was mostly due to the addition of mutation-based diagnostic criteria (i.e., AML, myelodysplasia-related) or a new entity associated with TP53 mutation. In both classifications, MDS diagnosis required the confirmation of multi-hit TP53 alterations. Among 14 patients with TP53 mutations, 11 harbored multi-hit TP53 alterations, including four with TP53 mutations and loss of heterozygosity. Adverse prognosis was associated with multi-hit TP53 alterations (P=0.009) in patients with MDS-EB, emphasizing the importance of detecting the mutations at diagnosis. The implementation of these classifications may lead to the identification of different subtypes from previously heterogeneous diagnostic categories based on genetic characteristics.

Phylogenetic analysis of human parainfluenza type 3 virus strains responsible for the outbreak during the COVID-19 pandemic in Seoul, South Korea.

BACKGROUND: Human parainfluenza virus 3 (HPIV3) is a major respiratory pathogen that causes acute respiratory infections in infants and children. Since September 2021, an out-of-season HPIV3 rebound has been noted in Korea. The objective of this study was to analyze the molecular characteristics of the HPIV3 strains responsible for the outbreak in Seoul, South Korea. METHODS: A total of 61 HPIV3-positive nasopharyngeal swab specimens were collected between October and November 2021. Using 33 HPIV3-positive specimens, partial nucleotide sequences of the HPIV3 hemagglutinin-neuraminidase (HN) gene were aligned with previously published HN gene sequences for phylogenetic and genetic distance (p-distance) analyses. RESULTS: Phylogenetic tree revealed that all Seoul HPIV3 strains grouped within the phylogenetic subcluster C3. However, these strains formed a unique cluster that branched separately from the C3a lineage. This cluster showed 99% bootstrap support with a p-distance < 0.001. Genetic distances within the other C3 lineages ranged from 0.013 (C3a) to 0.023 (C3c). Deduced amino acid sequences of the HN gene revealed four protein substitutions in Seoul HPIV3 strains that have rarely been observed in other reference strains: A22T, K31N, G387S, and E514K. CONCLUSIONS: Phylogenetic analysis of Seoul HPIV3 strains revealed that the strain belonged to a separate cluster within subcluster C3. Genetic distances among strains within subcluster C3 suggest the emergence of a new genetic lineage. The emergence of a new genetic lineage could pose a potential risk of a new epidemic. Further monitoring of the circulating HPIV3 strains is needed to understand the importance of newly discovered mutations.

Performance Evaluation of Alere i Influenza A&B in Detecting Influenza Viruses A and B.

OBJECTIVE: Alere i Influenza A&B is an isothermal nucleic acid amplification-based integrated system used for detecting and differentiating between influenza virus A and influenza virus B. We evaluated the clinical performances of Alere i Influenza A&B compared to that of real-time PCR, multiplex real-time PCR, and two rapid influenza diagnostic kits. METHODS: Nasopharyngeal aspiration specimens (n=315) from patients with signs of acute respiratory infection were collected between 2015 and 2016. Samples were tested using real-time PCR, the multiplex RT-PCR Anyplex II RV16 Detection kit, Alere i Influenza A&B, BD Veritor™ System Flu A+B, and the Sofia Influenza A+B Fluorescence Immunoassay. Positive influenza specimens detected by the Anyplex II RV16 Detection kit were tested by real-time PCR. RESULTS: Compared to that of multiplex RT-PCR (influenza A, n=88; influenza B, n=82; influenza-negative, n=145), the sensitivities of Alere i, Sofia, and Veritor for influenza A were 97.7%, 72.7%, and 71.6%, respectively, whereas for influenza B, the sensitivities were 96.3%, 80.4%, and 75.6%, respectively. The specificity of Alere i, Sofia, and Veritor was 100.0%. CONCLUSIONS: The clinical performance of Alere i Influenza A&B is satisfactory, with the advantage of a significantly shorter test time than other molecular assays. It is suitable for point-of-care testing and rapid influenza diagnostic tests because of its high sensitivity and specificity.

Performance evaluation of three rapid antigen tests for the diagnosis of group A Streptococci.

OBJECTIVE: To compare the diagnostic performance of three rapid antigen detection tests (RADTs) for group A Streptococcus (GAS). DESIGN: A hospital-based, cross-sectional, retrospective study. SETTING: A comparative study of rapid diagnostic tests for GAS using clinical specimens in a single institute. PARTICIPANTS: 225 children in the outpatient clinics ofKorea University Guro Hospitalwith suspicious symptoms were subjected to throat swab sampling. A dual-swab applicator was used. Samples were stored at below -70°C in a 10 mL transport tube containing 1 mL liquid Stuart's transport medium. OUTCOME MEASURES: All tests were performed in the laboratory by trained clinical laboratory scientists. Sensitivity, specificity, accuracy and kappa index of three RADTs were compared with the reference PCR test and culture results. RESULTS: Of the 225 patients suspected of having GAS, 67 and 90 were positive for GAS in the culture and PCR tests, respectively. Compared with the reference culture, the sensitivity for GAS was 92.5% (CI 83.4 to 97.5), 71.6% (CI 59.3 to 81.9) and 74.63% (CI 62.5 to 84.4) for careUS Strep A Plus, SD Bioline and BD Veritor, respectively, and the specificity was 97.0% (CI 93.1 to 99.0), 94.6% (CI 90.1 to 97.5) and 92.9% (CI 87.8 to 96.2) for careUS Strep A Plus, SD Bioline and BD Veritor, respectively. Compared with the reference GAS real-time PCR, the sensitivity was 73.3% (CI 62.9 to 82.1), 63.3% (CI 52.5 to 73.2) and 67.8% (CI 57.1 to 77.2) for careUS Strep A Plus, SD Bioline and BD Veritor, respectively, and the specificity was 99.3% (CI 95.9 to 99.9), 100.0% (CI 97.3 to 100.0) and 99.3% (CI 95.9 to 99.9) for careUS Strep A Plus, SD Bioline and BD Veritor, respectively. CONCLUSIONS: The careUS Strep A Plus is a useful test that showed highly comparable results with those of the culture test and superior performances among the three RADTs. The use of RADTs should be encouraged to provide acceptable and fast results using simple equipment.

Diagnostic performance of the Xpert Carba-R assay for active surveillance of rectal carbapenemase-producing organisms in intensive care unit patients.

Background: There are growing concerns regarding the spread of carbapenemase-producing organisms (CPOs) among patients in long-term care facilities (LTCFs) and hospitals in South Korea. We have established a screening protocol for the detection of CPOs in high-risk patients upon admission to intensive care units (ICUs). The diagnostic performance of the Xpert Carba-R assay was compared to that of rectal culture for CPO detection in high-risk patients upon ICU admission. Methods: A total of 408 consecutive rectal swabs were obtained from December 2016 to December 2017. CPO screening was performed using the Xpert Carba-R assay (Cepheid, Sunnyvale, CA, USA). When a carbapenemase gene was detected, additional rectal swabs were incubated overnight and inoculated on chromID CARBA medium (bioMérieux, Marcy l'Etoile, France). Bacterial carbapenemase genes, including blaKPC, blaNDM, blaVIM, blaIMP-1, and blaOXA-48, were confirmed by conventional PCR. The diagnostic performance of the Carba-R assay was ascertained based on the culture results. Results: The prevalence of CPO carriage was 7.4% according to the Carba-R assay and 3.7% according to rectal culture. The median Ct values of IMP-1 and KPC were significantly different (35.2 vs. 26.6, P = 0.0143). The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the Carba-R assay were 100.0% (95% confidence interval [CI], 78.2-100.0), 96.7% (94.4-98.2), 53.6% (40.4-66.4) and 100.0% (99.0-100.0), respectively. Conclusions: We demonstrated the prevalence of CPO carriage in high-risk patients upon ICU admission and evaluated the diagnostic performance of the Carba-R assay. The combined use of the Xpert Carba-R assay and culture produces rapid and reliable results for the active surveillance of rectal CPO in ICU patients.

The Effects of Weight Control Behaviors among Korean Obese Adults.

BACKGROUND: This study aimed to identify and examine the effects of weight control behaviors correlated with weight loss in obese individuals who attempted to lose weight within the past year. METHODS: In this cross-sectional study, data from 9,461 obese individuals were collected from the fifth and sixth Korean National Health and Nutrition Examination Survey (2010-2014). Three of nine verified methods of weight control suggested in the survey were selected: diet therapy (reduced food intake), exercise therapy (exercise), and medication therapy (prescribed weight loss medications). Participants were divided into one of seven groups (diet therapy alone; exercise therapy alone; drug therapy alone; combined diet and exercise therapy; combined exercise and drug therapy; combined diet and drug therapy; or combined diet, exercise, and drug therapy). Logistic regression analysis was used to determine whether the group that tried to lose weight in the past year had indeed lost weight compared to the group that did not. RESULTS: The odds ratios for weight loss (≥3 but <6 kg vs. ≥6 but <10 kg) for the combined therapies were 2.05 (95% confidence interval, 1.23-3.41) for combined diet and exercise therapy and 5.43 (1.74-16.92) for combined diet, exercise, and drug therapy. CONCLUSION: All levels of weight loss were significantly associated with combined diet and exercise therapy. Weight loss ≥6 kg but <10 kg was significantly associated with combined diet and exercise therapy as well as with combined diet, exercise, and medication therapy among individuals who tried to lose weight in the past year.

Relationship between Marital Status and Metabolic Syndrome in Korean Middle-Aged Women: The Sixth Korea National Health and Nutrition Examination Survey (2013-2014).

BACKGROUND: This study aimed to investigate the relationship between marital status and the incidence of metabolic syndrome in Korean middle-aged women. METHODS: Based on data from the sixth Korea National Health and Nutrition Examination Survey (2013-2014), 3,225 women aged 40-69 years were subjected to the analysis. Marital status was categorized as married, unmarried, separated, widowed, or divorced. The odds ratios (ORs) for metabolic syndrome were calculated based on marital status. After adjustment for age, income level, education level, alcohol intake, smoking status, leisure physical activity, menopause status, daily calories, and fat intake, changes in the OR for metabolic syndrome based on marital status were examined by multivariate logistic regression analysis. RESULTS: The OR for metabolic syndrome in the widowed group to the married group was 4.818 (95% confidence interval [CI], 3.861-6.002; P<0.001) and that after adjustment of age, economic level, education level, alcohol intake, smoking status, physical activity, menopause status, total daily calories, and fat intake was 2.141 (CI, 1.432-3.199; P<0.001), both of which were statistically significant. The OR for metabolic syndrome in the unmarried group to the married group was 0.246 (CI, 0.141-0.431; P<0.001) after adjustment of all components. On the contrary, the ORs of the separated group and the divorced group to the married group were not significant. CONCLUSION: In comparison with the married middle-aged group, the widowed middle-aged group tended to have a higher risk of metabolic syndrome, which is speculated to be related to socioeconomic factors and health behavior.