Calibration of High-Density Lipoprotein Cholesterol Values From the Korea National Health and Nutrition Examination Survey Data, 2008 to 2015

Yun, Yeo-Min,Song, Junghan,Ji, Misuk,Kim, Jeong-Ho,Kim, Yongkang,Park, Taesung,Song, Sang Hoon,Park, Seungman,Kim, Min Jin,Nho, Sun Jin,Oh, Kyung Won The Korean Society for Laboratory Medicine 2017 Annals of Laboratory Medicine Vol.37 No.1

<P><B>Background</B></P><P>For correct interpretation of the high-density lipoprotein cholesterol (HDL-C) data from the Korea National Health and Nutrition Examination Survey (KNHANES), the values should be comparable to reference values. We aimed to suggest a way to calibrate KNHANES HDL-C data from 2008 to 2015 to the Centers for Disease Control and Prevention (CDC) reference method values.</P><P><B>Methods</B></P><P>We derived three calibration equations based on comparisons between the HDL-C values of the KNHANES laboratory and the CDC reference method values in 2009, 2012, and 2015 using commutable frozen serum samples. The selection of calibration equation for correcting KNHANES HDL-C in each year was determined by the accuracy-based external quality assurance results of the KNHANES laboratory.</P><P><B>Results</B></P><P>Significant positive biases of HDL-C values were observed in all years (2.85-9.40%). We created the following calibration equations: standard HDL-C=0.872×[original KNHANES HDL-C]+2.460 for 2008, 2009, and 2010; standard HDL-C=0.952×[original KNHANES HDL-C]+1.096 for 2012, 2013, and 2014; and standard HDL-C=1.01×[original KNHANES HDL-C]-3.172 for 2011 and 2015. We calibrated the biases of KNHANES HDL-C data using the calibration equations.</P><P><B>Conclusions</B></P><P>Since the KNHANES HDL-C values (2008-2015) showed substantial positive biases compared with the CDC reference method values, we suggested using calibration equations to correct KNHANES data from these years. Since the necessity for correcting the biases depends on the characteristics of research topics, each researcher should determine whether to calibrate KNHANES HDL-C data or not for each study.</P>

Biochemical and Genetic Analysis of Seven Korean Individuals With Suspected Metachromatic Leukodystrophy

Han, Minje,Jun, Sun-Hee,Lee, Yun-Jin,Eun, Baik-Lin,Lee, Seung Jun,Seong, Moon-Woo,Park, Sung Sup,Song, Sang Hoon,Park, Hyung-Doo,Song, Junghan The Korean Society for Laboratory Medicine 2015 Annals of Laboratory Medicine Vol.35 No.4

<P>Metachromatic leukodystrophy (MLD) is an autosomal recessive disease caused by a deficiency in arylsulfatase A (ARSA). However, decreased ARSA activity is also observed in pseudodeficiency (PD). To distinguish between MLD and PD, we performed gene mutation and sulfatide analyses by using dried blood spots (DBSs) from seven Korean individuals who underwent an analysis of ARSA activity. DNA was extracted from DBSs, and PCR-direct sequencing of <I>ARSA</I> was performed. The cDNA obtained was analyzed to confirm a novel mutation. Of the seven subjects, three were confirmed as having MLD, one was confirmed as having MLD-PD, one was confirmed as having PD, and the remaining two were obligate heterozygotes. We verified the novel pathogenic variant c.1107+1delG by performing familial and cDNA analyses. Sulfatide concentrations in DBSs were analyzed and were quantified by using ultra-performance liquid chromatography and tandem mass spectrometry, respectively. Total sulfatide concentration was inversely correlated with ARSA activity (Spearman's coefficient of rank correlation, <I>P</I>=0.929, <I>P</I>=0.0025). The results of this mutational and biochemical study on MLD will increase our understanding of the genetic characteristics of MLD in Koreans.</P>

Annals of Laboratory Medicine: Quantum Leap into the Higher Quality

The Korean Society for Laboratory Medicine 2012 Annals of Laboratory Medicine Vol.32 No.2

Detection of Allergen Specific IgE by AdvanSure Allergy Screen Test

Oh, Eun-Jee,Lee, Sun-Ah,Lim, Jihyang,Park, Yeon-Joon,Han, Kyungja,Kim, Yonggoo Korean Society for Laboratory Medicine (KAMJE) 2010 Annals of Laboratory Medicine Vol.30 No.4

<P>BACKGROUND: In vitro serum allergen-specific IgE tests have been routinely used in the clinical diagnosis of allergic diseases. We evaluated the clinical usefulness of a newly introduced multiple antigen screen test, Advansure Allergy Screen (LG Life Science, Korea) (LG-Screen) for the detection of allergen specific IgE. METHODS: A total of 180 sera (80 for inhalant and 100 for food panels) were tested by LG-Screen and RIDA Allergy Screen (R-biopharm, Germany) (RIDA-Screen) assays. According to the 58-60 specific allergens or allergen groups, the positive rates and agreement rates were analyzed using the cut off levels of class 2. For the quantitation of total IgE and specific IgE, nephelometry and ImmunoCAP test were performed in the sera showing discrepant results between the two allergy screen assays. RESULTS: The agreement rate and kappa value (k) of total IgE between the two allergy screen assays was 73.9% and 0.333. LG-Screen showed higher agreement rate with nephelometry than RIDA-Screen. The positive rates to common outdoor inhalant and food allergens were significantly higher in RIDA-Screen. Overall agreement rate of specific IgE between the two allergy screen assays for 58 allergens was 86.7% (6,086/7,020) (k, 0.293). In samples showing discrepant results between the two allergy screen assays, concordance rate of allergy screen assay with ImmunoCAP assay was 70.9% (449/633) for LG-Screen (k, 0.585) and 29.1% (184/633) for RIDA-Screen (k, -0.303). CONCLUSIONS: LG-Screen showed a favorable agreement with RIDA-Screen and ImmunoCAP assays, and it could be used for the detection of allergen specific IgE in the clinical laboratory.</P>

Evaluation of the VIDAS Anti-HCV Assay for Detection of Hepatitis C Virus Infection

Hyun, Jungwon,Ko, Dae-Hyun,Kang, Hee Jung,Whang, Dong Hee,Cha, Young Joo,Kim, Hyun Soo The Korean Society for Laboratory Medicine 2016 Annals of Laboratory Medicine Vol.36 No.6

<P><B>Background</B></P><P>Anti-hepatitis C virus antibody (anti-HCV) assays are recommended for screening HCV-infected persons. The VIDAS Anti-HCV Assay (bioMérieux, France), based on the enzyme-linked fluorescence test principle, was recently introduced in Korea. We evaluated the clinical performance of the VIDAS assay.</P><P><B>Methods</B></P><P>One hundred HCV-positive and 1,002 HCV-negative blood samples confirmed by Architect anti-HCV (Abbott Laboratories, USA) and COBAS TaqMan HCV real-time PCR (Roche Diagnostics, USA) or the Procleix Ultrio Plus Assay (Gen-Probe Incorporated, USA) were obtained from the Human Serum Bank (HSB) and tested by VIDAS. In case of discrepant results, we conducted a recombinant immunoblot assay (RIBA).</P><P><B>Results</B></P><P>The agreement rates for known HCV-positive and HCV-negative samples between the VIDAS assay and the HSB testing were 100% (95% confidence interval [CI]: 96.4-100%) and 99.5% (95% CI: 98.8-99.8%), respectively. One of the five discrepant samples was positive for Core 2+ and NS3-2 2+ reactivity, two samples were negative, and the other two were indeterminate regarding NS4 2+ reactivity in RIBA. We observed a significant but weak positive correlation between the titers of VIDAS and Architect assays (r=0.315, <I>P</I><0.001).</P><P><B>Conclusions</B></P><P>The VIDAS anti-HCV assay, developed on the VIDAS automated immunoassay platform based on the ready-to-use, single-sample test concept may be useful in small-to-medium-sized laboratories. It showed good agreement with Architect anti-HCV and COBAS PCR assays and is therefore useful for detection of HCV infection. Weakly test-positive (ambiguous) samples require additional testing by another anti-HCV, RIBA, or HCV RNA assay.</P>

Combined Use of the Modified Hodge Test and Carbapenemase Inhibition Test for Detection of Carbapenemase-Producing <i>Enterobacteriaceae</i> and Metallo-β-Lactamase-Producing <i>Pseudomonas</i> spp.

Song, Wonkeun,Hong, Seong Geun,Yong, Dongeun,Jeong, Seok Hoon,Kim, Hyun Soo,Kim, Han-Sung,Kim, Jae-Seok,Bae, Il Kwon The Korean Society for Laboratory Medicine 2015 Annals of Laboratory Medicine Vol.35 No.2

<P><B>Background</B></P><P>We evaluated the combined use of the modified Hodge test (MHT) and carbapenemase inhibition test (CIT) using phenylboronic acid (PBA) and EDTA to detect carbapenemase-producing <I>Enterobacteriaceae</I> (CPE) and metallo-β-lactamase (MBL)-producing <I>Pseudomonas</I> spp.</P><P><B>Methods</B></P><P>A total of 49 isolates of CPE (15 <I>Klebsiella pneumoniae</I> carbapenemase [KPC], 5 Guiana extended-spectrum β-lactamase [GES]-5, 9 New Delhi metallo-β-lactamase [NDM]-1, 5 Verona integron-encoded metallo-β-lactamase [VIM]-2, 3 imipenem-hydrolyzing β-lactamase [IMP], and 12 oxacillinase [OXA]-48-like), 25 isolates of MBL-producing <I>Pseudomonas</I> spp. (14 VIM-2 and 11 IMP), and 35 carbapenemase-negative controls were included. The MHT was performed for all isolates as recommended by the Clinical and Laboratory Standards Institute. Enhanced growth of the indicator strain was measured in mm with a ruler. The CIT was performed by directly dripping PBA and EDTA solutions onto carbapenem disks that were placed on Mueller-Hinton agar plates seeded with the test strain.</P><P><B>Results</B></P><P>Considering the results of the MHT with the ertapenem disk in <I>Enterobacteriaceae</I> and <I>Pseudomonas</I> spp., the CIT with the meropenem disk in <I>Enterobacteriaceae</I>, and the imipenem disk in <I>Pseudomonas</I> spp., three combined disk tests, namely MHT-positive plus PBA-positive, EDTA-positive, and MHT-positive plus PBA-negative plus EDTA-negative, had excellent sensitivity and specificity for the detection of KPC- (100% sensitivity and 100% specificity), MBL- (94% sensitivity and 100% specificity), and OXA-48-like-producing isolates (100% sensitivity and 100% specificity), respectively.</P><P><B>Conclusions</B></P><P>Combined use of the MHT and CIT with PBA and EDTA, for the detection of CPE and MBL-producing <I>Pseudomonas</I> spp., is effective in detecting and characterizing carbapenemases in routine laboratories.</P>

Evaluation of the Clinical Performance of an Automated Procalcitonin Assay for the Quantitative Detection of Bloodstream Infection

Kim, Kyung-Eun,Han, Jin-Yeong Korean Society for Laboratory Medicine (KAMJE) 2010 Annals of Laboratory Medicine Vol.30 No.2

<P>BACKGROUND: Bloodstream infection (BSI) is associated with a high mortality rate. Since the origin of infection is demonstrated in approximately 2/3rds of cases, early and established biomarkers are warranted. We evaluated the clinical performances of automated procalcitonin (PCT) and C-reactive protein (CRP) assays for the quantitative detection of BSI. Analytical performance of the VIDAS(R) BRAHMS PCT assay (bioMérieux, France) was assessed and also compared with the semi-quantitative PCT-Q test (BRAHMS Aktiengesellschaft, Germany). METHODS: We prospectively included consecutive patients divided into 3 groups at the Dong-A University Medical Center. Patients were categorized according to the criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference (ACCP/SCCM), and also on the basis of catheter-associated bacteremia. RESULTS: A total 77 patients were enrolled. All mean values of PCT and PCT-Q were consistent with the reference value. Measured PCT concentrations showed good linearity (r=0.983). The between-run, within-run, and total imprecisions were below 5%. The PCT levels in gram-negative bacteremia were significantly higher than those in gram-positive bacteremia. Furthermore, the PCT concentrations were significantly different among non-infection, bacteremia, sepsis, severe sepsis, and septic shock groups. Our study showed that PCT >0.3 ng/mL had 95.0% sensitivity and 97.3% specificity, whereas CRP >5.46 mg/dL had 85.0% sensitivity and 86.5% specificity for diagnosing sepsis. CONCLUSIONS: We suggest that, compared with CRP, PCT is a better diagnostic and discriminative biomarker of sepsis categorized according to the ACCP/SCCM. Moreover, catheter-associated bacteremia could be discriminated from sepsis using PCT concentration.</P>

Prevalence of Major Methicillin-Resistant <i>Staphylococcus aureus</i> Clones in Korea Between 2001 and 2008

Kang, Gi Su,Jung, Yung Hee,Kim, Hwa Su,Lee, Yeong Seon,Park, Chan,Lee, Kwang Jun,Cha, Jeong Ok The Korean Society for Laboratory Medicine 2016 Annals of Laboratory Medicine Vol.36 No.6

<P><B>Background</B></P><P>Methicillin-resistant <I>Staphylococcus aureus</I> (MRSA) are important pathogens causing nosocomial infections in Korean hospitals. This study aimed to investigate the epidemiological and genetic diversity of clinical <I>S. aureus</I> isolates in healthcare settings from 2001 to 2008.</P><P><B>Methods</B></P><P>Samples and data were obtained from 986 individuals as part of the National Antimicrobial Surveillance Project, involving 10 regions nationwide. Molecular typing studies, including multilocus sequence typing (MLST) and staphylococcal cassette chromosome <I>mec</I> (SCC<I>mec</I>) typing were performed, and a representative clone of Korean MRSA was classified by combinational grouping using a DiversiLab (DL; bioMérieux, France) repetitive element polymerase chain reaction (rep-PCR) system.</P><P><B>Results</B></P><P>Nine Korean MRSA clones (KMRSA-1 to -9) were identified by analysis of genetic backgrounds and molecular characteristics. KMRSA-1 to -3, expressing clonal complex (CC) 5 (carrying SCC<I>mec</I> II), CC8 (carrying SCC<I>mec</I> III), and CC72 (carrying SCC<I>mec</I> IV) were spread nationwide. In contrast, KMRSA-6 was highly prevalent in Gyeongsangnam-do, and KMRSA-4 was highly prevalent in Jeollanam-do and Jeollabuk-do.</P><P><B>Conclusions</B></P><P>Epidemic KMRSA clones were genetically similar to major clones identified from the USA, with the exception of KMRSA-2, which had the SCC<I>mec</I> III type. Our results provide important insights into the distribution and molecular genetics of MRSA strains in Korea and may aid in the monitoring of MRSA spread throughout the country.</P>

Current Recommendations for Laboratory Testing and Use of Bone Turnover Markers in Management of Osteoporosis

Lee, Jehoon,Vasikaran, Samuel The Korean Society for Laboratory Medicine 2012 Annals of Laboratory Medicine Vol.32 No.2

<P>Osteoporosis is a major health problem worldwide, and is projected to increase exponentially due to the aging of the population. The absolute fracture risk in individual subjects is calculated by the use of algorithms which include bone mineral density (BMD), age, gender, history of prior fracture and other risk factors. This review describes the laboratory investigations into osteoporosis which include serum calcium, phosphate, creatinine, alkaline phosphatase and 25-hydroxyvitamin D and, additionally in men, testosterone. Parathyroid hormone (PTH) is measured in patients with abnormal serum calcium to determine its cause. Other laboratory investigations such as thyroid function testing, screening for multiple myeloma, and screening for Cushing's syndrome, are performed if indicated. Measurement of bone turnover markers (BTMs) is currently not included in algorithms for fracture risk calculations due to the lack of data. However, BTMs may be useful for monitoring osteoporosis treatment. Further studies of the reference BTMs serum carboxy terminal telopeptide of collagen type I (s-CTX) and serum procollagen type I N-terminal propeptide (s-PINP) in fracture risk prediction and in monitoring various treatments for osteoporosis may help expedite their inclusion in routine clinical practice.</P>

<i>PRSS1</i> , <i>SPINK1</i> , <i>CFTR</i> , and <i>CTRC</i> Pathogenic Variants in Korean Patients With Idiopathic Pancreatitis

Cho, Sun-Mi,Shin, Saeam,Lee, Kyung-A The Korean Society for Laboratory Medicine 2016 Annals of Laboratory Medicine Vol.36 No.6

<P><B>Background</B></P><P>This study aimed to identify pathogenic variants of <I>PRSS1</I>, <I>SPINK1</I>, <I>CFTR</I>, and <I>CTRC</I> genes in Korean patients with idiopathic pancreatitis.</P><P><B>Methods</B></P><P>The study population consisted of 116 Korean subjects (65 males, 51 females; mean age, 30.4 yr, range, 1-88 yr) diagnosed with idiopathic chronic pancreatitis (ICP), idiopathic recurrent acute pancreatitis (IRAP), or idiopathic acute pancreatitis (IAP). We analyzed sequences of targeted regions in the <I>PRSS1</I>, <I>SPINK1</I>, <I>CFTR</I>, and <I>CTRC</I> genes, copy numbers of <I>PRSS1</I> and <I>SPINK1</I>, and clinical data from medical records.</P><P><B>Results</B></P><P>We identified three types of pathogenic <I>PRSS1</I> variants in 11 patients, including p.N29I (n=1), p.R122H (n=1), and p.G208A (n=9). Sixteen patients exhibited heterozygous pathogenic variants of <I>SPINK1</I>, including c.194+2T>C (n=12), p.N34S (n=3), and a novel pathogenic splicing variation c.194+1G>A. A heterozygous <I>CFTR</I> p.Q1352H pathogenic variant was detected in eight patients. One patient carried a heterozygous <I>CTRC</I> p.P249L pathogenic variant, which is a known high-risk variant for pancreatitis. All patients had normal <I>PRSS1</I> and <I>SPINK1</I> gene copy numbers. Weight loss occurred more frequently in patients carrying the p.G208A pathogenic variant, while pancreatic duct stones occurred more frequently in patients with the c.194+2T>C pathogenic variant.</P><P><B>Conclusions</B></P><P>Pathogenic variants of <I>PRSS1</I>, <I>SPINK1</I>, and <I>CFTR</I> were associated with idiopathic pancreatitis, while pathogenic variants of <I>CTRC</I> were not. Copy number variations of <I>PRSS1</I> and <I>SPINK1</I> were not detected.</P>